Fix a rounding error that resulted in seams at some zoom levels when

rendering filters that use BackgroundImage.

(bzr r9508.1.81)

7 files changed, 47 insertions, 30 deletions

diff --git a/src/display/nr-filter-diffuselighting.cpp b/src/display/nr-filter-diffuselighting.cpp
index e2954c3b1..0a46a5c86 100644
--- a/src/display/nr-filter-diffuselighting.cpp
+++ b/src/display/nr-filter-diffuselighting.cpp
@@ -128,9 +128,10 @@ void FilterDiffuseLighting::render_cairo(FilterSlot &slot)
     cairo_surface_t *input = slot.getcairo(_input);
     cairo_surface_t *out = ink_cairo_surface_create_same_size(input, CAIRO_CONTENT_COLOR_ALPHA);
 
-    NRRectL const &slot_area = slot.get_slot_area();
+    Geom::Rect slot_area = slot.get_slot_area();
+    Geom::Point p = slot_area.min();
     Geom::Affine trans = slot.get_units().get_matrix_primitiveunits2pb();
-    double x0 = slot_area.x0, y0 = slot_area.y0;
+    double x0 = p[Geom::X], y0 = p[Geom::Y];
     double scale = surfaceScale * trans.descrim();
 
     switch (light_type) {
diff --git a/src/display/nr-filter-gaussian.cpp b/src/display/nr-filter-gaussian.cpp
index fdffabfeb..326c37160 100644
--- a/src/display/nr-filter-gaussian.cpp
+++ b/src/display/nr-filter-gaussian.cpp
@@ -82,7 +82,7 @@ static inline Tt round_cast(Ts v) {
     static Ts const rndoffset(.5);
     return static_cast<Tt>(v+rndoffset);
 }
-
+/*
 template<>
 inline unsigned char round_cast(double v) {
     // This (fast) rounding method is based on:
@@ -99,7 +99,7 @@ inline unsigned char round_cast(double v) {
     static double const rndoffset(.5);
     return static_cast<unsigned char>(v+rndoffset);
 #endif
-}
+}*/
 
 template<typename Tt, typename Ts>
 static inline Tt clip_round_cast(Ts const v) {
@@ -142,7 +142,7 @@ FilterGaussian::~FilterGaussian()
 static int
 _effect_area_scr(double const deviation)
 {
-    return (int)std::ceil(deviation * 3.0);
+    return (int)std::ceil(std::fabs(deviation) * 3.0);
 }
 
 static void
diff --git a/src/display/nr-filter-image.cpp b/src/display/nr-filter-image.cpp
index eea4f9781..0cb7901b3 100644
--- a/src/display/nr-filter-image.cpp
+++ b/src/display/nr-filter-image.cpp
@@ -91,11 +91,11 @@ void FilterImage::render_cairo(FilterSlot &slot)
         double scaleX = feImageWidth / area.width();
         double scaleY = feImageHeight / area.height();
 
-        NRRectL const &sa = slot.get_slot_area();
+        Geom::Rect sa = slot.get_slot_area();
         cairo_surface_t *out = cairo_image_surface_create(CAIRO_FORMAT_ARGB32,
-            sa.x1 - sa.x0, sa.y1 - sa.y0);
+            sa.width(), sa.height());
         cairo_t *ct = cairo_create(out);
-        cairo_translate(ct, -sa.x0, -sa.y0);
+        cairo_translate(ct, -sa.min()[Geom::X], -sa.min()[Geom::Y]);
         ink_cairo_transform(ct, pu2pb); // we are now in primitive units
         cairo_translate(ct, feImageX, feImageY);
         cairo_scale(ct, scaleX, scaleY);
@@ -179,12 +179,12 @@ void FilterImage::render_cairo(FilterSlot &slot)
             CAIRO_FORMAT_ARGB32, image->get_width(), image->get_height(), image->get_rowstride());
     }
 
