Implement crop rect for SkImageFilter

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 "SkTestImageFilters.h"
 
-class FailImageFilter : public SkImageFilter {
-public:
-    FailImageFilter() : INHERITED(0) {}
-
-    SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(FailImageFilter)
-protected:
-    virtual bool onFilterImage(Proxy*, const SkBitmap& src, const SkMatrix&,
-                               SkBitmap* result, SkIPoint* offset) {
-        return false;
-    }
-
-    FailImageFilter(SkFlattenableReadBuffer& buffer) : INHERITED(buffer) {}
-
-private:
-    typedef SkImageFilter INHERITED;
-};
-
-// register the filter with the flattenable registry
-static SkFlattenable::Registrar gFailImageFilterReg("FailImageFilter",
-                                                    FailImageFilter::CreateProc);
-
-class IdentityImageFilter : public SkImageFilter {
-public:
-    IdentityImageFilter() : INHERITED(0) {}
-
-    SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(IdentityImageFilter)
-protected:
-    virtual bool onFilterImage(Proxy*, const SkBitmap& src, const SkMatrix&,
-                               SkBitmap* result, SkIPoint* offset) {
-        *result = src;
-        return true;
-    }
-
-    IdentityImageFilter(SkFlattenableReadBuffer& buffer) : INHERITED(buffer) {}
-
-private:
-    typedef SkImageFilter INHERITED;
-};
-
-// register the filter with the flattenable registry
-static SkFlattenable::Registrar gIdentityImageFilterReg("IdentityImageFilter",
-                                                        IdentityImageFilter::CreateProc);
-
-
 ///////////////////////////////////////////////////////////////////////////////
 
 static void draw_paint(SkCanvas* canvas, const SkRect& r, SkImageFilter* imf) {
     SkPaint paint;
     paint.setImageFilter(imf);
-    paint.setColor(SK_ColorGREEN);
+    paint.setColor(SK_ColorBLACK);
     canvas->save();
     canvas->clipRect(r);
     canvas->drawPaint(paint);
     canvas->restore();
 }
 
 static void draw_line(SkCanvas* canvas, const SkRect& r, SkImageFilter* imf) {
     SkPaint paint;
     paint.setColor(SK_ColorBLUE);
     paint.setImageFilter(imf);
     paint.setStrokeWidth(r.width()/10);
+    canvas->save();
+    canvas->clipRect(r);
     canvas->drawLine(r.fLeft, r.fTop, r.fRight, r.fBottom, paint);
+    canvas->restore();
 }
 
 static void draw_rect(SkCanvas* canvas, const SkRect& r, SkImageFilter* imf) {
     SkPaint paint;
     paint.setColor(SK_ColorYELLOW);
     paint.setImageFilter(imf);
     SkRect rr(r);
     rr.inset(r.width()/10, r.height()/10);
+    canvas->save();
+    canvas->clipRect(r);
     canvas->drawRect(rr, paint);
+    canvas->restore();
 }
 
 static void draw_path(SkCanvas* canvas, const SkRect& r, SkImageFilter* imf) {
     SkPaint paint;
     paint.setColor(SK_ColorMAGENTA);
     paint.setImageFilter(imf);
     paint.setAntiAlias(true);
+    canvas->save();
+    canvas->clipRect(r);
     canvas->drawCircle(r.centerX(), r.centerY(), r.width()*2/5, paint);
+    canvas->restore();
 }
 
 static void draw_text(SkCanvas* canvas, const SkRect& r, SkImageFilter* imf) {
     SkPaint paint;
     paint.setImageFilter(imf);
-    paint.setColor(SK_ColorCYAN);
+    paint.setColor(SK_ColorGREEN);
     paint.setAntiAlias(true);
     paint.setTextSize(r.height()/2);
     paint.setTextAlign(SkPaint::kCenter_Align);
+    canvas->save();
+    canvas->clipRect(r);
     canvas->drawText("Text", 4, r.centerX(), r.centerY(), paint);
+    canvas->restore();
 }
 
 static void draw_bitmap(SkCanvas* canvas, const SkRect& r, SkImageFilter* imf) {
     SkPaint paint;
-    paint.setImageFilter(imf);
 
