Merge redundant *-fns.h into respective filter headers.

Move gaussian blur to filters directory.
Blend filter effect.

(bzr r9508.1.16)

76 files changed, 705 insertions, 1466 deletions

diff --git a/src/Makefile_insert b/src/Makefile_insert
index 36c9de34f..2298ddb42 100644
--- a/src/Makefile_insert
+++ b/src/Makefile_insert
@@ -152,7 +152,6 @@ ink_common_sources +=	\
 	sp-desc.cpp sp-desc.h						\
 	sp-ellipse.cpp sp-ellipse.h					\
 	sp-filter.cpp sp-filter.h number-opt-number.h			\
-	sp-filter-fns.h							\
 	sp-filter-primitive.cpp	sp-filter-primitive.h			\
 	sp-filter-reference.cpp	sp-filter-reference.h			\
 	sp-filter-units.h						\
@@ -161,8 +160,6 @@ ink_common_sources +=	\
 	sp-flowtext.h sp-flowtext.cpp					\
         sp-font.cpp sp-font.h						\
         sp-font-face.cpp sp-font-face.h					\
-	sp-gaussian-blur.cpp sp-gaussian-blur.h				\
-	sp-gaussian-blur-fns.h						\
         sp-glyph.cpp sp-glyph.h						\
         sp-glyph-kerning.cpp sp-glyph-kerning.h				\
 	sp-gradient.cpp sp-gradient.h					\
diff --git a/src/desktop-style.cpp b/src/desktop-style.cpp
index 26f29d172..1b277a381 100644
--- a/src/desktop-style.cpp
+++ b/src/desktop-style.cpp
@@ -28,7 +28,7 @@
 #include "filters/blend.h"
 #include "sp-filter.h"
 #include "sp-filter-reference.h"
-#include "sp-gaussian-blur.h"
+#include "filters/gaussian-blur.h"
 #include "sp-flowtext.h"
 #include "sp-flowregion.h"
 #include "sp-flowdiv.h"
diff --git a/src/display/cairo-utils.cpp b/src/display/cairo-utils.cpp
index a063a62bb..36202f42e 100644
--- a/src/display/cairo-utils.cpp
+++ b/src/display/cairo-utils.cpp
@@ -337,11 +337,21 @@ ink_cairo_surface_copy(cairo_surface_t *s)
 {
     cairo_surface_t *ns = ink_cairo_surface_create_identical(s);
 
-    cairo_t *ct = cairo_create(ns);
-    cairo_set_source_surface(ct, s, 0, 0);
-    cairo_set_operator(ct, CAIRO_OPERATOR_SOURCE);
-    cairo_paint(ct);
-    cairo_destroy(ct);
+    if (cairo_surface_get_type(s) == CAIRO_SURFACE_TYPE_IMAGE) {
+        // use memory copy instead of using a Cairo context
+        cairo_surface_flush(s);
+        int stride = cairo_image_surface_get_stride(s);
+        int h = cairo_image_surface_get_height(s);
+        memcpy(cairo_image_surface_get_data(ns), cairo_image_surface_get_data(s), stride * h);
+        cairo_surface_mark_dirty(ns);
+    } else {
+        // generic implementation
+        cairo_t *ct = cairo_create(ns);
+        cairo_set_source_surface(ct, s, 0, 0);
+        cairo_set_operator(ct, CAIRO_OPERATOR_SOURCE);
+        cairo_paint(ct);
+        cairo_destroy(ct);
+    }
 
     return ns;
 }
diff --git a/src/display/nr-arena-group.cpp b/src/display/nr-arena-group.cpp
index 0fa5f332a..3bc78ea56 100644
--- a/src/display/nr-arena-group.cpp
+++ b/src/display/nr-arena-group.cpp
@@ -14,12 +14,10 @@
 
 #include "display/nr-arena-group.h"
 #include "display/nr-filter.h"
-#include "display/nr-filter-gaussian.h"
 #include "display/nr-filter-types.h"
 #include "style.h"
 #include "sp-filter.h"
 #include "sp-filter-reference.h"
-#include "sp-gaussian-blur.h"
 #include "filters/blend.h"
 #include "display/nr-filter-blend.h"
 #include "helper/geom.h"
diff --git a/src/display/nr-arena-image.cpp b/src/display/nr-arena-image.cpp
index 325cff65a..422b691b7 100644
--- a/src/display/nr-arena-image.cpp
+++ b/src/display/nr-arena-image.cpp
@@ -21,12 +21,8 @@
 #include "display/cairo-utils.h"
 #include "display/nr-arena.h"
 #include "display/nr-filter.h"
-#include "display/nr-filter-gaussian.h"
 #include "sp-filter.h"
 #include "sp-filter-reference.h"
-#include "sp-gaussian-blur.h"
-#include "filters/blend.h"
-#include "display/nr-filter-blend.h"
 
 int nr_arena_image_x_sample = 1;
 int nr_arena_image_y_sample = 1;
diff --git a/src/display/nr-arena-item.h b/src/display/nr-arena-item.h
index 468d352bc..447307535 100644
--- a/src/display/nr-arena-item.h
+++ b/src/display/nr-arena-item.h
@@ -1,6 +1,3 @@
-#ifndef __NR_ARENA_ITEM_H__
-#define __NR_ARENA_ITEM_H__
-
 /*
  * RGBA display list system for inkscape
  *
@@ -13,6 +10,22 @@
  * Released under GNU GPL, read the file 'COPYING' for more information
  */
 
+#ifndef SEEN_DISPLAY_NR_ARENA_ITEM_H
+#define SEEN_DISPLAY_NR_ARENA_ITEM_H
+
+#include <cairo.h>
+#include <2geom/matrix.h>
+#include <libnr/nr-rect-l.h>
+#include <libnr/nr-pixblock.h>
+#include <libnr/nr-object.h>
+#include "gc-soft-ptr.h"
+#include "nr-arena-forward.h"
+
+namespace Inkscape {
+namespace Filters {
+class Filter;
+} }
+
 #define NR_TYPE_ARENA_ITEM (nr_arena_item_get_type ())
 #define NR_ARENA_ITEM(o) (NR_CHECK_INSTANCE_CAST ((o), NR_TYPE_ARENA_ITEM, NRArenaItem))
 #define NR_IS_ARENA_ITEM(o) (NR_CHECK_INSTANCE_TYPE ((o), NR_TYPE_ARENA_ITEM))
@@ -52,15 +65,6 @@
 
 #define NR_ARENA_ITEM_RENDER_NO_CACHE (1 << 0)
 
-#include <2geom/matrix.h>
-#include <libnr/nr-rect-l.h>
-#include <libnr/nr-pixblock.h>
-#include <libnr/nr-object.h>
-#include "gc-soft-ptr.h"
-#include "nr-arena-forward.h"
-#include "display/nr-filter.h"
-#include <cairo.h>
-
 struct NRGC {
     NRGC(NRGC const *p) : parent(p) {}
     NRGC const *parent;
@@ -181,8 +185,7 @@ NRArenaItem *nr_arena_item_detach (NRArenaItem *parent, NRArenaItem *child);
 #define NR_ARENA_ITEM_SET_KEY(i,k) (((NRArenaItem *) (i))->key = (k))
 #define NR_ARENA_ITEM_GET_KEY(i) (((NRArenaItem *) (i))->key)
 
-
-#endif /* !__NR_ARENA_ITEM_H__ */
+#endif /* !SEEN_DISPLAY_NR_ARENA_ITEM_H */
 
 /*
   Local Variables:
diff --git a/src/display/nr-filter-blend.cpp b/src/display/nr-filter-blend.cpp
index 4645d9bc0..4ce37ae3b 100644
--- a/src/display/nr-filter-blend.cpp
+++ b/src/display/nr-filter-blend.cpp
@@ -15,6 +15,11 @@
  * Released under GNU GPL, read the file 'COPYING' for more information
  */
 
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "display/cairo-utils.h"
 #include "display/nr-filter-blend.h"
 #include "display/nr-filter-pixops.h"
 #include "display/nr-filter-primitive.h"
@@ -24,6 +29,7 @@
 #include "libnr/nr-pixblock.h"
 #include "libnr/nr-blit.h"
 #include "libnr/nr-pixops.h"
+#include "preferences.h"
 
 namespace Inkscape {
 namespace Filters {
@@ -125,6 +131,247 @@ FilterPrimitive * FilterBlend::create() {
 FilterBlend::~FilterBlend()
 {}
 
+#define EXTRACT_ARGB32(px,a,r,g,b) \
+    guint32 a, r, g, b; \
+    a = (px & 0xff000000) >> 24; \
+    r = (px & 0x00ff0000) >> 16; \
+    g = (px & 0x0000ff00) >> 8;  \
+    b = (px & 0x000000ff);
+
+#define ASSEMBLE_ARGB32(px,a,r,g,b) \
+    guint32 px = (a << 24) | (r << 16) | (g << 8) | b;
+
+// cr = (1-qa)*cb + (1-qb)*ca + ca*cb
+struct BlendMultiply {
+    void operator()(guint32 in1, guint32 in2, guint32 *out)
+    {
+        EXTRACT_ARGB32(in1, aa, ra, ga, ba)
+        EXTRACT_ARGB32(in2, ab, rb, gb, bb)
+
+        guint32 ao = 255*255 - (255-aa)*(255-ab);        ao = (ao + 127) / 255;
+        guint32 ro = (255-aa)*rb + (255-ab)*ra + ra*rb;  ro = (ro + 127) / 255;
+        guint32 go = (255-aa)*gb + (255-ab)*ga + ga*gb;  go = (go + 127) / 255;
+        guint32 bo = (255-aa)*bb + (255-ab)*ba + ba*bb;  bo = (bo + 127) / 255;
+
+        ASSEMBLE_ARGB32(pxout, ao, ro, go, bo)
+        *out = pxout;
+    }
+};
+
+// cr = cb + ca - ca * cb
+struct BlendScreen {
+    void operator()(guint32 in1, guint32 in2, guint32 *out)
+    {
+        EXTRACT_ARGB32(in1, aa, ra, ga, ba)
+        EXTRACT_ARGB32(in2, ab, rb, gb, bb)
+
+        guint32 ao = 255*255 - (255-aa)*(255-ab);    ao = (ao + 127) / 255;
+        guint32 ro = 255*(rb + ra) - ra * rb;        ro = (ro + 127) / 255;
+        guint32 go = 255*(gb + ga) - ga * gb;        go = (go + 127) / 255;
+        guint32 bo = 255*(bb + ba) - ba * bb;        bo = (bo + 127) / 255;
+
+        ASSEMBLE_ARGB32(pxout, ao, ro, go, bo)
+        *out = pxout;
+    }
+};
+
+// cr = Min ((1 - qa) * cb + ca, (1 - qb) * ca + cb)
+struct BlendDarken {
+    void operator()(guint32 in1, guint32 in2, guint32 *out)
+    {
+        EXTRACT_ARGB32(in1, aa, ra, ga, ba)
+        EXTRACT_ARGB32(in2, ab, rb, gb, bb)
+
+        guint32 ao = 255*255 - (255-aa)*(255-ab);                           ao = (ao + 127) / 255;
+        guint32 ro = std::min((255-aa)*rb + 255*ra, (255-ab)*ra + 255*rb);  ro = (ro + 127) / 255;
+        guint32 go = std::min((255-aa)*gb + 255*ga, (255-ab)*ga + 255*gb);  go = (go + 127) / 255;
+        guint32 bo = std::min((255-aa)*bb + 255*ba, (255-ab)*ba + 255*bb);  bo = (bo + 127) / 255;
+
+        ASSEMBLE_ARGB32(pxout, ao, ro, go, bo)
+        *out = pxout;
+    }
+};
+
+// cr = Max ((1 - qa) * cb + ca, (1 - qb) * ca + cb)
+struct BlendLighten {
+    void operator()(guint32 in1, guint32 in2, guint32 *out)
+    {
+        EXTRACT_ARGB32(in1, aa, ra, ga, ba)
+        EXTRACT_ARGB32(in2, ab, rb, gb, bb)
+
+        guint32 ao = 255*255 - (255-aa)*(255-ab);                           ao = (ao + 127) / 255;
+        guint32 ro = std::max((255-aa)*rb + 255*ra, (255-ab)*ra + 255*rb);  ro = (ro + 127) / 255;
+        guint32 go = std::max((255-aa)*gb + 255*ga, (255-ab)*ga + 255*gb);  go = (go + 127) / 255;
+        guint32 bo = std::max((255-aa)*bb + 255*ba, (255-ab)*ba + 255*bb);  bo = (bo + 127) / 255;
+
+        ASSEMBLE_ARGB32(pxout, ao, ro, go, bo)
+        *out = pxout;
+    }
+};
+
+/*
+struct BlendAlpha
+static inline void blend_alpha(guint32 in1, guint32 in2, guint32 *out)
+{
+    EXTRACT_ARGB32(in1, a1, a2, a3, a4);
+    EXTRACT_ARGB32(in2, b1, b2, b3, b4);
+
+    guint32 o1 = 255*255 - (255-a1)*(255-b1);  o1 = (o1+127) / 255;
+    guint32 o2 = 255*255 - (255-a2)*(255-b2);  o2 = (o2+127) / 255;
+    guint32 o3 = 255*255 - (255-a3)*(255-b3);  o3 = (o3+127) / 255;
+    guint32 o4 = 255*255 - (255-a4)*(255-b4);  o4 = (o4+127) / 255;
+
+    ASSEMBLE_ARGB32(pxout, o1, o2, o3, o4);
+    *out = pxout;
+}
+*/
+
+template <typename Blend>
+void surface_blend(cairo_surface_t *in1, cairo_surface_t *in2, cairo_surface_t *out)
+{
+    cairo_surface_flush(in1);
+    cairo_surface_flush(in2);
+
+    // WARNING: code below assumes that:
+    // 1. Cairo ARGB32 surface strides are always divisible by 4
+    // 2. We can only receive CAIRO_FORMAT_ARGB32 or CAIRO_FORMAT_A8 surfaces
+
+    int w = cairo_image_surface_get_width(in2);
+    int h = cairo_image_surface_get_height(in2);
+    int stride1   = cairo_image_surface_get_stride(in1);
+    int stride2   = cairo_image_surface_get_stride(in2);
+    int strideout = cairo_image_surface_get_stride(out);
+    int bpp1   = cairo_image_surface_get_format(in1) == CAIRO_FORMAT_A8 ? 1 : 4;
+    int bpp2   = cairo_image_surface_get_format(in2) == CAIRO_FORMAT_A8 ? 1 : 4;
+    // assumption: out surface is CAIRO_FORMAT_ARGB32 if at least one input is ARGB32
+
+    guint32 *const in1_data = (guint32*) cairo_image_surface_get_data(in1);
+    guint32 *const in2_data = (guint32*) cairo_image_surface_get_data(in2);
+    guint32 *const out_data = (guint32*) cairo_image_surface_get_data(out);
+
+    #if HAVE_OPENMP
+    Inkscape::Preferences *prefs = Inkscape::Preferences::get();
+    int num_threads = prefs->getIntLimited("/options/threading/numthreads", omp_get_num_procs(), 1, 256);
+    #endif
+
+    if (bpp1 == 4) {
+        if (bpp2 == 4) {
+            #if HAVE_OPENMP
+            #pragma omp parallel for num_threads(num_threads)
+            #endif
+            for (int i = 0; i < h; ++i) {
+                guint32 *in1_p = in1_data + i * stride1/4;
+                guint32 *in2_p = in2_data + i * stride2/4;
+                guint32 *out_p = out_data + i * strideout/4;
+                for (int j = 0; j < w; ++j) {
+                    Blend()(*in1_p, *in2_p, out_p);
+                    ++in1_p;
+                    ++in2_p;
+                    ++out_p;
+                }
+            }
+        } else {
+            // bpp2 == 1
+            #if HAVE_OPENMP
+            #pragma omp parallel for num_threads(num_threads)
+            #endif
+            for (int i = 0; i < h; ++i) {
+                guint32 *in1_p = in1_data + i * stride1/4;
+                guint8  *in2_p = reinterpret_cast<guint8*>(in2_data) + i * stride2;
+                guint32 *out_p = out_data + i * strideout/4;
+                for (int j = 0; j < w; ++j) {
+                    guint32 in2_px = *in2_p;
+                    in2_px <<= 24;
+                    Blend()(*in1_p, in2_px, out_p);
+                    ++in1_p;
+                    ++in2_p;
+                    ++out_p;
+                }
+            }
+        }
+    } else {
+        if (bpp2 == 4) {
+            // bpp1 == 1
+            #if HAVE_OPENMP
+            #pragma omp parallel for num_threads(num_threads)
+            #endif
+            for (int i = 0; i < h; ++i) {
+                guint8  *in1_p = reinterpret_cast<guint8*>(in1_data) + i * stride1;
+                guint32 *in2_p = in2_data + i * stride2/4;
+                guint32 *out_p = out_data + i * strideout/4;
+                for (int j = 0; j < w; ++j) {
+                    guint32 in1_px = *in1_p;
+                    in1_px <<= 24;
+                    Blend()(in1_px, *in2_p, out_p);
+                    ++in1_p;
+                    ++in2_p;
+                    ++out_p;
+                }
+            }
+        } else {
+            // bpp1 == 1 && bpp2 == 1
+            // don't do anything - this should have been handled via Cairo blending
+            g_assert_not_reached();
+        }
+    }
+
+    cairo_surface_mark_dirty(out);
+}
+
+void FilterBlend::render_cairo(FilterSlot &slot)
+{
+    cairo_surface_t *input1 = slot.getcairo(_input);
+    cairo_surface_t *input2 = slot.getcairo(_input2);
+
+    cairo_content_t ct1 = cairo_surface_get_content(input1);
+    cairo_content_t ct2 = cairo_surface_get_content(input2);
+
+    // input2 is the "background" image
+    // out should be ARGB32 if any of the inputs is ARGB32
+    cairo_surface_t *out = NULL;
+    if ((ct1 == CAIRO_CONTENT_ALPHA && ct2 == CAIRO_CONTENT_ALPHA)
+        || _blend_mode == BLEND_NORMAL)
+    {
+        out = ink_cairo_surface_copy(input2);
+        cairo_t *out_ct = cairo_create(out);
+        cairo_set_source_surface(out_ct, input1, 0, 0);
+        cairo_paint(out_ct);
+        cairo_destroy(out_ct);
+    } else {
+        // blend mode != normal and at least 1 surface is not pure alpha
+        // create surface identical to the ARGB32 surface
+        if (ct1 == CAIRO_CONTENT_ALPHA) {
+            out = ink_cairo_surface_create_identical(input2);
+        } else {
+            out = ink_cairo_surface_create_identical(input1);
+        }
+
+        // TODO: convert to Cairo blending operators once we start using the 1.10 series
+        switch (_blend_mode) {
+            case BLEND_MULTIPLY:
+                surface_blend<BlendMultiply>(input1, input2, out);
+                break;
+            case BLEND_SCREEN:
+                surface_blend<BlendScreen>(input1, input2, out);
+                break;
+            case BLEND_DARKEN:
+                surface_blend<BlendDarken>(input1, input2, out);
+                break;
+            case BLEND_LIGHTEN:
+                surface_blend<BlendLighten>(input1, input2, out);
+                break;
+            case BLEND_NORMAL:
+            default:
+                // this was handled before
+                g_assert_not_reached();
+                break;
+        }
+    }
+
+    slot.set(_output, out);
+    cairo_surface_destroy(out);
+}
+
 int FilterBlend::render(FilterSlot &slot, FilterUnits const & /*units*/) {
     NRPixBlock *in1 = slot.get(_input);
     NRPixBlock *in2 = slot.get(_input2);
@@ -202,6 +449,12 @@ int FilterBlend::render(FilterSlot &slot, FilterUnits const & /*units*/) {
     return 0;
 }
 
