Flesh out the Painting API a bit.

sky/engine/core/painting/Canvas.h

Index: sky/engine/core/painting/Canvas.h
diff --git a/sky/engine/core/painting/Canvas.h b/sky/engine/core/painting/Canvas.h
index 8cb0b21ba530138306c792e5f647e223f0ca4e04..f3594cb9839f9c1f492ca7dd6d49b182a254db8a 100644
--- a/sky/engine/core/painting/Canvas.h
+++ b/sky/engine/core/painting/Canvas.h
@@ -22,10 +22,25 @@ public:
 
     // Width/Height define a culling rect which Skia may use for optimizing
     // out draw calls issued outside the rect.
-    double width() const { return m_size.width(); }
-    double height() const { return m_size.height(); }
+    float width() const { return m_size.width(); }

[reed1, 2015/05/13 20:38:58]

Do we really need to expose width/height to the clients?

Another way to allow "smart" clients to cull themselves is to pass a rect (which
they could ignore) to their paint method:

void Node::paint(Canvas*, const Rect* dirtyArea) { ... }

[Matt Perry, 2015/05/13 21:02:04]

I'm not sure - I think Ian is changing the way we're going to initiate a paint,
so I'll hold off on changing this for now.

+    float height() const { return m_size.height(); }
 
-    void drawCircle(double x, double y, double radius, Paint* paint);
+    void save();
+    void saveLayer(Vector<float> bounds, Paint* paint);
+    void restore();
+
+    void translate(float dx, float dy);
+    void scale(float sx, float sy);
+    void rotate(float degrees);
+    void skew(float sx, float sy);
+    void concat(Vector<float> matrix);
+
+    void clipRect(Vector<float> rect);
+
+    void drawPaint(Paint* paint);
+    void drawRect(Vector<float> rect, Paint* paint);

[reed1, 2015/05/13 20:38:57]

const Paint& ?

[Matt Perry, 2015/05/13 21:02:04]

I'm at the mercy of the IDL compiler as to how this interface looks. We could
change the compiler, but for now I'll leave it as a pointer (though I added
const).

+    void drawOval(Vector<float> rect, Paint* paint);
+    void drawCircle(float x, float y, float radius, Paint* paint);
 
 protected:
     PassRefPtr<DisplayList> finishRecording();