Implement crop rect support for the merge image filter.

gm/imagefilterscropped.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "gm.h"
 #include "SkCanvas.h"
 #include "SkColorFilter.h"
 #include "SkColorPriv.h"
 #include "SkShader.h"
 
 #include "SkBlurImageFilter.h"
 #include "SkColorFilterImageFilter.h"
+#include "SkMergeImageFilter.h"
+#include "SkOffsetImageFilter.h"
 #include "SkTestImageFilters.h"
 
 ///////////////////////////////////////////////////////////////////////////////
 
 static void draw_paint(SkCanvas* canvas, const SkRect& r, SkImageFilter* imf) {
     SkPaint paint;
     paint.setImageFilter(imf);
     paint.setColor(SK_ColorBLACK);
     canvas->save();
     canvas->clipRect(r);
@@ skipping 96 matching lines @@
         // reciprocal scale that is applied at record time, which is
         // the intended behavior of drawSprite.
         return kSkipScaledReplay_Flag;
     }
 
     virtual void onDraw(SkCanvas* canvas) {
         void (*drawProc[])(SkCanvas*, const SkRect&, SkImageFilter*) = {
             draw_sprite, draw_bitmap, draw_path, draw_paint, draw_text
         };
 
-        SkColorFilter* cf = SkColorFilter::CreateModeFilter(SK_ColorRED,
-                                                     SkXfermode::kSrcIn_Mode);
+        SkAutoTUnref<SkColorFilter> cf(
+            SkColorFilter::CreateModeFilter(SK_ColorBLUE, SkXfermode::kSrcIn_Mode));
         SkIRect cropRect = SkIRect::MakeXYWH(10, 10, 44, 44);
         SkIRect bogusRect = SkIRect::MakeXYWH(-100, -100, 10, 10);
 
+        SkAutoTUnref<SkImageFilter> offset(new SkOffsetImageFilter(
+            SkIntToScalar(-10), SkIntToScalar(-10)));
+
+        SkAutoTUnref<SkImageFilter> cfOffset(SkColorFilterImageFilter::Create(cf.get(), offset.get()));
+
         SkImageFilter* filters[] = {
             NULL,
-            SkColorFilterImageFilter::Create(cf, NULL, &cropRect),
+            SkColorFilterImageFilter::Create(cf.get(), NULL, &cropRect),
             new SkBlurImageFilter(1.0f, 1.0f, NULL, &cropRect),
             new SkBlurImageFilter(8.0f, 0.0f, NULL, &cropRect),
             new SkBlurImageFilter(0.0f, 8.0f, NULL, &cropRect),
             new SkBlurImageFilter(8.0f, 8.0f, NULL, &cropRect),
+            new SkMergeImageFilter(NULL, cfOffset.get(), SkXfermode::kSrcOver_Mode, &cropRect),
             new SkBlurImageFilter(8.0f, 8.0f, NULL, &bogusRect),
-            SkColorFilterImageFilter::Create(cf, NULL, &bogusRect),
+            SkColorFilterImageFilter::Create(cf.get(), NULL, &bogusRect),
         };
-        cf->unref();
 
         SkRect r = SkRect::MakeWH(SkIntToScalar(64), SkIntToScalar(64));
         SkScalar MARGIN = SkIntToScalar(16);
         SkScalar DX = r.width() + MARGIN;
         SkScalar DY = r.height() + MARGIN;
 
         canvas->translate(MARGIN, MARGIN);
         for (size_t j = 0; j < SK_ARRAY_COUNT(drawProc); ++j) {
             canvas->save();
             for (size_t i = 0; i < SK_ARRAY_COUNT(filters); ++i) {
@@ skipping 10 matching lines @@
     }
 
 private:
     typedef GM INHERITED;
 };
 
 ///////////////////////////////////////////////////////////////////////////////
 
 static skiagm::GM* MyFactory(void*) { return new ImageFiltersCroppedGM; }
 static skiagm::GMRegistry reg(MyFactory);