gm/shapes.cpp

   1 /*
   2  * Copyright 2016 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 "SkRandom.h"
  10 #include "SkRRect.h"
  11
  12 namespace skiagm {
  13
  14 /*
  15  * This is the base class for two GMs that cover various corner cases with primitive Skia shapes
  16  * (zero radius, near-zero radius, inner shape overlap, etc.) It uses an xfermode of darken to help
  17  * double-blended and/or dropped pixels stand out.
  18  */
  19 class ShapesGM : public GM {
  20 protected:
  21     ShapesGM(const char* name, bool antialias) : fName(name), fAntialias(antialias) {
  22         fShapes.push_back().setOval(SkRect::MakeXYWH(-5, 25, 200, 100));
  23         fRotations.push_back(21);
  24
  25         fShapes.push_back().setRect(SkRect::MakeXYWH(95, 75, 125, 100));
  26         fRotations.push_back(94);
  27
  28         fShapes.push_back().setRectXY(SkRect::MakeXYWH(0, 75, 150, 100), 1e-5f, 1e-5f);
  29         fRotations.push_back(132);
  30
  31         fShapes.push_back().setRectXY(SkRect::MakeXYWH(15, -20, 100, 100), 20, 15);
  32         fRotations.push_back(282);
  33
  34         fSimpleShapeCount = fShapes.count();
  35
  36         fShapes.push_back().setNinePatch(SkRect::MakeXYWH(140, -50, 90, 110), 10, 5, 25, 35);
  37         fRotations.push_back(0);
  38
  39         fShapes.push_back().setNinePatch(SkRect::MakeXYWH(160, -60, 60, 90), 10, 60, 50, 30);
  40         fRotations.push_back(-35);
  41
  42         fShapes.push_back().setNinePatch(SkRect::MakeXYWH(220, -120, 60, 90), 1, 89, 59, 1);
  43         fRotations.push_back(65);
  44
  45         SkVector radii[4] = {{4, 6}, {12, 8}, {24, 16}, {32, 48}};
  46         fShapes.push_back().setRectRadii(SkRect::MakeXYWH(150, -129, 80, 160), radii);
  47         fRotations.push_back(265);
  48
  49         SkVector radii2[4] = {{0, 0}, {80, 60}, {0, 0}, {80, 60}};
  50         fShapes.push_back().setRectRadii(SkRect::MakeXYWH(180, -30, 80, 60), radii2);
  51         fRotations.push_back(295);
  52
  53         if (!antialias) {
  54             fName.append("_bw");
  55         }
  56     }
  57
  58     SkString onShortName() override final { return fName; }
  59     SkISize onISize() override { return SkISize::Make(500, 500); }
  60
  61     void onOnceBeforeDraw() override {
  62         fPaint.setAntiAlias(fAntialias);
  63     }
  64
  65     void onDraw(SkCanvas* canvas) override {
  66         canvas->clear(SK_ColorWHITE);
  67
  68         canvas->save();
  69         canvas->translate(canvas->imageInfo().width() / 2.f, canvas->imageInfo().height() / 2.f);
  70         this->drawShapes(canvas);
  71         canvas->restore();
  72     }
  73
  74     virtual void drawShapes(SkCanvas* canvas) const = 0;
  75
  76 protected:
  77     SkString             fName;
  78     bool                 fAntialias;
  79     SkPaint              fPaint;
  80     SkTArray<SkRRect>    fShapes;
  81     SkTArray<SkScalar>   fRotations;
  82     int                  fSimpleShapeCount;
  83
  84 private:
  85     typedef GM INHERITED;
  86 };
  87
  88 class SimpleShapesGM : public ShapesGM {
  89 public:
  90     SimpleShapesGM(bool antialias) : INHERITED("simpleshapes", antialias) {}
  91
  92 private:
  93     void drawShapes(SkCanvas* canvas) const override {
  94         SkRandom rand(2);
  95         for (int i = 0; i < fShapes.count(); i++) {
  96             SkPaint paint(fPaint);
  97             paint.setColor(rand.nextU() & ~0x808080);
  98             paint.setAlpha(128);  // Use alpha to detect double blends.
  99             const SkRRect& shape = fShapes[i];
 100             canvas->save();
 101             canvas->rotate(fRotations[i]);
 102             switch (shape.getType()) {
 103                 case SkRRect::kRect_Type:
 104                     canvas->drawRect(shape.rect(), paint);
 105                     break;
 106                 case SkRRect::kOval_Type:
 107                     canvas->drawOval(shape.rect(), paint);
 108                     break;
 109                 default:
 110                     canvas->drawRRect(shape, paint);
 111                     break;
 112             }
 113             canvas->restore();
 114         }
 115     }
 116
 117     typedef ShapesGM INHERITED;
 118 };
 119
 120 class InnerShapesGM : public ShapesGM {
 121 public:
 122     InnerShapesGM(bool antialias) : INHERITED("innershapes", antialias) {}
 123
 124 private:
 125     void drawShapes(SkCanvas* canvas) const override {
 126         SkRandom rand;
 127         for (int i = 0; i < fShapes.count(); i++) {
 128             const SkRRect& outer = fShapes[i];
 129             const SkRRect& inner = fShapes[(i * 7 + 11) % fSimpleShapeCount];
 130             float s = 0.95f * SkTMin(outer.rect().width() / inner.rect().width(),
 131                                      outer.rect().height() / inner.rect().height());
 132             SkMatrix innerXform;
 133             float dx = (rand.nextF() - 0.5f) * (outer.rect().width() - s * inner.rect().width());
 134             float dy = (rand.nextF() - 0.5f) * (outer.rect().height() - s * inner.rect().height());
 135             innerXform.setTranslate(outer.rect().centerX() + dx, outer.rect().centerY() + dy);
 136             if (s < 1) {
 137                 innerXform.preScale(s, s);
 138             }
 139             innerXform.preTranslate(-inner.rect().centerX(), -inner.rect().centerY());
 140             SkRRect xformedInner;
 141             inner.transform(innerXform, &xformedInner);
 142             SkPaint paint(fPaint);
 143             paint.setColor(rand.nextU() & ~0x808080);
 144             paint.setAlpha(128);  // Use alpha to detect double blends.
 145             canvas->save();
 146             canvas->rotate(fRotations[i]);
 147             canvas->drawDRRect(outer, xformedInner, paint);
 148             canvas->restore();
 149         }
 150     }
 151
 152     typedef ShapesGM INHERITED;
 153 };
 154
 155 //////////////////////////////////////////////////////////////////////////////
 156
 157 DEF_GM( return new SimpleShapesGM(true); )
 158 DEF_GM( return new SimpleShapesGM(false); )
 159 DEF_GM( return new InnerShapesGM(true); )
 160 DEF_GM( return new InnerShapesGM(false); )
 161
 162 }