+bool FilterBlend::can_handle_affine(Geom::Matrix const &)
+{
+    // blend is a per-pixel primitive and is immutable under transformations
+    return true;
+}
+
 void FilterBlend::set_input(int slot) {
     _input = slot;
 }
diff --git a/src/display/nr-filter-blend.h b/src/display/nr-filter-blend.h
index ffdd62118..45da07f27 100644
--- a/src/display/nr-filter-blend.h
+++ b/src/display/nr-filter-blend.h
@@ -39,7 +39,9 @@ public:
     static FilterPrimitive *create();
     virtual ~FilterBlend();
 
+    virtual void render_cairo(FilterSlot &slot);
     virtual int render(FilterSlot &slot, FilterUnits const &units);
+    virtual bool can_handle_affine(Geom::Matrix const &);
 
     virtual void set_input(int slot);
     virtual void set_input(int input, int slot);
diff --git a/src/display/nr-filter-gaussian.cpp b/src/display/nr-filter-gaussian.cpp
index 2e6bed070..1e59748c4 100644
--- a/src/display/nr-filter-gaussian.cpp
+++ b/src/display/nr-filter-gaussian.cpp
@@ -32,8 +32,6 @@
 #include "display/nr-filter-gaussian.h"
 #include "display/nr-filter-types.h"
 #include "display/nr-filter-units.h"
-#include "libnr/nr-blit.h"
-#include "libnr/nr-pixblock.h"
 #include <2geom/matrix.h>
 #include "util/fixed_point.h"
 #include "preferences.h"
@@ -193,21 +191,6 @@ _effect_subsample_step_log2(double const deviation, int const quality)
     return stepsize_l2;
 }
 
-/**
- * Sanity check function for indexing pixblocks.
- * Catches reading and writing outside the pixblock area.
- * When enabled, decreases filter rendering speed massively.
- */
-static inline void
-_check_index(NRPixBlock const * const pb, int const location, int const line)
-{
-    if (false) {
-        int max_loc = pb->rs * (pb->area.y1 - pb->area.y0);
-        if (location < 0 || location >= max_loc)
-            g_warning("Location %d out of bounds (0 ... %d) at line %d", location, max_loc, line);
-    }
-}
-
 static void calcFilter(double const sigma, double b[N]) {
     assert(N==3);
     std::complex<double> const d1_org(1.40098,  1.00236);
@@ -287,8 +270,10 @@ filter2D_IIR(PT *const dest, int const dstr1, int const dstr2,
 {
 #if G_BYTE_ORDER == G_LITTLE_ENDIAN
     static unsigned int const alpha_PC = PC-1;
+    #define PREMUL_ALPHA_LOOP for(unsigned int c=0; c<PC-1; ++c)
 #else
     static unsigned int const alpha_PC = 0;
+    #define PREMUL_ALPHA_LOOP for(unsigned int c=1; c<PC; ++c)
 #endif
 
 #if HAVE_OPENMP
@@ -327,7 +312,7 @@ filter2D_IIR(PT *const dest, int const dstr1, int const dstr2,
         dstimg -= dstr1;
         if ( PREMULTIPLIED_ALPHA ) {
             dstimg[alpha_PC] = clip_round_cast<PT>(v[0][alpha_PC]);
-            for(unsigned int c=0; c<alpha_PC; c++) dstimg[c] = clip_round_cast<PT>(v[0][c], std::numeric_limits<PT>::min(), dstimg[alpha_PC]);
+            PREMUL_ALPHA_LOOP dstimg[c] = clip_round_cast<PT>(v[0][c], std::numeric_limits<PT>::min(), dstimg[alpha_PC]);
         } else {
             for(unsigned int c=0; c<PC; c++) dstimg[c] = clip_round_cast<PT>(v[0][c]);
         }
@@ -342,7 +327,7 @@ filter2D_IIR(PT *const dest, int const dstr1, int const dstr2,
             dstimg -= dstr1;
             if ( PREMULTIPLIED_ALPHA ) {
                 dstimg[alpha_PC] = clip_round_cast<PT>(v[0][alpha_PC]);
-                for(unsigned int c=0; c<alpha_PC; c++) dstimg[c] = clip_round_cast<PT>(v[0][c], std::numeric_limits<PT>::min(), dstimg[alpha_PC]);
+                PREMUL_ALPHA_LOOP dstimg[c] = clip_round_cast<PT>(v[0][c], std::numeric_limits<PT>::min(), dstimg[alpha_PC]);
             } else {
                 for(unsigned int c=0; c<PC; c++) dstimg[c] = clip_round_cast<PT>(v[0][c]);
             }
@@ -457,93 +442,6 @@ filter2D_FIR(PT *const dst, int const dstr1, int const dstr2,
     }
 }
 
-template<typename PT, unsigned int PC>
-static void
-downsample(PT *const dst, int const dstr1, int const dstr2, int const dn1, int const dn2,
-           PT const *const src, int const sstr1, int const sstr2, int const sn1, int const sn2,
-           int const step1_l2, int const step2_l2)
-{
-    unsigned int const divisor_l2 = step1_l2+step2_l2; // step1*step2=2^(step1_l2+step2_l2)
-    unsigned int const round_offset = (1<<divisor_l2)/2;
-    int const step1 = 1<<step1_l2;
-    int const step2 = 1<<step2_l2;
-    int const step1_2 = step1/2;
-    int const step2_2 = step2/2;
-    for(int dc2 = 0 ; dc2 < dn2 ; dc2++) {
-        int const sc2_begin = (dc2<<step2_l2)-step2_2;
-        int const sc2_end = sc2_begin+step2;
-        for(int dc1 = 0 ; dc1 < dn1 ; dc1++) {
-            int const sc1_begin = (dc1<<step1_l2)-step1_2;
-            int const sc1_end = sc1_begin+step1;
-            unsigned int sum[PC];
-            std::fill_n(sum, PC, 0);
-            for(int sc2 = sc2_begin ; sc2 < sc2_end ; sc2++) {
-                for(int sc1 = sc1_begin ; sc1 < sc1_end ; sc1++) {
-                    for(unsigned int ch = 0 ; ch < PC ; ch++) {
-                        sum[ch] += src[clip(sc2,0,sn2-1)*sstr2+clip(sc1,0,sn1-1)*sstr1+ch];
-                    }
-                }
-            }
-            for(unsigned int ch = 0 ; ch < PC ; ch++) {
-                dst[dc2*dstr2+dc1*dstr1+ch] = static_cast<PT>((sum[ch]+round_offset)>>divisor_l2);
-            }
-        }
-    }
-}
-
-template<typename PT, unsigned int PC>
-static void
-upsample(PT *const dst, int const dstr1, int const dstr2, unsigned int const dn1, unsigned int const dn2,
-         PT const *const src, int const sstr1, int const sstr2, unsigned int const sn1, unsigned int const sn2,
-         unsigned int const step1_l2, unsigned int const step2_l2)
-{
-    assert(((sn1-1)<<step1_l2)>=dn1 && ((sn2-1)<<step2_l2)>=dn2); // The last pixel of the source image should fall outside the destination image
-    unsigned int const divisor_l2 = step1_l2+step2_l2; // step1*step2=2^(step1_l2+step2_l2)
-    unsigned int const round_offset = (1<<divisor_l2)/2;
-    unsigned int const step1 = 1<<step1_l2;
-    unsigned int const step2 = 1<<step2_l2;
-    for ( unsigned int sc2 = 0 ; sc2 < sn2-1 ; sc2++ ) {
-        unsigned int const dc2_begin = (sc2 << step2_l2);
-        unsigned int const dc2_end = std::min(dn2, dc2_begin+step2);
-        for ( unsigned int sc1 = 0 ; sc1 < sn1-1 ; sc1++ ) {
-            unsigned int const dc1_begin = (sc1 << step1_l2);
-            unsigned int const dc1_end = std::min(dn1, dc1_begin+step1);
-            for ( unsigned int byte = 0 ; byte < PC ; byte++) {
-
-                // get 4 values at the corners of the pixel from src
-                PT a00 = src[sstr2* sc2    + sstr1* sc1    + byte];
-                PT a10 = src[sstr2* sc2    + sstr1*(sc1+1) + byte];
-                PT a01 = src[sstr2*(sc2+1) + sstr1* sc1    + byte];
-                PT a11 = src[sstr2*(sc2+1) + sstr1*(sc1+1) + byte];
-
-                // initialize values for linear interpolation
-                unsigned int a0 = a00*step2/*+a01*0*/;
-                unsigned int a1 = a10*step2/*+a11*0*/;
-
-                // iterate over the rectangle to be interpolated
-                for ( unsigned int dc2 = dc2_begin ; dc2 < dc2_end ; dc2++ ) {
-
-                    // prepare linear interpolation for this row
-                    unsigned int a = a0*step1/*+a1*0*/+round_offset;
-
-                    for ( unsigned int dc1 = dc1_begin ; dc1 < dc1_end ; dc1++ ) {
-
-                        // simple linear interpolation
-                        dst[dstr2*dc2 + dstr1*dc1 + byte] = static_cast<PT>(a>>divisor_l2);
-
-                        // compute a = a0*(ix-1)+a1*(xi+1)+round_offset
-                        a = a - a0 + a1;
-                    }
-
-                    // compute a0 = a00*(iy-1)+a01*(yi+1) and similar for a1
-                    a0 = a0 - a00 + a01;
-                    a1 = a1 - a10 + a11;
-                }
-            }
-        }
-    }
-}
-
 static void
 gaussian_pass_IIR(Geom::Dim2 d, double deviation, cairo_surface_t *src, cairo_surface_t *dest,
     IIRValue **tmpdata, int num_threads)
@@ -735,315 +633,6 @@ void FilterGaussian::render_cairo(FilterSlot &slot)
     }
 }
 
