Implement correct clipping for image filters.

gm/imagefiltersscaled.cpp

 /*
  * Copyright 2014 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 "SkColor.h"
 #include "SkBitmapSource.h"
 #include "SkBlurImageFilter.h"
 #include "SkDisplacementMapEffect.h"
 #include "SkDropShadowImageFilter.h"
 #include "SkGradientShader.h"
 #include "SkMorphologyImageFilter.h"
+#include "SkOffsetImageFilter.h"
 #include "SkScalar.h"
 
 namespace skiagm {
 
 class ImageFiltersScaledGM : public GM {
 public:
     ImageFiltersScaledGM() : fInitialized(false) {
         this->setBGColor(0x00000000);
     }
 
@@ skipping 63 matching lines @@
             new SkBlurImageFilter(SkIntToScalar(4), SkIntToScalar(4)),
             new SkDropShadowImageFilter(SkIntToScalar(5), SkIntToScalar(10), SkIntToScalar(3),
                                         SK_ColorYELLOW),
             new SkDisplacementMapEffect(SkDisplacementMapEffect::kR_ChannelSelectorType,
                                         SkDisplacementMapEffect::kR_ChannelSelectorType,
                                         SkIntToScalar(12),
                                         gradient.get(),
                                         checkerboard.get()),
             new SkDilateImageFilter(1, 1, checkerboard.get()),
             new SkErodeImageFilter(1, 1, checkerboard.get()),
+            new SkOffsetImageFilter(SkIntToScalar(32), 0),
         };
 
         SkVector scales[] = {
             SkVector::Make(SkScalarInvert(2), SkScalarInvert(2)),
             SkVector::Make(SkIntToScalar(1), SkIntToScalar(1)),
             SkVector::Make(SkIntToScalar(1), SkIntToScalar(2)),
             SkVector::Make(SkIntToScalar(2), SkIntToScalar(1)),
             SkVector::Make(SkIntToScalar(2), SkIntToScalar(2)),
         };
 
         SkRect r = SkRect::MakeWH(SkIntToScalar(64), SkIntToScalar(64));
         SkScalar margin = SkIntToScalar(16);
         SkRect bounds = r;
         bounds.outset(margin, margin);
 
         for (size_t j = 0; j < SK_ARRAY_COUNT(scales); ++j) {
             canvas->save();
             for (size_t i = 0; i < SK_ARRAY_COUNT(filters); ++i) {
                 SkPaint paint;
                 paint.setColor(SK_ColorBLUE);
                 paint.setImageFilter(filters[i]);
                 paint.setAntiAlias(true);
                 canvas->save();
                 canvas->scale(scales[j].fX, scales[j].fY);
-                canvas->clipRect(bounds);
+                if (5 == i) {
+                    canvas->translate(SkIntToScalar(-32), 0);
+                }
                 canvas->drawCircle(r.centerX(), r.centerY(),
                                    SkScalarDiv(r.width()*2, SkIntToScalar(5)), paint);
                 canvas->restore();
                 canvas->translate(r.width() * scales[j].fX + margin, 0);
             }
             canvas->restore();
             canvas->translate(0, r.height() * scales[j].fY + margin);
         }
 
         for (size_t i = 0; i < SK_ARRAY_COUNT(filters); ++i) {
             filters[i]->unref();
         }
     }
 
 private:
     bool fInitialized;
     SkBitmap fCheckerboard;
     SkBitmap fGradientCircle;
     typedef GM INHERITED;
 };
 
 //////////////////////////////////////////////////////////////////////////////
 
 static GM* MyFactory(void*) { return new ImageFiltersScaledGM; }
 static GMRegistry reg(MyFactory);
 
 }