gm/clipdrawdraw.cpp

   1 /*
   2  * Copyright 2014 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
  10 namespace skiagm {
  11
  12 // This GM exercises the use case found in crbug.com/423834.
  13 // The following pattern:
  14 //    save();
  15 //    clipRect(rect, noAA);
  16 //    drawRect(bigRect, noAA);
  17 //    restore();
  18 //
  19 //    drawRect(rect, noAA);
  20 // can leave 1 pixel wide remnants of the first rect.
  21 class ClipDrawDrawGM : public GM {
  22 public:
  23     ClipDrawDrawGM() { this->setBGColor(0xFFCCCCCC); }
  24
  25 protected:
  26     SkString onShortName() override { return SkString("clipdrawdraw"); }
  27
  28     SkISize onISize() override { return SkISize::Make(512, 512); }
  29
  30     static void Draw(SkCanvas* canvas, const SkRect& rect) {
  31         SkPaint p;
  32         p.setAntiAlias(false);
  33
  34         const SkRect bigRect = SkRect::MakeWH(600, 600);
  35
  36         canvas->save();
  37             // draw a black rect through the clip
  38             canvas->save();
  39                 canvas->clipRect(rect);
  40                 canvas->drawRect(bigRect, p);
  41             canvas->restore();
  42
  43             // now draw the white rect on top
  44             p.setColor(SK_ColorWHITE);
  45             canvas->drawRect(rect, p);
  46         canvas->restore();
  47     }
  48
  49     void onDraw(SkCanvas* canvas) override {
  50         // Vertical remnant
  51         const SkRect rect1 = SkRect::MakeLTRB(136.5f, 137.5f, 338.5f, 293.5f);
  52
  53         // Horizontal remnant
  54         // 179.488 rounds the right way (i.e., 179), 179.499 rounds the wrong way (i.e., 180)
  55         const SkRect rect2 = SkRect::MakeLTRB(207.5f, 179.499f, 530.5f, 429.5f);
  56
  57         Draw(canvas, rect1);
  58         Draw(canvas, rect2);
  59     }
  60
  61 private:
  62     typedef GM INHERITED;
  63 };
  64
  65 //////////////////////////////////////////////////////////////////////////////
  66
  67 DEF_GM(return SkNEW(ClipDrawDrawGM);)
  68
  69 }