Eliminate "unit-constants.h".

(bzr r12380.1.54)

29 files changed, 95 insertions, 151 deletions

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 537e13200..4f7592119 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -481,7 +481,6 @@ set(inkscape_SRC
 	unclump.h
 	undo-stack-observer.h
 	unicoderange.h
-	unit-constants.h
 	uri-references.h
 	uri.h
 	vanishing-point.h
diff --git a/src/Makefile_insert b/src/Makefile_insert
index ff64dc183..429c725cd 100644
--- a/src/Makefile_insert
+++ b/src/Makefile_insert
@@ -250,7 +250,6 @@ ink_common_sources +=	\
 	unclump.cpp unclump.h			\
 	undo-stack-observer.h			\
 	unicoderange.cpp unicoderange.h		\
-	unit-constants.h			\
 	uri.cpp uri.h				\
 	uri-references.cpp uri-references.h	\
 	vanishing-point.cpp vanishing-point.h	\
diff --git a/src/document.cpp b/src/document.cpp
index a024cc790..afd0a6ddc 100644
--- a/src/document.cpp
+++ b/src/document.cpp
@@ -62,7 +62,7 @@
 #include "sp-object-repr.h"
 #include "sp-symbol.h"
 #include "transf_mat_3x4.h"
-#include "unit-constants.h"
+#include "util/units.h"
 #include "xml/repr.h"
 #include "xml/rebase-hrefs.h"
 #include "libcroco/cr-cascade.h"
@@ -966,7 +966,7 @@ void SPDocument::setupViewport(SPItemCtx *ctx)
     if (root->viewBox_set) { // if set, take from viewBox
         ctx->viewport = root->viewBox;
     } else { // as a last resort, set size to A4
-        ctx->viewport = Geom::Rect::from_xywh(0, 0, 210 * PX_PER_MM, 297 * PX_PER_MM);
+        ctx->viewport = Geom::Rect::from_xywh(0, 0, 210 * Inkscape::Util::Quantity::convert(1, "mm", "px"), 297 * Inkscape::Util::Quantity::convert(1, "mm", "px"));
     }
     ctx->i2vp = Geom::identity();
 }
diff --git a/src/doxygen-main.cpp b/src/doxygen-main.cpp
index 42eb5dd13..a1d3f3604 100644
--- a/src/doxygen-main.cpp
+++ b/src/doxygen-main.cpp
@@ -348,7 +348,7 @@ namespace XML {}
  * Inkscape::Whiteboard::UndoStackObserver [\ref undo-stack-observer.cpp, \ref composite-undo-stack-observer.cpp]
  * [\ref document-undo.cpp]
  *
- * {\ref dialogs/} [\ref decimal-round.h] [\ref enums.h] [\ref unit-constants.h]
+ * {\ref dialogs/} [\ref decimal-round.h] [\ref enums.h]
  */
 
 
diff --git a/src/extension/internal/cairo-render-context.cpp b/src/extension/internal/cairo-render-context.cpp
index d7a560f04..09b769229 100644
--- a/src/extension/internal/cairo-render-context.cpp
+++ b/src/extension/internal/cairo-render-context.cpp
@@ -44,12 +44,11 @@
 #include "sp-pattern.h"
 #include "sp-mask.h"
 #include "sp-clippath.h"
+#include "util/units.h"
 #ifdef WIN32
 #include "libnrtype/FontFactory.h" // USE_PANGO_WIN32
 #endif
 
-#include <unit-constants.h>
-
 #include "cairo-render-context.h"
 #include "cairo-renderer.h"
 #include "extension/system.h"
@@ -855,7 +854,7 @@ CairoRenderContext::_finishSurfaceSetup(cairo_surface_t *surface, cairo_matrix_t
     _surface = surface;
 
     if (_vector_based_target) {
-        cairo_scale(_cr, PT_PER_PX, PT_PER_PX);
+        cairo_scale(_cr, Inkscape::Util::Quantity::convert(1, "px", "pt"), Inkscape::Util::Quantity::convert(1, "px", "pt"));
     } else if (cairo_surface_get_content(_surface) != CAIRO_CONTENT_ALPHA) {
         // set background color on non-alpha surfaces
         // TODO: bgcolor should be derived from SPDocument
diff --git a/src/extension/internal/cairo-renderer-pdf-out.cpp b/src/extension/internal/cairo-renderer-pdf-out.cpp
index 6f641fd36..da4cf1bc1 100644
--- a/src/extension/internal/cairo-renderer-pdf-out.cpp
+++ b/src/extension/internal/cairo-renderer-pdf-out.cpp
@@ -39,7 +39,7 @@
 #include <2geom/affine.h>
 #include "document.h"
 
-#include "unit-constants.h"
+#include "util/units.h"
 
 namespace Inkscape {
 namespace Extension {
@@ -197,7 +197,7 @@ CairoRendererPdfOutput::save(Inkscape::Extension::Output *mod, SPDocument *doc,
 
     float new_bleedmargin_px = 0.;
     try {
-        new_bleedmargin_px = mod->get_param_float("bleed") * PX_PER_MM;
+        new_bleedmargin_px = mod->get_param_float("bleed") * Inkscape::Util::Quantity::convert(1, "mm", "px");
     }
     catch(...) {
         g_warning("Parameter <bleed> might not exist");
diff --git a/src/extension/internal/cairo-renderer.cpp b/src/extension/internal/cairo-renderer.cpp
index 0a3cff26a..f7ab63c98 100644
--- a/src/extension/internal/cairo-renderer.cpp
+++ b/src/extension/internal/cairo-renderer.cpp
@@ -55,7 +55,7 @@
 #include "sp-mask.h"
 #include "sp-clippath.h"
 
-#include <unit-constants.h>
+#include "util/units.h"
 #include "helper/png-write.h"
 #include "helper/pixbuf-ops.h"
 
@@ -442,7 +442,7 @@ static void sp_asbitmap_render(SPItem *item, CairoRenderContext *ctx)
     */
     res = ctx->getBitmapResolution();
     if(res == 0) {
-        res = PX_PER_IN;
+        res = Inkscape::Util::Quantity::convert(1, "in", "px");
     }
     TRACE(("sp_asbitmap_render: resolution: %f\n", res ));
 
