gm/bitmapshader.cpp

   1
   2 /*
   3  * Copyright 2013 Google Inc.
   4  *
   5  * Use of this source code is governed by a BSD-style license that can be
   6  * found in the LICENSE file.
   7  */
   8 #include "gm.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 static void adopt_shader(SkPaint* paint, SkShader* shader) {
  39     paint->setShader(shader);
  40     SkSafeUnref(shader);
  41 }
  42
  43 class BitmapShaderGM : public GM {
  44
  45 protected:
  46     void onOnceBeforeDraw() override {
  47         this->setBGColor(SK_ColorGRAY);
  48         draw_bm(&fBitmap);
  49         draw_mask(&fMask);
  50     }
  51
  52     virtual SkString onShortName() {
  53         return SkString("bitmapshaders");
  54     }
  55
  56     virtual SkISize onISize() {
  57         return SkISize::Make(150, 100);
  58     }
  59
  60     virtual void onDraw(SkCanvas* canvas) {
  61         SkPaint paint;
  62
  63         for (int i = 0; i < 2; i++) {
  64             SkMatrix s;
  65             s.reset();
  66             if (1 == i) {
  67                 s.setScale(1.5f, 1.5f);
  68                 s.postTranslate(2, 2);
  69             }
  70
  71             canvas->save();
  72             adopt_shader(&paint, SkShader::CreateBitmapShader(fBitmap, SkShader::kClamp_TileMode,
  73                                                               SkShader::kClamp_TileMode, &s));
  74
  75             // draw the shader with a bitmap mask
  76             canvas->drawBitmap(fMask, 0, 0, &paint);
  77             canvas->drawBitmap(fMask, 30, 0, &paint);
  78
  79             canvas->translate(0, 25);
  80
  81             canvas->drawCircle(10, 10, 10, paint);
  82             canvas->drawCircle(40, 10, 10, paint); // no blue circle expected
  83
  84             canvas->translate(0, 25);
  85
  86             // clear the shader, colorized by a solid color with a bitmap mask
  87             paint.setShader(NULL);
  88             paint.setColor(SK_ColorGREEN);
  89             canvas->drawBitmap(fMask, 0, 0, &paint);
  90             canvas->drawBitmap(fMask, 30, 0, &paint);
  91
  92             canvas->translate(0, 25);
  93
  94             adopt_shader(&paint, SkShader::CreateBitmapShader(fMask, SkShader::kRepeat_TileMode,
  95                                                               SkShader::kRepeat_TileMode, &s));
  96             paint.setColor(SK_ColorRED);
  97
  98             // draw the mask using the shader and a color
  99             canvas->drawRect(SkRect::MakeXYWH(0, 0, 20, 20), paint);
 100             canvas->drawRect(SkRect::MakeXYWH(30, 0, 20, 20), paint);
 101             canvas->restore();
 102             canvas->translate(60, 0);
 103         }
 104     }
 105
 106 private:
 107     SkBitmap fBitmap;
 108     SkBitmap fMask;
 109
 110     typedef GM INHERITED;
 111 };
 112
 113 //////////////////////////////////////////////////////////////////////////////
 114
 115 static GM* MyFactory(void*) { return new BitmapShaderGM; }
 116 static GMRegistry reg(MyFactory);
 117
 118 }