gm/bitmapshader.cpp

   1 /*
   2  * Copyright 2013 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 #include "gm.h"
   8 #include "sk_tool_utils.h"
   9
  10 #include "SkBitmap.h"
  11 #include "SkPaint.h"
  12 #include "SkShader.h"
  13
  14 namespace skiagm {
  15
  16 static void draw_bm(SkBitmap* bm) {
  17     SkPaint bluePaint;
  18     bluePaint.setColor(SK_ColorBLUE);
  19
  20     bm->allocN32Pixels(20, 20);
  21     bm->eraseColor(SK_ColorRED);
  22
  23     SkCanvas canvas(*bm);
  24     canvas.drawCircle(10, 10, 5, bluePaint);
  25 }
  26
  27 static void draw_mask(SkBitmap* bm) {
  28     SkPaint circlePaint;
  29     circlePaint.setColor(SK_ColorBLACK);
  30
  31     bm->allocPixels(SkImageInfo::MakeA8(20, 20));
  32     bm->eraseColor(SK_ColorTRANSPARENT);
  33
  34     SkCanvas canvas(*bm);
  35     canvas.drawCircle(10, 10, 10, circlePaint);
  36 }
  37
  38 class BitmapShaderGM : public GM {
  39
  40 protected:
  41     void onOnceBeforeDraw() override {
  42         this->setBGColor(sk_tool_utils::color_to_565(SK_ColorGRAY));
  43         draw_bm(&fBitmap);
  44         draw_mask(&fMask);
  45     }
  46
  47     SkString onShortName() override {
  48         return SkString("bitmapshaders");
  49     }
  50
  51     SkISize onISize() override {
  52         return SkISize::Make(150, 100);
  53     }
  54
  55     void onDraw(SkCanvas* canvas) override {
  56         SkPaint paint;
  57
  58         for (int i = 0; i < 2; i++) {
  59             SkMatrix s;
  60             s.reset();
  61             if (1 == i) {
  62                 s.setScale(1.5f, 1.5f);
  63                 s.postTranslate(2, 2);
  64             }
  65
  66             canvas->save();
  67             paint.setShader(SkShader::MakeBitmapShader(fBitmap, SkShader::kClamp_TileMode,
  68                                                        SkShader::kClamp_TileMode, &s));
  69
  70             // draw the shader with a bitmap mask
  71             canvas->drawBitmap(fMask, 0, 0, &paint);
  72             canvas->drawBitmap(fMask, 30, 0, &paint);
  73
  74             canvas->translate(0, 25);
  75
  76             canvas->drawCircle(10, 10, 10, paint);
  77             canvas->drawCircle(40, 10, 10, paint); // no blue circle expected
  78
  79             canvas->translate(0, 25);
  80
  81             // clear the shader, colorized by a solid color with a bitmap mask
  82             paint.setShader(nullptr);
  83             paint.setColor(SK_ColorGREEN);
  84             canvas->drawBitmap(fMask, 0, 0, &paint);
  85             canvas->drawBitmap(fMask, 30, 0, &paint);
  86
  87             canvas->translate(0, 25);
  88
  89             paint.setShader(SkShader::MakeBitmapShader(fMask, SkShader::kRepeat_TileMode,
  90                                                        SkShader::kRepeat_TileMode, &s));
  91             paint.setColor(SK_ColorRED);
  92
  93             // draw the mask using the shader and a color
  94             canvas->drawRect(SkRect::MakeXYWH(0, 0, 20, 20), paint);
  95             canvas->drawRect(SkRect::MakeXYWH(30, 0, 20, 20), paint);
  96             canvas->restore();
  97             canvas->translate(60, 0);
  98         }
  99     }
 100
 101 private:
 102     SkBitmap fBitmap;
 103     SkBitmap fMask;
 104
 105     typedef GM INHERITED;
 106 };
 107
 108 //////////////////////////////////////////////////////////////////////////////
 109
 110 static GM* MyFactory(void*) { return new BitmapShaderGM; }
 111 static GMRegistry reg(MyFactory);
 112
 113 }