@@ -463,8 +463,8 @@ static void sp_asbitmap_render(SPItem *item, CairoRenderContext *ctx)
     }
 
     // The width and height of the bitmap in pixels
-    unsigned width =  ceil(bbox->width() * (res / PX_PER_IN));
-    unsigned height = ceil(bbox->height() * (res / PX_PER_IN));
+    unsigned width =  ceil(bbox->width() * (res / Inkscape::Util::Quantity::convert(1, "in", "px")));
+    unsigned height = ceil(bbox->height() * (res / Inkscape::Util::Quantity::convert(1, "in", "px")));
 
     if (width == 0 || height == 0) return;
 
@@ -477,7 +477,7 @@ static void sp_asbitmap_render(SPItem *item, CairoRenderContext *ctx)
     double shift_y = bbox->max()[Geom::Y];
 
     // For default 90 dpi, snap bitmap to pixel grid
-    if (res == PX_PER_IN) { 
+    if (res == Inkscape::Util::Quantity::convert(1, "in", "px")) { 
         shift_x = round (shift_x);
         shift_y = -round (-shift_y); // Correct rounding despite coordinate inversion.
                                      // Remove the negations when the inversion is gone.
@@ -629,7 +629,7 @@ CairoRenderer::setupDocument(CairoRenderContext *ctx, SPDocument *doc, bool page
 
     if (ctx->_vector_based_target) {
         // convert from px to pt
-        d *= Geom::Scale(PT_PER_PX);
+        d *= Geom::Scale(Inkscape::Util::Quantity::convert(1, "px", "pt"));
     }
 
     ctx->_width = d.width();
@@ -647,11 +647,11 @@ CairoRenderer::setupDocument(CairoRenderContext *ctx, SPDocument *doc, bool page
         } else {
             double high = doc->getHeight();
             if (ctx->_vector_based_target)
-                high *= PT_PER_PX;
+                high *= Inkscape::Util::Quantity::convert(1, "px", "pt");
 
             // this transform translates the export drawing to a virtual page (0,0)-(width,height)
-            Geom::Affine tp(Geom::Translate(-d.left() * (ctx->_vector_based_target ? PX_PER_PT : 1.0),
-                                            (d.bottom() - high) * (ctx->_vector_based_target ? PX_PER_PT : 1.0)));
+            Geom::Affine tp(Geom::Translate(-d.left() * (ctx->_vector_based_target ? Inkscape::Util::Quantity::convert(1, "pt", "px") : 1.0),
+                                            (d.bottom() - high) * (ctx->_vector_based_target ? Inkscape::Util::Quantity::convert(1, "pt", "px") : 1.0)));
             ctx->transform(tp);
         }
     }
diff --git a/src/extension/internal/emf-win32-inout.cpp b/src/extension/internal/emf-win32-inout.cpp
index e9360a0ea..62cb53413 100644
--- a/src/extension/internal/emf-win32-inout.cpp
+++ b/src/extension/internal/emf-win32-inout.cpp
@@ -37,7 +37,6 @@
 #include "extension/output.h"
 #include "display/drawing.h"
 #include "display/drawing-item.h"
-#include "unit-constants.h"
 #include "clear-n_.h"
 #include "document.h"
 
diff --git a/src/extension/internal/emf-win32-print.cpp b/src/extension/internal/emf-win32-print.cpp
index 2b79fd5a4..99f101bb8 100644
--- a/src/extension/internal/emf-win32-print.cpp
+++ b/src/extension/internal/emf-win32-print.cpp
@@ -43,8 +43,6 @@
 
 #include "emf-win32-print.h"
 
-#include "unit-constants.h"
-
 #include "extension/system.h"
 #include "extension/print.h"
 #include "document.h"
diff --git a/src/extension/internal/gdkpixbuf-input.cpp b/src/extension/internal/gdkpixbuf-input.cpp
index abfad518f..994258ccc 100644
--- a/src/extension/internal/gdkpixbuf-input.cpp
+++ b/src/extension/internal/gdkpixbuf-input.cpp
@@ -12,7 +12,7 @@
 #include "selection-chemistry.h"
 #include "sp-image.h"
 #include "document-undo.h"
-#include "unit-constants.h"
+#include "util/units.h"
 #include "image-resolution.h"
 #include <set>
 
@@ -79,7 +79,7 @@ GdkpixbufInput::open(Inkscape::Extension::Input *mod, char const *uri)
 
         double width = gdk_pixbuf_get_width(pb);
         double height = gdk_pixbuf_get_height(pb);
-        double defaultxdpi = prefs->getDouble("/dialogs/import/defaultxdpi/value", PX_PER_IN);
+        double defaultxdpi = prefs->getDouble("/dialogs/import/defaultxdpi/value", Inkscape::Util::Quantity::convert(1, "in", "px"));
         bool forcexdpi = prefs->getBool("/dialogs/import/forcexdpi");
         ImageResolution *ir = 0;
         double xscale = 1;
diff --git a/src/extension/internal/latex-pstricks.cpp b/src/extension/internal/latex-pstricks.cpp
index c1eddf539..2ece1ba87 100644
--- a/src/extension/internal/latex-pstricks.cpp
+++ b/src/extension/internal/latex-pstricks.cpp
@@ -21,7 +21,7 @@
 #include <2geom/hvlinesegment.h>
 #include <errno.h>
 #include <signal.h>
-#include <unit-constants.h>
+#include "util/units.h"
 #include "helper/geom-curves.h"
 
 #include "extension/print.h"
@@ -117,8 +117,8 @@ unsigned int PrintLatex::begin (Inkscape::Extension::Print *mod, SPDocument *doc
     }
 
     // width and height in pt
-    _width = doc->getWidth() * PT_PER_PX;
-    _height = doc->getHeight() * PT_PER_PX;
+    _width = doc->getWidth() * Inkscape::Util::Quantity::convert(1, "px", "pt");
+    _height = doc->getHeight() * Inkscape::Util::Quantity::convert(1, "px", "pt");
 
     if (res >= 0) {
 
diff --git a/src/extension/internal/latex-text-renderer.cpp b/src/extension/internal/latex-text-renderer.cpp
index ecc201733..57a71b467 100644
--- a/src/extension/internal/latex-text-renderer.cpp
+++ b/src/extension/internal/latex-text-renderer.cpp
@@ -39,7 +39,7 @@
 #include "sp-rect.h"
 #include "text-editing.h"
 
