[paint] Add internal push_rotate/pop_rotate API

src/hb-ft-colr.hh

@@ -361,14 +361,12 @@ _hb_ft_paint (hb_ft_paint_context_t *c,
       float dx = paint.u.rotate.center_x / 65536.f;
       float dy = paint.u.rotate.center_y / 65536.f;
       float a = paint.u.rotate.angle / 65536.f;
-      float cc = cosf (a * (float) M_PI);
-      float ss = sinf (a * (float) M_PI);
       c->funcs->push_translate (c->data, +dx, +dy);
-      c->funcs->push_transform (c->data, cc, ss, -ss, cc, 0., 0.);
+      c->funcs->push_rotate (c->data, a);
       c->funcs->push_translate (c->data, -dx, -dy);
       c->recurse (paint.u.rotate.paint);
       c->funcs->pop_translate (c->data, -dx, -dy);
-      c->funcs->pop_transform (c->data);
+      c->funcs->pop_rotate (c->data, a);
       c->funcs->pop_translate (c->data, +dx, +dy);
     }
     break;

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

@@ -1078,11 +1078,9 @@ struct PaintRotate
   void paint_glyph (hb_paint_context_t *c, uint32_t varIdxBase) const
   {
     float a = angle.to_float (c->instancer (varIdxBase, 0));
-    float cc = cosf (a * (float) M_PI);
-    float ss = sinf (a * (float) M_PI);
-    c->funcs->push_transform (c->data, cc, ss, -ss, cc, 0., 0.);
+    c->funcs->push_rotate (c->data, a);
     c->recurse (this+src);
-    c->funcs->pop_transform (c->data);
+    c->funcs->pop_rotate (c->data, a);
   }
 
   HBUINT8		format; /* format = 24 (noVar) or 25(Var) */
@@ -1114,16 +1112,14 @@ struct PaintRotateAroundCenter
   void paint_glyph (hb_paint_context_t *c, uint32_t varIdxBase) const
   {
     float a = angle.to_float (c->instancer (varIdxBase, 0));
-    float cc = cosf (a * (float) M_PI);
-    float ss = sinf (a * (float) M_PI);
     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, cc, ss, -ss, cc, 0., 0.);
+    c->funcs->push_rotate (c->data, a);
     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_rotate (c->data, a);
     c->funcs->pop_translate (c->data, +tCenterX, +tCenterY);
   }
 

src/hb-paint.hh

@@ -201,6 +201,23 @@ struct hb_paint_funcs_t
     if (sx != 1.f || sy != 1.f)
       pop_transform (paint_data);
   }
+
+  void push_rotate (void *paint_data,
+                    float a)
+  {
+    if (a)
+    {
+      float cc = cosf (a * (float) M_PI);
+      float ss = sinf (a * (float) M_PI);
+      push_transform (paint_data, cc, ss, -ss, cc, 0.f, 0.f);
+    }
+  }
+  void pop_rotate (void *paint_data,
+                    float a)
+  {
+    if (a)
+      pop_transform (paint_data);
+  }
 };
 DECLARE_NULL_INSTANCE (hb_paint_funcs_t);