Add bench and gm for shapes

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1677253002

patch from issue 1686673002 at patchset 20001 (http://crrev.com/1686673002#ps20001)

Review URL: https://codereview.chromium.org/1677253002

1 files changed, 164 insertions, 0 deletions

diff --git a/gm/shapes.cpp b/gm/shapes.cpp
new file mode 100644
index 0000000000..02b6a9827b
--- /dev/null
+++ b/gm/shapes.cpp
@@ -0,0 +1,164 @@
+
+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "gm.h"
+#include "SkRandom.h"
+#include "SkRRect.h"
+
+namespace skiagm {
+
+/*
+ * This is the base class for two GMs that cover various corner cases with primitive Skia shapes
+ * (zero radius, near-zero radius, inner shape overlap, etc.) It uses an xfermode of darken to help
+ * double-blended and/or dropped pixels stand out.
+ */
+class ShapesGM : public GM {
+protected:
+    ShapesGM(const char* name, bool antialias) : fName(name), fAntialias(antialias) {
+        fShapes.push_back().setOval(SkRect::MakeXYWH(-5, 25, 200, 100));
+        fRotations.push_back(21);
+
+        fShapes.push_back().setRect(SkRect::MakeXYWH(95, 75, 125, 100));
+        fRotations.push_back(94);
+
+        fShapes.push_back().setRectXY(SkRect::MakeXYWH(0, 75, 150, 100), 1e-5f, 1e-5f);
+        fRotations.push_back(132);
+
+        fShapes.push_back().setRectXY(SkRect::MakeXYWH(15, -20, 100, 100), 20, 15);
+        fRotations.push_back(282);
+
+        fSimpleShapeCount = fShapes.count();
+
+        fShapes.push_back().setNinePatch(SkRect::MakeXYWH(140, -50, 90, 110), 10, 5, 25, 35);
+        fRotations.push_back(0);
+
+        fShapes.push_back().setNinePatch(SkRect::MakeXYWH(160, -60, 60, 90), 10, 60, 50, 30);
+        fRotations.push_back(-35);
+
+        fShapes.push_back().setNinePatch(SkRect::MakeXYWH(220, -120, 60, 90), 1, 89, 59, 1);
+        fRotations.push_back(65);
+
+        SkVector radii[4] = {{4, 6}, {12, 8}, {24, 16}, {32, 48}};
+        fShapes.push_back().setRectRadii(SkRect::MakeXYWH(150, -129, 80, 160), radii);
+        fRotations.push_back(265);
+
+        SkVector radii2[4] = {{0, 0}, {80, 60}, {0, 0}, {80, 60}};
+        fShapes.push_back().setRectRadii(SkRect::MakeXYWH(180, -30, 80, 60), radii2);
+        fRotations.push_back(295);
+
+        if (!antialias) {
+            fName.append("_bw");
+        }
+    }
+
+    SkString onShortName() override final { return fName; }
+    SkISize onISize() override { return SkISize::Make(500, 500); }
+
+    void onOnceBeforeDraw() override {
+        fPaint.setXfermodeMode(SkXfermode::kDarken_Mode);
+        fPaint.setAntiAlias(fAntialias);
+    }
+
+    void onDraw(SkCanvas* canvas) override {
+        canvas->clear(SK_ColorWHITE);
+
+        canvas->save();
+        canvas->translate(canvas->imageInfo().width() / 2.f, canvas->imageInfo().height() / 2.f);
+        this->drawShapes(canvas);
+        canvas->restore();
+    }
+
+    virtual void drawShapes(SkCanvas* canvas) const = 0;
+
+protected:
+    SkString             fName;
+    bool                 fAntialias;
+    SkPaint              fPaint;
+    SkTArray<SkRRect>    fShapes;
+    SkTArray<SkScalar>   fRotations;
+    int                  fSimpleShapeCount;
+
+private:
+    typedef GM INHERITED;
+};
+
+class SimpleShapesGM : public ShapesGM {
+public:
+    SimpleShapesGM(bool antialias) : INHERITED("simpleshapes", antialias) {}
+
+private:
+    void drawShapes(SkCanvas* canvas) const override {
+        SkRandom rand(2);
+        for (int i = 0; i < fShapes.count(); i++) {
+            SkPaint paint(fPaint);
+            paint.setColor(rand.nextU() & ~0x808080);
+            paint.setAlpha(128);  // Use alpha to detect double blends.
+            const SkRRect& shape = fShapes[i];
+            canvas->save();
+            canvas->rotate(fRotations[i]);
+            switch (shape.getType()) {
+                case SkRRect::kRect_Type:
+                    canvas->drawRect(shape.rect(), paint);
+                    break;
+                case SkRRect::kOval_Type:
+                    canvas->drawOval(shape.rect(), paint);
+                    break;
+                default:
+                    canvas->drawRRect(shape, paint);
+                    break;
+            }
+            canvas->restore();
+        }
+    }
+
+    typedef ShapesGM INHERITED;
+};
+
+class InnerShapesGM : public ShapesGM {
+public:
+    InnerShapesGM(bool antialias) : INHERITED("innershapes", antialias) {}
+
+private:
+    void drawShapes(SkCanvas* canvas) const override {
+        SkRandom rand;
+        for (int i = 0; i < fShapes.count(); i++) {
+            const SkRRect& outer = fShapes[i];
+            const SkRRect& inner = fShapes[(i * 7 + 11) % fSimpleShapeCount];
+            float s = 0.95f * SkTMin(outer.rect().width() / inner.rect().width(),
+                                     outer.rect().height() / inner.rect().height());
+            SkMatrix innerXform;
+            float dx = (rand.nextF() - 0.5f) * (outer.rect().width() - s * inner.rect().width());
+            float dy = (rand.nextF() - 0.5f) * (outer.rect().height() - s * inner.rect().height());
+            innerXform.setTranslate(outer.rect().centerX() + dx, outer.rect().centerY() + dy);
+            if (s < 1) {
+                innerXform.preScale(s, s);
+            }
+            innerXform.preTranslate(-inner.rect().centerX(), -inner.rect().centerY());
+            SkRRect xformedInner;
+            inner.transform(innerXform, &xformedInner);
+            SkPaint paint(fPaint);
+            paint.setColor(rand.nextU() & ~0x808080);
+            paint.setAlpha(128);  // Use alpha to detect double blends.
+            canvas->save();
+            canvas->rotate(fRotations[i]);
+            canvas->drawDRRect(outer, xformedInner, paint);
+            canvas->restore();
+        }
+    }
+
+    typedef ShapesGM INHERITED;
+};
+
+//////////////////////////////////////////////////////////////////////////////
+
+DEF_GM( return new SimpleShapesGM(true); )
+DEF_GM( return new SimpleShapesGM(false); )
+DEF_GM( return new InnerShapesGM(true); )
+DEF_GM( return new InnerShapesGM(false); )
+
+}