-#include <unit-constants.h>
+#include "util/units.h"
 
 #include "extension/system.h"
 
@@ -611,7 +611,7 @@ LaTeXTextRenderer::setupDocument(SPDocument *doc, bool pageBoundingBox, float bl
     // scaling of the image when including it in LaTeX
 
     os << "  \\ifx\\svgwidth\\undefined%\n";
-    os << "    \\setlength{\\unitlength}{" << d.width() * PT_PER_PX << "bp}%\n"; // note: 'bp' is the Postscript pt unit in LaTeX, see LP bug #792384
+    os << "    \\setlength{\\unitlength}{" << d.width() * Inkscape::Util::Quantity::convert(1, "px", "pt") << "bp}%\n"; // note: 'bp' is the Postscript pt unit in LaTeX, see LP bug #792384
     os << "    \\ifx\\svgscale\\undefined%\n";
     os << "      \\relax%\n";
     os << "    \\else%\n";
diff --git a/src/extension/internal/pdfinput/pdf-parser.cpp b/src/extension/internal/pdfinput/pdf-parser.cpp
index 3be7af34f..3b63e9cbe 100644
--- a/src/extension/internal/pdfinput/pdf-parser.cpp
+++ b/src/extension/internal/pdfinput/pdf-parser.cpp
@@ -34,7 +34,7 @@ extern "C" {
 #include "svg-builder.h"
 #include "Gfx.h"
 #include "pdf-parser.h"
-#include "unit-constants.h"
+#include "util/units.h"
 
 #include "goo/gmem.h"
 #include "goo/GooTimer.h"
@@ -279,14 +279,14 @@ PdfParser::PdfParser(XRef *xrefA, Inkscape::Extension::Internal::SvgBuilder *bui
   ignoreUndef = 0;
   operatorHistory = NULL;
   builder = builderA;
-  builder->setDocumentSize(state->getPageWidth()*PX_PER_PT,
-                           state->getPageHeight()*PX_PER_PT);
+  builder->setDocumentSize(state->getPageWidth()*Inkscape::Util::Quantity::convert(1, "pt", "px"),
+                           state->getPageHeight()*Inkscape::Util::Quantity::convert(1, "pt", "px"));
 
   double *ctm = state->getCTM();
   double scaledCTM[6];
   for (int i = 0; i < 6; ++i) {
     baseMatrix[i] = ctm[i];
-    scaledCTM[i] = PX_PER_PT * ctm[i];
+    scaledCTM[i] = Inkscape::Util::Quantity::convert(1, "pt", "px") * ctm[i];
   }
   saveState();
   builder->setTransform((double*)&scaledCTM);
diff --git a/src/extension/internal/pdfinput/svg-builder.cpp b/src/extension/internal/pdfinput/svg-builder.cpp
index 75849f6cc..6d9ac1b1a 100644
--- a/src/extension/internal/pdfinput/svg-builder.cpp
+++ b/src/extension/internal/pdfinput/svg-builder.cpp
@@ -33,7 +33,7 @@
 #include "svg/css-ostringstream.h"
 #include "svg/svg-color.h"
 #include "color.h"
-#include "unit-constants.h"
+#include "util/units.h"
 #include "io/stringstream.h"
 #include "io/base64stream.h"
 #include "display/nr-filter-utils.h"
@@ -777,7 +777,7 @@ gchar *SvgBuilder::_createGradient(GfxShading *shading, double *matrix, bool for
         Geom::Affine pat_matrix(matrix[0], matrix[1], matrix[2], matrix[3],
                               matrix[4], matrix[5]);
         if ( !for_shading && _is_top_level ) {
-            Geom::Affine flip(1.0, 0.0, 0.0, -1.0, 0.0, _height * PT_PER_PX);
+            Geom::Affine flip(1.0, 0.0, 0.0, -1.0, 0.0, _height * Inkscape::Util::Quantity::convert(1, "px", "pt"));
             pat_matrix *= flip;
         }
         gchar *transform_text = sp_svg_transform_write(pat_matrix);
diff --git a/src/helper/pixbuf-ops.cpp b/src/helper/pixbuf-ops.cpp
index 9cd1967d8..75c002c57 100644
--- a/src/helper/pixbuf-ops.cpp
+++ b/src/helper/pixbuf-ops.cpp
@@ -29,7 +29,7 @@
 #include "sp-root.h"
 #include "sp-use.h"
 #include "sp-defs.h"
-#include "unit-constants.h"
+#include "util/units.h"
 
 #include "helper/pixbuf-ops.h"
 
@@ -121,7 +121,7 @@ GdkPixbuf *sp_generate_internal_bitmap(SPDocument *doc, gchar const */*filename*
     origin[Geom::X] = origin[Geom::X] + (screen[Geom::X].extent() * ((1 - padding) / 2));
     origin[Geom::Y] = origin[Geom::Y] + (screen[Geom::Y].extent() * ((1 - padding) / 2));
 
-    Geom::Scale scale( (xdpi / PX_PER_IN),   (ydpi / PX_PER_IN));
+    Geom::Scale scale( (xdpi / Inkscape::Util::Quantity::convert(1, "in", "px")),   (ydpi / Inkscape::Util::Quantity::convert(1, "in", "px")));
     Geom::Affine affine = scale * Geom::Translate(-origin * scale);
 
     /* Create ArenaItems and set transform */
diff --git a/src/main.cpp b/src/main.cpp
index d425b88bb..577cc3d79 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -68,7 +68,7 @@
 #include "color.h"
 #include "sp-item.h"
 #include "sp-root.h"
-#include "unit-constants.h"
+#include "util/units.h"
 
 #include "svg/svg.h"
 #include "svg/svg-color.h"
@@ -1524,7 +1524,7 @@ static int sp_do_export_png(SPDocument *doc)
 
