gm/tiledscaledbitmap.cpp

   1 /*
   2  * Copyright 2014 Google Inc.
   3  *
   4  * Use of this source code is governed by a BSD-style license that can be
   5  * found in the LICENSE file.
   6  */
   7
   8 #include "gm.h"
   9
  10 #include "Resources.h"
  11 #include "SkBitmap.h"
  12 #include "SkPaint.h"
  13 #include "SkShader.h"
  14 #include "SkStream.h"
  15
  16  /***
  17   *
  18   * This GM reproduces Skia bug 2904, in which a tiled bitmap shader was failing to draw correctly
  19   * when fractional image scaling was ignored by the high quality bitmap scaler.
  20   *
  21   ***/
  22
  23 namespace skiagm {
  24
  25 class TiledScaledBitmapGM : public GM {
  26 public:
  27
  28     TiledScaledBitmapGM() {
  29     }
  30
  31 protected:
  32     SkString onShortName() override {
  33         return SkString("tiledscaledbitmap");
  34     }
  35
  36     SkISize onISize() override {
  37         return SkISize::Make(1016, 616);
  38     }
  39
  40     static SkBitmap make_bm(int width, int height) {
  41         SkBitmap bm;
  42         bm.allocN32Pixels(width, height);
  43         bm.eraseColor(SK_ColorTRANSPARENT);
  44         SkCanvas canvas(bm);
  45         SkPaint paint;
  46         paint.setAntiAlias(true);
  47         canvas.drawCircle(width/2.f, height/2.f, width/4.f, paint);
  48         return bm;
  49     }
  50
  51     void onOnceBeforeDraw() override {
  52         fBitmap = make_bm(360, 288);
  53     }
  54
  55     void onDraw(SkCanvas* canvas) override {
  56         SkPaint paint;
  57
  58         paint.setAntiAlias(true);
  59         paint.setFilterQuality(kHigh_SkFilterQuality);
  60
  61         SkMatrix mat;
  62         mat.setScale(121.f/360.f, 93.f/288.f);
  63         mat.postTranslate(-72, -72);
  64
  65         paint.setShader(SkShader::MakeBitmapShader(fBitmap, SkShader::kRepeat_TileMode,
  66                                                    SkShader::kRepeat_TileMode, &mat));
  67         canvas->drawRect({ 8, 8, 1008, 608 }, paint);
  68     }
  69
  70 private:
  71     SkBitmap fBitmap;
  72
  73     typedef GM INHERITED;
  74 };
  75
  76 //////////////////////////////////////////////////////////////////////////////
  77
  78 DEF_GM(return new TiledScaledBitmapGM;)
  79 }