Fix for #955141: Converting clipped object to pattern produces rasterised pattern.

(bzr r11914)

2 files changed, 29 insertions, 2 deletions

diff --git a/src/display/drawing-context.h b/src/display/drawing-context.h
index fb6662202..b8c4667c2 100644
--- a/src/display/drawing-context.h
+++ b/src/display/drawing-context.h
@@ -101,6 +101,8 @@ public:
     cairo_t *raw() { return _ct; }
     cairo_surface_t *rawTarget() { return cairo_get_group_target(_ct); }
 
+    DrawingSurface *surface() { return _surface; } // Needed to find scale in drawing-item.cpp
+
 private:
     DrawingContext(cairo_t *ct, DrawingSurface *surface, bool destroy);
 
diff --git a/src/display/drawing-item.cpp b/src/display/drawing-item.cpp
index 0fb1f0018..b443ad22a 100644
--- a/src/display/drawing-item.cpp
+++ b/src/display/drawing-item.cpp
@@ -20,6 +20,7 @@
 #include "nr-filter.h"
 #include "preferences.h"
 #include "style.h"
+#include "2geom/rect.h"
 
 namespace Inkscape {
 
@@ -540,8 +541,17 @@ DrawingItem::render(DrawingContext &ct, Geom::IntRect const &area, unsigned flag
         iarea.intersectWith(_drawbox);
     }
 
-    DrawingSurface intermediate(*iarea);
+    // Must use same scale factor between "logical space" (coordinates in the
+    // rendering) and "physical space" (surface pixels). See drawing-surface.cpp.
+    // See bug 955141.
+    // There must be a better lib2geom way of finding sarea.
+    DrawingSurface* ds = ct.surface();
+    Geom::Scale scale = ds->scale();
+    Geom::Rect rarea( *iarea );
+    Geom::Point sarea( rarea.dimensions() * scale );
+    DrawingSurface intermediate( *iarea, sarea.ceil() );
     DrawingContext ict(intermediate);
+
     unsigned render_result = RENDER_OK;
 
     // 1. Render clipping path with alpha = opacity.
@@ -614,9 +624,24 @@ DrawingItem::render(DrawingContext &ct, Geom::IntRect const &area, unsigned flag
         cachect.fill();
         _cache->markClean(*carea);
     }
-    ct.rectangle(*carea);
+
+    ct.rectangle(*carea); // Area to be filled
+
+    // Account for difference between logical and physical spaces.
+    ct.scale( intermediate.scale().inverse() );
+
+    // Must shift origin to compensate for scaling.
+    Geom::Point factor( Geom::Point(1,1) - intermediate.scale().vector() );
+    Geom::Point origin( intermediate.origin() );
+    Geom::Point shift( origin[Geom::X] * factor[Geom::X], origin[Geom::Y] * factor[Geom::Y] ); 
+    ct.translate( -shift );
+
     ct.setSource(&intermediate);
     ct.fill();
+
+    ct.translate(  shift );
+    ct.scale( intermediate.scale() );
+
     ct.setSource(0,0,0,0);
     // the call above is to clear a ref on the intermediate surface held by ct