     // default dpi
     if (dpi == 0.0) {
-        dpi = PX_PER_IN;
+        dpi = Inkscape::Util::Quantity::convert(1, "in", "px");
     }
 
     unsigned long int width = 0;
@@ -1537,7 +1537,7 @@ static int sp_do_export_png(SPDocument *doc)
             g_warning("Export width %lu out of range (1 - %lu). Nothing exported.", width, (unsigned long int)PNG_UINT_31_MAX);
             return 1;
         }
-        dpi = (gdouble) width * PX_PER_IN / area.width();
+        dpi = (gdouble) width * Inkscape::Util::Quantity::convert(1, "in", "px") / area.width();
     }
 
     if (sp_export_height) {
@@ -1547,15 +1547,15 @@ static int sp_do_export_png(SPDocument *doc)
             g_warning("Export height %lu out of range (1 - %lu). Nothing exported.", height, (unsigned long int)PNG_UINT_31_MAX);
             return 1;
         }
-        dpi = (gdouble) height * PX_PER_IN / area.height();
+        dpi = (gdouble) height * Inkscape::Util::Quantity::convert(1, "in", "px") / area.height();
     }
 
     if (!sp_export_width) {
-        width = (unsigned long int) (area.width() * dpi / PX_PER_IN + 0.5);
+        width = (unsigned long int) (area.width() * dpi / Inkscape::Util::Quantity::convert(1, "in", "px") + 0.5);
     }
 
     if (!sp_export_height) {
-        height = (unsigned long int) (area.height() * dpi / PX_PER_IN + 0.5);
+        height = (unsigned long int) (area.height() * dpi / Inkscape::Util::Quantity::convert(1, "in", "px") + 0.5);
     }
 
     guint32 bgcolor = 0x00000000;
diff --git a/src/selection-chemistry.cpp b/src/selection-chemistry.cpp
index dc786f340..5976555f4 100644
--- a/src/selection-chemistry.cpp
+++ b/src/selection-chemistry.cpp
@@ -89,7 +89,7 @@ SPCycleType SP_CYCLING = SP_CYCLE_FOCUS;
 #include "sp-item.h"
 #include "box3d.h"
 #include "persp3d.h"
-#include "unit-constants.h"
+#include "util/units.h"
 #include "xml/simple-document.h"
 #include "sp-filter-reference.h"
 #include "gradient-drag.h"
@@ -3397,7 +3397,7 @@ void sp_selection_create_bitmap_copy(SPDesktop *desktop)
         res = prefs_res;
     } else if (0 < prefs_min) {
         // If minsize is given, look up minimum bitmap size (default 250 pixels) and calculate resolution from it
-        res = PX_PER_IN * prefs_min / MIN(bbox->width(), bbox->height());
+        res = Inkscape::Util::Quantity::convert(1, "in", "px") * prefs_min / MIN(bbox->width(), bbox->height());
     } else {
         float hint_xdpi = 0, hint_ydpi = 0;
         Glib::ustring hint_filename;
@@ -3412,14 +3412,14 @@ void sp_selection_create_bitmap_copy(SPDesktop *desktop)
                 res = hint_xdpi;
             } else {
                 // if all else fails, take the default 90 dpi
-                res = PX_PER_IN;
+                res = Inkscape::Util::Quantity::convert(1, "in", "px");
             }
         }
     }
 
     // The width and height of the bitmap in pixels
-    unsigned width = (unsigned) floor(bbox->width() * res / PX_PER_IN);
-    unsigned height =(unsigned) floor(bbox->height() * res / PX_PER_IN);
+    unsigned width = (unsigned) floor(bbox->width() * res / Inkscape::Util::Quantity::convert(1, "in", "px"));
+    unsigned height =(unsigned) floor(bbox->height() * res / Inkscape::Util::Quantity::convert(1, "in", "px"));
 
     // Find out if we have to run an external filter
     gchar const *run = NULL;
@@ -3451,7 +3451,7 @@ void sp_selection_create_bitmap_copy(SPDesktop *desktop)
 
     double shift_x = bbox->min()[Geom::X];
     double shift_y = bbox->max()[Geom::Y];
-    if (res == PX_PER_IN) { // for default 90 dpi, snap it to pixel grid
+    if (res == Inkscape::Util::Quantity::convert(1, "in", "px")) { // for default 90 dpi, snap it to pixel grid
         shift_x = round(shift_x);
         shift_y = -round(-shift_y); // this gets correct rounding despite coordinate inversion, remove the negations when the inversion is gone
     }
@@ -3484,7 +3484,7 @@ void sp_selection_create_bitmap_copy(SPDesktop *desktop)
         // Create the repr for the image
         Inkscape::XML::Node * repr = xml_doc->createElement("svg:image");
         sp_embed_image(repr, pb, "image/png");
-        if (res == PX_PER_IN) { // for default 90 dpi, snap it to pixel grid
+        if (res == Inkscape::Util::Quantity::convert(1, "in", "px")) { // for default 90 dpi, snap it to pixel grid
             sp_repr_set_svg_double(repr, "width", width);
             sp_repr_set_svg_double(repr, "height", height);
         } else {
diff --git a/src/sp-text.cpp b/src/sp-text.cpp
index d84bbdc6c..9e0befcca 100644
--- a/src/sp-text.cpp
+++ b/src/sp-text.cpp
@@ -55,7 +55,6 @@
 #include "sp-tspan.h"
 
 #include "text-editing.h"
-#include "unit-constants.h"
 
 /*#####################################################
 #  SPTEXT
diff --git a/src/style.cpp b/src/style.cpp
index 479f30597..f617973ca 100644
--- a/src/style.cpp
+++ b/src/style.cpp
@@ -45,7 +45,7 @@
 #include "svg/css-ostringstream.h"
 #include "xml/repr.h"
 #include "xml/simple-document.h"
-#include "unit-constants.h"
+#include "util/units.h"
 #include "macros.h"
 #include "preferences.h"
 
