src/third_party/skia/gm/canvasstate.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
   8 #include "gm.h"
   9 #include "SkCanvas.h"
  10 #include "SkPaint.h"
  11 #include "SkPath.h"
  12 #include "SkRect.h"
  13
  14 namespace skiagm {
  15
  16 /*
  17  * This GM exercises the flags to SkCanvas::save(). The canvas' save() and
  18  * restore actions can be limited to only a portion of the canvas' state through
  19  * the use of flags when calling save.
  20  */
  21 class CanvasStateGM : public GM {
  22     SkSize  fSize;
  23     enum {
  24         WIDTH = 150,
  25         HEIGHT = 150,
  26     };
  27
  28     SkPaint fFillPaint;
  29     SkPaint fStrokePaint;
  30
  31     SkPath fPath;
  32
  33     SkRect fOutlineRect;
  34     SkRect fFillRect;
  35
  36
  37 public:
  38     CanvasStateGM() {
  39         fSize.set(SkIntToScalar(WIDTH), SkIntToScalar(HEIGHT));
  40
  41         fFillPaint.setColor(SK_ColorRED);
  42         fFillPaint.setStyle(SkPaint::kFill_Style);
  43
  44         fStrokePaint.setColor(SK_ColorBLUE);
  45         fStrokePaint.setStyle(SkPaint::kStroke_Style);
  46         fStrokePaint.setStrokeWidth(1);
  47
  48         fPath.moveTo(25, 25);
  49         fPath.lineTo(125, 25);
  50         fPath.lineTo(75, 125);
  51         fPath.close();
  52
  53         fOutlineRect = SkRect::MakeXYWH(1, 1, WIDTH-2, HEIGHT-2);
  54         fFillRect = SkRect::MakeXYWH(10, 10, WIDTH-20, HEIGHT-20);
  55     }
  56
  57 protected:
  58     virtual SkString onShortName() SK_OVERRIDE {
  59         return SkString("canvas-state");
  60     }
  61
  62     virtual SkISize onISize() SK_OVERRIDE {
  63         return SkISize::Make(WIDTH*3, HEIGHT*4);
  64     }
  65
  66     virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
  67
  68         SkCanvas::SaveFlags flags[] = { SkCanvas::kMatrix_SaveFlag,
  69                                         SkCanvas::kClip_SaveFlag,
  70                                         SkCanvas::kMatrixClip_SaveFlag };
  71
  72         // columns -- flags
  73         // rows -- permutations of setting the clip and matrix
  74         for (int i = 0; i < static_cast<int>(SK_ARRAY_COUNT(flags)); ++i) {
  75             for (int j = 0; j < 2; ++j) {
  76                 for (int k = 0; k < 2; ++k) {
  77                     this->drawTestPattern(i, (2*j)+k, canvas, flags[i],
  78                                           SkToBool(j), SkToBool(k));
  79                 }
  80             }
  81         }
  82     }
  83
  84
  85     virtual uint32_t onGetFlags() const SK_OVERRIDE { return kSkipPicture_Flag; }
  86
  87 private:
  88     void drawTestPattern(int x, int y, SkCanvas* canvas,
  89                          SkCanvas::SaveFlags flags, bool doClip, bool doScale) {
  90         canvas->save();
  91         canvas->translate(SkIntToScalar(x*WIDTH), SkIntToScalar(y*HEIGHT));
  92
  93         canvas->drawRect(fOutlineRect, fStrokePaint);
  94         canvas->save(flags);
  95         if(doClip) {
  96             canvas->clipPath(fPath);
  97         }
  98         if (doScale) {
  99             canvas->scale(SkDoubleToScalar(0.5), SkDoubleToScalar(0.5));
 100         }
 101         canvas->restore();
 102         canvas->drawRect(fFillRect, fFillPaint);
 103
 104         canvas->restore();
 105     }
 106
 107     typedef GM INHERITED;
 108 };
 109
 110 //////////////////////////////////////////////////////////////////////////////
 111
 112 class CanvasLayerStateGM : public GM {
 113 public:
 114     CanvasLayerStateGM() {
 115         fBluePaint.setColor(SK_ColorBLUE);
 116         fBluePaint.setStyle(SkPaint::kFill_Style);
 117
 118         fRect = SkRect::MakeXYWH(SPACER, SPACER, WIDTH-(2*SPACER), (HEIGHT-(2*SPACER)) / 7);
 119     }
 120
 121 protected:
 122     virtual SkString onShortName() SK_OVERRIDE {
 123         return SkString("canvas-layer-state");
 124     }
 125
 126     virtual SkISize onISize() SK_OVERRIDE {
 127         return SkISize::Make(WIDTH, HEIGHT);
 128     }
 129
 130     virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
 131
 132         // clear the canvas to red
 133         canvas->drawColor(SK_ColorRED);
 134
 135 #ifdef SK_SUPPORT_LEGACY_CLIPTOLAYERFLAG
 136         // both rects should appear
 137         drawTestPattern(canvas, 255, SkCanvas::kARGB_NoClipLayer_SaveFlag);
 138
 139         canvas->translate(0, 2*(fRect.height() + 10));
 140
 141         // only the top rect should appear
 142         drawTestPattern(canvas, 255, SkCanvas::kARGB_ClipLayer_SaveFlag);
 143
 144         canvas->translate(0, 2*(fRect.height() + 10));
 145
 146         // only the bottom rect should appear
 147         drawTestPattern(canvas, 0, SkCanvas::kARGB_NoClipLayer_SaveFlag);
 148 #endif
 149     }
 150
 151     virtual uint32_t onGetFlags() const SK_OVERRIDE { return kSkipGPU_Flag; }
 152
 153 private:
 154     // draw a rect within the layer's bounds and again outside the layer's bounds
 155     void drawTestPattern(SkCanvas* canvas, U8CPU layerAlpha, SkCanvas::SaveFlags flags) {
 156         canvas->saveLayerAlpha(&fRect, layerAlpha, flags);
 157         canvas->drawRect(fRect, fBluePaint);
 158         canvas->translate(0, fRect.height() + 10);
 159         canvas->drawRect(fRect, fBluePaint);
 160         canvas->restore();
 161     }
 162
 163     enum {
 164         WIDTH = 400,
 165         HEIGHT = 400,
 166         SPACER = 10,
 167     };
 168
 169     SkPaint fBluePaint;
 170     SkRect fRect;
 171
 172     typedef GM INHERITED;
 173 };
 174
 175 //////////////////////////////////////////////////////////////////////////////
 176
 177 DEF_GM( return SkNEW(CanvasStateGM); )
 178 DEF_GM( return SkNEW(CanvasLayerStateGM); )
 179
 180 } // end namespace