samplecode/SampleManyRects.cpp

   1
   2 /*
   3  * Copyright 2013 Google Inc.
   4  *
   5  * Use of this source code is governed by a BSD-style license that can be
   6  * found in the LICENSE file.
   7  */
   8 #include "SampleCode.h"
   9 #include "SkCanvas.h"
  10 #include "SkDevice.h"
  11 #include "SkPaint.h"
  12 #include "SkRandom.h"
  13 #include "SkShader.h"
  14 #include "SkView.h"
  15
  16 /**
  17  * Animated sample used to develop batched rect implementation in GrInOrderDrawBuffer.
  18  */
  19 class ManyRectsView : public SampleView {
  20 private:
  21     enum {
  22         N = 1000,
  23     };
  24
  25 public:
  26     ManyRectsView() {}
  27
  28 protected:
  29     bool onQuery(SkEvent* evt) override {
  30         if (SampleCode::TitleQ(*evt)) {
  31             SampleCode::TitleR(evt, "ManyRects");
  32             return true;
  33         }
  34         return this->INHERITED::onQuery(evt);
  35     }
  36
  37     virtual void onDrawContent(SkCanvas* canvas) {
  38         SkISize dsize = canvas->getDeviceSize();
  39         canvas->clear(0xFFF0E0F0);
  40
  41         for (int i = 0; i < N; ++i) {
  42             SkRect rect = SkRect::MakeWH(SkIntToScalar(fRandom.nextRangeU(10, 100)),
  43                                          SkIntToScalar(fRandom.nextRangeU(10, 100)));
  44             int x = fRandom.nextRangeU(0, dsize.fWidth);
  45             int y = fRandom.nextRangeU(0, dsize.fHeight);
  46             canvas->save();
  47
  48             canvas->translate(SkIntToScalar(x), SkIntToScalar(y));
  49             // Rotation messes up the GPU batching because of the clip below. We don't notice
  50             // that the rect is inside the clip so the clip changes interrupt batching.
  51             if (false) {
  52                 SkMatrix rotate;
  53                 rotate.setRotate(fRandom.nextUScalar1() * 360,
  54                                  SkIntToScalar(x) + SkScalarHalf(rect.fRight),
  55                                  SkIntToScalar(y) + SkScalarHalf(rect.fBottom));
  56                 canvas->concat(rotate);
  57             }
  58             SkRect clipRect = rect;
  59             // This clip will always contain the entire rect. It's here to give the GPU batching
  60             // code a little more challenge.
  61             clipRect.outset(10, 10);
  62             canvas->clipRect(clipRect);
  63             SkPaint paint;
  64             paint.setColor(fRandom.nextU());
  65             canvas->drawRect(rect, paint);
  66             canvas->restore();
  67         }
  68         this->inval(NULL);
  69     }
  70
  71 private:
  72     SkRandom fRandom;
  73     typedef SampleView INHERITED;
  74 };
  75
  76 //////////////////////////////////////////////////////////////////////////////
  77
  78 static SkView* MyFactory() { return new ManyRectsView; }
  79 static SkViewRegister reg(MyFactory);