@@ -2483,11 +2483,11 @@ sp_style_css_size_px_to_units(double size, int unit)
 
         case SP_CSS_UNIT_NONE: unit_size = size; break;
         case SP_CSS_UNIT_PX: unit_size = size; break;
-        case SP_CSS_UNIT_PT: unit_size = size * PT_PER_PX;  break;
-        case SP_CSS_UNIT_PC: unit_size = size * (PT_PER_PX / PT_PER_PC);  break;
-        case SP_CSS_UNIT_MM: unit_size = size * MM_PER_PX;  break;
-        case SP_CSS_UNIT_CM: unit_size = size * CM_PER_PX;  break;
-        case SP_CSS_UNIT_IN: unit_size = size * IN_PER_PX;  break;
+        case SP_CSS_UNIT_PT: unit_size = size * Inkscape::Util::Quantity::convert(1, "px", "pt");  break;
+        case SP_CSS_UNIT_PC: unit_size = size * (Inkscape::Util::Quantity::convert(1, "px", "pt") / Inkscape::Util::Quantity::convert(1, "pc", "pt"));  break;
+        case SP_CSS_UNIT_MM: unit_size = size * Inkscape::Util::Quantity::convert(1, "px", "mm");  break;
+        case SP_CSS_UNIT_CM: unit_size = size * Inkscape::Util::Quantity::convert(1, "px", "cm");  break;
+        case SP_CSS_UNIT_IN: unit_size = size * Inkscape::Util::Quantity::convert(1, "px", "in");  break;
         case SP_CSS_UNIT_EM: unit_size = size / SP_CSS_FONT_SIZE_DEFAULT; break;
         case SP_CSS_UNIT_EX: unit_size = size * 2.0 / SP_CSS_FONT_SIZE_DEFAULT ; break;
         case SP_CSS_UNIT_PERCENT: unit_size = size * 100.0 / SP_CSS_FONT_SIZE_DEFAULT; break;
@@ -3400,19 +3400,19 @@ sp_style_read_ilength(SPILength *val, gchar const *str)
             } else if (!strcmp(e, "pt")) {
                 /* Userspace / DEVICESCALE */
                 val->unit = SP_CSS_UNIT_PT;
-                val->computed = value * PX_PER_PT;
+                val->computed = value * Inkscape::Util::Quantity::convert(1, "pt", "px");
             } else if (!strcmp(e, "pc")) {
                 val->unit = SP_CSS_UNIT_PC;
-                val->computed = value * PX_PER_PC;
+                val->computed = value * Inkscape::Util::Quantity::convert(1, "pc", "px");
             } else if (!strcmp(e, "mm")) {
                 val->unit = SP_CSS_UNIT_MM;
-                val->computed = value * PX_PER_MM;
+                val->computed = value * Inkscape::Util::Quantity::convert(1, "mm", "px");
             } else if (!strcmp(e, "cm")) {
                 val->unit = SP_CSS_UNIT_CM;
-                val->computed = value * PX_PER_CM;
+                val->computed = value * Inkscape::Util::Quantity::convert(1, "cm", "px");
             } else if (!strcmp(e, "in")) {
                 val->unit = SP_CSS_UNIT_IN;
-                val->computed = value * PX_PER_IN;
+                val->computed = value * Inkscape::Util::Quantity::convert(1, "in", "px");
             } else if (!strcmp(e, "em")) {
                 /* EM square */
                 val->unit = SP_CSS_UNIT_EM;
@@ -3971,23 +3971,23 @@ sp_style_write_ilength(gchar *p, gint const len, gchar const *const key,
                     return g_strlcpy(p, os.str().c_str(), len);
                     break;
                 case SP_CSS_UNIT_PT:
-                    os << key << ":" << val->computed * PT_PER_PX << "pt;";
+                    os << key << ":" << val->computed * Inkscape::Util::Quantity::convert(1, "px", "pt") << "pt;";
                     return g_strlcpy(p, os.str().c_str(), len);
                     break;
                 case SP_CSS_UNIT_PC:
-                    os << key << ":" << val->computed * PT_PER_PX / 12.0 << "pc;";
+                    os << key << ":" << val->computed * Inkscape::Util::Quantity::convert(1, "px", "pt") / 12.0 << "pc;";
                     return g_strlcpy(p, os.str().c_str(), len);
                     break;
                 case SP_CSS_UNIT_MM:
-                    os << key << ":" << val->computed * MM_PER_PX << "mm;";
+                    os << key << ":" << val->computed * Inkscape::Util::Quantity::convert(1, "px", "mm") << "mm;";
                     return g_strlcpy(p, os.str().c_str(), len);
                     break;
                 case SP_CSS_UNIT_CM:
-                    os << key << ":" << val->computed * CM_PER_PX << "cm;";
+                    os << key << ":" << val->computed * Inkscape::Util::Quantity::convert(1, "px", "cm") << "cm;";
                     return g_strlcpy(p, os.str().c_str(), len);
                     break;
                 case SP_CSS_UNIT_IN:
-                    os << key << ":" << val->computed * IN_PER_PX << "in;";
+                    os << key << ":" << val->computed * Inkscape::Util::Quantity::convert(1, "px", "in") << "in;";
                     return g_strlcpy(p, os.str().c_str(), len);
                     break;
                 case SP_CSS_UNIT_EM:
diff --git a/src/svg/svg-length.cpp b/src/svg/svg-length.cpp
index d2f4332d8..7f93f9f0f 100644
--- a/src/svg/svg-length.cpp
+++ b/src/svg/svg-length.cpp
@@ -23,7 +23,7 @@
 
 #include "svg.h"
 #include "stringstream.h"
-#include "../unit-constants.h"
+#include "util/units.h"
 