-int FilterGaussian::render(FilterSlot &slot, FilterUnits const &units)
-{
-    // TODO: Meaningful return values? (If they're checked at all.)
-
-    /* in holds the input pixblock */
-    NRPixBlock *original_in = slot.get(_input);
-
-    /* If to either direction, the standard deviation is zero or
-     * input image is not defined,
-     * a transparent black image should be returned. */
-    if (_deviation_x <= 0 || _deviation_y <= 0 || original_in == NULL) {
-        NRPixBlock *src = original_in;
-        if (src == NULL) {
-            g_warning("Missing source image for feGaussianBlur (in=%d)", _input);
-            // A bit guessing here, but source graphic is likely to be of
-            // right size
-            src = slot.get(NR_FILTER_SOURCEGRAPHIC);
-        }
-        NRPixBlock *out = new NRPixBlock;
-        nr_pixblock_setup_fast(out, src->mode, src->area.x0, src->area.y0,
-                               src->area.x1, src->area.y1, true);
-        if (out->size != NR_PIXBLOCK_SIZE_TINY && out->data.px != NULL) {
-            out->empty = false;
-            slot.set(_output, out);
-        }
-        return 0;
-    }
-
-    // Gaussian blur is defined to operate on non-premultiplied color values.
-    //   So, convert the input first it uses non-premultiplied color values.
-    //   And please note that this should not be done AFTER resampling, as resampling a non-premultiplied image
-    //   does not simply yield a non-premultiplied version of the resampled premultiplied image!!!
-    NRPixBlock *in = original_in;
-    if (in->mode == NR_PIXBLOCK_MODE_R8G8B8A8N) {
-        in = nr_pixblock_new_fast(NR_PIXBLOCK_MODE_R8G8B8A8P,
-                                  original_in->area.x0, original_in->area.y0,
-                                  original_in->area.x1, original_in->area.y1,
-                                  false);
-        if (!in) {
-            // ran out of memory
-            return 0;
-        }
-        nr_blit_pixblock_pixblock(in, original_in);
-    }
-
-    Geom::Matrix trans = units.get_matrix_primitiveunits2pb();
-
-    // Some common constants
-    int const width_org = in->area.x1-in->area.x0, height_org = in->area.y1-in->area.y0;
-    double const deviation_x_org = _deviation_x * trans.expansionX();
-    double const deviation_y_org = _deviation_y * trans.expansionY();
-    int const PC = NR_PIXBLOCK_BPP(in);
-#if HAVE_OPENMP
-    int const NTHREADS = std::max(1,std::min(8, Inkscape::Preferences::get()->getInt("/options/threading/numthreads", omp_get_num_procs())));
-#else
-    int const NTHREADS = 1;
-#endif // HAVE_OPENMP
-
-    // Subsampling constants
-    int const quality = slot.get_blurquality();
-    int const x_step_l2 = _effect_subsample_step_log2(deviation_x_org, quality);
-    int const y_step_l2 = _effect_subsample_step_log2(deviation_y_org, quality);
-    int const x_step = 1<<x_step_l2;
-    int const y_step = 1<<y_step_l2;
-    bool const resampling = x_step > 1 || y_step > 1;
-    int const width = resampling ? static_cast<int>(ceil(static_cast<double>(width_org)/x_step))+1 : width_org;
-    int const height = resampling ? static_cast<int>(ceil(static_cast<double>(height_org)/y_step))+1 : height_org;
-    double const deviation_x = deviation_x_org / x_step;
-    double const deviation_y = deviation_y_org / y_step;
-    int const scr_len_x = _effect_area_scr(deviation_x);
-    int const scr_len_y = _effect_area_scr(deviation_y);
-
-    // Decide which filter to use for X and Y
-    // This threshold was determined by trial-and-error for one specific machine,
-    // so there's a good chance that it's not optimal.
-    // Whatever you do, don't go below 1 (and preferrably not even below 2), as
-    // the IIR filter gets unstable there.
-    bool const use_IIR_x = deviation_x > 3;
-    bool const use_IIR_y = deviation_y > 3;
-
-    // new buffer for the subsampled output
-    NRPixBlock *out = new NRPixBlock;
-    nr_pixblock_setup_fast(out, in->mode, in->area.x0/x_step,       in->area.y0/y_step,
-                                          in->area.x0/x_step+width, in->area.y0/y_step+height, true);
-    if (out->size != NR_PIXBLOCK_SIZE_TINY && out->data.px == NULL) {
-        // alas, we've accomplished a lot, but ran out of memory - so abort
-        if (in != original_in) nr_pixblock_free(in);
-        delete out;
-        return 0;
-    }
-    // Temporary storage for IIR filter
-    // NOTE: This can be eliminated, but it reduces the precision a bit
-    IIRValue * tmpdata[NTHREADS];
-    std::fill_n(tmpdata, NTHREADS, (IIRValue*)0);
-    if ( use_IIR_x || use_IIR_y ) {
-        for(int i=0; i<NTHREADS; i++) {
-            tmpdata[i] = new IIRValue[std::max(width,height)*PC];
-            if (tmpdata[i] == NULL) {
-                if (in != original_in) nr_pixblock_free(in);
-                nr_pixblock_release(out);
-                while(i-->0) {
-                    delete[] tmpdata[i];
-                }
-                delete out;
-                return 0;
-            }
-        }
-    }
-
-    // Resampling (if necessary), goes from in -> out (setting ssin to out if used)
-    NRPixBlock *ssin = in;
-    if ( resampling ) {
-        ssin = out;
-        // Downsample
-        switch(in->mode) {
-        case NR_PIXBLOCK_MODE_A8:        ///< Grayscale
-            downsample<unsigned char,1>(NR_PIXBLOCK_PX(out), 1, out->rs, width, height, NR_PIXBLOCK_PX(in), 1, in->rs, width_org, height_org, x_step_l2, y_step_l2);
-            break;
-        case NR_PIXBLOCK_MODE_R8G8B8:    ///< 8 bit RGB
-            downsample<unsigned char,3>(NR_PIXBLOCK_PX(out), 3, out->rs, width, height, NR_PIXBLOCK_PX(in), 3, in->rs, width_org, height_org, x_step_l2, y_step_l2);
-            break;
-        //case NR_PIXBLOCK_MODE_R8G8B8A8N: ///< Normal 8 bit RGBA
-        //    downsample<unsigned char,4>(NR_PIXBLOCK_PX(out), 4, out->rs, width, height, NR_PIXBLOCK_PX(in), 4, in->rs, width_org, height_org, x_step_l2, y_step_l2);
-        //    break;
-        case NR_PIXBLOCK_MODE_R8G8B8A8P: ///< Premultiplied 8 bit RGBA
-            downsample<unsigned char,4>(NR_PIXBLOCK_PX(out), 4, out->rs, width, height, NR_PIXBLOCK_PX(in), 4, in->rs, width_org, height_org, x_step_l2, y_step_l2);
-            break;
-        default:
-            assert(false);
-        };
-    }
-
-    // Horizontal filtering, goes from ssin -> out (ssin might be equal to out, but these algorithms can be used in-place)
-    if (use_IIR_x) {
-        // Filter variables
-        IIRValue b[N+1];  // scaling coefficient + filter coefficients (can be 10.21 fixed point)
-        double bf[N];  // computed filter coefficients
-        double M[N*N]; // matrix used for initialization procedure (has to be double)
-
-        // Compute filter (x)
-        calcFilter(deviation_x, bf);
-        for(size_t i=0; i<N; i++) bf[i] = -bf[i];
-        b[0] = 1; // b[0] == alpha (scaling coefficient)
-        for(size_t i=0; i<N; i++) {
-            b[i+1] = bf[i];
-            b[0] -= b[i+1];
-        }
-
-        // Compute initialization matrix (x)
-        calcTriggsSdikaM(bf, M);
-
-        // Filter (x)
-        switch(in->mode) {
-        case NR_PIXBLOCK_MODE_A8:        ///< Grayscale
-            filter2D_IIR<unsigned char,1,false>(NR_PIXBLOCK_PX(out), 1, out->rs, NR_PIXBLOCK_PX(ssin), 1, ssin->rs, width, height, b, M, tmpdata, NTHREADS);
-            break;
-        case NR_PIXBLOCK_MODE_R8G8B8:    ///< 8 bit RGB
-            filter2D_IIR<unsigned char,3,false>(NR_PIXBLOCK_PX(out), 3, out->rs, NR_PIXBLOCK_PX(ssin), 3, ssin->rs, width, height, b, M, tmpdata, NTHREADS);
-            break;
-        //case NR_PIXBLOCK_MODE_R8G8B8A8N: ///< Normal 8 bit RGBA
-        //    filter2D_IIR<unsigned char,4,false>(NR_PIXBLOCK_PX(out), 4, out->rs, NR_PIXBLOCK_PX(ssin), 4, ssin->rs, width, height, b, M, tmpdata, NTHREADS);
-        //    break;
-        case NR_PIXBLOCK_MODE_R8G8B8A8P: ///< Premultiplied 8 bit RGBA
-            filter2D_IIR<unsigned char,4,true >(NR_PIXBLOCK_PX(out), 4, out->rs, NR_PIXBLOCK_PX(ssin), 4, ssin->rs, width, height, b, M, tmpdata, NTHREADS);
-            break;
-        default:
-            assert(false);
-        };
-    } else if ( scr_len_x > 0 ) { // !use_IIR_x
-        // Filter kernel for x direction
-        FIRValue kernel[scr_len_x+1];
-        _make_kernel(kernel, deviation_x);
-
-        // Filter (x)
-        switch(in->mode) {
-        case NR_PIXBLOCK_MODE_A8:        ///< Grayscale
-            filter2D_FIR<unsigned char,1>(NR_PIXBLOCK_PX(out), 1, out->rs, NR_PIXBLOCK_PX(ssin), 1, ssin->rs, width, height, kernel, scr_len_x, NTHREADS);
-            break;
-        case NR_PIXBLOCK_MODE_R8G8B8:    ///< 8 bit RGB
-            filter2D_FIR<unsigned char,3>(NR_PIXBLOCK_PX(out), 3, out->rs, NR_PIXBLOCK_PX(ssin), 3, ssin->rs, width, height, kernel, scr_len_x, NTHREADS);
-            break;
-        //case NR_PIXBLOCK_MODE_R8G8B8A8N: ///< Normal 8 bit RGBA
-        //    filter2D_FIR<unsigned char,4>(NR_PIXBLOCK_PX(out), 4, out->rs, NR_PIXBLOCK_PX(ssin), 4, ssin->rs, width, height, kernel, scr_len_x, NTHREADS);
-        //    break;
-        case NR_PIXBLOCK_MODE_R8G8B8A8P: ///< Premultiplied 8 bit RGBA
-            filter2D_FIR<unsigned char,4>(NR_PIXBLOCK_PX(out), 4, out->rs, NR_PIXBLOCK_PX(ssin), 4, ssin->rs, width, height, kernel, scr_len_x, NTHREADS);
-            break;
-        default:
-            assert(false);
-        };
-    } else if ( out != ssin ) { // out can be equal to ssin if resampling is used
-        nr_blit_pixblock_pixblock(out, ssin);
-    }
-
-    // Vertical filtering, goes from out -> out
-    if (use_IIR_y) {
-        // Filter variables
-        IIRValue b[N+1];  // scaling coefficient + filter coefficients (can be 10.21 fixed point)
-        double bf[N];  // computed filter coefficients
-        double M[N*N]; // matrix used for initialization procedure (has to be double)
-
-        // Compute filter (y)
-        calcFilter(deviation_y, bf);
-        for(size_t i=0; i<N; i++) bf[i] = -bf[i];
-        b[0] = 1; // b[0] == alpha (scaling coefficient)
-        for(size_t i=0; i<N; i++) {
-            b[i+1] = bf[i];
-            b[0] -= b[i+1];
-        }
-
-        // Compute initialization matrix (y)
-        calcTriggsSdikaM(bf, M);
-
-        // Filter (y)
-        switch(in->mode) {
-        case NR_PIXBLOCK_MODE_A8:        ///< Grayscale
-            filter2D_IIR<unsigned char,1,false>(NR_PIXBLOCK_PX(out), out->rs, 1, NR_PIXBLOCK_PX(out), out->rs, 1, height, width, b, M, tmpdata, NTHREADS);
-            break;
-        case NR_PIXBLOCK_MODE_R8G8B8:    ///< 8 bit RGB
-            filter2D_IIR<unsigned char,3,false>(NR_PIXBLOCK_PX(out), out->rs, 3, NR_PIXBLOCK_PX(out), out->rs, 3, height, width, b, M, tmpdata, NTHREADS);
-            break;
-        //case NR_PIXBLOCK_MODE_R8G8B8A8N: ///< Normal 8 bit RGBA
-        //    filter2D_IIR<unsigned char,4,false>(NR_PIXBLOCK_PX(out), out->rs, 4, NR_PIXBLOCK_PX(out), out->rs, 4, height, width, b, M, tmpdata, NTHREADS);
-        //    break;
-        case NR_PIXBLOCK_MODE_R8G8B8A8P: ///< Premultiplied 8 bit RGBA
-            filter2D_IIR<unsigned char,4,true >(NR_PIXBLOCK_PX(out), out->rs, 4, NR_PIXBLOCK_PX(out), out->rs, 4, height, width, b, M, tmpdata, NTHREADS);
-            break;
-        default:
-            assert(false);
-        };
-    } else if ( scr_len_y > 0 ) { // !use_IIR_y
-        // Filter kernel for y direction
-        FIRValue kernel[scr_len_y+1];
-        _make_kernel(kernel, deviation_y);
-
-        // Filter (y)
-        switch(in->mode) {
-        case NR_PIXBLOCK_MODE_A8:        ///< Grayscale
-            filter2D_FIR<unsigned char,1>(NR_PIXBLOCK_PX(out), out->rs, 1, NR_PIXBLOCK_PX(out), out->rs, 1, height, width, kernel, scr_len_y, NTHREADS);
-            break;
-        case NR_PIXBLOCK_MODE_R8G8B8:    ///< 8 bit RGB
-            filter2D_FIR<unsigned char,3>(NR_PIXBLOCK_PX(out), out->rs, 3, NR_PIXBLOCK_PX(out), out->rs, 3, height, width, kernel, scr_len_y, NTHREADS);
-            break;
-        //case NR_PIXBLOCK_MODE_R8G8B8A8N: ///< Normal 8 bit RGBA
-        //    filter2D_FIR<unsigned char,4>(NR_PIXBLOCK_PX(out), out->rs, 4, NR_PIXBLOCK_PX(out), out->rs, 4, height, width, kernel, scr_len_y, NTHREADS);
-        //    break;
-        case NR_PIXBLOCK_MODE_R8G8B8A8P: ///< Premultiplied 8 bit RGBA
-            filter2D_FIR<unsigned char,4>(NR_PIXBLOCK_PX(out), out->rs, 4, NR_PIXBLOCK_PX(out), out->rs, 4, height, width, kernel, scr_len_y, NTHREADS);
-            break;
-        default:
-            assert(false);
-        };
-    }
-
-    for(int i=0; i<NTHREADS; i++) {
-        delete[] tmpdata[i]; // deleting a nullptr has no effect, so this is safe
-    }
-
-    // Upsampling, stores (the upsampled) out using slot.set(_output, ...)
-    if ( !resampling ) {
-        // No upsampling needed
-        out->empty = FALSE;
-        slot.set(_output, out);
-    } else {
-        // New buffer for the final output, same resolution as the in buffer
-        NRPixBlock *finalout = new NRPixBlock;
-        nr_pixblock_setup_fast(finalout, in->mode, in->area.x0, in->area.y0,
-                                                   in->area.x1, in->area.y1, true);
-        if (finalout->size != NR_PIXBLOCK_SIZE_TINY && finalout->data.px == NULL) {
-            // alas, we've accomplished a lot, but ran out of memory - so abort
-            if (in != original_in) nr_pixblock_free(in);
-            nr_pixblock_release(out);
-            delete out;
-            return 0;
-        }
-
-        // Upsample
-        switch(in->mode) {
-        case NR_PIXBLOCK_MODE_A8:        ///< Grayscale
-            upsample<unsigned char,1>(NR_PIXBLOCK_PX(finalout), 1, finalout->rs, width_org, height_org, NR_PIXBLOCK_PX(out), 1, out->rs, width, height, x_step_l2, y_step_l2);
-            break;
-        case NR_PIXBLOCK_MODE_R8G8B8:    ///< 8 bit RGB
-            upsample<unsigned char,3>(NR_PIXBLOCK_PX(finalout), 3, finalout->rs, width_org, height_org, NR_PIXBLOCK_PX(out), 3, out->rs, width, height, x_step_l2, y_step_l2);
-            break;
-        //case NR_PIXBLOCK_MODE_R8G8B8A8N: ///< Normal 8 bit RGBA
-        //    upsample<unsigned char,4>(NR_PIXBLOCK_PX(finalout), 4, finalout->rs, width_org, height_org, NR_PIXBLOCK_PX(out), 4, out->rs, width, height, x_step_l2, y_step_l2);
-        //    break;
-        case NR_PIXBLOCK_MODE_R8G8B8A8P: ///< Premultiplied 8 bit RGBA
-            upsample<unsigned char,4>(NR_PIXBLOCK_PX(finalout), 4, finalout->rs, width_org, height_org, NR_PIXBLOCK_PX(out), 4, out->rs, width, height, x_step_l2, y_step_l2);
-            break;
-        default:
-            assert(false);
-        };
-
-        // We don't need the out buffer anymore
-        nr_pixblock_release(out);
-        delete out;
-
-        // The final out buffer gets returned
-        finalout->empty = FALSE;
-        slot.set(_output, finalout);
-    }
-
-    // If we downsampled the input, clean up the downsampled data
-    if (in != original_in) nr_pixblock_free(in);
-
-    return 0;
-}
-
 void FilterGaussian::area_enlarge(NRRectL &area, Geom::Matrix const &trans)
 {
     int area_x = _effect_area_scr(_deviation_x * trans.expansionX());
@@ -1057,8 +646,14 @@ void FilterGaussian::area_enlarge(NRRectL &area, Geom::Matrix const &trans)
     area.y1 += area_max;
 }
 
-FilterTraits FilterGaussian::get_input_traits() {
-    return TRAIT_PARALLER;
+bool FilterGaussian::can_handle_affine(Geom::Matrix const &m)
+{
+    if (Geom::are_near(_deviation_x, _deviation_y)) {
+        // TODO after 2Geom sync, change this to m.preservesAngles()
+        return Geom::are_near(m[0], m[3]) && Geom::are_near(m[1], -m[2]);
+    } else {
+        return false;
+    }
 }
 
 void FilterGaussian::set_deviation(double deviation)
diff --git a/src/display/nr-filter-gaussian.h b/src/display/nr-filter-gaussian.h
index 7bcabdba9..01ce9efcb 100644
--- a/src/display/nr-filter-gaussian.h
+++ b/src/display/nr-filter-gaussian.h
@@ -39,9 +39,8 @@ public:
     virtual ~FilterGaussian();
 
     virtual void render_cairo(FilterSlot &slot);
-    virtual int render(FilterSlot &slot, FilterUnits const &units);
     virtual void area_enlarge(NRRectL &area, Geom::Matrix const &m);
-    virtual FilterTraits get_input_traits();
+    virtual bool can_handle_affine(Geom::Matrix const &m);
 
     /**
      * Set the standard deviation value for gaussian blur. Deviation along
diff --git a/src/display/nr-filter-primitive.h b/src/display/nr-filter-primitive.h
index a7ae0125e..89927fdbd 100644
--- a/src/display/nr-filter-primitive.h
+++ b/src/display/nr-filter-primitive.h
@@ -44,7 +44,7 @@ public:
     virtual ~FilterPrimitive();
 
     virtual void render_cairo(FilterSlot &slot);
-    virtual int render(FilterSlot &slot, FilterUnits const &units) = 0;
+    virtual int render(FilterSlot &slot, FilterUnits const &units) { return 0; }
     virtual void area_enlarge(NRRectL &area, Geom::Matrix const &m);
 
     /**
@@ -109,6 +109,20 @@ public:
      */
     virtual FilterTraits get_input_traits();
 
+    /** @brief Indicate whether the filter primitive can handle the given affine.
+     *
+     * Results of some filter primitives depend on the coordinate system used when rendering.
+     * A gaussian blur will equal x and y deviation will remain unchanged by rotations.
+     * Per-pixel filters like color matrix and blend will not change regardless of
+     * the transformation.
+     *
+     * When any filter returns false, filter rendering is performed on an intermediate surface
+     * with edges parallel to the axes of the user coordinate system. This means
+     * the matrices from FilterUnits will contain at most a (possibly non-uniform) scale
+     * and a translation. When all primitives of the filter return false, the rendering is
+     * performed in display coordinate space and no intermediate surface is used. */
+    virtual bool can_handle_affine(Geom::Matrix const &) { return false; }
+
 protected:
     int _input;
     int _output;
diff --git a/src/display/nr-filter-slot.cpp b/src/display/nr-filter-slot.cpp
index d700cd433..5371499e4 100644
--- a/src/display/nr-filter-slot.cpp
+++ b/src/display/nr-filter-slot.cpp
@@ -20,7 +20,6 @@
 #include "display/nr-filter-types.h"
 #include "display/nr-filter-gaussian.h"
 #include "display/nr-filter-slot.h"
-#include "display/nr-filter-getalpha.h"
 #include "display/nr-filter-units.h"
 #include "display/pixblock-scaler.h"
 #include "display/pixblock-transform.h"
@@ -131,10 +130,9 @@ cairo_surface_t *FilterSlot::getcairo(int slot_nr)
                 cairo_surface_destroy(tr);
             } break;
             case NR_FILTER_BACKGROUNDIMAGE: {
-                // TODO
-                //cairo_surface_t *bg = _get_transformed_background();
-                //_set_internal(NR_FILTER_BACKGROUNDIMAGE, bg);
-                //cairo_surface_destroy(bg);
+                cairo_surface_t *bg = _get_transformed_background();
+                _set_internal(NR_FILTER_BACKGROUNDIMAGE, bg);
+                cairo_surface_destroy(bg);
             } break;
             case NR_FILTER_SOURCEALPHA: {
                 cairo_surface_t *src = getcairo(NR_FILTER_SOURCEGRAPHIC);
@@ -158,8 +156,12 @@ cairo_surface_t *FilterSlot::getcairo(int slot_nr)
 
     if (s == _slots.end()) {
         // create empty surface
-        // TODO
-        return NULL;
+        cairo_surface_t *empty = cairo_surface_create_similar(
+            _source_graphic, cairo_surface_get_content(_source_graphic),
+            _slot_area.x1 - _slot_area.x0, _slot_area.y1 - _slot_area.y0);
+        _set_internal(slot_nr, empty);
+        cairo_surface_destroy(empty);
+        s = _slots.find(slot_nr);
     }
     return s->second;
 
