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 "SkOffsetImageFilter.h"
  #include "SkBitmapSource.h"
  
  #define WIDTH 400
  #define HEIGHT 100
  #define MARGIN 12
  
  namespace skiagm {
  
  class OffsetImageFilterGM : public GM {
  public:
      OffsetImageFilterGM() : fInitialized(false) {
          this->setBGColor(0xFF000000);
      }
  
  protected:
      virtual SkString onShortName() {
          return SkString("offsetimagefilter");
      }
  
      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() {
          return make_isize(WIDTH, HEIGHT);
      }
  
      void drawClippedBitmap(SkCanvas* canvas, const SkBitmap& bitmap, const SkPaint& paint,
                             SkScalar x, SkScalar y) {
          canvas->save();
          canvas->clipRect(SkRect::MakeXYWH(x, y,
              SkIntToScalar(bitmap.width()), SkIntToScalar(bitmap.height())));
          canvas->drawBitmap(bitmap, x, y, &paint);
          canvas->restore();
      }
  
      virtual void onDraw(SkCanvas* canvas) {
          if (!fInitialized) {
              make_bitmap();
              make_checkerboard();
              fInitialized = true;
          }
          canvas->clear(0x00000000);
          SkPaint paint;
  
          int x = 0, y = 0;
          for (size_t i = 0; i < 4; i++) {
              SkBitmap* bitmap = (i & 0x01) ? &fCheckerboard : &fBitmap;
              SkIRect cropRect = SkIRect::MakeXYWH(x + i * 12,
                                                   y + i * 8,
                                                   bitmap->width() - i * 8,
                                                   bitmap->height() - i * 12);
              SkImageFilter::CropRect rect(SkRect::Make(cropRect));
              SkAutoTUnref<SkImageFilter> tileInput(SkNEW_ARGS(SkBitmapSource, (*bitmap)));
              SkScalar dx = SkIntToScalar(i*5);
              SkScalar dy = SkIntToScalar(i*10);
              SkAutoTUnref<SkImageFilter> filter(SkNEW_ARGS(
                  SkOffsetImageFilter, (dx, dy, tileInput, &rect)));
              paint.setImageFilter(filter);
              drawClippedBitmap(canvas, *bitmap, paint, SkIntToScalar(x), SkIntToScalar(y));
              x += bitmap->width() + MARGIN;
              if (x + bitmap->width() > WIDTH) {
                  x = 0;
                  y += bitmap->height() + MARGIN;
              }
          }
      }
  private:
      typedef GM INHERITED;
      SkBitmap fBitmap, fCheckerboard;
      bool fInitialized;
  };
  
  //////////////////////////////////////////////////////////////////////////////
  
  static GM* MyFactory(void*) { return new OffsetImageFilterGM; }
  static GMRegistry reg(MyFactory);
  
  }
  