 
 static unsigned sp_svg_length_read_lff(gchar const *str, SVGLength::Unit *unit, float *val, float *computed, char **next);
@@ -365,7 +365,7 @@ static unsigned sp_svg_length_read_lff(gchar const *str, SVGLength::Unit *unit,
                     *unit = SVGLength::PT;
                 }
                 if (computed) {
-                    *computed = v * PX_PER_PT;
+                    *computed = v * Inkscape::Util::Quantity::convert(1, "pt", "px");
                 }
                 break;
             case UVAL('p','c'):
@@ -373,7 +373,7 @@ static unsigned sp_svg_length_read_lff(gchar const *str, SVGLength::Unit *unit,
                     *unit = SVGLength::PC;
                 }
                 if (computed) {
-                    *computed = v * PX_PER_PC;
+                    *computed = v * Inkscape::Util::Quantity::convert(1, "pc", "px");
                 }
                 break;
             case UVAL('m','m'):
@@ -381,7 +381,7 @@ static unsigned sp_svg_length_read_lff(gchar const *str, SVGLength::Unit *unit,
                     *unit = SVGLength::MM;
                 }
                 if (computed) {
-                    *computed = v * PX_PER_MM;
+                    *computed = v * Inkscape::Util::Quantity::convert(1, "mm", "px");
                 }
                 break;
             case UVAL('c','m'):
@@ -389,7 +389,7 @@ static unsigned sp_svg_length_read_lff(gchar const *str, SVGLength::Unit *unit,
                     *unit = SVGLength::CM;
                 }
                 if (computed) {
-                    *computed = v * PX_PER_CM;
+                    *computed = v * Inkscape::Util::Quantity::convert(1, "cm", "px");
                 }
                 break;
             case UVAL('i','n'):
@@ -397,7 +397,7 @@ static unsigned sp_svg_length_read_lff(gchar const *str, SVGLength::Unit *unit,
                     *unit = SVGLength::INCH;
                 }
                 if (computed) {
-                    *computed = v * PX_PER_IN;
+                    *computed = v * Inkscape::Util::Quantity::convert(1, "in", "px");
                 }
                 break;
             case UVAL('f','t'):
@@ -405,7 +405,7 @@ static unsigned sp_svg_length_read_lff(gchar const *str, SVGLength::Unit *unit,
                     *unit = SVGLength::FOOT;
                 }
                 if (computed) {
-                    *computed = v * PX_PER_FT;
+                    *computed = v * Inkscape::Util::Quantity::convert(1, "ft", "px");
                 }
                 break;
             case UVAL('e','m'):
diff --git a/src/text-editing.cpp b/src/text-editing.cpp
index 401f56bb2..0d30863d9 100644
--- a/src/text-editing.cpp
+++ b/src/text-editing.cpp
@@ -24,7 +24,7 @@
 #include "inkscape.h"
 #include "message-stack.h"
 #include "style.h"
-#include "unit-constants.h"
+#include "util/units.h"
 
 #include "document.h"
 #include "xml/repr.h"
@@ -1278,23 +1278,23 @@ sp_te_adjust_linespacing_screen (SPItem *text, Inkscape::Text::Layout::iterator
             style->line_height.value = style->line_height.computed;
             break;
         case SP_CSS_UNIT_PT:
-            style->line_height.computed += zby * PT_PER_PX;
+            style->line_height.computed += zby * Inkscape::Util::Quantity::convert(1, "px", "pt");
             style->line_height.value = style->line_height.computed;
             break;
         case SP_CSS_UNIT_PC:
-            style->line_height.computed += zby * (PT_PER_PX / 12);
+            style->line_height.computed += zby * (Inkscape::Util::Quantity::convert(1, "px", "pt") / 12);
             style->line_height.value = style->line_height.computed;
             break;
         case SP_CSS_UNIT_MM:
-            style->line_height.computed += zby * MM_PER_PX;
+            style->line_height.computed += zby * Inkscape::Util::Quantity::convert(1, "px", "mm");
             style->line_height.value = style->line_height.computed;
             break;
         case SP_CSS_UNIT_CM:
-            style->line_height.computed += zby * CM_PER_PX;
+            style->line_height.computed += zby * Inkscape::Util::Quantity::convert(1, "px", "cm");
             style->line_height.value = style->line_height.computed;
             break;
         case SP_CSS_UNIT_IN:
-            style->line_height.computed += zby * IN_PER_PX;
+            style->line_height.computed += zby * Inkscape::Util::Quantity::convert(1, "px", "in");
             style->line_height.value = style->line_height.computed;
             break;
     }
diff --git a/src/ui/clipboard.cpp b/src/ui/clipboard.cpp
index 72ddd90a9..629960613 100644
--- a/src/ui/clipboard.cpp
+++ b/src/ui/clipboard.cpp
@@ -79,7 +79,7 @@
 #include "text-editing.h"
 #include "tools-switch.h"
 #include "path-chemistry.h"
-#include "unit-constants.h"
+#include "util/units.h"
 #include "helper/png-write.h"
 #include "svg/svg-color.h"
 #include "sp-namedview.h"
@@ -1078,14 +1078,14 @@ void ClipboardManagerImpl::_onGet(Gtk::SelectionData &sel, guint /*info*/)
     try {
         if (out == outlist.end() && target == "image/png")
         {
-            gdouble dpi = PX_PER_IN;
+            gdouble dpi = Inkscape::Util::Quantity::convert(1, "in", "px");
             guint32 bgcolor = 0x00000000;
 
             Geom::Point origin (_clipboardSPDoc->getRoot()->x.computed, _clipboardSPDoc->getRoot()->y.computed);
             Geom::Rect area = Geom::Rect(origin, origin + _clipboardSPDoc->getDimensions());
 
-            unsigned long int width = (unsigned long int) (area.width() * dpi / PX_PER_IN + 0.5);
-            unsigned long int height = (unsigned long int) (area.height() * dpi / PX_PER_IN + 0.5);
+            unsigned long int width = (unsigned long int) (area.width() * dpi / Inkscape::Util::Quantity::convert(1, "in", "px") + 0.5);
+            unsigned long int height = (unsigned long int) (area.height() * dpi / Inkscape::Util::Quantity::convert(1, "in", "px") + 0.5);
 
             // read from namedview
             Inkscape::XML::Node *nv = sp_repr_lookup_name (_clipboardSPDoc->rroot, "sodipodi:namedview");
diff --git a/src/ui/dialog/export.cpp b/src/ui/dialog/export.cpp
index 5cb9357c3..063902aa7 100644
--- a/src/ui/dialog/export.cpp
+++ b/src/ui/dialog/export.cpp
@@ -50,7 +50,6 @@
 
 #include "ui/widget/unit-menu.h"
 #include "util/units.h"
-#include "unit-constants.h"
 #include "helper/window.h"
 #include "inkscape-private.h"
 #include "document.h"
@@ -98,7 +97,7 @@
 