@@ -189,7 +191,23 @@ cairo_surface_t *FilterSlot::_get_transformed_source_graphic()
 
 cairo_surface_t *FilterSlot::_get_transformed_background()
 {
-    return NULL;
+    Geom::Matrix trans = _units.get_matrix_display2pb();
+
+    cairo_surface_t *bg = cairo_get_target(_background_ct);
+    cairo_surface_t *tbg = cairo_surface_create_similar(
+        bg, cairo_surface_get_content(bg),
+        _slot_area.x1 - _slot_area.x0, _slot_area.y1 - _slot_area.y0);
+    cairo_t *tbg_ct = cairo_create(tbg);
+
+    cairo_translate(tbg_ct, -_slot_area.x0, -_slot_area.y0);
+    ink_cairo_transform(tbg_ct, trans);
+    cairo_translate(tbg_ct, _background_area->x0, _background_area->y0);
+    cairo_set_source_surface(tbg_ct, bg, 0, 0);
+    cairo_set_operator(tbg_ct, CAIRO_OPERATOR_SOURCE);
+    cairo_paint(tbg_ct);
+    cairo_destroy(tbg_ct);
+
+    return tbg;
 }
 
 cairo_surface_t *FilterSlot::get_result(int res)
@@ -299,11 +317,6 @@ void FilterSlot::set(int slot_nr, cairo_surface_t *surface)
                               trans[1] * x1 + trans[3] * y0 + trans[5],
                               trans[1] * x1 + trans[3] * y1 + trans[5]);
 
-            cairo_surface_t *trans_s = cairo_surface_create_similar(s,
-                CAIRO_CONTENT_COLOR, max_x - min_x, max_y - min_y);
-            cairo_t *ct = cairo_create(trans_s);
-            
-
             nr_pixblock_setup_fast(trans_pb, pb->mode,
                                    min_x, min_y,
                                    max_x, max_y, true);
diff --git a/src/filter-chemistry.cpp b/src/filter-chemistry.cpp
index 363663ac3..298531db0 100644
--- a/src/filter-chemistry.cpp
+++ b/src/filter-chemistry.cpp
@@ -22,9 +22,9 @@
 #include "filter-enums.h"
 
 #include "filters/blend.h"
+#include "filters/gaussian-blur.h"
 #include "sp-filter.h"
 #include "sp-filter-reference.h"
-#include "sp-gaussian-blur.h"
 #include "svg/css-ostringstream.h"
 #include "libnr/nr-matrix-fns.h"
 
diff --git a/src/filter-chemistry.h b/src/filter-chemistry.h
index 1b18ec11a..67531d630 100644
--- a/src/filter-chemistry.h
+++ b/src/filter-chemistry.h
@@ -1,6 +1,3 @@
-#ifndef __SP_FILTER_CHEMISTRY_H__
-#define __SP_FILTER_CHEMISTRY_H__
-
 /*
  * Various utility methods for filters
  *
@@ -14,8 +11,14 @@
  * Released under GNU GPL, read the file 'COPYING' for more information
  */
 
+#ifndef SEEN_SP_FILTER_CHEMISTRY_H
+#define SEEN_SP_FILTER_CHEMISTRY_H
+
 #include "forward.h"
-#include "sp-filter.h"
+#include "display/nr-filter-types.h"
+
+class SPFilter;
+class SPFilterPrimitive;
 
 SPFilterPrimitive *filter_add_primitive(SPFilter *filter, Inkscape::Filters::FilterPrimitiveType);
 SPFilter *new_filter (SPDocument *document);
diff --git a/src/filters/Makefile_insert b/src/filters/Makefile_insert
index dde7cdb68..ea9ff4b56 100644
--- a/src/filters/Makefile_insert
+++ b/src/filters/Makefile_insert
@@ -1,59 +1,46 @@
 ## Makefile.am fragment sourced by src/Makefile.am.
 
 ink_common_sources +=	\
-	filters/blend.cpp							\
-	filters/blend-fns.h						\
-	filters/blend.h							\
-	filters/colormatrix.cpp					\
-	filters/colormatrix-fns.h					\
-	filters/colormatrix.h						\
-	filters/componenttransfer.cpp				\
-	filters/componenttransfer-fns.h			\
+	filters/blend.cpp				\
+	filters/blend.h					\
+	filters/colormatrix.cpp				\
+	filters/colormatrix.h				\
+	filters/componenttransfer.cpp			\
 	filters/componenttransfer-funcnode.cpp		\
 	filters/componenttransfer-funcnode.h		\
-	filters/componenttransfer.h				\
-	filters/composite.cpp						\
-	filters/composite-fns.h					\
-	filters/composite.h						\
-	filters/convolvematrix.cpp					\
-	filters/convolvematrix-fns.h				\
-	filters/convolvematrix.h					\
-	filters/diffuselighting.cpp				\
-	filters/diffuselighting-fns.h				\
-	filters/diffuselighting.h					\
-	filters/displacementmap.cpp				\
-	filters/displacementmap-fns.h				\
-	filters/displacementmap.h					\
-	filters/distantlight.cpp					\
-	filters/distantlight.h						\
-	filters/flood.cpp							\
-	filters/flood-fns.h						\
-	filters/flood.h							\
-	filters/image.cpp							\
-	filters/image-fns.h						\
-	filters/image.h							\
-	filters/merge.cpp							\
-	filters/merge-fns.h						\
-	filters/merge.h							\
-	filters/mergenode.cpp						\
-	filters/mergenode.h						\
-	filters/morphology.cpp						\
-	filters/morphology-fns.h					\
-	filters/morphology.h						\
-	filters/offset.cpp							\
-	filters/offset-fns.h						\
-	filters/offset.h							\
-	filters/pointlight.cpp						\
-	filters/pointlight.h						\
-	filters/specularlighting.cpp				\
-	filters/specularlighting-fns.h				\
-	filters/specularlighting.h					\
-	filters/spotlight.cpp						\
-	filters/spotlight.h						\
-	filters/tile.cpp							\
-	filters/tile-fns.h							\
-	filters/tile.h								\
-	filters/turbulence.cpp						\
-	filters/turbulence-fns.h					\
+	filters/componenttransfer.h			\
+	filters/composite.cpp				\
+	filters/composite.h				\
+	filters/convolvematrix.cpp			\
+	filters/convolvematrix.h			\
+	filters/diffuselighting.cpp			\
+	filters/diffuselighting.h			\
+	filters/displacementmap.cpp			\
+	filters/displacementmap.h			\
+	filters/distantlight.cpp			\
+	filters/distantlight.h				\
+	filters/flood.cpp				\
+	filters/flood.h					\
+	filters/gaussian-blur.cpp			\
+	filters/gaussian-blur.h				\
+	filters/image.cpp				\
+	filters/image.h					\
+	filters/merge.cpp				\
+	filters/merge.h					\
+	filters/mergenode.cpp				\
+	filters/mergenode.h				\
+	filters/morphology.cpp				\
+	filters/morphology.h				\
+	filters/offset.cpp				\
+	filters/offset.h				\
+	filters/pointlight.cpp				\
+	filters/pointlight.h				\
+	filters/specularlighting.cpp			\
+	filters/specularlighting.h			\
+	filters/spotlight.cpp				\
+	filters/spotlight.h				\
+	filters/tile.cpp				\
+	filters/tile.h					\
+	filters/turbulence.cpp				\
 	filters/turbulence.h
 
diff --git a/src/filters/blend-fns.h b/src/filters/blend-fns.h
deleted file mode 100644
index f08ed9dd1..000000000
--- a/src/filters/blend-fns.h
+++ /dev/null
@@ -1,38 +0,0 @@
-#ifndef SP_FEBLEND_FNS_H
-#define SP_FEBLEND_FNS_H
-
-/** \file 
- * Macros and fn declarations related to gaussian blur filter.
- */
-
-#include <glib-object.h>
-#include <glib/gtypes.h>
-
-namespace Inkscape {
-namespace XML {
-class Node;
-}
-}
-
-class SPFeBlend;
-
-#define SP_TYPE_FEBLEND (sp_feBlend_get_type())
-#define SP_FEBLEND(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), SP_TYPE_FEBLEND, SPFeBlend))
-#define SP_FEBLEND_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass), SP_TYPE_FEBLEND, SPFeBlendClass))
-#define SP_IS_FEBLEND(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj), SP_TYPE_FEBLEND))
-#define SP_IS_FEBLEND_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), SP_TYPE_FEBLEND))
-
-GType sp_feBlend_get_type();
-
-#endif /* !SP_FEBLEND_FNS_H */
-
-/*
-  Local Variables:
-  mode:c++
-  c-file-style:"stroustrup"
-  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
-  indent-tabs-mode:nil
-  fill-column:99
-  End:
-*/
-// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :
diff --git a/src/filters/blend.cpp b/src/filters/blend.cpp
index 5998d7be3..795cbff20 100644
--- a/src/filters/blend.cpp
+++ b/src/filters/blend.cpp
@@ -20,9 +20,10 @@
 
 #include <string.h>
 
+#include "sp-filter.h"
+#include "filters/blend.h"
 #include "attributes.h"
 #include "svg/svg.h"
-#include "blend.h"
 #include "xml/repr.h"
 
 #include "display/nr-filter.h"
diff --git a/src/filters/blend.h b/src/filters/blend.h
index 9f3cab475..4fd763166 100644
--- a/src/filters/blend.h
+++ b/src/filters/blend.h
@@ -1,10 +1,6 @@
-#ifndef SP_FEBLEND_H_SEEN
-#define SP_FEBLEND_H_SEEN
-
-/** \file
- * SVG <feBlend> implementation, see Blend.cpp.
- */
-/*
+/** @file
+ * @brief SVG blend filter effect
+ *//*
  * Authors:
  *   Hugo Rodrigues <haa.rodrigues@gmail.com>
  *   Niko Kiirala <niko@kiirala.com>
@@ -14,16 +10,21 @@
  * Released under GNU GPL, read the file 'COPYING' for more information
  */
 
-#include "sp-filter.h"
-#include "blend-fns.h"
+#ifndef SP_FEBLEND_H_SEEN
+#define SP_FEBLEND_H_SEEN
 
+#include "sp-filter-primitive.h"
 #include "display/nr-filter-blend.h"
 
-/* FeBlend base class */
+#define SP_TYPE_FEBLEND (sp_feBlend_get_type())
+#define SP_FEBLEND(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), SP_TYPE_FEBLEND, SPFeBlend))
+#define SP_FEBLEND_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass), SP_TYPE_FEBLEND, SPFeBlendClass))
+#define SP_IS_FEBLEND(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj), SP_TYPE_FEBLEND))
+#define SP_IS_FEBLEND_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), SP_TYPE_FEBLEND))
+
 class SPFeBlendClass;
 
 struct SPFeBlend : public SPFilterPrimitive {
-    /** BLEND ATTRIBUTES HERE */
     Inkscape::Filters::FilterBlendMode blend_mode;
     int in2;
 };
diff --git a/src/filters/colormatrix-fns.h b/src/filters/colormatrix-fns.h
deleted file mode 100644
index 3a4a8d35c..000000000
--- a/src/filters/colormatrix-fns.h
+++ /dev/null
@@ -1,38 +0,0 @@
-#ifndef SP_FECOLORMATRIX_FNS_H
-#define SP_FECOLORMATRIX_FNS_H
-
-/** \file 
- * Macros and fn declarations related to gaussian blur filter.
- */
-
-#include <glib-object.h>
-#include <glib/gtypes.h>
-
-namespace Inkscape {
-namespace XML {
-class Node;
-}
-}
-
-class SPFeColorMatrix;
-
-#define SP_TYPE_FECOLORMATRIX (sp_feColorMatrix_get_type())
-#define SP_FECOLORMATRIX(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), SP_TYPE_FECOLORMATRIX, SPFeColorMatrix))
-#define SP_FECOLORMATRIX_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass), SP_TYPE_FECOLORMATRIX, SPFeColorMatrixClass))
-#define SP_IS_FECOLORMATRIX(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj), SP_TYPE_FECOLORMATRIX))
-#define SP_IS_FECOLORMATRIX_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), SP_TYPE_FECOLORMATRIX))
-
-GType sp_feColorMatrix_get_type();
-
-#endif /* !SP_FECOLORMATRIX_FNS_H */
-
-/*
-  Local Variables:
-  mode:c++
-  c-file-style:"stroustrup"
-  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
-  indent-tabs-mode:nil
-  fill-column:99
-  End:
-*/
-// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :
diff --git a/src/filters/colormatrix.cpp b/src/filters/colormatrix.cpp
index 3f60ea05c..07567cce6 100644
--- a/src/filters/colormatrix.cpp
+++ b/src/filters/colormatrix.cpp
@@ -27,6 +27,7 @@
 #include "xml/repr.h"
 #include "helper-fns.h"
 
+#include "display/nr-filter.h"
 #include "display/nr-filter-colormatrix.h"
 
 /* FeColorMatrix base class */
diff --git a/src/filters/colormatrix.h b/src/filters/colormatrix.h
index 69be96928..71c19db4d 100644
--- a/src/filters/colormatrix.h
+++ b/src/filters/colormatrix.h
@@ -1,10 +1,6 @@
-#ifndef SP_FECOLORMATRIX_H_SEEN
-#define SP_FECOLORMATRIX_H_SEEN
-
-/** \file
- * SVG <feColorMatrix> implementation, see ColorMatrix.cpp.
- */
-/*
+/** @file
+ * @brief SVG color matrix filter effect
+ *//*
  * Authors:
  *   Hugo Rodrigues <haa.rodrigues@gmail.com>
  *
@@ -12,17 +8,22 @@
  *
  * Released under GNU GPL, read the file 'COPYING' for more information
  */
+#ifndef SP_FECOLORMATRIX_H_SEEN
+#define SP_FECOLORMATRIX_H_SEEN
 
-#include "sp-filter.h"
-#include "colormatrix-fns.h"
-#include "display/nr-filter-colormatrix.h"
 #include <vector>
+#include "sp-filter-primitive.h"
+#include "display/nr-filter-colormatrix.h"
+
+#define SP_TYPE_FECOLORMATRIX (sp_feColorMatrix_get_type())
+#define SP_FECOLORMATRIX(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), SP_TYPE_FECOLORMATRIX, SPFeColorMatrix))
+#define SP_FECOLORMATRIX_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass), SP_TYPE_FECOLORMATRIX, SPFeColorMatrixClass))
+#define SP_IS_FECOLORMATRIX(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj), SP_TYPE_FECOLORMATRIX))
+#define SP_IS_FECOLORMATRIX_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), SP_TYPE_FECOLORMATRIX))
 
-/* FeColorMatrix base class */
 class SPFeColorMatrixClass;
 
 struct SPFeColorMatrix : public SPFilterPrimitive {
-    /** COLORMATRIX ATTRIBUTES HERE */
     Inkscape::Filters::FilterColorMatrixType type;
     gdouble value;
     std::vector<gdouble> values;
@@ -34,7 +35,6 @@ struct SPFeColorMatrixClass {
 
 GType sp_feColorMatrix_get_type();
 
-
 #endif /* !SP_FECOLORMATRIX_H_SEEN */
 
 /*
diff --git a/src/filters/componenttransfer-fns.h b/src/filters/componenttransfer-fns.h
deleted file mode 100644
index 49983770a..000000000
--- a/src/filters/componenttransfer-fns.h
+++ /dev/null
@@ -1,38 +0,0 @@
-#ifndef SP_FECOMPONENTTRANSFER_FNS_H
-#define SP_FECOMPONENTTRANSFER_FNS_H
-
-/** \file 
- * Macros and fn declarations related to gaussian blur filter.
- */
-
-#include <glib-object.h>
-#include <glib/gtypes.h>
-
-namespace Inkscape {
-namespace XML {
-class Node;
-}
-}
-
-class SPFeComponentTransfer;
-
-#define SP_TYPE_FECOMPONENTTRANSFER (sp_feComponentTransfer_get_type())
-#define SP_FECOMPONENTTRANSFER(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), SP_TYPE_FECOMPONENTTRANSFER, SPFeComponentTransfer))
-#define SP_FECOMPONENTTRANSFER_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass), SP_TYPE_FECOMPONENTTRANSFER, SPFeComponentTransferClass))
-#define SP_IS_FECOMPONENTTRANSFER(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj), SP_TYPE_FECOMPONENTTRANSFER))
-#define SP_IS_FECOMPONENTTRANSFER_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), SP_TYPE_FECOMPONENTTRANSFER))
-
-GType sp_feComponentTransfer_get_type();
-
-#endif /* !SP_FECOMPONENTTRANSFER_FNS_H */
-
-/*
-  Local Variables:
-  mode:c++
-  c-file-style:"stroustrup"
-  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
-  indent-tabs-mode:nil
-  fill-column:99
-  End:
-*/
-// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :
diff --git a/src/filters/componenttransfer.cpp b/src/filters/componenttransfer.cpp
index 27e63eaa6..4853ab8cd 100644
--- a/src/filters/componenttransfer.cpp
+++ b/src/filters/componenttransfer.cpp
@@ -22,9 +22,10 @@
 #include "document.h"
 #include "attributes.h"
 #include "svg/svg.h"
-#include "componenttransfer.h"
-#include "componenttransfer-funcnode.h"
+#include "filters/componenttransfer.h"
+#include "filters/componenttransfer-funcnode.h"
 #include "xml/repr.h"
+#include "display/nr-filter.h"
 #include "display/nr-filter-component-transfer.h"
 
