text: /*
   * 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 "SkArithmeticMode.h"
  #include "SkOffsetImageFilter.h"
  #include "SkXfermodeImageFilter.h"
  #include "SkBitmapSource.h"
  
  #define WIDTH 600
  #define HEIGHT 600
  #define MARGIN 12
  
  namespace skiagm {
  
  class XfermodeImageFilterGM : public GM {
  public:
      XfermodeImageFilterGM(){
          this->setBGColor(0xFF000000);
      }
  
  protected:
      virtual SkString onShortName() SK_OVERRIDE {
          return SkString("xfermodeimagefilter");
      }
  
      void make_bitmap() {
          fBitmap.setConfig(SkBitmap::kARGB_8888_Config, 80, 80);
          fBitmap.allocPixels();
          SkBitmapDevice device(fBitmap);
          SkCanvas canvas(&device);
          canvas.clear(0x00000000);
          SkPaint paint;
          paint.setAntiAlias(true);
          paint.setColor(0xD000D000);
          paint.setTextSize(SkIntToScalar(96));
          const char* str = "e";
          canvas.drawText(str, strlen(str), SkIntToScalar(15), SkIntToScalar(65), paint);
      }
  
      void make_checkerboard() {
          fCheckerboard.setConfig(SkBitmap::kARGB_8888_Config, 80, 80);
          fCheckerboard.allocPixels();
          SkBitmapDevice device(fCheckerboard);
          SkCanvas canvas(&device);
          canvas.clear(0x00000000);
          SkPaint darkPaint;
          darkPaint.setColor(0xFF404040);
          SkPaint lightPaint;
          lightPaint.setColor(0xFFA0A0A0);
          for (int y = 0; y < 80; y += 16) {
            for (int x = 0; x < 80; x += 16) {
              canvas.save();
              canvas.translate(SkIntToScalar(x), SkIntToScalar(y));
              canvas.drawRect(SkRect::MakeXYWH(0, 0, 8, 8), darkPaint);
              canvas.drawRect(SkRect::MakeXYWH(8, 0, 8, 8), lightPaint);
              canvas.drawRect(SkRect::MakeXYWH(0, 8, 8, 8), lightPaint);
              canvas.drawRect(SkRect::MakeXYWH(8, 8, 8, 8), darkPaint);
              canvas.restore();
            }
          }
      }
  
      virtual SkISize onISize() SK_OVERRIDE {
          return make_isize(WIDTH, HEIGHT);
      }
  
      static void drawClippedBitmap(SkCanvas* canvas, const SkBitmap& bitmap, const SkPaint& paint,
                             int x, int y) {
          canvas->save();
          canvas->translate(SkIntToScalar(x), SkIntToScalar(y));
          canvas->clipRect(SkRect::MakeWH(
              SkIntToScalar(bitmap.width()), SkIntToScalar(bitmap.height())));
          canvas->drawBitmap(bitmap, 0, 0, &paint);
          canvas->restore();
      }
  
      static void drawClippedPaint(SkCanvas* canvas, const SkRect& rect, const SkPaint& paint,
                            int x, int y) {
          canvas->save();
          canvas->translate(SkIntToScalar(x), SkIntToScalar(y));
          canvas->clipRect(rect);
          canvas->drawPaint(paint);
          canvas->restore();
      }
  
      virtual void onOnceBeforeDraw() SK_OVERRIDE {
          make_bitmap();
          make_checkerboard();
      }
  
      virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
          canvas->clear(0x00000000);
          SkPaint paint;
  
          const struct {
              SkXfermode::Mode  fMode;
              const char*         fLabel;
          } gModes[] = {
              { SkXfermode::kClear_Mode,    "Clear"     },
              { SkXfermode::kSrc_Mode,      "Src"       },
              { SkXfermode::kDst_Mode,      "Dst"       },
              { SkXfermode::kSrcOver_Mode,  "SrcOver"   },
              { SkXfermode::kDstOver_Mode,  "DstOver"   },
              { SkXfermode::kSrcIn_Mode,    "SrcIn"     },
              { SkXfermode::kDstIn_Mode,    "DstIn"     },
              { SkXfermode::kSrcOut_Mode,   "SrcOut"    },
              { SkXfermode::kDstOut_Mode,   "DstOut"    },
              { SkXfermode::kSrcATop_Mode,  "SrcATop"   },
              { SkXfermode::kDstATop_Mode,  "DstATop"   },
              { SkXfermode::kXor_Mode,      "Xor"       },
  
              { SkXfermode::kPlus_Mode,         "Plus"          },
              { SkXfermode::kModulate_Mode,     "Modulate"      },
              { SkXfermode::kScreen_Mode,       "Screen"        },
              { SkXfermode::kOverlay_Mode,      "Overlay"       },
              { SkXfermode::kDarken_Mode,       "Darken"        },
              { SkXfermode::kLighten_Mode,      "Lighten"       },
              { SkXfermode::kColorDodge_Mode,   "ColorDodge"    },
              { SkXfermode::kColorBurn_Mode,    "ColorBurn"     },
              { SkXfermode::kHardLight_Mode,    "HardLight"     },
              { SkXfermode::kSoftLight_Mode,    "SoftLight"     },
              { SkXfermode::kDifference_Mode,   "Difference"    },
              { SkXfermode::kExclusion_Mode,    "Exclusion"     },
              { SkXfermode::kMultiply_Mode,     "Multiply"      },
              { SkXfermode::kHue_Mode,          "Hue"           },
              { SkXfermode::kSaturation_Mode,   "Saturation"    },
              { SkXfermode::kColor_Mode,        "Color"         },
              { SkXfermode::kLuminosity_Mode,   "Luminosity"    },
          };
  