     SkIRect bounds;
     r.roundOut(&bounds);
 
     SkBitmap bm;
     bm.setConfig(SkBitmap::kARGB_8888_Config, bounds.width(), bounds.height());
     bm.allocPixels();
     bm.eraseColor(SK_ColorTRANSPARENT);
     SkCanvas c(bm);
     draw_path(&c, r, NULL);
 
+    paint.setImageFilter(imf);
+    canvas->save();
+    canvas->clipRect(r);
     canvas->drawBitmap(bm, 0, 0, &paint);
+    canvas->restore();
 }
 
 static void draw_sprite(SkCanvas* canvas, const SkRect& r, SkImageFilter* imf) {
     SkPaint paint;
-    paint.setImageFilter(imf);
 
     SkIRect bounds;
     r.roundOut(&bounds);
 
     SkBitmap bm;
     bm.setConfig(SkBitmap::kARGB_8888_Config, bounds.width(), bounds.height());
     bm.allocPixels();
-    bm.eraseColor(SK_ColorTRANSPARENT);
+    bm.eraseColor(SK_ColorRED);
     SkCanvas c(bm);
-    draw_path(&c, r, NULL);
+    
+    SkIRect cropRect = SkIRect::MakeXYWH(10, 10, 44, 44);
+    paint.setColor(SK_ColorGREEN);
+    c.drawRect(SkRect::Make(cropRect), paint);
 
+    paint.setImageFilter(imf);
     SkPoint loc = { r.fLeft, r.fTop };
     canvas->getTotalMatrix().mapPoints(&loc, 1);
     canvas->drawSprite(bm,
                        SkScalarRoundToInt(loc.fX), SkScalarRoundToInt(loc.fY),
                        &paint);
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
-class ImageFiltersBaseGM : public skiagm::GM {
+class ImageFiltersCroppedGM : public skiagm::GM {
 public:
-    ImageFiltersBaseGM () {}
+    ImageFiltersCroppedGM () {}
 
 protected:
 
     virtual SkString onShortName() {
-        return SkString("imagefiltersbase");
+        return SkString("imagefilterscropped");
     }
 
     virtual SkISize onISize() { return SkISize::Make(700, 460); }
 
     void draw_frame(SkCanvas* canvas, const SkRect& r) {
         SkPaint paint;
         paint.setStyle(SkPaint::kStroke_Style);
         paint.setColor(SK_ColorRED);
         canvas->drawRect(r, paint);
     }
 
     virtual uint32_t onGetFlags() const {
         // Because of the use of drawSprite, this test is excluded
         // from scaled replay tests because drawSprite ignores the
         // 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_paint,
             draw_line, draw_rect, draw_path, draw_text,
             draw_bitmap,
             draw_sprite
         };
 
         SkColorFilter* cf = SkColorFilter::CreateModeFilter(SK_ColorRED,
                                                      SkXfermode::kSrcIn_Mode);
+        SkIRect cropRect = SkIRect::MakeXYWH(10, 10, 44, 44);
+
         SkImageFilter* filters[] = {
             NULL,
-            new IdentityImageFilter,
-            new FailImageFilter,
-            SkColorFilterImageFilter::Create(cf),
-            new SkBlurImageFilter(12.0f, 0.0f),
+            SkColorFilterImageFilter::Create(cf, 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),
         };
         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 i = 0; i < SK_ARRAY_COUNT(drawProc); ++i) {
             canvas->save();
             for (size_t j = 0; j < SK_ARRAY_COUNT(filters); ++j) {
                 drawProc[i](canvas, r, filters[j]);
-
-                draw_frame(canvas, r);
                 canvas->translate(0, DY);
             }
             canvas->restore();
             canvas->translate(DX, 0);
         }
 
         for(size_t j = 0; j < SK_ARRAY_COUNT(filters); ++j) {
             SkSafeUnref(filters[j]);
         }
     }
 
 private:
     typedef GM INHERITED;
 };
 
 ///////////////////////////////////////////////////////////////////////////////
 
-static skiagm::GM* MyFactory(void*) { return new ImageFiltersBaseGM; }
+static skiagm::GM* MyFactory(void*) { return new ImageFiltersCroppedGM; }
 static skiagm::GMRegistry reg(MyFactory);