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      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         if (!antialias) {
     23             fName.append("_bw");
     24         }
     25     }
     26 
     27     SkString onShortName() override final { return fName; }
     28     SkISize onISize() override { return SkISize::Make(500, 500); }
     29 
     30     void onOnceBeforeDraw() override {
     31         fShapes.push_back().setOval(SkRect::MakeXYWH(-5, 25, 200, 100));
     32         fRotations.push_back(21);
     33 
     34         fShapes.push_back().setRect(SkRect::MakeXYWH(95, 75, 125, 100));
     35         fRotations.push_back(94);
     36 
     37         fShapes.push_back().setRectXY(SkRect::MakeXYWH(0, 75, 150, 100), 1e-5f, 1e-5f);
     38         fRotations.push_back(132);
     39 
     40         fShapes.push_back().setRectXY(SkRect::MakeXYWH(15, -20, 100, 100), 20, 15);
     41         fRotations.push_back(282);
     42 
     43         fSimpleShapeCount = fShapes.count();
     44 
     45         fShapes.push_back().setNinePatch(SkRect::MakeXYWH(140, -50, 90, 110), 10, 5, 25, 35);
     46         fRotations.push_back(0);
     47 
     48         fShapes.push_back().setNinePatch(SkRect::MakeXYWH(160, -60, 60, 90), 10, 60, 50, 30);
     49         fRotations.push_back(-35);
     50 
     51         fShapes.push_back().setNinePatch(SkRect::MakeXYWH(220, -120, 60, 90), 1, 89, 59, 1);
     52         fRotations.push_back(65);
     53 
     54         SkVector radii[4] = {{4, 6}, {12, 8}, {24, 16}, {32, 48}};
     55         fShapes.push_back().setRectRadii(SkRect::MakeXYWH(150, -129, 80, 160), radii);
     56         fRotations.push_back(265);
     57 
     58         SkVector radii2[4] = {{0, 0}, {80, 60}, {0, 0}, {80, 60}};
     59         fShapes.push_back().setRectRadii(SkRect::MakeXYWH(180, -30, 80, 60), radii2);
     60         fRotations.push_back(295);
     61 
     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.setAlphaf(0.5f);  // 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.setAlphaf(0.5f);  // 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 }
    163