          int x = 0, y = 0;
          SkAutoTUnref<SkImageFilter> background(SkNEW_ARGS(SkBitmapSource, (fCheckerboard)));
          for (size_t i = 0; i < SK_ARRAY_COUNT(gModes); i++) {
              SkAutoTUnref<SkXfermode> mode(SkXfermode::Create(gModes[i].fMode));
              SkAutoTUnref<SkImageFilter> filter(SkNEW_ARGS(
                  SkXfermodeImageFilter, (mode, background)));
              paint.setImageFilter(filter);
              drawClippedBitmap(canvas, fBitmap, paint, x, y);
              x += fBitmap.width() + MARGIN;
              if (x + fBitmap.width() > WIDTH) {
                  x = 0;
                  y += fBitmap.height() + MARGIN;
              }
          }
          // Test arithmetic mode as image filter
          SkAutoTUnref<SkXfermode> mode(SkArithmeticMode::Create(0, SK_Scalar1, SK_Scalar1, 0));
          SkAutoTUnref<SkImageFilter> filter(SkNEW_ARGS(SkXfermodeImageFilter, (mode, background)));
          paint.setImageFilter(filter);
          drawClippedBitmap(canvas, fBitmap, paint, x, y);
          x += fBitmap.width() + MARGIN;
          if (x + fBitmap.width() > WIDTH) {
              x = 0;
              y += fBitmap.height() + MARGIN;
          }
          // Test NULL mode
          filter.reset(SkNEW_ARGS(SkXfermodeImageFilter, (NULL, background)));
          paint.setImageFilter(filter);
          drawClippedBitmap(canvas, fBitmap, paint, x, y);
          x += fBitmap.width() + MARGIN;
          if (x + fBitmap.width() > WIDTH) {
              x = 0;
              y += fBitmap.height() + MARGIN;
          }
          SkRect clipRect = SkRect::MakeWH(SkIntToScalar(fBitmap.width() + 4),
                                           SkIntToScalar(fBitmap.height() + 4));
          // Test offsets on SrcMode (uses fixed-function blend)
          SkAutoTUnref<SkImageFilter> foreground(SkNEW_ARGS(SkBitmapSource, (fBitmap)));
          SkAutoTUnref<SkImageFilter> offsetForeground(SkNEW_ARGS(SkOffsetImageFilter,
              (SkIntToScalar(4), SkIntToScalar(-4), foreground)));
          SkAutoTUnref<SkImageFilter> offsetBackground(SkNEW_ARGS(SkOffsetImageFilter,
              (SkIntToScalar(4), SkIntToScalar(4), background)));
          mode.reset(SkXfermode::Create(SkXfermode::kSrcOver_Mode));
          filter.reset(SkNEW_ARGS(SkXfermodeImageFilter,
              (mode, offsetBackground, offsetForeground)));
          paint.setImageFilter(filter);
          drawClippedPaint(canvas, clipRect, paint, x, y);
          x += fBitmap.width() + MARGIN;
          if (x + fBitmap.width() > WIDTH) {
              x = 0;
              y += fBitmap.height() + MARGIN;
          }
          // Test offsets on Darken (uses shader blend)
          mode.reset(SkXfermode::Create(SkXfermode::kDarken_Mode));
          filter.reset(SkNEW_ARGS(SkXfermodeImageFilter, (mode, offsetBackground, offsetForeground)));
          paint.setImageFilter(filter);
          drawClippedPaint(canvas, clipRect, paint, x, y);
          x += fBitmap.width() + MARGIN;
          if (x + fBitmap.width() > WIDTH) {
              x = 0;
              y += fBitmap.height() + MARGIN;
          }
          // Test cropping
          static const size_t nbSamples = 3;
          SkXfermode::Mode sampledModes[nbSamples] = {SkXfermode::kOverlay_Mode,
                                                      SkXfermode::kSrcOver_Mode,
                                                      SkXfermode::kPlus_Mode};
          int offsets[nbSamples][4] = {{ 10,  10, -16, -16},
                                       { 10,  10,  10,  10},
                                       {-10, -10,  -6,  -6}};
          for (size_t i = 0; i < nbSamples; ++i) {
              SkIRect cropRect = SkIRect::MakeXYWH(offsets[i][0],
                                                   offsets[i][1],
                                                   fBitmap.width()  + offsets[i][2],
                                                   fBitmap.height() + offsets[i][3]);
              SkImageFilter::CropRect rect(SkRect::Make(cropRect));
              mode.reset(SkXfermode::Create(sampledModes[i]));
              filter.reset(SkNEW_ARGS(SkXfermodeImageFilter,
                                      (mode, offsetBackground, offsetForeground, &rect)));
              paint.setImageFilter(filter);
              drawClippedPaint(canvas, clipRect, paint, x, y);
              x += fBitmap.width() + MARGIN;
              if (x + fBitmap.width() > WIDTH) {
                  x = 0;
                  y += fBitmap.height() + MARGIN;
              }
          }
      }
  private:
      SkBitmap fBitmap, fCheckerboard;
      typedef GM INHERITED;
  };
  
  //////////////////////////////////////////////////////////////////////////////
  
  DEF_GM( return new XfermodeImageFilterGM; );
  
  }
  