[ft-paint] Implement FT_COLR_PAINTFORMAT_ROTATE

src/hb-ft-colr.hh

@@ -188,7 +188,25 @@ _hb_ft_paint (FT_OpaquePaint opaque_paint,
       paint_funcs->pop_transform (paint_data);
     }
     break;
-    case FT_COLR_PAINTFORMAT_ROTATE: break;
+    case FT_COLR_PAINTFORMAT_ROTATE:
+    {
+      float a = paint.u.rotate.angle / 65536.f;
+      float cc = cosf (a * (float) M_PI);
+      float ss = sinf (a * (float) M_PI);
+      paint_funcs->push_transform (paint_data,
+				   1.f, 0.f, 0.f, 1.f,
+				   -paint.u.rotate.center_x / 65536.f,
+				   -paint.u.rotate.center_y / 65536.f);
+      paint_funcs->push_transform (paint_data, cc, ss, -ss, cc, 0., 0.);
+      paint_funcs->push_transform (paint_data,
+				   1.f, 0.f, 0.f, 1.f,
+				   +paint.u.rotate.center_x / 65536.f,
+				   +paint.u.rotate.center_y / 65536.f);
+      paint_recurse (paint.u.rotate.paint);
+      paint_funcs->pop_transform (paint_data);
+      paint_funcs->pop_transform (paint_data);
+      paint_funcs->pop_transform (paint_data);
+    }
     case FT_COLR_PAINTFORMAT_SKEW: break;
     case FT_COLR_PAINTFORMAT_COMPOSITE:
     {