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 #include "gm.h"
   8 #include "SkGradientShader.h"
   9
  10 namespace skiagm {
  11
  12 static SkShader* MakeLinear(SkScalar width, SkScalar height, bool alternate) {
  13   SkPoint pts[2] = { {0, 0}, {width, height}};
  14   SkColor colors[2] = {SK_ColorRED, SK_ColorGREEN};
  15   if (alternate) {
  16     pts[1].fY = 0;
  17     colors[0] = SK_ColorBLUE;
  18     colors[1] = SK_ColorYELLOW;
  19   }
  20   return SkGradientShader::CreateLinear(pts, colors, NULL, 2,
  21                                         SkShader::kClamp_TileMode, NULL);
  22 }
  23
  24 ///////////////////////////////////////////////////////////////////////////////
  25
  26 class ShaderBoundsGM : public GM {
  27 public:
  28     typedef SkShader* (*ShaderGenFunc)(SkScalar width, SkScalar height,
  29                                        bool alternate);
  30     ShaderBoundsGM(ShaderGenFunc maker, const SkString& name)
  31         : fShaderMaker(maker),
  32           fName(name) {
  33     }
  34
  35 protected:
  36     SkString onShortName() {
  37         return fName;
  38     }
  39
  40     virtual SkISize onISize() { return make_isize(320, 240); }
  41
  42     virtual SkMatrix onGetInitialTransform() const SK_OVERRIDE {
  43         SkMatrix result;
  44         SkScalar scale = 0.8f;
  45         result.setScale(scale, scale);
  46         result.postTranslate(SkIntToScalar(7), SkIntToScalar(23));
  47         return result;
  48     }
  49
  50     virtual void onDraw(SkCanvas* canvas) {
  51         // The PDF device has already clipped to the content area, but we
  52         // do it again here so that the raster and pdf results are consistent.
  53         canvas->clipRect(SkRect::MakeWH(SkIntToScalar(320),
  54                                         SkIntToScalar(240)));
  55
  56         SkMatrix canvasScale;
  57         SkScalar scale = 0.7f;
  58         canvasScale.setScale(scale, scale);
  59         canvas->concat(canvasScale);
  60
  61         // Background shader.
  62         SkPaint paint;
  63         paint.setShader(MakeShader(559, 387, false))->unref();
  64         SkRect r = SkRect::MakeXYWH(SkIntToScalar(-12), SkIntToScalar(-41),
  65                                     SkIntToScalar(571), SkIntToScalar(428));
  66         canvas->drawRect(r, paint);
  67
  68         // Constrained shader.
  69         paint.setShader(MakeShader(101, 151, true))->unref();
  70         r = SkRect::MakeXYWH(SkIntToScalar(43), SkIntToScalar(71),
  71                              SkIntToScalar(101), SkIntToScalar(151));
  72         canvas->clipRect(r);
  73         canvas->drawRect(r, paint);
  74     }
  75
  76     SkShader* MakeShader(int width, int height, bool background) {
  77         SkScalar scale = 0.5f;
  78         if (background) {
  79             scale = 0.6f;
  80         }
  81         SkScalar shaderWidth = SkScalarDiv(SkIntToScalar(width), scale);
  82         SkScalar shaderHeight = SkScalarDiv(SkIntToScalar(height), scale);
  83         SkShader* shader = fShaderMaker(shaderWidth, shaderHeight, background);
  84         SkMatrix shaderScale;
  85         shaderScale.setScale(scale, scale);
  86         shader->setLocalMatrix(shaderScale);
  87         return shader;
  88     }
  89
  90 private:
  91     typedef GM INHERITED;
  92
  93     ShaderGenFunc fShaderMaker;
  94     SkString fName;
  95
  96     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 }