-    NRRectL const &sa = slot.get_slot_area();
+    Geom::Rect sa = slot.get_slot_area();
     cairo_surface_t *out = cairo_image_surface_create(CAIRO_FORMAT_ARGB32,
-        sa.x1 - sa.x0, sa.y1 - sa.y0);
+        sa.width(), sa.height());
 
     cairo_t *ct = cairo_create(out);
-    cairo_translate(ct, -sa.x0, -sa.y0);
+    cairo_translate(ct, -sa.min()[Geom::X], -sa.min()[Geom::Y]);
     // now ct is in pb coordinates
     ink_cairo_transform(ct, slot.get_units().get_matrix_primitiveunits2pb());
     // now ct is in the coordinates of feImageX etc.
diff --git a/src/display/nr-filter-slot.cpp b/src/display/nr-filter-slot.cpp
index 63f9dc1a6..ce07ff086 100644
--- a/src/display/nr-filter-slot.cpp
+++ b/src/display/nr-filter-slot.cpp
@@ -46,14 +46,18 @@ FilterSlot::FilterSlot(NRArenaItem *item, cairo_t *bgct, NRRectL const *bgarea,
         Geom::Point(_source_graphic_area->x1, _source_graphic_area->y1));
 
     Geom::Affine trans = _units.get_matrix_display2pb();
-
     Geom::Rect bbox_trans = bbox * trans;
     Geom::Point min = bbox_trans.min();
-    Geom::Point max = bbox_trans.max();
-    _slot_area.x0 = floor(min[X]);
-    _slot_area.y0 = floor(min[Y]);
-    _slot_area.x1 = ceil(max[X]);
-    _slot_area.y1 = ceil(max[Y]);
+    _slot_x = min[X];
+    _slot_y = min[Y];
+
+    if (trans.isTranslation()) {
+        _slot_w = _source_graphic_area->x1 - _source_graphic_area->x0;
+        _slot_h = _source_graphic_area->y1 - _source_graphic_area->y0;
+    } else {
+        _slot_w = ceil(bbox_trans.width());
+        _slot_h = ceil(bbox_trans.height());
+    }
 }
 
 FilterSlot::~FilterSlot()
@@ -115,7 +119,7 @@ cairo_surface_t *FilterSlot::getcairo(int slot_nr)
         // create empty surface
         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);
+            _slot_w, _slot_h);
         _set_internal(slot_nr, empty);
         cairo_surface_destroy(empty);
         s = _slots.find(slot_nr);
@@ -127,17 +131,17 @@ cairo_surface_t *FilterSlot::_get_transformed_source_graphic()
 {
     Geom::Affine trans = _units.get_matrix_display2pb();
 
-    if (trans.isIdentity()) {
+    if (trans.isTranslation()) {
         cairo_surface_reference(_source_graphic);
         return _source_graphic;
     }
 
     cairo_surface_t *tsg = cairo_surface_create_similar(
         _source_graphic, cairo_surface_get_content(_source_graphic),
-        _slot_area.x1 - _slot_area.x0, _slot_area.y1 - _slot_area.y0);
+        _slot_w, _slot_h);
     cairo_t *tsg_ct = cairo_create(tsg);
 
-    cairo_translate(tsg_ct, -_slot_area.x0, -_slot_area.y0);
+    cairo_translate(tsg_ct, -_slot_x, -_slot_y);
     ink_cairo_transform(tsg_ct, trans);
     cairo_translate(tsg_ct, _source_graphic_area->x0, _source_graphic_area->y0);
     cairo_set_source_surface(tsg_ct, _source_graphic, 0, 0);
@@ -155,10 +159,10 @@ cairo_surface_t *FilterSlot::_get_transformed_background()
     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);
+        _slot_w, _slot_h);
     cairo_t *tbg_ct = cairo_create(tbg);
 
