gm/shaderbounds.cpp

   1 /*
   2  * Copyright 2012 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 #include "SkGradientShader.h"
  10
  11 namespace skiagm {
  12
  13 static sk_sp<SkShader> MakeLinear(SkScalar width, SkScalar height, bool alternate,
  14                             const SkMatrix& localMatrix) {
  15     SkPoint pts[2] = { {0, 0}, {width, height}};
  16     SkColor colors[2] = {SK_ColorRED, SK_ColorGREEN};
  17     if (alternate) {
  18         pts[1].fY = 0;
  19         colors[0] = SK_ColorBLUE;
  20         colors[1] = SK_ColorYELLOW;
  21     }
  22     return SkGradientShader::MakeLinear(pts, colors, nullptr, 2, SkShader::kClamp_TileMode,
  23                                         0, &localMatrix);
  24 }
  25
  26 ///////////////////////////////////////////////////////////////////////////////
  27
  28 class ShaderBoundsGM : public GM {
  29 public:
  30     typedef sk_sp<SkShader> (*ShaderGenFunc)(SkScalar width, SkScalar height,
  31                                              bool alternate, const SkMatrix& localMatrix);
  32     ShaderBoundsGM(ShaderGenFunc maker, const SkString& name)
  33         : fShaderMaker(maker),
  34           fName(name) {
  35     }
  36
  37 protected:
  38
  39     SkString onShortName() override {
  40         return fName;
  41     }
  42
  43     SkISize onISize() override { return SkISize::Make(320, 240); }
  44
  45     SkMatrix onGetInitialTransform() const override {
  46         SkMatrix result;
  47         SkScalar scale = 0.8f;
  48         result.setScale(scale, scale);
  49         result.postTranslate(SkIntToScalar(7), SkIntToScalar(23));
  50         return result;
  51     }
  52
  53     void onDraw(SkCanvas* canvas) override {
  54         // The PDF device has already clipped to the content area, but we
  55         // do it again here so that the raster and pdf results are consistent.
  56         canvas->clipRect(SkRect::MakeWH(SkIntToScalar(320),
  57                                         SkIntToScalar(240)));
  58
  59         SkMatrix canvasScale;
  60         SkScalar scale = 0.7f;
  61         canvasScale.setScale(scale, scale);
  62         canvas->concat(canvasScale);
  63
  64         // Background shader.
  65         SkPaint paint;
  66         paint.setShader(MakeShader(559, 387, false));
  67         SkRect r = SkRect::MakeXYWH(SkIntToScalar(-12), SkIntToScalar(-41),
  68                                     SkIntToScalar(571), SkIntToScalar(428));
  69         canvas->drawRect(r, paint);
  70
  71         // Constrained shader.
  72         paint.setShader(MakeShader(101, 151, true));
  73         r = SkRect::MakeXYWH(SkIntToScalar(43), SkIntToScalar(71),
  74                              SkIntToScalar(101), SkIntToScalar(151));
  75         canvas->clipRect(r);
  76         canvas->drawRect(r, paint);
  77     }
  78
  79     sk_sp<SkShader> MakeShader(int width, int height, bool background) {
  80         SkScalar scale = 0.5f;
  81         if (background) {
  82             scale = 0.6f;
  83         }
  84         SkScalar shaderWidth = width / scale;
  85         SkScalar shaderHeight = height / scale;
  86         SkMatrix shaderScale = SkMatrix::MakeScale(scale);
  87         return fShaderMaker(shaderWidth, shaderHeight, background, shaderScale);
  88     }
  89
  90 private:
  91     typedef GM INHERITED;
  92
  93     ShaderGenFunc fShaderMaker;
  94     SkString fName;
  95
  96     sk_sp<SkShader> MakeShader(bool background);
  97 };
  98
  99 ///////////////////////////////////////////////////////////////////////////////
 100
 101 static GM* MyFactory(void*) {
 102     return new ShaderBoundsGM(MakeLinear, SkString("shaderbounds_linear"));
 103 }
 104 static GMRegistry reg(MyFactory);
 105
 106 }