Mozart: Implement basic input event dispatch with hit testing.

mojo/services/geometry/cpp/geometry_util.cc

Index: mojo/services/geometry/cpp/geometry_util.cc
diff --git a/mojo/services/geometry/cpp/geometry_util.cc b/mojo/services/geometry/cpp/geometry_util.cc
index 570f707a2462db19f7e2cbfeb79c8308e8b5c573..f81e0ea2c2acec5437d04522c32a873bd42008cd 100644
--- a/mojo/services/geometry/cpp/geometry_util.cc
+++ b/mojo/services/geometry/cpp/geometry_util.cc
@@ -26,4 +26,22 @@ void SetTranslationTransform(Transform* transform, float x, float y, float z) {
   transform->matrix[11] = z;
 }
 
+Point TransformPoint(const Transform& transform, const Point& point) {
+  // TODO(jeffbrown): If w is 0, then the point should be at infinity.
+  // Also, we should perhaps be using PointF here rather than Point.
+  float w = transform.matrix[12] * point.x + transform.matrix[13] * point.y +
+            transform.matrix[15];
+  if (!w)
+    w = 1.f / w;
+
+  Point result;
+  result.x = (transform.matrix[0] * point.x + transform.matrix[1] * point.y +
+              transform.matrix[3]) *
+             w;
+  result.y = (transform.matrix[4] * point.x + transform.matrix[5] * point.y +
+              transform.matrix[7]) *
+             w;
+  return result;
+}
+
 }  // namespace mojo