Add GM to test conic path rendering

gm/conicpaths.cpp

+/*
+ * Copyright 2013 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 "SkCanvas.h"
+#include "SkTArray.h"
+
+namespace skiagm {
+
+class ConicPathsGM : public GM {
+protected:
+
+    virtual SkString onShortName() SK_OVERRIDE {
+        return SkString("conicpaths");
+    }
+
+    virtual SkISize onISize() SK_OVERRIDE { 
+        return SkISize::Make(800, 600);
+    }
+
+    virtual void onOnceBeforeDraw() SK_OVERRIDE {
+        {
+            SkPath* conicCirlce = &fPaths.push_back();
+            conicCirlce->moveTo(0, -0);
+            conicCirlce->conicTo(SkIntToScalar(0), SkIntToScalar(50),
+                                        SkIntToScalar(50), SkIntToScalar(50),
+                                        SkScalarHalf(SkScalarSqrt(2)));
+            conicCirlce->rConicTo(SkIntToScalar(50), SkIntToScalar(0),
+                                         SkIntToScalar(50), SkIntToScalar(-50),
+                                         SkScalarHalf(SkScalarSqrt(2)));
+            conicCirlce->rConicTo(SkIntToScalar(0), SkIntToScalar(-50),
+                                         SkIntToScalar(-50), SkIntToScalar(-50),
+                                         SkScalarHalf(SkScalarSqrt(2)));
+            conicCirlce->rConicTo(SkIntToScalar(-50), SkIntToScalar(0),
+                                         SkIntToScalar(-50), SkIntToScalar(50),
+                                         SkScalarHalf(SkScalarSqrt(2)));
+
+        }
+        {
+            SkPath* hyperbola = &fPaths.push_back();
+            hyperbola->moveTo(0, -0);
+            hyperbola->conicTo(SkIntToScalar(0), SkIntToScalar(100),
+                                        SkIntToScalar(100), SkIntToScalar(100),
+                                        SkIntToScalar(2));
+        }
+        {
+            SkPath* thinHyperbola = &fPaths.push_back();
+            thinHyperbola->moveTo(0, -0);
+            thinHyperbola->conicTo(SkIntToScalar(100), SkIntToScalar(100),
+                                        SkIntToScalar(5), SkIntToScalar(0),
+                                        SkIntToScalar(2));
+        }
+        {
+            SkPath* veryThinHyperbola = &fPaths.push_back();
+            veryThinHyperbola->moveTo(0, -0);
+            veryThinHyperbola->conicTo(SkIntToScalar(100), SkIntToScalar(100),
+                                        SkIntToScalar(1), SkIntToScalar(0),
+                                        SkIntToScalar(2));
+        }
+        {
+            SkPath* closedHyperbola = &fPaths.push_back();
+            closedHyperbola->moveTo(0, -0);
+            closedHyperbola->conicTo(SkIntToScalar(100), SkIntToScalar(100),
+                                        SkIntToScalar(0), SkIntToScalar(0),
+                                        SkIntToScalar(2));
+        }
+        {
+            // using 1 as weight defaults to using quadTo
+            SkPath* nearParabola = &fPaths.push_back();
+            nearParabola->moveTo(0, -0);
+            nearParabola->conicTo(SkIntToScalar(0), SkIntToScalar(100),
+                                        SkIntToScalar(100), SkIntToScalar(100),
+                                        0.999);
+        }
+        {
+            SkPath* thinEllipse = &fPaths.push_back();
+            thinEllipse->moveTo(0, -0);
+            thinEllipse->conicTo(SkIntToScalar(100), SkIntToScalar(100),
+                                        SkIntToScalar(5), SkIntToScalar(0),
+                                        SK_ScalarHalf);
+        }
+        {
+            SkPath* veryThinEllipse = &fPaths.push_back();
+            veryThinEllipse->moveTo(0, -0);
+            veryThinEllipse->conicTo(SkIntToScalar(100), SkIntToScalar(100),
+                                        SkIntToScalar(1), SkIntToScalar(0),
+                                        SK_ScalarHalf);
+        }
+        {
+            SkPath* closedEllipse = &fPaths.push_back();
+            closedEllipse->moveTo(0, -0);
+            closedEllipse->conicTo(SkIntToScalar(100), SkIntToScalar(100),
+                                        SkIntToScalar(0), SkIntToScalar(0),
+                                        SK_ScalarHalf);
+        }
+    }
+
+    virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
+        static const SkAlpha kAlphaValue[] = { 0xFF, 0x40 };
+
+        enum {
+            kMargin = 15,
+        };
+        int wrapX = canvas->getDeviceSize().fWidth - kMargin;
+
+        SkScalar maxH = 0;
+        canvas->translate(SkIntToScalar(kMargin), SkIntToScalar(kMargin));
+        canvas->save();
+
+        SkScalar x = SkIntToScalar(kMargin);
+        for (int p = 0; p < fPaths.count(); ++p) {
+            for (size_t a = 0; a < SK_ARRAY_COUNT(kAlphaValue); ++a) {
+                for (int aa = 0; aa < 2; ++aa) {
+                    for (int fh = 0; fh < 2; ++fh) {
+
+                        const SkRect& bounds = fPaths[p].getBounds();
+
+                        if (x + bounds.width() > wrapX) {
+                            canvas->restore();
+                            canvas->translate(0, maxH + SkIntToScalar(kMargin));
+                            canvas->save();
+                            maxH = 0;
+                            x = SkIntToScalar(kMargin);
+                        }
+
+                        SkPaint paint;
+                        paint.setARGB(kAlphaValue[a], 0, 0, 0);
+                        paint.setAntiAlias(SkToBool(aa));
+                        if (fh == 1) {
+                            paint.setStyle(SkPaint::kStroke_Style);
+                            paint.setStrokeWidth(0);
+                        } else if (fh == 0) {
+                            paint.setStyle(SkPaint::kFill_Style);
+                        }
+                        canvas->save();
+                        canvas->translate(-bounds.fLeft, -bounds.fTop);
+                        canvas->drawPath(fPaths[p], paint);
+                        canvas->restore();
+
+                        maxH = SkMaxScalar(maxH, bounds.height());
+
+                        SkScalar dx = bounds.width() + SkIntToScalar(kMargin);
+                        x += dx;
+                        canvas->translate(dx, 0);
+                    }
+                }
+            }
+        }
+        canvas->restore();
+    }
+
+private:
+    SkTArray<SkPath> fPaths;
+    typedef GM INHERITED;
+};
+
+//////////////////////////////////////////////////////////////////////////////
+
+DEF_GM( return SkNEW(ConicPathsGM); )
+}