 #define SP_EXPORT_MIN_SIZE 1.0
 
-#define DPI_BASE PX_PER_IN
+#define DPI_BASE Inkscape::Util::Quantity::convert(1, "in", "px")
 
 #define EXPORT_COORD_PRECISION 3
 
@@ -1048,8 +1047,8 @@ void Export::onExport ()
 
             Geom::OptRect area = item->desktopVisualBounds();
             if (area) {
-                gint width = (gint) (area->width() * dpi / PX_PER_IN + 0.5);
-                gint height = (gint) (area->height() * dpi / PX_PER_IN + 0.5);
+                gint width = (gint) (area->width() * dpi / DPI_BASE + 0.5);
+                gint height = (gint) (area->height() * dpi / DPI_BASE + 0.5);
 
                 if (width > 1 && height > 1) {
                     // Do export
diff --git a/src/ui/dialog/inkscape-preferences.cpp b/src/ui/dialog/inkscape-preferences.cpp
index bc648002d..7890b0b4c 100644
--- a/src/ui/dialog/inkscape-preferences.cpp
+++ b/src/ui/dialog/inkscape-preferences.cpp
@@ -28,7 +28,7 @@
 #include "preferences.h"
 #include "verbs.h"
 #include "selcue.h"
-#include "unit-constants.h"
+#include "util/units.h"
 #include <iostream>
 #include "enums.h"
 #include "desktop-handles.h"
@@ -1428,10 +1428,10 @@ void InkscapePreferences::initPageBitmaps()
                            _("Automatically reload linked images when file is changed on disk"));
     _misc_bitmap_editor.init("/options/bitmapeditor/value", true);
     _page_bitmaps.add_line( false, _("_Bitmap editor:"), _misc_bitmap_editor, "", "", true);
-    _importexport_export_res.init("/dialogs/export/defaultxdpi/value", 0.0, 6000.0, 1.0, 1.0, PX_PER_IN, true, false);
+    _importexport_export_res.init("/dialogs/export/defaultxdpi/value", 0.0, 6000.0, 1.0, 1.0, Inkscape::Util::Quantity::convert(1, "in", "px"), true, false);
     _page_bitmaps.add_line( false, _("Default export _resolution:"), _importexport_export_res, _("dpi"),
                             _("Default bitmap resolution (in dots per inch) in the Export dialog"), false);
-    _bitmap_copy_res.init("/options/createbitmap/resolution", 1.0, 6000.0, 1.0, 1.0, PX_PER_IN, true, false);
+    _bitmap_copy_res.init("/options/createbitmap/resolution", 1.0, 6000.0, 1.0, 1.0, Inkscape::Util::Quantity::convert(1, "in", "px"), true, false);
     _page_bitmaps.add_line( false, _("Resolution for Create Bitmap _Copy:"), _bitmap_copy_res, _("dpi"),
                             _("Resolution used by the Create Bitmap Copy command"), false);
     {
@@ -1443,7 +1443,7 @@ void InkscapePreferences::initPageBitmaps()
         _bitmap_import_quality.init("/dialogs/import/quality", 1, 100, 1, 1, 100, true, false);
         _page_bitmaps.add_line( false, _("Bitmap import quality:"), _bitmap_import_quality, "%", "Bitmap import quality (jpeg only). 100 is best quality", false);
     }
-    _importexport_import_res.init("/dialogs/import/defaultxdpi/value", 0.0, 6000.0, 1.0, 1.0, PX_PER_IN, true, false);
+    _importexport_import_res.init("/dialogs/import/defaultxdpi/value", 0.0, 6000.0, 1.0, 1.0, Inkscape::Util::Quantity::convert(1, "in", "px"), true, false);
     _page_bitmaps.add_line( false, _("Default _import resolution:"), _importexport_import_res, _("dpi"),
                             _("Default bitmap resolution (in dots per inch) for bitmap import"), false);
     _importexport_import_res_override.init(_("Override file resolution"), "/dialogs/import/forcexdpi", false);
diff --git a/src/ui/dialog/print.cpp b/src/ui/dialog/print.cpp
index 2ab8cf121..4c8c77f96 100644
--- a/src/ui/dialog/print.cpp
+++ b/src/ui/dialog/print.cpp
@@ -26,7 +26,7 @@
 #include "ui/widget/rendering-options.h"
 #include "document.h"
 
-#include "unit-constants.h"
+#include "util/units.h"
 #include "helper/png-write.h"
 #include "svg/svg-color.h"
 #include "io/sys.h"
@@ -72,8 +72,8 @@ static void draw_page(
 
             sp_export_png_file(junk->_doc, tmp_png.c_str(), 0.0, 0.0,
                 width, height,
-                (unsigned long)(width * dpi / PX_PER_IN),
-                (unsigned long)(height * dpi / PX_PER_IN),
+                (unsigned long)(width * dpi / Inkscape::Util::Quantity::convert(1, "in", "px")),
+                (unsigned long)(height * dpi / Inkscape::Util::Quantity::convert(1, "in", "px")),
                 dpi, dpi, bgcolor, NULL, NULL, true, NULL);
 
             // This doesn't seem to work:
@@ -90,7 +90,7 @@ static void draw_page(
                 cairo_t *cr = gtk_print_context_get_cairo_context (context);
                 cairo_matrix_t m;
                 cairo_get_matrix(cr, &m);
-                cairo_scale(cr, PT_PER_IN / dpi, PT_PER_IN / dpi);
+                cairo_scale(cr, Inkscape::Util::Quantity::convert(1, "in", "pt") / dpi, Inkscape::Util::Quantity::convert(1, "in", "pt") / dpi);
                 // FIXME: why is the origin offset??
                 cairo_set_source_surface(cr, png->cobj(), -16.0, -16.0);
                 cairo_paint(cr);
@@ -195,8 +195,8 @@ Print::Print(SPDocument *doc, SPItem *base) :
     // set up paper size to match the document size
     gtk_print_operation_set_unit (_printop, GTK_UNIT_POINTS);
     GtkPageSetup *page_setup = gtk_page_setup_new();
-    gdouble doc_width = _doc->getWidth() * PT_PER_PX;
-    gdouble doc_height = _doc->getHeight() * PT_PER_PX;
+    gdouble doc_width = _doc->getWidth() * Inkscape::Util::Quantity::convert(1, "px", "pt");
+    gdouble doc_height = _doc->getHeight() * Inkscape::Util::Quantity::convert(1, "px", "pt");
     GtkPaperSize *paper_size;
     if (doc_width > doc_height) {
         gtk_page_setup_set_orientation (page_setup, GTK_PAGE_ORIENTATION_LANDSCAPE);
diff --git a/src/ui/dialog/text-edit.cpp b/src/ui/dialog/text-edit.cpp
index a662495a0..4a25f723b 100644
--- a/src/ui/dialog/text-edit.cpp
+++ b/src/ui/dialog/text-edit.cpp
@@ -58,7 +58,7 @@ extern "C" {
 #include "widgets/font-selector.h"
 #include <glibmm/i18n.h>
 #include <glibmm/markup.h>
-#include "unit-constants.h"
+#include "util/units.h"
 #include "sp-textpath.h"
 