-    cairo_translate(tbg_ct, -_slot_area.x0, -_slot_area.y0);
+    cairo_translate(tbg_ct, -_slot_x, -_slot_y);
     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);
@@ -186,7 +190,7 @@ cairo_surface_t *FilterSlot::get_result(int res)
 
     cairo_translate(r_ct, -_source_graphic_area->x0, -_source_graphic_area->y0);
     ink_cairo_transform(r_ct, trans);
-    cairo_translate(r_ct, _slot_area.x0, _slot_area.y0);
+    cairo_translate(r_ct, _slot_x, _slot_y);
     cairo_set_source_surface(r_ct, getcairo(res), 0, 0);
     cairo_set_operator(r_ct, CAIRO_OPERATOR_SOURCE);
     cairo_paint(r_ct);
@@ -237,6 +241,13 @@ int FilterSlot::get_blurquality(void) {
     return blurquality;
 }
 
+Geom::Rect FilterSlot::get_slot_area() const {
+    Geom::Point p(_slot_x, _slot_y);
+    Geom::Point dim(_slot_w, _slot_h);
+    Geom::Rect r(p, p+dim);
+    return r;
+}
+
 } /* namespace Filters */
 } /* namespace Inkscape */
 
diff --git a/src/display/nr-filter-slot.h b/src/display/nr-filter-slot.h
index f477b7b73..3b08743ed 100644
--- a/src/display/nr-filter-slot.h
+++ b/src/display/nr-filter-slot.h
@@ -65,7 +65,7 @@ public:
     int get_blurquality(void);
 
     FilterUnits const &get_units() const { return _units; }
-    NRRectL const &get_slot_area() const { return _slot_area; }
+    Geom::Rect get_slot_area() const;
     NRRectL const &get_sg_area() const { return *_source_graphic_area; }
 
 private:
@@ -76,7 +76,9 @@ private:
     //Geom::Rect _source_bbox; ///< bounding box of source graphic surface
     //Geom::Rect _intermediate_bbox; ///< bounding box of intermediate surfaces
 
-    NRRectL _slot_area;
+//    NRRectL _slot_area;
+    int _slot_w, _slot_h;
+    double _slot_x, _slot_y;
     cairo_surface_t *_source_graphic;
     cairo_t *_background_ct;
     NRRectL const *_source_graphic_area;
diff --git a/src/display/nr-filter-specularlighting.cpp b/src/display/nr-filter-specularlighting.cpp
index e9e3f2b28..eddab36a1 100644
--- a/src/display/nr-filter-specularlighting.cpp
+++ b/src/display/nr-filter-specularlighting.cpp
@@ -140,9 +140,10 @@ void FilterSpecularLighting::render_cairo(FilterSlot &slot)
     cairo_surface_t *input = slot.getcairo(_input);
     cairo_surface_t *out = ink_cairo_surface_create_same_size(input, CAIRO_CONTENT_COLOR_ALPHA);
 
-    NRRectL const &slot_area = slot.get_slot_area();
     Geom::Affine trans = slot.get_units().get_matrix_primitiveunits2pb();
-    double x0 = slot_area.x0, y0 = slot_area.y0;
+    Geom::Point p = slot.get_slot_area().min();
+    double x0 = p[Geom::X];
+    double y0 = p[Geom::Y];
     double scale = surfaceScale * trans.descrim();
     double ks = specularConstant;
     double se = specularExponent;
diff --git a/src/display/nr-filter-turbulence.cpp b/src/display/nr-filter-turbulence.cpp
index c1a3abd45..6aa435715 100644
--- a/src/display/nr-filter-turbulence.cpp
+++ b/src/display/nr-filter-turbulence.cpp
@@ -376,9 +376,11 @@ void FilterTurbulence::render_cairo(FilterSlot &slot)
     }
 
     Geom::Affine unit_trans = slot.get_units().get_matrix_primitiveunits2pb().inverse();
-    NRRectL const &slot_area = slot.get_slot_area();
+    Geom::Rect slot_area = slot.get_slot_area();
+    double x0 = slot_area.min()[Geom::X];
+    double y0 = slot_area.min()[Geom::Y];
 
-    ink_cairo_surface_synthesize(out, Turbulence(*gen, unit_trans, slot_area.x0, slot_area.y0));
+    ink_cairo_surface_synthesize(out, Turbulence(*gen, unit_trans, x0, y0));
 
     cairo_surface_mark_dirty(out);