Merge pull request #2220 from abarth/add_canvas_transform

Introduce Canvas.transform

sky/engine/core/dart/painting.dart

@@ -217,7 +217,21 @@ class Canvas extends NativeFieldWrapperClass2 {
   void rotate(double radians) native "Canvas_rotate";
   void skew(double sx, double sy) native "Canvas_skew";
   void concat(Float64List matrix4) native "Canvas_concat";
-  void setMatrix(Float64List matrix4) native "Canvas_setMatrix";
+
+  void _transform(Float64List matrix4) native "Canvas_transform";
+  void transform(Float64List matrix4) {
+    if (matrix4.length != 16)
+      throw new ArgumentError("[matrix4] must have 16 entries.");
+    _transform(matrix4);
+  }
+
+  void _setMatrix(Float64List matrix4) native "Canvas_setMatrix";
+  void setMatrix(Float64List matrix4) {
+    if (matrix4.length != 16)
+      throw new ArgumentError("[matrix4] must have 16 entries.");
+    _setMatrix(matrix4);
+  }
+
   Float64List getTotalMatrix() native "Canvas_getTotalMatrix";
   void clipRect(Rect rect) native "Canvas_clipRect";
   void clipRRect(RRect rrect) native "Canvas_clipRRect";

sky/engine/core/painting/Canvas.cpp

@@ -33,17 +33,6 @@ static void Canvas_concat(Dart_NativeArguments args) {
     Dart_ThrowException(es.GetDartException(args, true));
 }
 
-static void Canvas_setMatrix(Dart_NativeArguments args) {
-  DartArgIterator it(args);
-  Float64List matrix4 = it.GetNext<Float64List>();
-  if (it.had_exception())
-    return;
-  ExceptionState es;
-  GetReceiver<Canvas>(args)->setMatrix(matrix4, es);
-  if (es.had_exception())
-    Dart_ThrowException(es.GetDartException(args, true));
-}
-
 IMPLEMENT_WRAPPERTYPEINFO(Canvas);
 
 #define FOR_EACH_BINDING(V) \
@@ -55,6 +44,8 @@ IMPLEMENT_WRAPPERTYPEINFO(Canvas);
   V(Canvas, scale) \
   V(Canvas, rotate) \
   V(Canvas, skew) \
+  V(Canvas, transform) \
+  V(Canvas, setMatrix) \
   V(Canvas, getTotalMatrix) \
   V(Canvas, clipRect) \
   V(Canvas, clipRRect) \
@@ -77,7 +68,6 @@ IMPLEMENT_WRAPPERTYPEINFO(Canvas);
 
   // These are custom because of ExceptionState:
   // V(Canvas, concat)
-  // V(Canvas, setMatrix)
 
 FOR_EACH_BINDING(DART_NATIVE_CALLBACK)
 
@@ -85,7 +75,6 @@ void Canvas::RegisterNatives(DartLibraryNatives* natives) {
   natives->Register({
     { "Canvas_constructor", Canvas_constructor, 3, true },
     { "Canvas_concat", Canvas_concat, 2, true },
-    { "Canvas_setMatrix", Canvas_setMatrix, 2, true },
 FOR_EACH_BINDING(DART_REGISTER_NATIVE)
   });
 }
@@ -165,6 +154,20 @@ void Canvas::skew(float sx, float sy)
     m_canvas->skew(sx, sy);
 }
 
+void Canvas::transform(const Float64List& matrix4)
+{
+    if (!m_canvas)
+        return;
+    m_canvas->concat(toSkMatrix(matrix4));
+}
+
+void Canvas::setMatrix(const Float64List& matrix4)
+{
+    if (!m_canvas)
+        return;
+    m_canvas->setMatrix(toSkMatrix(matrix4));
+}
+
 void Canvas::concat(const Float64List& matrix4, ExceptionState& es)
 {
     if (!m_canvas)
@@ -176,17 +179,6 @@ void Canvas::concat(const Float64List& matrix4, ExceptionState& es)
     m_canvas->concat(sk_matrix);
 }
 
-void Canvas::setMatrix(const Float64List& matrix4, ExceptionState& es)
-{
-    if (!m_canvas)
-        return es.ThrowTypeError("No canvas");
-
-    SkMatrix sk_matrix = toSkMatrix(matrix4, es);
-    if (es.had_exception())
-        return;
-    m_canvas->setMatrix(sk_matrix);
-}
-
 Float64List Canvas::getTotalMatrix()
 {
     // Maybe we should throw an exception instead of returning an empty matrix?

sky/engine/core/painting/Canvas.h

@@ -45,9 +45,12 @@ public:
     void scale(float sx, float sy);
     void rotate(float radians);
     void skew(float sx, float sy);
+    void transform(const Float64List& matrix4);
+    void setMatrix(const Float64List& matrix4);
+
+    // TODO(abarth): Remove concat.
     void concat(const Float64List& matrix4, ExceptionState&);
 
-    void setMatrix(const Float64List& matrix4, ExceptionState&);
     Float64List getTotalMatrix();
 
     void clipRect(const Rect& rect);

sky/engine/core/painting/Matrix.cpp

@@ -22,15 +22,29 @@ SkMatrix toSkMatrix(const Float64List& matrix4, ExceptionState& es)
         return sk_matrix;
     }
 
-    for (intptr_t i = 0; i < 9; ++i)
+    for (int i = 0; i < 9; ++i)
         sk_matrix[i] = matrix4[kSkMatrixIndexToMatrix4Index[i]];
     return sk_matrix;
 }
 
+SkMatrix toSkMatrix(const Float64List& matrix4)
+{
+    ASSERT(matrix4.data());
+    SkMatrix sk_matrix;
+    for (int i = 0; i < 9; ++i) {
+        int matrix4_index = kSkMatrixIndexToMatrix4Index[i];
+        if (matrix4_index < matrix4.num_elements())
+            sk_matrix[i] = matrix4[matrix4_index];
+        else
+            sk_matrix[i] = 0.0;
+    }
+    return sk_matrix;
+}
+
 Float64List toMatrix4(const SkMatrix& sk_matrix)
 {
     Float64List matrix4(Dart_NewTypedData(Dart_TypedData_kFloat64, 16));
-    for (intptr_t i = 0; i < 9; ++i)
+    for (int i = 0; i < 9; ++i)
         matrix4[kSkMatrixIndexToMatrix4Index[i]] = sk_matrix[i];
     matrix4[10] = 1.0; // Identity along the z axis.
     return matrix4;

sky/engine/core/painting/Matrix.h

@@ -11,7 +11,11 @@
 
 namespace blink {
 
+// TODO(abarth): Remove this version of toSkMatrix and do the error checking
+// inside the VM.
 SkMatrix toSkMatrix(const Float64List& matrix4, ExceptionState& es);
+
+SkMatrix toSkMatrix(const Float64List& matrix4);
 Float64List toMatrix4(const SkMatrix& sk_matrix);
 
 }  // namespace blink