 /* FeComponentTransfer base class */
diff --git a/src/filters/componenttransfer.h b/src/filters/componenttransfer.h
index 8281d9aea..be66d5a82 100644
--- a/src/filters/componenttransfer.h
+++ b/src/filters/componenttransfer.h
@@ -1,10 +1,6 @@
-#ifndef SP_FECOMPONENTTRANSFER_H_SEEN
-#define SP_FECOMPONENTTRANSFER_H_SEEN
-
-/** \file
- * SVG <feComponentTransfer> implementation, see ComponentTransfer.cpp.
- */
-/*
+/** @file
+ * @brief SVG component transferfilter effect
+ *//*
  * Authors:
  *   Hugo Rodrigues <haa.rodrigues@gmail.com>
  *
@@ -12,18 +8,25 @@
  *
  * Released under GNU GPL, read the file 'COPYING' for more information
  */
+#ifndef SP_FECOMPONENTTRANSFER_H_SEEN
+#define SP_FECOMPONENTTRANSFER_H_SEEN
+
+#include "sp-filter-primitive.h"
 
-#include "sp-filter.h"
-#include "componenttransfer-fns.h"
-#include "display/nr-filter-component-transfer.h"
-#include <vector>
+#define SP_TYPE_FECOMPONENTTRANSFER (sp_feComponentTransfer_get_type())
+#define SP_FECOMPONENTTRANSFER(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), SP_TYPE_FECOMPONENTTRANSFER, SPFeComponentTransfer))
+#define SP_FECOMPONENTTRANSFER_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass), SP_TYPE_FECOMPONENTTRANSFER, SPFeComponentTransferClass))
+#define SP_IS_FECOMPONENTTRANSFER(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj), SP_TYPE_FECOMPONENTTRANSFER))
+#define SP_IS_FECOMPONENTTRANSFER_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), SP_TYPE_FECOMPONENTTRANSFER))
+
+namespace Inkscape {
+namespace Filters {
+class FilterComponentTransfer;
+} }
 
-/* FeComponentTransfer base class */
 class SPFeComponentTransferClass;
 
 struct SPFeComponentTransfer : public SPFilterPrimitive {
-    /** COMPONENTTRANSFER ATTRIBUTES HERE */
-
     Inkscape::Filters::FilterComponentTransfer *renderer;
 };
 
diff --git a/src/filters/composite-fns.h b/src/filters/composite-fns.h
deleted file mode 100644
index c79cb17bb..000000000
--- a/src/filters/composite-fns.h
+++ /dev/null
@@ -1,38 +0,0 @@
-#ifndef SP_FECOMPOSITE_FNS_H
-#define SP_FECOMPOSITE_FNS_H
-
-/** \file 
- * Macros and fn declarations related to gaussian blur filter.
- */
-
-#include <glib-object.h>
-#include <glib/gtypes.h>
-
-namespace Inkscape {
-namespace XML {
-class Node;
-}
-}
-
-class SPFeComposite;
-
-#define SP_TYPE_FECOMPOSITE (sp_feComposite_get_type())
-#define SP_FECOMPOSITE(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), SP_TYPE_FECOMPOSITE, SPFeComposite))
-#define SP_FECOMPOSITE_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass), SP_TYPE_FECOMPOSITE, SPFeCompositeClass))
-#define SP_IS_FECOMPOSITE(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj), SP_TYPE_FECOMPOSITE))
-#define SP_IS_FECOMPOSITE_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), SP_TYPE_FECOMPOSITE))
-
-GType sp_feComposite_get_type();
-
-#endif /* !SP_FECOMPOSITE_FNS_H */
-
-/*
-  Local Variables:
-  mode:c++
-  c-file-style:"stroustrup"
-  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
-  indent-tabs-mode:nil
-  fill-column:99
-  End:
-*/
-// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :
diff --git a/src/filters/composite.cpp b/src/filters/composite.cpp
index 93c692f94..0c534e01d 100644
--- a/src/filters/composite.cpp
+++ b/src/filters/composite.cpp
@@ -19,10 +19,12 @@
 
 #include "attributes.h"
 #include "svg/svg.h"
-#include "composite.h"
+#include "filters/composite.h"
 #include "helper-fns.h"
 #include "xml/repr.h"
+#include "display/nr-filter.h"
 #include "display/nr-filter-composite.h"
+#include "sp-filter.h"
 
 /* FeComposite base class */
 
diff --git a/src/filters/composite.h b/src/filters/composite.h
index 095d7616d..126d8e71b 100644
--- a/src/filters/composite.h
+++ b/src/filters/composite.h
@@ -1,10 +1,6 @@
-#ifndef SP_FECOMPOSITE_H_SEEN
-#define SP_FECOMPOSITE_H_SEEN
-
-/** \file
- * SVG <feComposite> implementation, see Composite.cpp.
- */
-/*
+/** @file
+ * @brief SVG composite filter effect
+ *//*
  * Authors:
  *   Hugo Rodrigues <haa.rodrigues@gmail.com>
  *
@@ -12,9 +8,16 @@
  *
  * Released under GNU GPL, read the file 'COPYING' for more information
  */
+#ifndef SP_FECOMPOSITE_H_SEEN
+#define SP_FECOMPOSITE_H_SEEN
 
-#include "sp-filter.h"
-#include "composite-fns.h"
+#include "sp-filter-primitive.h"
+
+#define SP_TYPE_FECOMPOSITE (sp_feComposite_get_type())
+#define SP_FECOMPOSITE(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), SP_TYPE_FECOMPOSITE, SPFeComposite))
+#define SP_FECOMPOSITE_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass), SP_TYPE_FECOMPOSITE, SPFeCompositeClass))
+#define SP_IS_FECOMPOSITE(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj), SP_TYPE_FECOMPOSITE))
+#define SP_IS_FECOMPOSITE_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), SP_TYPE_FECOMPOSITE))
 
 enum FeCompositeOperator {
     // Default value is 'over', but let's distinquish specifying the
@@ -29,7 +32,6 @@ enum FeCompositeOperator {
     COMPOSITE_ENDOPERATOR
 };
 
-/* FeComposite base class */
 class SPFeCompositeClass;
 
 struct SPFeComposite : public SPFilterPrimitive {
@@ -44,7 +46,6 @@ struct SPFeCompositeClass {
 
 GType sp_feComposite_get_type();
 
-
 #endif /* !SP_FECOMPOSITE_H_SEEN */
 
 /*
diff --git a/src/filters/convolvematrix-fns.h b/src/filters/convolvematrix-fns.h
deleted file mode 100644
index 76baf7f41..000000000
--- a/src/filters/convolvematrix-fns.h
+++ /dev/null
@@ -1,38 +0,0 @@
-#ifndef SP_FECONVOLVEMATRIX_FNS_H
-#define SP_FECONVOLVEMATRIX_FNS_H
-
-/** \file 
- * Macros and fn declarations related to gaussian blur filter.
- */
-
-#include <glib-object.h>
-#include <glib/gtypes.h>
-
-namespace Inkscape {
-namespace XML {
-class Node;
-}
-}
-
-class SPFeConvolveMatrix;
-
-#define SP_TYPE_FECONVOLVEMATRIX (sp_feConvolveMatrix_get_type())
-#define SP_FECONVOLVEMATRIX(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), SP_TYPE_FECONVOLVEMATRIX, SPFeConvolveMatrix))
-#define SP_FECONVOLVEMATRIX_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass), SP_TYPE_FECONVOLVEMATRIX, SPFeConvolveMatrixClass))
-#define SP_IS_FECONVOLVEMATRIX(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj), SP_TYPE_FECONVOLVEMATRIX))
-#define SP_IS_FECONVOLVEMATRIX_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), SP_TYPE_FECONVOLVEMATRIX))
-
-GType sp_feConvolveMatrix_get_type();
-
-#endif /* !SP_FECONVOLVEMATRIX_FNS_H */
-
-/*
-  Local Variables:
-  mode:c++
-  c-file-style:"stroustrup"
-  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
-  indent-tabs-mode:nil
-  fill-column:99
-  End:
-*/
-// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :
diff --git a/src/filters/convolvematrix.cpp b/src/filters/convolvematrix.cpp
index 6440f340a..4444b82ce 100644
--- a/src/filters/convolvematrix.cpp
+++ b/src/filters/convolvematrix.cpp
@@ -19,15 +19,15 @@
 #endif
 
 #include <string.h>
-
+#include <math.h>
 #include <vector>
 #include "attributes.h"
 #include "svg/svg.h"
-#include "convolvematrix.h"
+#include "filters/convolvematrix.h"
 #include "helper-fns.h"
 #include "xml/repr.h"
+#include "display/nr-filter.h"
 #include "display/nr-filter-convolve-matrix.h"
-#include <math.h>
 
 /* FeConvolveMatrix base class */
 
diff --git a/src/filters/convolvematrix.h b/src/filters/convolvematrix.h
index 1e8545040..11120698d 100644
--- a/src/filters/convolvematrix.h
+++ b/src/filters/convolvematrix.h
@@ -1,8 +1,5 @@
-#ifndef SP_FECONVOLVEMATRIX_H_SEEN
-#define SP_FECONVOLVEMATRIX_H_SEEN
-
-/** \file
- * SVG <feConvolveMatrix> implementation, see ConvolveMatrix.cpp.
+/** @file
+ * @brief SVG matrix convolution filter effect
  */
 /*
  * Authors:
@@ -13,18 +10,23 @@
  *
  * Released under GNU GPL, read the file 'COPYING' for more information
  */
+#ifndef SP_FECONVOLVEMATRIX_H_SEEN
+#define SP_FECONVOLVEMATRIX_H_SEEN
 
-#include "sp-filter.h"
-#include "convolvematrix-fns.h"
+#include <vector>
+#include "sp-filter-primitive.h"
 #include "number-opt-number.h"
 #include "display/nr-filter-convolve-matrix.h"
-#include <vector>
 
-/* FeConvolveMatrix base class */
+#define SP_TYPE_FECONVOLVEMATRIX (sp_feConvolveMatrix_get_type())
+#define SP_FECONVOLVEMATRIX(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), SP_TYPE_FECONVOLVEMATRIX, SPFeConvolveMatrix))
+#define SP_FECONVOLVEMATRIX_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass), SP_TYPE_FECONVOLVEMATRIX, SPFeConvolveMatrixClass))
+#define SP_IS_FECONVOLVEMATRIX(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj), SP_TYPE_FECONVOLVEMATRIX))
+#define SP_IS_FECONVOLVEMATRIX_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), SP_TYPE_FECONVOLVEMATRIX))
+
 class SPFeConvolveMatrixClass;
 
 struct SPFeConvolveMatrix : public SPFilterPrimitive {
-    /* CONVOLVEMATRIX ATTRIBUTES */
     NumberOptNumber order;
     std::vector<gdouble> kernelMatrix;
     double divisor, bias;
@@ -32,7 +34,7 @@ struct SPFeConvolveMatrix : public SPFilterPrimitive {
     Inkscape::Filters::FilterConvolveMatrixEdgeMode edgeMode;
     NumberOptNumber kernelUnitLength;
     bool preserveAlpha;
-    //some helper variables:
+
     bool targetXIsSet;
     bool targetYIsSet;
     bool divisorIsSet;
@@ -45,7 +47,6 @@ struct SPFeConvolveMatrixClass {
 
 GType sp_feConvolveMatrix_get_type();
 
-
 #endif /* !SP_FECONVOLVEMATRIX_H_SEEN */
 
 /*
diff --git a/src/filters/diffuselighting-fns.h b/src/filters/diffuselighting-fns.h
deleted file mode 100644
index b91ed80f6..000000000
--- a/src/filters/diffuselighting-fns.h
+++ /dev/null
@@ -1,38 +0,0 @@
-#ifndef SP_FEDIFFUSELIGHTING_FNS_H
-#define SP_FEDIFFUSELIGHTING_FNS_H
-
-/** \file 
- * Macros and fn declarations related to gaussian blur filter.
- */
-
-#include <glib-object.h>
-#include <glib/gtypes.h>
-
-namespace Inkscape {
-namespace XML {
-class Node;
-}
-}
-
-class SPFeDiffuseLighting;
-
-#define SP_TYPE_FEDIFFUSELIGHTING (sp_feDiffuseLighting_get_type())
-#define SP_FEDIFFUSELIGHTING(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), SP_TYPE_FEDIFFUSELIGHTING, SPFeDiffuseLighting))
-#define SP_FEDIFFUSELIGHTING_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass), SP_TYPE_FEDIFFUSELIGHTING, SPFeDiffuseLightingClass))
-#define SP_IS_FEDIFFUSELIGHTING(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj), SP_TYPE_FEDIFFUSELIGHTING))
-#define SP_IS_FEDIFFUSELIGHTING_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), SP_TYPE_FEDIFFUSELIGHTING))
-
-GType sp_feDiffuseLighting_get_type();
-
-#endif /* !SP_FEDIFFUSELIGHTING_FNS_H */
-
-/*
-  Local Variables:
-  mode:c++
-  c-file-style:"stroustrup"
-  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
-  indent-tabs-mode:nil
-  fill-column:99
-  End:
-*/
-// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :
diff --git a/src/filters/diffuselighting.cpp b/src/filters/diffuselighting.cpp
index bdc569083..117b9d145 100644
--- a/src/filters/diffuselighting.cpp
+++ b/src/filters/diffuselighting.cpp
@@ -23,7 +23,8 @@
 #include "svg/svg.h"
 #include "sp-object.h"
 #include "svg/svg-color.h"
-#include "diffuselighting.h"
+#include "filters/diffuselighting.h"
+#include "display/nr-filter.h"
 #include "xml/repr.h"
 #include "display/nr-filter-diffuselighting.h"
 
diff --git a/src/filters/diffuselighting.h b/src/filters/diffuselighting.h
index 3c6c0ae73..0cb62c5a7 100644
--- a/src/filters/diffuselighting.h
+++ b/src/filters/diffuselighting.h
@@ -1,46 +1,46 @@
-#ifndef SP_FEDIFFUSELIGHTING_H_SEEN
-#define SP_FEDIFFUSELIGHTING_H_SEEN
-
-/** \file
- * SVG <feDiffuseLighting> implementation, see DiffuseLighting.cpp.
- */
-/*
+/** @file
+ * @brief SVG diffuse lighting filter effect
+ *//*
  * Authors:
  *   Hugo Rodrigues <haa.rodrigues@gmail.com>
  *   Jean-Rene Reinhard <jr@komite.net>
  *
- * Copyright (C) 2006 Hugo Rodrigues
- *               2007 authors
- *
+ * Copyright (C) 2006-2007 Authors
  * Released under GNU GPL, read the file 'COPYING' for more information
  */
 
-#include "sp-filter.h"
-#include "diffuselighting-fns.h"
+#ifndef SP_FEDIFFUSELIGHTING_H_SEEN
+#define SP_FEDIFFUSELIGHTING_H_SEEN
+
+#include "sp-filter-primitive.h"
+#include "number-opt-number.h"
 
 namespace Inkscape {
 namespace Filters {
 class FilterDiffuseLighting;
-}
-}
+} }
+
+#define SP_TYPE_FEDIFFUSELIGHTING (sp_feDiffuseLighting_get_type())
+#define SP_FEDIFFUSELIGHTING(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), SP_TYPE_FEDIFFUSELIGHTING, SPFeDiffuseLighting))
+#define SP_FEDIFFUSELIGHTING_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass), SP_TYPE_FEDIFFUSELIGHTING, SPFeDiffuseLightingClass))
+#define SP_IS_FEDIFFUSELIGHTING(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj), SP_TYPE_FEDIFFUSELIGHTING))
+#define SP_IS_FEDIFFUSELIGHTING_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), SP_TYPE_FEDIFFUSELIGHTING))
+
+namespace Inkscape {
+namespace Filters {
+class FilterDiffuseLighting;
+} }
 
-/* FeDiffuseLighting base class */
 class SPFeDiffuseLightingClass;
 
 struct SPFeDiffuseLighting : public SPFilterPrimitive {
-    /** DIFFUSELIGHTING ATTRIBUTES HERE */
-    /** surfaceScale attribute */
     gfloat surfaceScale;
     guint surfaceScale_set : 1;
-    /** diffuseConstant attribute */
     gfloat diffuseConstant;
     guint diffuseConstant_set : 1;
-    /** kernelUnitLength attribute */
     NumberOptNumber kernelUnitLength;
-    /** lighting-color property */
     guint32 lighting_color;
     guint lighting_color_set : 1;
-    /** pointer to the associated renderer */
     Inkscape::Filters::FilterDiffuseLighting *renderer;
 };
 
@@ -50,7 +50,6 @@ struct SPFeDiffuseLightingClass {
 
 GType sp_feDiffuseLighting_get_type();
 
-
 #endif /* !SP_FEDIFFUSELIGHTING_H_SEEN */
 
 /*
diff --git a/src/filters/displacementmap-fns.h b/src/filters/displacementmap-fns.h
deleted file mode 100644
index 6d92c6b78..000000000
--- a/src/filters/displacementmap-fns.h
+++ /dev/null
@@ -1,38 +0,0 @@
-#ifndef SP_FEDISPLACEMENTMAP_FNS_H
-#define SP_FEDISPLACEMENTMAP_FNS_H
-
-/** \file 
- * Macros and fn declarations related to gaussian blur filter.
- */
-
-#include <glib-object.h>
-#include <glib/gtypes.h>
-
-namespace Inkscape {
-namespace XML {
-class Node;
-}
-}
-
-class SPFeDisplacementMap;
-
-#define SP_TYPE_FEDISPLACEMENTMAP (sp_feDisplacementMap_get_type())
-#define SP_FEDISPLACEMENTMAP(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), SP_TYPE_FEDISPLACEMENTMAP, SPFeDisplacementMap))
-#define SP_FEDISPLACEMENTMAP_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass), SP_TYPE_FEDISPLACEMENTMAP, SPFeDisplacementMapClass))
-#define SP_IS_FEDISPLACEMENTMAP(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj), SP_TYPE_FEDISPLACEMENTMAP))
-#define SP_IS_FEDISPLACEMENTMAP_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), SP_TYPE_FEDISPLACEMENTMAP))
-
-GType sp_feDisplacementMap_get_type();
-
-#endif /* !SP_FEDISPLACEMENTMAP_FNS_H */
-
-/*
-  Local Variables:
-  mode:c++
-  c-file-style:"stroustrup"
-  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
-  indent-tabs-mode:nil
-  fill-column:99
-  End:
-*/
-// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :
diff --git a/src/filters/displacementmap.cpp b/src/filters/displacementmap.cpp
index baa17d785..cfa8e427e 100644
--- a/src/filters/displacementmap.cpp
+++ b/src/filters/displacementmap.cpp
@@ -19,10 +19,12 @@
 
