gm/xfermodes2.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 #include "SkBitmap.h"
  10 #include "SkShader.h"
  11 #include "SkBlendModePriv.h"
  12 #include "SkColorPriv.h"
  13
  14 namespace skiagm {
  15
  16 class Xfermodes2GM : public GM {
  17 public:
  18     Xfermodes2GM() {}
  19
  20 protected:
  21     SkString onShortName() override {
  22         return SkString("xfermodes2");
  23     }
  24
  25     SkISize onISize() override {
  26         return SkISize::Make(455, 475);
  27     }
  28
  29     void onDraw(SkCanvas* canvas) override {
  30         canvas->translate(SkIntToScalar(10), SkIntToScalar(20));
  31
  32         const SkScalar w = SkIntToScalar(kSize);
  33         const SkScalar h = SkIntToScalar(kSize);
  34
  35         SkPaint labelP;
  36         labelP.setAntiAlias(true);
  37         sk_tool_utils::set_portable_typeface(&labelP);
  38         labelP.setTextAlign(SkPaint::kCenter_Align);
  39
  40         const int W = 6;
  41
  42         SkScalar x = 0, y = 0;
  43         for (size_t m = 0; m <= (size_t)SkBlendMode::kLastMode; m++) {
  44             SkBlendMode mode = static_cast<SkBlendMode>(m);
  45
  46             canvas->save();
  47
  48             canvas->translate(x, y);
  49             SkPaint p;
  50             p.setAntiAlias(false);
  51             p.setStyle(SkPaint::kFill_Style);
  52             p.setShader(fBG);
  53             SkRect r = SkRect::MakeWH(w, h);
  54             canvas->drawRect(r, p);
  55
  56             canvas->saveLayer(&r, nullptr);
  57
  58             p.setShader(fDst);
  59             canvas->drawRect(r, p);
  60             p.setShader(fSrc);
  61             p.setBlendMode(mode);
  62             canvas->drawRect(r, p);
  63
  64             canvas->restore();
  65
  66             r.inset(-SK_ScalarHalf, -SK_ScalarHalf);
  67             p.setStyle(SkPaint::kStroke_Style);
  68             p.setShader(nullptr);
  69             p.setBlendMode(SkBlendMode::kSrcOver);
  70             canvas->drawRect(r, p);
  71
  72             canvas->restore();
  73
  74 #if 1
  75             canvas->drawString(SkBlendMode_Name(mode),
  76                                x + w/2, y - labelP.getTextSize()/2, labelP);
  77 #endif
  78             x += w + SkIntToScalar(10);
  79             if ((m % W) == W - 1) {
  80                 x = 0;
  81                 y += h + SkIntToScalar(30);
  82             }
  83         }
  84     }
  85
  86 private:
  87     void onOnceBeforeDraw() override {
  88         const uint32_t kCheckData[] = {
  89             SkPackARGB32(0xFF, 0x42, 0x41, 0x42),
  90             SkPackARGB32(0xFF, 0xD6, 0xD3, 0xD6),
  91             SkPackARGB32(0xFF, 0xD6, 0xD3, 0xD6),
  92             SkPackARGB32(0xFF, 0x42, 0x41, 0x42)
  93         };
  94         SkBitmap bg;
  95         bg.allocN32Pixels(2, 2, true);
  96         memcpy(bg.getPixels(), kCheckData, sizeof(kCheckData));
  97
  98         SkMatrix lm;
  99         lm.setScale(SkIntToScalar(16), SkIntToScalar(16));
 100         fBG = SkShader::MakeBitmapShader(bg, SkShader::kRepeat_TileMode, SkShader::kRepeat_TileMode,
 101                                          &lm);
 102
 103         SkBitmap srcBmp;
 104         srcBmp.allocN32Pixels(kSize, kSize);
 105         SkPMColor* pixels = reinterpret_cast<SkPMColor*>(srcBmp.getPixels());
 106
 107         for (int y = 0; y < kSize; ++y) {
 108             int c = y * (1 << kShift);
 109             SkPMColor rowColor = SkPackARGB32(c, c, 0, c/2);
 110             for (int x = 0; x < kSize; ++x) {
 111                 pixels[kSize * y + x] = rowColor;
 112             }
 113         }
 114         fSrc = SkShader::MakeBitmapShader(srcBmp, SkShader::kClamp_TileMode,
 115                                           SkShader::kClamp_TileMode);
 116         SkBitmap dstBmp;
 117         dstBmp.allocN32Pixels(kSize, kSize);
 118         pixels = reinterpret_cast<SkPMColor*>(dstBmp.getPixels());
 119
 120         for (int x = 0; x < kSize; ++x) {
 121             int c = x * (1 << kShift);
 122             SkPMColor colColor = SkPackARGB32(c, 0, c, c/2);
 123             for (int y = 0; y < kSize; ++y) {
 124                 pixels[kSize * y + x] = colColor;
 125             }
 126         }
 127         fDst = SkShader::MakeBitmapShader(dstBmp, SkShader::kClamp_TileMode,
 128                                           SkShader::kClamp_TileMode);
 129     }
 130
 131     enum {
 132         kShift = 2,
 133         kSize = 256 >> kShift,
 134     };
 135
 136     sk_sp<SkShader> fBG;
 137     sk_sp<SkShader> fSrc;
 138     sk_sp<SkShader> fDst;
 139
 140     typedef GM INHERITED;
 141 };
 142
 143 //////////////////////////////////////////////////////////////////////////////
 144
 145 static GM* MyFactory(void*) { return new Xfermodes2GM; }
 146 static GMRegistry reg(MyFactory);
 147
 148 }