Implement crop rect support for SkRectShaderImageFilter

src/effects/SkRectShaderImageFilter.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkRectShaderImageFilter.h"
 #include "SkBitmap.h"
 #include "SkCanvas.h"
 #include "SkDevice.h"
 #include "SkFlattenableBuffers.h"
 #include "SkShader.h"
 
 SkRectShaderImageFilter* SkRectShaderImageFilter::Create(SkShader* s, const SkRect& rect) {
     SkASSERT(s);
-    return SkNEW_ARGS(SkRectShaderImageFilter, (s, rect));
+#ifdef SK_CROP_RECT_IS_INT
+    SkIRect cropRect;
+    rect.roundOut(&cropRect);
+#else
+    CropRect cropRect(rect);
+#endif
+    return SkNEW_ARGS(SkRectShaderImageFilter, (s, &cropRect));
 }
 
-SkRectShaderImageFilter::SkRectShaderImageFilter(SkShader* s, const SkRect& rect)
-  : INHERITED(NULL)
-  , fShader(s)
-  , fRect(rect) {
+SkRectShaderImageFilter::SkRectShaderImageFilter(SkShader* s, const CropRect* cropRect)
+  : INHERITED(NULL, cropRect)
+  , fShader(s) {
     SkASSERT(s);
     s->ref();
 }
 
 SkRectShaderImageFilter::SkRectShaderImageFilter(SkFlattenableReadBuffer& buffer)
   : INHERITED(buffer) {
     fShader = buffer.readFlattenableT<SkShader>();
-    buffer.readRect(&fRect);
 }
 
 void SkRectShaderImageFilter::flatten(SkFlattenableWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
 
     buffer.writeFlattenable(fShader);
-    buffer.writeRect(fRect);
 }
 
 SkRectShaderImageFilter::~SkRectShaderImageFilter() {
     SkSafeUnref(fShader);
 }
 
 bool SkRectShaderImageFilter::onFilterImage(Proxy* proxy,
                                             const SkBitmap& source,
-                                            const SkMatrix&,
+                                            const SkMatrix& ctm,
                                             SkBitmap* result,
-                                            SkIPoint*) {
-    SkRect rect(fRect);
-    if (rect.isEmpty()) {
-        rect = SkRect::MakeWH(SkIntToScalar(source.width()), SkIntToScalar(source.height()));
-    }
-
-    if (rect.isEmpty()) {
+                                            SkIPoint* offset) {
+    SkIRect bounds;
+    source.getBounds(&bounds);
+    if (!this->applyCropRect(&bounds, ctm)) {
         return false;
     }
 
-    SkAutoTUnref<SkBaseDevice> device(proxy->createDevice(SkScalarCeilToInt(rect.width()),
-                                                          SkScalarCeilToInt(rect.height())));
+    SkAutoTUnref<SkBaseDevice> device(proxy->createDevice(bounds.width(),
+                                                          bounds.height()));
     SkCanvas canvas(device.get());
     SkPaint paint;
     paint.setShader(fShader);
+    SkMatrix matrix;
+    matrix.setTranslate(-SkIntToScalar(bounds.fLeft), -SkIntToScalar(bounds.fTop));
+    fShader->setLocalMatrix(matrix);
+    SkRect rect = SkRect::MakeWH(SkIntToScalar(bounds.width()), SkIntToScalar(bounds.height()));
     canvas.drawRect(rect, paint);
     *result = device.get()->accessBitmap(false);
+    offset->fX += bounds.fLeft;
+    offset->fY += bounds.fTop;
     return true;
 }