 #include "attributes.h"
 #include "svg/svg.h"
-#include "displacementmap.h"
+#include "filters/displacementmap.h"
 #include "xml/repr.h"
-#include "display/nr-filter-displacement-map.h"
+#include "sp-filter.h"
 #include "helper-fns.h"
+#include "display/nr-filter.h"
+#include "display/nr-filter-displacement-map.h"
 
 /* FeDisplacementMap base class */
 
diff --git a/src/filters/displacementmap.h b/src/filters/displacementmap.h
index 6a8ac9cd9..414b3e663 100644
--- a/src/filters/displacementmap.h
+++ b/src/filters/displacementmap.h
@@ -1,10 +1,6 @@
-#ifndef SP_FEDISPLACEMENTMAP_H_SEEN
-#define SP_FEDISPLACEMENTMAP_H_SEEN
-
 /** \file
- * SVG <feDisplacementMap> implementation, see DisplacementMap.cpp.
- */
-/*
+ * SVG displacement map filter effect
+ *//*
  * Authors:
  *   Hugo Rodrigues <haa.rodrigues@gmail.com>
  *
@@ -13,8 +9,16 @@
  * Released under GNU GPL, read the file 'COPYING' for more information
  */
 
-#include "sp-filter.h"
-#include "displacementmap-fns.h"
+#ifndef SP_FEDISPLACEMENTMAP_H_SEEN
+#define SP_FEDISPLACEMENTMAP_H_SEEN
+
+#include "sp-filter-primitive.h"
+
+#define SP_TYPE_FEDISPLACEMENTMAP (sp_feDisplacementMap_get_type())
+#define SP_FEDISPLACEMENTMAP(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), SP_TYPE_FEDISPLACEMENTMAP, SPFeDisplacementMap))
+#define SP_FEDISPLACEMENTMAP_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass), SP_TYPE_FEDISPLACEMENTMAP, SPFeDisplacementMapClass))
+#define SP_IS_FEDISPLACEMENTMAP(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj), SP_TYPE_FEDISPLACEMENTMAP))
+#define SP_IS_FEDISPLACEMENTMAP_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), SP_TYPE_FEDISPLACEMENTMAP))
 
 enum FilterDisplacementMapChannelSelector {
     DISPLACEMENTMAP_CHANNEL_RED,
@@ -24,11 +28,9 @@ enum FilterDisplacementMapChannelSelector {
     DISPLACEMENTMAP_CHANNEL_ENDTYPE
 };
 
-/* FeDisplacementMap base class */
 class SPFeDisplacementMapClass;
 
 struct SPFeDisplacementMap : public SPFilterPrimitive {
-    /** DISPLACEMENTMAP ATTRIBUTES HERE */
     int in2; 
     double scale;
     FilterDisplacementMapChannelSelector xChannelSelector;
@@ -41,7 +43,6 @@ struct SPFeDisplacementMapClass {
 
 GType sp_feDisplacementMap_get_type();
 
-
 #endif /* !SP_FEDISPLACEMENTMAP_H_SEEN */
 
 /*
diff --git a/src/filters/distantlight.cpp b/src/filters/distantlight.cpp
index 41584c4a4..de33d967e 100644
--- a/src/filters/distantlight.cpp
+++ b/src/filters/distantlight.cpp
@@ -22,9 +22,9 @@
 
 #include "attributes.h"
 #include "document.h"
-#include "distantlight.h"
-#include "diffuselighting-fns.h"
-#include "specularlighting-fns.h"
+#include "filters/distantlight.h"
+#include "filters/diffuselighting.h"
+#include "filters/specularlighting.h"
 #include "xml/repr.h"
 
 #define SP_MACROS_SILENT
diff --git a/src/filters/flood-fns.h b/src/filters/flood-fns.h
deleted file mode 100644
index 8cc507274..000000000
--- a/src/filters/flood-fns.h
+++ /dev/null
@@ -1,38 +0,0 @@
-#ifndef SP_FEFLOOD_FNS_H
-#define SP_FEFLOOD_FNS_H
-
-/** \file 
- * Macros and fn declarations related to gaussian blur filter.
- */
-
-#include <glib-object.h>
-#include <glib/gtypes.h>
-
-namespace Inkscape {
-namespace XML {
-class Node;
-}
-}
-
-class SPFeFlood;
-
-#define SP_TYPE_FEFLOOD (sp_feFlood_get_type())
-#define SP_FEFLOOD(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), SP_TYPE_FEFLOOD, SPFeFlood))
-#define SP_FEFLOOD_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass), SP_TYPE_FEFLOOD, SPFeFloodClass))
-#define SP_IS_FEFLOOD(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj), SP_TYPE_FEFLOOD))
-#define SP_IS_FEFLOOD_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), SP_TYPE_FEFLOOD))
-
-GType sp_feFlood_get_type();
-
-#endif /* !SP_FEFLOOD_FNS_H */
-
-/*
-  Local Variables:
-  mode:c++
-  c-file-style:"stroustrup"
-  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
-  indent-tabs-mode:nil
-  fill-column:99
-  End:
-*/
-// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :
diff --git a/src/filters/flood.cpp b/src/filters/flood.cpp
index 221b0daf2..8b7d4c5cd 100644
--- a/src/filters/flood.cpp
+++ b/src/filters/flood.cpp
@@ -21,9 +21,12 @@
 
 #include "attributes.h"
 #include "svg/svg.h"
-#include "flood.h"
+#include "svg/svg-color.h"
+#include "filters/flood.h"
 #include "xml/repr.h"
 #include "helper-fns.h"
+#include "display/nr-filter.h"
+#include "display/nr-filter-flood.h"
 
 /* FeFlood base class */
 
diff --git a/src/filters/flood.h b/src/filters/flood.h
index f386e2cd4..220faca83 100644
--- a/src/filters/flood.h
+++ b/src/filters/flood.h
@@ -1,10 +1,6 @@
-#ifndef SP_FEFLOOD_H_SEEN
-#define SP_FEFLOOD_H_SEEN
-
-/** \file
- * SVG <feFlood> implementation, see Flood.cpp.
- */
-/*
+/** @file
+ * @brief SVG flood filter effect
+ *//*
  * Authors:
  *   Hugo Rodrigues <haa.rodrigues@gmail.com>
  *
@@ -13,18 +9,21 @@
  * Released under GNU GPL, read the file 'COPYING' for more information
  */
 
-#include "sp-filter.h"
-#include "flood-fns.h"
+#ifndef SP_FEFLOOD_H_SEEN
+#define SP_FEFLOOD_H_SEEN
+
+#include "sp-filter-primitive.h"
 #include "svg/svg-icc-color.h"
 
-#include "display/nr-filter.h"
-#include "display/nr-filter-flood.h"
+#define SP_TYPE_FEFLOOD (sp_feFlood_get_type())
+#define SP_FEFLOOD(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), SP_TYPE_FEFLOOD, SPFeFlood))
+#define SP_FEFLOOD_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass), SP_TYPE_FEFLOOD, SPFeFloodClass))
+#define SP_IS_FEFLOOD(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj), SP_TYPE_FEFLOOD))
+#define SP_IS_FEFLOOD_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), SP_TYPE_FEFLOOD))
 
-/* FeFlood base class */
 class SPFeFloodClass;
 
 struct SPFeFlood : public SPFilterPrimitive {
-    /** FLOOD ATTRIBUTES HERE */
     guint32 color;
     SVGICCColor *icc;
     double opacity;
diff --git a/src/sp-gaussian-blur.cpp b/src/filters/gaussian-blur.cpp
index e6eab5032..3f7cea0c9 100644
--- a/src/sp-gaussian-blur.cpp
+++ b/src/filters/gaussian-blur.cpp
@@ -20,7 +20,7 @@
 
 #include "attributes.h"
 #include "svg/svg.h"
-#include "sp-gaussian-blur.h"
+#include "filters/gaussian-blur.h"
 #include "xml/repr.h"
 
 #include "display/nr-filter.h"
diff --git a/src/sp-gaussian-blur-fns.h b/src/filters/gaussian-blur.h
index 030739263..5607080fe 100644
--- a/src/sp-gaussian-blur-fns.h
+++ b/src/filters/gaussian-blur.h
@@ -1,20 +1,19 @@
-#ifndef SP_GAUSSIANBLUR_FNS_H
-#define SP_GAUSSIANBLUR_FNS_H
-
-/** \file 
- * Macros and fn declarations related to gaussian blur filter.
+/** @file
+ * @brief SVG Gaussian blur filter effect
+ *//*
+ * Authors:
+ *   Hugo Rodrigues <haa.rodrigues@gmail.com>
+ *
+ * Copyright (C) 2006 Hugo Rodrigues
+ *
+ * Released under GNU GPL, read the file 'COPYING' for more information
  */
 
-#include <glib-object.h>
-#include <glib/gtypes.h>
-
-namespace Inkscape {
-namespace XML {
-class Node;
-}
-}
+#ifndef SP_GAUSSIANBLUR_H_SEEN
+#define SP_GAUSSIANBLUR_H_SEEN
 
-class SPGaussianBlur;
+#include "sp-filter-primitive.h"
+#include "number-opt-number.h"
 
 #define SP_TYPE_GAUSSIANBLUR (sp_gaussianBlur_get_type())
 #define SP_GAUSSIANBLUR(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), SP_TYPE_GAUSSIANBLUR, SPGaussianBlur))
@@ -22,11 +21,23 @@ class SPGaussianBlur;
 #define SP_IS_GAUSSIANBLUR(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj), SP_TYPE_GAUSSIANBLUR))
 #define SP_IS_GAUSSIANBLUR_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), SP_TYPE_GAUSSIANBLUR))
 
+/* GaussianBlur base class */
+class SPGaussianBlurClass;
+
+struct SPGaussianBlur : public SPFilterPrimitive {
+    /** stdDeviation attribute */
+    NumberOptNumber stdDeviation;
+};
+
+struct SPGaussianBlurClass {
+    SPFilterPrimitiveClass parent_class;
+};
+
 GType sp_gaussianBlur_get_type();
 void  sp_gaussianBlur_setDeviation(SPGaussianBlur *blur, float num);
 void  sp_gaussianBlur_setDeviation(SPGaussianBlur *blur, float num, float optnum);
 
-#endif /* !SP_GAUSSIANBLUR_FNS_H */
+#endif /* !SP_GAUSSIANBLUR_H_SEEN */
 
 /*
   Local Variables:
diff --git a/src/filters/image-fns.h b/src/filters/image-fns.h
deleted file mode 100644
index 0a8b453fe..000000000
--- a/src/filters/image-fns.h
+++ /dev/null
@@ -1,38 +0,0 @@
-#ifndef SP_FEIMAGE_FNS_H
-#define SP_FEIMAGE_FNS_H
-
-/** \file 
- * Macros and fn declarations related to gaussian blur filter.
- */
-
-#include <glib-object.h>
-#include <glib/gtypes.h>
-
-namespace Inkscape {
-namespace XML {
-class Node;
-}
-}
-
-class SPFeImage;
-
-#define SP_TYPE_FEIMAGE (sp_feImage_get_type())
-#define SP_FEIMAGE(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), SP_TYPE_FEIMAGE, SPFeImage))
-#define SP_FEIMAGE_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass), SP_TYPE_FEIMAGE, SPFeImageClass))
-#define SP_IS_FEIMAGE(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj), SP_TYPE_FEIMAGE))
-#define SP_IS_FEIMAGE_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), SP_TYPE_FEIMAGE))
-
-GType sp_feImage_get_type();
-
-#endif /* !SP_FEIMAGE_FNS_H */
-
-/*
-  Local Variables:
-  mode:c++
-  c-file-style:"stroustrup"
-  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
-  indent-tabs-mode:nil
-  fill-column:99
-  End:
-*/
-// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :
diff --git a/src/filters/image.h b/src/filters/image.h
index 78e719ac7..a8fb65d6a 100644
--- a/src/filters/image.h
+++ b/src/filters/image.h
@@ -1,10 +1,6 @@
-#ifndef SP_FEIMAGE_H_SEEN
-#define SP_FEIMAGE_H_SEEN
-
-/** \file
- * SVG <feImage> implementation, see Image.cpp.
- */
-/*
+/** @file
+ * @brief SVG image filter effect
+ *//*
  * Authors:
  *   Felipe Corrêa da Silva Sanches <juca@members.fsf.org>
  *   Hugo Rodrigues <haa.rodrigues@gmail.com>
@@ -14,17 +10,23 @@
  * Released under GNU GPL, read the file 'COPYING' for more information
  */
 
-#include "sp-filter.h"
-#include "image-fns.h"
+#ifndef SP_FEIMAGE_H_SEEN
+#define SP_FEIMAGE_H_SEEN
+
+#include "sp-filter-primitive.h"
 #include "svg/svg-length.h"
 #include "sp-item.h"
 #include "uri-references.h"
 
-/* FeImage base class */
+#define SP_TYPE_FEIMAGE (sp_feImage_get_type())
+#define SP_FEIMAGE(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), SP_TYPE_FEIMAGE, SPFeImage))
+#define SP_FEIMAGE_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass), SP_TYPE_FEIMAGE, SPFeImageClass))
+#define SP_IS_FEIMAGE(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj), SP_TYPE_FEIMAGE))
+#define SP_IS_FEIMAGE_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), SP_TYPE_FEIMAGE))
+
 class SPFeImageClass;
 
 struct SPFeImage : public SPFilterPrimitive {
-    /** IMAGE ATTRIBUTES HERE */
     gchar *href;
     SVGLength x, y, height, width;
     SPDocument *document;
@@ -41,7 +43,6 @@ struct SPFeImageClass {
 
 GType sp_feImage_get_type();
 
-
 #endif /* !SP_FEIMAGE_H_SEEN */
 
 /*
diff --git a/src/filters/merge-fns.h b/src/filters/merge-fns.h
deleted file mode 100644
index 24bda1ae2..000000000
--- a/src/filters/merge-fns.h
+++ /dev/null
@@ -1,38 +0,0 @@
-#ifndef SP_FEMERGE_FNS_H
-#define SP_FEMERGE_FNS_H
-
-/** \file 
- * Macros and fn declarations related to gaussian blur filter.
- */
-
-#include <glib-object.h>
-#include <glib/gtypes.h>
-
-namespace Inkscape {
-namespace XML {
-class Node;
-}
-}
-
-class SPFeMerge;
-
-#define SP_TYPE_FEMERGE (sp_feMerge_get_type())
-#define SP_FEMERGE(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), SP_TYPE_FEMERGE, SPFeMerge))
-#define SP_FEMERGE_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass), SP_TYPE_FEMERGE, SPFeMergeClass))
-#define SP_IS_FEMERGE(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj), SP_TYPE_FEMERGE))
-#define SP_IS_FEMERGE_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), SP_TYPE_FEMERGE))
-
-GType sp_feMerge_get_type();
-
-#endif /* !SP_FEMERGE_FNS_H */
-
-/*
-  Local Variables:
-  mode:c++
-  c-file-style:"stroustrup"
-  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
-  indent-tabs-mode:nil
-  fill-column:99
-  End:
-*/
-// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :
diff --git a/src/filters/merge.cpp b/src/filters/merge.cpp
index 437cb4b55..798b7dfcc 100644
--- a/src/filters/merge.cpp
+++ b/src/filters/merge.cpp
@@ -23,6 +23,7 @@
 
 #include "merge.h"
 #include "mergenode.h"
+#include "display/nr-filter.h"
 #include "display/nr-filter-merge.h"
 
 /* FeMerge base class */
diff --git a/src/filters/merge.h b/src/filters/merge.h
index 5d28faba9..c28eaa1f6 100644
--- a/src/filters/merge.h
+++ b/src/filters/merge.h
@@ -1,22 +1,23 @@
-#ifndef SP_FEMERGE_H_SEEN
-#define SP_FEMERGE_H_SEEN
-
 /** \file
- * SVG <feMerge> implementation, see Merge.cpp.
- */
-/*
+ * SVG merge filter effect
+ *//*
  * Authors:
  *   Hugo Rodrigues <haa.rodrigues@gmail.com>
  *
  * Copyright (C) 2006 Hugo Rodrigues
- *
  * Released under GNU GPL, read the file 'COPYING' for more information
  */
+#ifndef SP_FEMERGE_H_SEEN
+#define SP_FEMERGE_H_SEEN
+
+#include "sp-filter-primitive.h"
 
-#include "sp-filter.h"
-#include "merge-fns.h"
+#define SP_TYPE_FEMERGE (sp_feMerge_get_type())
+#define SP_FEMERGE(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), SP_TYPE_FEMERGE, SPFeMerge))
+#define SP_FEMERGE_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass), SP_TYPE_FEMERGE, SPFeMergeClass))
+#define SP_IS_FEMERGE(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj), SP_TYPE_FEMERGE))
+#define SP_IS_FEMERGE_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), SP_TYPE_FEMERGE))
 
