Switch AlphaThresholdFilter over to new onFilterImage interface

gm/imagealphathreshold.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 "gm.h"
 #include "SkAlphaThresholdFilter.h"
 #include "SkRandom.h"
 #include "SkSurface.h"
 
 #define WIDTH 500
 #define HEIGHT 500
 
 namespace {
 
 void draw_rects(SkCanvas* canvas) {
     SkPaint rectPaint;
     rectPaint.setColor(0xFF0000FF);
     canvas->drawRect(SkRect::MakeXYWH(0, 0, WIDTH / 2, HEIGHT / 2), rectPaint);
     rectPaint.setColor(0xBFFF0000);
     canvas->drawRect(SkRect::MakeXYWH(WIDTH / 2, 0, WIDTH / 2, HEIGHT / 2), rectPaint);
     rectPaint.setColor(0x3F00FF00);
     canvas->drawRect(SkRect::MakeXYWH(0, HEIGHT / 2, WIDTH / 2, HEIGHT / 2), rectPaint);
     rectPaint.setColor(0x00000000);
     canvas->drawRect(SkRect::MakeXYWH(WIDTH / 2, HEIGHT / 2, WIDTH / 2, HEIGHT / 2), rectPaint);
 }
 
-SkPaint create_filter_paint() {
+SkPaint create_filter_paint(SkImageFilter::CropRect* cropRect = nullptr) {
     SkIRect rects[2];
     rects[0] = SkIRect::MakeXYWH(0, 150, WIDTH, HEIGHT - 300);
     rects[1] = SkIRect::MakeXYWH(150, 0, WIDTH - 300, HEIGHT);
     SkRegion region;
     region.setRects(rects, 2);
 
     SkPaint paint;
-    paint.setImageFilter(SkAlphaThresholdFilter::Make(region, 0.2f, 0.7f, nullptr));
+    paint.setImageFilter(SkAlphaThresholdFilter::Make(region, 0.2f, 0.7f, nullptr, cropRect));
     return paint;
 }
 
 };
 
 namespace skiagm {
 
 class ImageAlphaThresholdGM : public GM {
 public:
-    ImageAlphaThresholdGM() {
+    ImageAlphaThresholdGM(bool useCropRect) : fUseCropRect(true) { 
         this->setBGColor(0xFFFFFFFF);
     }
 
 protected:
 
     SkString onShortName() override {
+        if (fUseCropRect) {
+            return SkString("imagealphathreshold_crop");
+        }
+
         return SkString("imagealphathreshold");
     }
 
     SkISize onISize() override {
         return SkISize::Make(WIDTH, HEIGHT);
     }
 
     void onDraw(SkCanvas* canvas) override {
         SkMatrix matrix;
         matrix.reset();
         matrix.setTranslate(WIDTH * .1f, HEIGHT * .1f);
         matrix.postScale(.8f, .8f);
 
         canvas->concat(matrix);
 
-        SkPaint paint = create_filter_paint();
+        SkRect r = SkRect::MakeLTRB(100, 100, WIDTH - 100, HEIGHT - 100);
+        SkImageFilter::CropRect cropRect(r);
+
+        SkPaint paint = create_filter_paint(fUseCropRect ? &cropRect : nullptr);
         canvas->saveLayer(nullptr, &paint);
         draw_rects(canvas);
 
         canvas->restore();
     }
 
 private:
+    bool fUseCropRect;
+
     typedef GM INHERITED;
 };
 
+
 class ImageAlphaThresholdSurfaceGM : public GM {
 public:
     ImageAlphaThresholdSurfaceGM() {
         this->setBGColor(0xFFFFFFFF);
     }
 
 protected:
     SkString onShortName() override {
         return SkString("imagealphathreshold_surface");
     }
@@ skipping 15 matching lines @@
         canvas->clipRect(SkRect::MakeLTRB(100, 100, WIDTH - 100, HEIGHT - 100));
         canvas->drawImage(surface->makeImageSnapshot().get(), 0, 0, &paint);
     }
 
 private:
     typedef GM INHERITED;
 };
 
 //////////////////////////////////////////////////////////////////////////////
 
-DEF_GM(return new ImageAlphaThresholdGM();)
+DEF_GM(return new ImageAlphaThresholdGM(true);)
+DEF_GM(return new ImageAlphaThresholdGM(false);)
 DEF_GM(return new ImageAlphaThresholdSurfaceGM();)
 
 }