[paint] Add internal push_scale/pop_scale API

src/hb-ft-colr.hh

@@ -345,16 +345,14 @@ _hb_ft_paint (hb_ft_paint_context_t *c,
     {
       float dx = paint.u.scale.center_x / 65536.f;
       float dy = paint.u.scale.center_y / 65536.f;
+      float sx = paint.u.scale.scale_x / 65536.f;
+      float sy = paint.u.scale.scale_y / 65536.f;
       c->funcs->push_translate (c->data, +dx, +dy);
-      c->funcs->push_transform (c->data,
+      c->funcs->push_scale (c->data, sx, sy);
-				paint.u.scale.scale_x / 65536.f,
-				0.f, 0.f,
-				paint.u.scale.scale_y / 65536.f,
-				0.f, 0.f);
       c->funcs->push_translate (c->data, -dx, -dy);
       c->recurse (paint.u.scale.paint);
       c->funcs->pop_translate (c->data, -dx, -dy);
-      c->funcs->pop_transform (c->data);
+      c->funcs->pop_scale (c->data, sx, sy);
       c->funcs->pop_translate (c->data, +dx, +dy);
     }
     break;

src/hb-ot-color-colr-table.hh

@@ -921,13 +921,11 @@ struct PaintScale
 
   void paint_glyph (hb_paint_context_t *c, uint32_t varIdxBase) const
   {
-    c->funcs->push_transform (c->data,
+    float sx = scaleX.to_float (c->instancer (varIdxBase, 0));
-			      scaleX.to_float (c->instancer (varIdxBase, 0)),
+    float sy = scaleY.to_float (c->instancer (varIdxBase, 1));
-			      0., 0.,
+    c->funcs->push_scale (c->data, sx, sy);
-			      scaleY.to_float (c->instancer (varIdxBase, 1)),
-			      0., 0.);
     c->recurse (this+src);
-    c->funcs->pop_transform (c->data);
+    c->funcs->pop_scale (c->data, sx, sy);
   }
 
   HBUINT8		format; /* format = 16 (noVar) or 17(Var) */
@@ -959,18 +957,16 @@ struct PaintScaleAroundCenter
 
   void paint_glyph (hb_paint_context_t *c, uint32_t varIdxBase) const
   {
+    float sx = scaleX.to_float (c->instancer (varIdxBase, 0));
+    float sy = scaleY.to_float (c->instancer (varIdxBase, 1));
     float tCenterX = centerX + c->instancer (varIdxBase, 2);
     float tCenterY = centerY + c->instancer (varIdxBase, 3);
     c->funcs->push_translate (c->data, +tCenterX, +tCenterY);
-    c->funcs->push_transform (c->data,
+    c->funcs->push_scale (c->data, sx, sy);
-			      scaleX.to_float (c->instancer (varIdxBase, 0)),
-			      0., 0.,
-			      scaleY.to_float (c->instancer (varIdxBase, 1)),
-			      0., 0.);
     c->funcs->push_translate (c->data, -tCenterX, -tCenterY);
     c->recurse (this+src);
     c->funcs->pop_translate (c->data, -tCenterX, -tCenterY);
-    c->funcs->pop_transform (c->data);
+    c->funcs->pop_scale (c->data, sx, sy);
     c->funcs->pop_translate (c->data, +tCenterX, +tCenterY);
   }
 
@@ -1006,9 +1002,9 @@ struct PaintScaleUniform
   void paint_glyph (hb_paint_context_t *c, uint32_t varIdxBase) const
   {
     float s = scale + c->instancer (varIdxBase, 0);
-    c->funcs->push_transform (c->data, s, 0., 0., s, 0., 0.);
+    c->funcs->push_scale (c->data, s, s);
     c->recurse (this+src);
-    c->funcs->pop_transform (c->data);
+    c->funcs->pop_scale (c->data, s, s);
   }
 
   HBUINT8		format; /* format = 20 (noVar) or 21(Var) */
@@ -1043,11 +1039,11 @@ struct PaintScaleUniformAroundCenter
     float tCenterX = centerX + c->instancer (varIdxBase, 1);
     float tCenterY = centerY + c->instancer (varIdxBase, 2);
     c->funcs->push_translate (c->data, +tCenterX, +tCenterY);
-    c->funcs->push_transform (c->data, s, 0., 0., s, 0., 0.);
+    c->funcs->push_scale (c->data, s, s);
     c->funcs->push_translate (c->data, -tCenterX, -tCenterY);
     c->recurse (this+src);
     c->funcs->push_translate (c->data, -tCenterX, -tCenterY);
-    c->funcs->pop_transform (c->data);
+    c->funcs->pop_scale (c->data, s, s);
     c->funcs->push_translate (c->data, +tCenterX, +tCenterY);
   }
 

src/hb-paint.hh

@@ -187,6 +187,20 @@ struct hb_paint_funcs_t
     if (dx || dy)
       pop_transform (paint_data);
   }
+
+  void push_scale (void *paint_data,
+                   float sx, float sy)
+  {
+    if (sx != 1.f || sy != 1.f)
+      push_transform (paint_data,
+		      sx, 0.f, 0.f, sy, 0.f, 0.f);
+  }
+  void pop_scale (void *paint_data,
+                  float sx, float sy)
+  {
+    if (sx != 1.f || sy != 1.f)
+      pop_transform (paint_data);
+  }
 };
 DECLARE_NULL_INSTANCE (hb_paint_funcs_t);