-/* FeMerge base class */
 class SPFeMergeClass;
 
 struct SPFeMerge : public SPFilterPrimitive {
diff --git a/src/filters/mergenode.cpp b/src/filters/mergenode.cpp
index 8a4e0dd0a..4ff569364 100644
--- a/src/filters/mergenode.cpp
+++ b/src/filters/mergenode.cpp
@@ -20,8 +20,9 @@
 
 #include "attributes.h"
 #include "xml/repr.h"
-#include "mergenode.h"
-#include "merge.h"
+#include "filters/mergenode.h"
+#include "filters/merge.h"
+#include "display/nr-filter-types.h"
 
 static void sp_feMergeNode_class_init(SPFeMergeNodeClass *klass);
 static void sp_feMergeNode_init(SPFeMergeNode *skeleton);
diff --git a/src/filters/morphology-fns.h b/src/filters/morphology-fns.h
deleted file mode 100644
index a0550405d..000000000
--- a/src/filters/morphology-fns.h
+++ /dev/null
@@ -1,38 +0,0 @@
-#ifndef SP_FEMORPHOLOGY_FNS_H
-#define SP_FEMORPHOLOGY_FNS_H
-
-/** \file 
- * Macros and fn declarations related to gaussian blur filter.
- */
-
-#include <glib-object.h>
-#include <glib/gtypes.h>
-
-namespace Inkscape {
-namespace XML {
-class Node;
-}
-}
-
-class SPFeMorphology;
-
-#define SP_TYPE_FEMORPHOLOGY (sp_feMorphology_get_type())
-#define SP_FEMORPHOLOGY(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), SP_TYPE_FEMORPHOLOGY, SPFeMorphology))
-#define SP_FEMORPHOLOGY_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass), SP_TYPE_FEMORPHOLOGY, SPFeMorphologyClass))
-#define SP_IS_FEMORPHOLOGY(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj), SP_TYPE_FEMORPHOLOGY))
-#define SP_IS_FEMORPHOLOGY_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), SP_TYPE_FEMORPHOLOGY))
-
-GType sp_feMorphology_get_type();
-
-#endif /* !SP_FEMORPHOLOGY_FNS_H */
-
-/*
-  Local Variables:
-  mode:c++
-  c-file-style:"stroustrup"
-  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
-  indent-tabs-mode:nil
-  fill-column:99
-  End:
-*/
-// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :
diff --git a/src/filters/morphology.cpp b/src/filters/morphology.cpp
index 1530dae8c..f6f9dc609 100644
--- a/src/filters/morphology.cpp
+++ b/src/filters/morphology.cpp
@@ -24,6 +24,7 @@
 #include "svg/svg.h"
 #include "morphology.h"
 #include "xml/repr.h"
+#include "display/nr-filter.h"
 #include "display/nr-filter-morphology.h"
 
 /* FeMorphology base class */
diff --git a/src/filters/morphology.h b/src/filters/morphology.h
index 20abf8a8d..01eb2f59b 100644
--- a/src/filters/morphology.h
+++ b/src/filters/morphology.h
@@ -1,10 +1,6 @@
-#ifndef SP_FEMORPHOLOGY_H_SEEN
-#define SP_FEMORPHOLOGY_H_SEEN
-
 /** \file
- * SVG <feMorphology> implementation, see Morphology.cpp.
- */
-/*
+ * @brief SVG morphology filter effect
+ *//*
  * Authors:
  *   Hugo Rodrigues <haa.rodrigues@gmail.com>
  *
@@ -13,18 +9,22 @@
  * Released under GNU GPL, read the file 'COPYING' for more information
  */
 
-#include "sp-filter.h"
-#include "morphology-fns.h"
+#ifndef SP_FEMORPHOLOGY_H_SEEN
+#define SP_FEMORPHOLOGY_H_SEEN
+
+#include "sp-filter-primitive.h"
 #include "number-opt-number.h"
-#include "display/nr-filter.h"
 #include "display/nr-filter-morphology.h"
 
+#define SP_TYPE_FEMORPHOLOGY (sp_feMorphology_get_type())
+#define SP_FEMORPHOLOGY(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), SP_TYPE_FEMORPHOLOGY, SPFeMorphology))
+#define SP_FEMORPHOLOGY_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass), SP_TYPE_FEMORPHOLOGY, SPFeMorphologyClass))
+#define SP_IS_FEMORPHOLOGY(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj), SP_TYPE_FEMORPHOLOGY))
+#define SP_IS_FEMORPHOLOGY_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), SP_TYPE_FEMORPHOLOGY))
 
-/* FeMorphology base class */
 class SPFeMorphologyClass;
 
 struct SPFeMorphology : public SPFilterPrimitive {
-    /** MORPHOLOGY ATTRIBUTES HERE */
     Inkscape::Filters::FilterMorphologyOperator Operator;
     NumberOptNumber radius;
 };
diff --git a/src/filters/offset-fns.h b/src/filters/offset-fns.h
deleted file mode 100644
index 38561c188..000000000
--- a/src/filters/offset-fns.h
+++ /dev/null
@@ -1,38 +0,0 @@
-#ifndef SP_FEOFFSET_FNS_H
-#define SP_FEOFFSET_FNS_H
-
-/** \file 
- * Macros and fn declarations related to gaussian blur filter.
- */
-
-#include <glib-object.h>
-#include <glib/gtypes.h>
-
-namespace Inkscape {
-namespace XML {
-class Node;
-}
-}
-
-class SPFeOffset;
-
-#define SP_TYPE_FEOFFSET (sp_feOffset_get_type())
-#define SP_FEOFFSET(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), SP_TYPE_FEOFFSET, SPFeOffset))
-#define SP_FEOFFSET_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass), SP_TYPE_FEOFFSET, SPFeOffsetClass))
-#define SP_IS_FEOFFSET(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj), SP_TYPE_FEOFFSET))
-#define SP_IS_FEOFFSET_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), SP_TYPE_FEOFFSET))
-
-GType sp_feOffset_get_type();
-
-#endif /* !SP_FEOFFSET_FNS_H */
-
-/*
-  Local Variables:
-  mode:c++
-  c-file-style:"stroustrup"
-  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
-  indent-tabs-mode:nil
-  fill-column:99
-  End:
-*/
-// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :
diff --git a/src/filters/offset.cpp b/src/filters/offset.cpp
index 61ea45ff2..b436fd0fb 100644
--- a/src/filters/offset.cpp
+++ b/src/filters/offset.cpp
@@ -20,9 +20,10 @@
 
 #include "attributes.h"
 #include "svg/svg.h"
-#include "offset.h"
+#include "filters/offset.h"
 #include "helper-fns.h"
 #include "xml/repr.h"
+#include "display/nr-filter.h"
 #include "display/nr-filter-offset.h"
 
 /* FeOffset base class */
diff --git a/src/filters/offset.h b/src/filters/offset.h
index 72d852514..5319ff84e 100644
--- a/src/filters/offset.h
+++ b/src/filters/offset.h
@@ -1,10 +1,6 @@
-#ifndef SP_FEOFFSET_H_SEEN
-#define SP_FEOFFSET_H_SEEN
-
-/** \file
- * SVG <feOffset> implementation, see Offset.cpp.
- */
-/*
+/** @file
+ * @brief SVG offset filter effect
+ *//*
  * Authors:
  *   Hugo Rodrigues <haa.rodrigues@gmail.com>
  *
@@ -13,14 +9,20 @@
  * Released under GNU GPL, read the file 'COPYING' for more information
  */
 
-#include "sp-filter.h"
-#include "offset-fns.h"
+#ifndef SP_FEOFFSET_H_SEEN
+#define SP_FEOFFSET_H_SEEN
+
+#include "sp-filter-primitive.h"
+
+#define SP_TYPE_FEOFFSET (sp_feOffset_get_type())
+#define SP_FEOFFSET(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), SP_TYPE_FEOFFSET, SPFeOffset))
+#define SP_FEOFFSET_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass), SP_TYPE_FEOFFSET, SPFeOffsetClass))
+#define SP_IS_FEOFFSET(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj), SP_TYPE_FEOFFSET))
+#define SP_IS_FEOFFSET_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), SP_TYPE_FEOFFSET))
 
-/* FeOffset base class */
 class SPFeOffsetClass;
 
 struct SPFeOffset : public SPFilterPrimitive {
-    /** OFFSET ATTRIBUTES HERE */
     double dx, dy;
 };
 
diff --git a/src/filters/pointlight.cpp b/src/filters/pointlight.cpp
index ce58cf13e..5bb662c0f 100644
--- a/src/filters/pointlight.cpp
+++ b/src/filters/pointlight.cpp
@@ -22,9 +22,9 @@
 
 #include "attributes.h"
 #include "document.h"
-#include "pointlight.h"
-#include "diffuselighting-fns.h"
-#include "specularlighting-fns.h"
+#include "filters/pointlight.h"
+#include "filters/diffuselighting.h"
+#include "filters/specularlighting.h"
 #include "xml/repr.h"
 
 #define SP_MACROS_SILENT
diff --git a/src/filters/specularlighting-fns.h b/src/filters/specularlighting-fns.h
deleted file mode 100644
index bd48ba684..000000000
--- a/src/filters/specularlighting-fns.h
+++ /dev/null
@@ -1,38 +0,0 @@
-#ifndef SP_FESPECULARLIGHTING_FNS_H
-#define SP_FESPECULARLIGHTING_FNS_H
-
-/** \file 
- * Macros and fn declarations related to gaussian blur filter.
- */
-
-#include <glib-object.h>
-#include <glib/gtypes.h>
-
-namespace Inkscape {
-namespace XML {
-class Node;
-}
-}
-
-class SPFeSpecularLighting;
-
-#define SP_TYPE_FESPECULARLIGHTING (sp_feSpecularLighting_get_type())
-#define SP_FESPECULARLIGHTING(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), SP_TYPE_FESPECULARLIGHTING, SPFeSpecularLighting))
-#define SP_FESPECULARLIGHTING_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass), SP_TYPE_FESPECULARLIGHTING, SPFeSpecularLightingClass))
-#define SP_IS_FESPECULARLIGHTING(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj), SP_TYPE_FESPECULARLIGHTING))
-#define SP_IS_FESPECULARLIGHTING_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), SP_TYPE_FESPECULARLIGHTING))
-
-GType sp_feSpecularLighting_get_type();
-
-#endif /* !SP_FESPECULARLIGHTING_FNS_H */
-
-/*
-  Local Variables:
-  mode:c++
-  c-file-style:"stroustrup"
-  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
-  indent-tabs-mode:nil
-  fill-column:99
-  End:
-*/
-// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :
diff --git a/src/filters/specularlighting.cpp b/src/filters/specularlighting.cpp
index 03a0c7f96..1b6000522 100644
--- a/src/filters/specularlighting.cpp
+++ b/src/filters/specularlighting.cpp
@@ -25,6 +25,7 @@
 #include "svg/svg-color.h"
 #include "specularlighting.h"
 #include "xml/repr.h"
+#include "display/nr-filter.h"
 #include "display/nr-filter-specularlighting.h"
 
 /* FeSpecularLighting base class */
diff --git a/src/filters/specularlighting.h b/src/filters/specularlighting.h
index cdca5f99f..8d26b8cfe 100644
--- a/src/filters/specularlighting.h
+++ b/src/filters/specularlighting.h
@@ -1,10 +1,6 @@
-#ifndef SP_FESPECULARLIGHTING_H_SEEN
-#define SP_FESPECULARLIGHTING_H_SEEN
-
-/** \file
- * SVG <feSpecularLighting> implementation, see SpecularLighting.cpp.
- */
-/*
+/** @file
+ * @brief SVG specular lighting filter effect
+ *//*
  * Authors:
  *   Hugo Rodrigues <haa.rodrigues@gmail.com>
  *   Jean-Rene Reinhard <jr@komite.net>
@@ -15,8 +11,17 @@
  * Released under GNU GPL, read the file 'COPYING' for more information
  */
 
-#include "sp-filter.h"
-#include "specularlighting-fns.h"
+#ifndef SP_FESPECULARLIGHTING_H_SEEN
+#define SP_FESPECULARLIGHTING_H_SEEN
+
+#include "sp-filter-primitive.h"
+#include "number-opt-number.h"
+
+#define SP_TYPE_FESPECULARLIGHTING (sp_feSpecularLighting_get_type())
+#define SP_FESPECULARLIGHTING(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), SP_TYPE_FESPECULARLIGHTING, SPFeSpecularLighting))
+#define SP_FESPECULARLIGHTING_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass), SP_TYPE_FESPECULARLIGHTING, SPFeSpecularLightingClass))
+#define SP_IS_FESPECULARLIGHTING(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj), SP_TYPE_FESPECULARLIGHTING))
+#define SP_IS_FESPECULARLIGHTING_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), SP_TYPE_FESPECULARLIGHTING))
 
 namespace Inkscape {
 namespace Filters {
@@ -24,23 +29,16 @@ class FilterSpecularLighting;
 }
 }
 
-/* FeSpecularLighting base class */
 class SPFeSpecularLightingClass;
 
 struct SPFeSpecularLighting : public SPFilterPrimitive {
-    /** SPECULARLIGHTING ATTRIBUTES HERE */
-    /** surfaceScale attribute */
     gfloat surfaceScale;
     guint surfaceScale_set : 1;
-    /** specularConstant attribute */
     gfloat specularConstant;
     guint specularConstant_set : 1;
-    /** specularConstant attribute */
     gfloat specularExponent;
     guint specularExponent_set : 1;
-    /** kernelUnitLenght attribute */
     NumberOptNumber kernelUnitLength;
-    /** lighting-color property */
     guint32 lighting_color;
     guint lighting_color_set : 1;
 
diff --git a/src/filters/spotlight.cpp b/src/filters/spotlight.cpp
index 3b518f0b4..10815cfb1 100644
--- a/src/filters/spotlight.cpp
+++ b/src/filters/spotlight.cpp
@@ -22,9 +22,9 @@
 
 #include "attributes.h"
 #include "document.h"
-#include "spotlight.h"
-#include "diffuselighting-fns.h"
-#include "specularlighting-fns.h"
+#include "filters/spotlight.h"
+#include "filters/diffuselighting.h"
+#include "filters/specularlighting.h"
 #include "xml/repr.h"
 
 #define SP_MACROS_SILENT
diff --git a/src/filters/tile-fns.h b/src/filters/tile-fns.h
deleted file mode 100644
index b7c4c5f27..000000000
--- a/src/filters/tile-fns.h
+++ /dev/null
@@ -1,38 +0,0 @@
-#ifndef SP_FETILE_FNS_H
-#define SP_FETILE_FNS_H
-
-/** \file 
- * Macros and fn declarations related to gaussian blur filter.
- */
-
-#include <glib-object.h>
-#include <glib/gtypes.h>
-
-namespace Inkscape {
-namespace XML {
-class Node;
-}
-}
-
-class SPFeTile;
-
-#define SP_TYPE_FETILE (sp_feTile_get_type())
-#define SP_FETILE(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), SP_TYPE_FETILE, SPFeTile))
-#define SP_FETILE_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass), SP_TYPE_FETILE, SPFeTileClass))
-#define SP_IS_FETILE(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj), SP_TYPE_FETILE))
-#define SP_IS_FETILE_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), SP_TYPE_FETILE))
-
-GType sp_feTile_get_type();
-
-#endif /* !SP_FETILE_FNS_H */
-
-/*
-  Local Variables:
-  mode:c++
-  c-file-style:"stroustrup"
-  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
-  indent-tabs-mode:nil
-  fill-column:99
-  End:
-*/
-// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :
diff --git a/src/filters/tile.cpp b/src/filters/tile.cpp
index 877f70b27..c87d78554 100644
--- a/src/filters/tile.cpp
+++ b/src/filters/tile.cpp
@@ -19,9 +19,10 @@
 
 #include "attributes.h"
 #include "svg/svg.h"
-#include "tile.h"
+#include "filters/tile.h"
 #include "xml/repr.h"
-
+#include "display/nr-filter.h"
+#include "display/nr-filter-tile.h"
 
 /* FeTile base class */
 
diff --git a/src/filters/tile.h b/src/filters/tile.h
index 9e12ca7ee..45c43213d 100644
--- a/src/filters/tile.h
+++ b/src/filters/tile.h
@@ -1,10 +1,6 @@
-#ifndef SP_FETILE_H_SEEN
-#define SP_FETILE_H_SEEN
-
-/** \file
- * SVG <feTile> implementation, see Tile.cpp.
- */
-/*
+/** @file
+ * @brief SVG tile filter effect
+ *//*
  * Authors:
  *   Hugo Rodrigues <haa.rodrigues@gmail.com>
  *
@@ -13,17 +9,21 @@
  * Released under GNU GPL, read the file 'COPYING' for more information
  */
 
-#include "sp-filter.h"
-#include "tile-fns.h"
+#ifndef SP_FETILE_H_SEEN
+#define SP_FETILE_H_SEEN
 
-#include "display/nr-filter.h"
-#include "display/nr-filter-tile.h"
+#include "sp-filter-primitive.h"
+
+#define SP_TYPE_FETILE (sp_feTile_get_type())
+#define SP_FETILE(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), SP_TYPE_FETILE, SPFeTile))
+#define SP_FETILE_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass), SP_TYPE_FETILE, SPFeTileClass))
+#define SP_IS_FETILE(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj), SP_TYPE_FETILE))
+#define SP_IS_FETILE_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), SP_TYPE_FETILE))
 