 namespace Inkscape {
@@ -401,7 +401,7 @@ void TextEdit::setPreviewText (Glib::ustring font_spec, Glib::ustring phrase)
 
     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
     int unit = prefs->getInt("/options/font/unitType", SP_CSS_UNIT_PT);
-    double pt_size = sp_style_css_size_units_to_px(sp_font_selector_get_size(fsel), unit) * PT_PER_PX;
+    double pt_size = sp_style_css_size_units_to_px(sp_font_selector_get_size(fsel), unit) * Inkscape::Util::Quantity::convert(1, "px", "pt");
 
     // Pango font size is in 1024ths of a point
     // C++11: Glib::ustring size = std::to_string( pt_size * PANGO_SCALE );
diff --git a/src/ui/widget/rendering-options.cpp b/src/ui/widget/rendering-options.cpp
index f26e71553..d6248df69 100644
--- a/src/ui/widget/rendering-options.cpp
+++ b/src/ui/widget/rendering-options.cpp
@@ -13,7 +13,7 @@
 #endif
 
 #include "rendering-options.h"
-#include "unit-constants.h"
+#include "util/units.h"
 #include <glibmm/i18n.h>
 
 namespace Inkscape {
@@ -59,8 +59,8 @@ RenderingOptions::RenderingOptions () :
     _radio_bitmap.signal_toggled().connect(sigc::mem_fun(*this, &RenderingOptions::_toggled));
 
     // configure default DPI
-    _dpi.setRange(PT_PER_IN,2400.0);
-    _dpi.setValue(PT_PER_IN);
+    _dpi.setRange(Inkscape::Util::Quantity::convert(1, "in", "pt"),2400.0);
+    _dpi.setValue(Inkscape::Util::Quantity::convert(1, "in", "pt"));
     _dpi.setIncrements(1.0,10.0);
     _dpi.setDigits(0);
     _dpi.update();
diff --git a/src/unit-constants.h b/src/unit-constants.h
deleted file mode 100644
index c56c0a6e8..000000000
--- a/src/unit-constants.h
+++ /dev/null
@@ -1,47 +0,0 @@
-#ifndef INKSCAPE_UNIT_CONSTANTS_H
-#define INKSCAPE_UNIT_CONSTANTS_H
-
-// 72 points per inch divided by the SVG-recommended value of 90 pixels per inch for computer screen
-// For now it is constant throughout Inkscape, later we may make it changeable.
-// Ideally this should be the only place to change it, but this is not guaranteed (be careful!)
-#define DEVICESCALE 0.8    
-
-#define PT_PER_IN 72.0
-#define PT_PER_PX DEVICESCALE
-#define PT_PER_PC 12.0
-#define PX_PER_PT (1/DEVICESCALE)
-#define PX_PER_PC (PX_PER_PT * PT_PER_PC)
-#define PX_PER_IN (PT_PER_IN / PT_PER_PX)
-#define PC_PER_IN (PT_PER_IN / PT_PER_PC)
-#define M_PER_IN 0.0254
-#define M_PER_PX (M_PER_IN / PX_PER_IN)
-#define CM_PER_IN 2.54
-#define MM_PER_IN 25.4
-#define MM_PER_MM 1.0
-#define MM_PER_CM 10.0
-#define MM_PER_M 1000.0
-#define IN_PER_PT (1 / PT_PER_IN)
-#define IN_PER_PX (1 / PX_PER_IN)
-#define IN_PER_CM (1 / CM_PER_IN)
-#define IN_PER_MM (1 / MM_PER_IN)
-#define IN_PER_FT 12.0
-#define FT_PER_IN (1 / IN_PER_FT)
-#define PT_PER_CM (PT_PER_IN / CM_PER_IN)
-#define PX_PER_CM (PX_PER_IN / CM_PER_IN)
-#define M_PER_PT (M_PER_IN / PT_PER_IN)
-#define PT_PER_M (PT_PER_IN / M_PER_IN)
-#define PX_PER_M (PX_PER_IN / M_PER_IN)
-#define CM_PER_PT (CM_PER_IN / PT_PER_IN)
-#define CM_PER_PX (CM_PER_IN / PX_PER_IN)
-#define MM_PER_PT (MM_PER_IN / PT_PER_IN)
-#define PT_PER_MM (PT_PER_IN / MM_PER_IN)
-#define PX_PER_MM (PX_PER_IN / MM_PER_IN)
-#define MM_PER_PX (MM_PER_IN / PX_PER_IN)
-#define PX_PER_FT (PX_PER_IN / FT_PER_IN)
-#define PT_PER_PT 1.0
-#define PC_PER_PC 1.0
-#define IN_PER_IN 1.0
-#define PX_PER_PX 1.0
-#define FT_PER_FT 1.0
-
-#endif /* !INKSCAPE_UNIT_CONSTANTS_H */
diff --git a/src/widgets/font-selector.cpp b/src/widgets/font-selector.cpp
index 7fa848f1e..5f9098d44 100644
--- a/src/widgets/font-selector.cpp
+++ b/src/widgets/font-selector.cpp
@@ -33,7 +33,6 @@
 #include "desktop.h"
 #include "widgets/font-selector.h"
 #include "preferences.h"
-#include "unit-constants.h"
 
 /* SPFontSelector */