 /* FeTile base class */
 class SPFeTileClass;
 
 struct SPFeTile : public SPFilterPrimitive {
-    /** TILE ATTRIBUTES HERE */
     
 };
 
@@ -33,7 +33,6 @@ struct SPFeTileClass {
 
 GType sp_feTile_get_type();
 
-
 #endif /* !SP_FETILE_H_SEEN */
 
 /*
diff --git a/src/filters/turbulence-fns.h b/src/filters/turbulence-fns.h
deleted file mode 100644
index 43b4450a5..000000000
--- a/src/filters/turbulence-fns.h
+++ /dev/null
@@ -1,38 +0,0 @@
-#ifndef SP_FETURBULENCE_FNS_H
-#define SP_FETURBULENCE_FNS_H
-
-/** \file 
- * Macros and fn declarations related to gaussian blur filter.
- */
-
-#include <glib-object.h>
-#include <glib/gtypes.h>
-
-namespace Inkscape {
-namespace XML {
-class Node;
-}
-}
-
-class SPFeTurbulence;
-
-#define SP_TYPE_FETURBULENCE (sp_feTurbulence_get_type())
-#define SP_FETURBULENCE(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), SP_TYPE_FETURBULENCE, SPFeTurbulence))
-#define SP_FETURBULENCE_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass), SP_TYPE_FETURBULENCE, SPFeTurbulenceClass))
-#define SP_IS_FETURBULENCE(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj), SP_TYPE_FETURBULENCE))
-#define SP_IS_FETURBULENCE_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), SP_TYPE_FETURBULENCE))
-
-GType sp_feTurbulence_get_type();
-
-#endif /* !SP_FETURBULENCE_FNS_H */
-
-/*
-  Local Variables:
-  mode:c++
-  c-file-style:"stroustrup"
-  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
-  indent-tabs-mode:nil
-  fill-column:99
-  End:
-*/
-// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :
diff --git a/src/filters/turbulence.h b/src/filters/turbulence.h
index 792a6181a..e9403a164 100644
--- a/src/filters/turbulence.h
+++ b/src/filters/turbulence.h
@@ -1,10 +1,6 @@
-#ifndef SP_FETURBULENCE_H_SEEN
-#define SP_FETURBULENCE_H_SEEN
-
-/** \file
- * SVG <feTurbulence> implementation, see Turbulence.cpp.
- */
-/*
+/** @file
+ * @brief SVG turbulence filter effect
+ *//*
  * Authors:
  *   Felipe Corrêa da Silva Sanches <juca@members.fsf.org>
  *   Hugo Rodrigues <haa.rodrigues@gmail.com>
@@ -14,11 +10,19 @@
  * Released under GNU GPL, read the file 'COPYING' for more information
  */
 
-#include "sp-filter.h"
-#include "turbulence-fns.h"
+#ifndef SP_FETURBULENCE_H_SEEN
+#define SP_FETURBULENCE_H_SEEN
+
+#include "sp-filter-primitive.h"
 #include "number-opt-number.h"
 #include "display/nr-filter-turbulence.h"
 
+#define SP_TYPE_FETURBULENCE (sp_feTurbulence_get_type())
+#define SP_FETURBULENCE(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), SP_TYPE_FETURBULENCE, SPFeTurbulence))
+#define SP_FETURBULENCE_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass), SP_TYPE_FETURBULENCE, SPFeTurbulenceClass))
+#define SP_IS_FETURBULENCE(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj), SP_TYPE_FETURBULENCE))
+#define SP_IS_FETURBULENCE_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), SP_TYPE_FETURBULENCE))
+
 /* FeTurbulence base class */
 class SPFeTurbulenceClass;
 
diff --git a/src/preferences-skeleton.h b/src/preferences-skeleton.h
index c334ae31e..0c8834951 100644
--- a/src/preferences-skeleton.h
+++ b/src/preferences-skeleton.h
@@ -344,7 +344,6 @@ static char const preferences_skeleton[] =
 "    <group id=\"workarounds\"\n"
 "           colorsontop=\"0\"\n"
 "           partialdynamic=\"0\"/>\n"
-"    <group id=\"threading\" numthreads=\"1\"/>\n"
 "  </group>\n"
 "\n"
 "  <group id=\"extensions\">"
diff --git a/src/sp-filter-fns.h b/src/sp-filter-fns.h
deleted file mode 100644
index 4e1b012a3..000000000
--- a/src/sp-filter-fns.h
+++ /dev/null
@@ -1,53 +0,0 @@
-#ifndef SEEN_SP_FILTER_FNS_H
-#define SEEN_SP_FILTER_FNS_H
-
-/** \file
- * Macros and fn declarations related to filters.
- */
-
-#include <glib/gtypes.h>
-#include <glib-object.h>
-#include "libnr/nr-forward.h"
-#include "sp-filter-units.h"
-#include "sp-filter-primitive.h"
-
-class SPFilter;
-
-namespace Inkscape {
-namespace XML {
-class Node;
-}
-}
-
-#define SP_TYPE_FILTER (sp_filter_get_type())
-#define SP_FILTER(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), SP_TYPE_FILTER, SPFilter))
-#define SP_FILTER_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass), SP_TYPE_FILTER, SPFilterClass))
-#define SP_IS_FILTER(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj), SP_TYPE_FILTER))
-#define SP_IS_FILTER_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), SP_TYPE_FILTER))
-
-#define SP_FILTER_FILTER_UNITS(f) (SP_FILTER(f)->filterUnits)
-#define SP_FILTER_PRIMITIVE_UNITS(f) (SP_FILTER(f)->primitiveUnits)
-
-GType sp_filter_get_type();
-
-//need to define function
-void sp_filter_set_filter_units(SPFilter *filter, SPFilterUnits filterUnits);
-//need to define function
-void sp_filter_set_primitive_units(SPFilter *filter, SPFilterUnits filterUnits);
-
-SPFilterPrimitive *add_primitive(SPFilter *filter, SPFilterPrimitive *primitive);
-SPFilterPrimitive *get_primitive(SPFilter *filter, int index);
-
-
-#endif /* !SEEN_SP_FILTER_FNS_H */
-
-/*
-  Local Variables:
-  mode:c++
-  c-file-style:"stroustrup"
-  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
-  indent-tabs-mode:nil
-  fill-column:99
-  End:
-*/
-// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :
diff --git a/src/sp-filter-primitive.h b/src/sp-filter-primitive.h
index 3a7e73861..1ed101489 100644
--- a/src/sp-filter-primitive.h
+++ b/src/sp-filter-primitive.h
@@ -15,9 +15,6 @@
  */
 
 #include "sp-object.h"
-#include "display/nr-filter.h"
-#include "display/nr-filter-primitive.h"
-#include "display/nr-filter-types.h"
 
 #define SP_TYPE_FILTER_PRIMITIVE (sp_filter_primitive_get_type ())
 #define SP_FILTER_PRIMITIVE(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), SP_TYPE_FILTER_PRIMITIVE, SPFilterPrimitive))
@@ -27,6 +24,12 @@
 
 class SPFilterPrimitive;
 class SPFilterPrimitiveClass;
+namespace Inkscape {
+namespace Filters {
+class Filter;
+class FilterPrimitive;
+} }
+
 
 struct SPFilterPrimitive : public SPObject {
     int image_in, image_out;
diff --git a/src/sp-filter-reference.cpp b/src/sp-filter-reference.cpp
index 18e187603..79860d5d8 100644
--- a/src/sp-filter-reference.cpp
+++ b/src/sp-filter-reference.cpp
@@ -1,3 +1,4 @@
+#include "sp-filter.h"
 #include "sp-filter-reference.h"
 
 bool
diff --git a/src/sp-filter-reference.h b/src/sp-filter-reference.h
index 216ff1d6f..e5a3bc8ec 100644
--- a/src/sp-filter-reference.h
+++ b/src/sp-filter-reference.h
@@ -2,8 +2,10 @@
 #define SEEN_SP_FILTER_REFERENCE_H
 
 #include "uri-references.h"
-#include "sp-filter-fns.h"
+
 class SPObject;
+class SPDocument;
+class SPFilter;
 
 class SPFilterReference : public Inkscape::URIReference {
 public:
@@ -18,7 +20,6 @@ protected:
     virtual bool _acceptObject(SPObject *obj) const;
 };
 
-
 #endif /* !SEEN_SP_FILTER_REFERENCE_H */
 
 /*
diff --git a/src/sp-filter.cpp b/src/sp-filter.cpp
index 4cbafe50c..44db09b86 100644
--- a/src/sp-filter.cpp
+++ b/src/sp-filter.cpp
@@ -28,6 +28,7 @@ using std::pair;
 #include "document.h"
 #include "sp-filter.h"
 #include "sp-filter-reference.h"
+#include "sp-filter-primitive.h"
 #include "uri.h"
 #include "xml/repr.h"
 #include <cstring>
diff --git a/src/sp-filter.h b/src/sp-filter.h
index 5ad3863e5..527a0b8a1 100644
--- a/src/sp-filter.h
+++ b/src/sp-filter.h
@@ -1,10 +1,6 @@
-#ifndef SP_FILTER_H_SEEN
-#define SP_FILTER_H_SEEN
-
 /** \file
- * SVG <filter> implementation, see sp-filter.cpp.
- */
-/*
+ * SVG <filter> element
+ *//*
  * Authors:
  *   Hugo Rodrigues <haa.rodrigues@gmail.com>
  *   Niko Kiirala <niko@kiirala.com>
@@ -13,6 +9,8 @@
  *
  * Released under GNU GPL, read the file 'COPYING' for more information
  */
+#ifndef SP_FILTER_H_SEEN
+#define SP_FILTER_H_SEEN
 
 #include <map>
 
@@ -21,18 +19,24 @@
 #include "number-opt-number.h"
 #include "sp-object.h"
 #include "sp-filter-units.h"
-#include "sp-filter-fns.h"
 #include "svg/svg-length.h"
-#include "display/nr-filter.h"
 
-/* Filter base class */
+#define SP_TYPE_FILTER (sp_filter_get_type())
+#define SP_FILTER(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), SP_TYPE_FILTER, SPFilter))
+#define SP_FILTER_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass), SP_TYPE_FILTER, SPFilterClass))
+#define SP_IS_FILTER(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj), SP_TYPE_FILTER))
+#define SP_IS_FILTER_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), SP_TYPE_FILTER))
 
-/* MACROS DEFINED IN FILE sp-filter-fns.h */
+#define SP_FILTER_FILTER_UNITS(f) (SP_FILTER(f)->filterUnits)
+#define SP_FILTER_PRIMITIVE_UNITS(f) (SP_FILTER(f)->primitiveUnits)
 
-struct SPFilterReference;
+namespace Inkscape {
+namespace Filters {
+class Filter;
+} }
 
-class SPFilter;
-class SPFilterClass;
+struct SPFilterReference;
+class SPFilterPrimitive;
 
 struct ltstr {
     bool operator()(const char* s1, const char* s2) const;
@@ -70,34 +74,31 @@ struct SPFilterClass {
     SPObjectClass parent_class;
 };
 
-/*
- * Initializes the given Inkscape::Filters::Filter object as a renderer for this
- * SPFilter object.
- */
+GType sp_filter_get_type();
+
+void sp_filter_set_filter_units(SPFilter *filter, SPFilterUnits filterUnits);
+void sp_filter_set_primitive_units(SPFilter *filter, SPFilterUnits filterUnits);
+SPFilterPrimitive *add_primitive(SPFilter *filter, SPFilterPrimitive *primitive);
+SPFilterPrimitive *get_primitive(SPFilter *filter, int index);
+
+/* Initializes the given Inkscape::Filters::Filter object as a renderer for this
+ * SPFilter object. */
 void sp_filter_build_renderer(SPFilter *sp_filter, Inkscape::Filters::Filter *nr_filter);
 
-/*
- * Returns the number of filter primitives in this SPFilter object.
- */
+/// Returns the number of filter primitives in this SPFilter object.
 int sp_filter_primitive_count(SPFilter *filter);
 
-/**
- * Returns a slot number for given image name, or -1 for unknown name.
- */
+/// Returns a slot number for given image name, or -1 for unknown name.
 int sp_filter_get_image_name(SPFilter *filter, gchar const *name);
-/**
- * Returns slot number for given image name, even if it's unknown.
- */
+
+/// Returns slot number for given image name, even if it's unknown.
 int sp_filter_set_image_name(SPFilter *filter, gchar const *name);
-/**
- * Finds image name based on it's slot number. Returns 0 for unknown slot
- * numbers.
- */
+
+/** Finds image name based on it's slot number. Returns 0 for unknown slot
+ * numbers. */
 gchar const *sp_filter_name_for_image(SPFilter const *filter, int const image);
 
-/*
- * Returns a result image name that is not in use inside this filter.
- */
+/// Returns a result image name that is not in use inside this filter.
 Glib::ustring sp_filter_get_new_result_name(SPFilter *filter);
 
 #endif /* !SP_FILTER_H_SEEN */
diff --git a/src/sp-gaussian-blur.h b/src/sp-gaussian-blur.h
deleted file mode 100644
index c86ee3288..000000000
--- a/src/sp-gaussian-blur.h
+++ /dev/null
@@ -1,45 +0,0 @@
-#ifndef SP_GAUSSIANBLUR_H_SEEN
-#define SP_GAUSSIANBLUR_H_SEEN
-
-/** \file
- * SVG <gaussianBlur> implementation, see sp-gaussianBlur.cpp.
- */
-/*
- * Authors:
- *   Hugo Rodrigues <haa.rodrigues@gmail.com>
- *
- * Copyright (C) 2006 Hugo Rodrigues
- *
- * Released under GNU GPL, read the file 'COPYING' for more information
- */
-
-#include "sp-filter.h"
-#include "sp-gaussian-blur-fns.h"
-
-/* GaussianBlur base class */
-class SPGaussianBlurClass;
-
-struct SPGaussianBlur : public SPFilterPrimitive {
-    /** stdDeviation attribute */
-    NumberOptNumber stdDeviation;
-};
-
-struct SPGaussianBlurClass {
-    SPFilterPrimitiveClass parent_class;
-};
-
-GType sp_gaussianBlur_get_type();
-
-
-#endif /* !SP_GAUSSIANBLUR_H_SEEN */
-
-/*
-  Local Variables:
-  mode:c++
-  c-file-style:"stroustrup"
-  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
-  indent-tabs-mode:nil
-  fill-column:99
-  End:
-*/
-// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :
diff --git a/src/sp-object-repr.cpp b/src/sp-object-repr.cpp
index 62143e3ab..cc289317e 100644
--- a/src/sp-object-repr.cpp
+++ b/src/sp-object-repr.cpp
@@ -59,7 +59,6 @@
 #include "color-profile-fns.h"
 #include "xml/repr.h"
 #include "sp-filter.h"
-#include "sp-gaussian-blur.h"
 #include "filters/blend.h"
 #include "filters/colormatrix.h"
 #include "filters/componenttransfer.h"
@@ -70,6 +69,7 @@
 #include "filters/distantlight.h"
 #include "filters/displacementmap.h"
 #include "filters/flood.h"
+#include "filters/gaussian-blur.h"
 #include "filters/image.h"
 #include "filters/merge.h"
 #include "filters/morphology.h"
diff --git a/src/spray-context.cpp b/src/spray-context.cpp
index 2bdac197f..ee168f136 100644
--- a/src/spray-context.cpp
+++ b/src/spray-context.cpp
@@ -1,5 +1,3 @@
-#define __SP_SPRAY_CONTEXT_C__
-
 /*
  * Spray Tool
  *
@@ -36,7 +34,6 @@
 #include "desktop.h"
 #include "desktop-events.h"
 #include "desktop-handles.h"
-#include "unistd.h"
 #include "desktop-style.h"
 #include "message-context.h"
 #include "pixmaps/cursor-spray.xpm"
@@ -72,9 +69,6 @@
 #include "style.h"
 #include "box3d.h"
 #include "sp-item-transform.h"
-#include "filter-chemistry.h"
-#include "sp-gaussian-blur-fns.h"
-#include "sp-gaussian-blur.h"
 
 #include "spray-context.h"
 #include "ui/dialog/dialog-manager.h"
diff --git a/src/tweak-context.cpp b/src/tweak-context.cpp
index 13299b5a4..36357ab84 100644
--- a/src/tweak-context.cpp
+++ b/src/tweak-context.cpp
@@ -72,8 +72,7 @@
 #include "box3d.h"
 #include "sp-item-transform.h"
 #include "filter-chemistry.h"
-#include "sp-gaussian-blur-fns.h"
-#include "sp-gaussian-blur.h"
+#include "filters/gaussian-blur.h"
 
 #include "tweak-context.h"
 
diff --git a/src/ui/dialog/filter-effects-dialog.cpp b/src/ui/dialog/filter-effects-dialog.cpp
index 1672c4b69..4ec719bf4 100644
--- a/src/ui/dialog/filter-effects-dialog.cpp
+++ b/src/ui/dialog/filter-effects-dialog.cpp
@@ -48,13 +48,13 @@
 #include "filters/convolvematrix.h"
 #include "filters/displacementmap.h"
 #include "filters/distantlight.h"
+#include "filters/gaussian-blur.h"
 #include "filters/merge.h"
 #include "filters/mergenode.h"
 #include "filters/offset.h"
 #include "filters/pointlight.h"
 #include "filters/spotlight.h"
 #include "sp-filter-primitive.h"
-#include "sp-gaussian-blur.h"
 
 #include "style.h"
 #include "svg/svg-color.h"