add specialty strokeRect() to SkStroke, which can return much cleaner results

Review URL: https://codereview.appspot.com/6843093

git-svn-id: http://skia.googlecode.com/svn/trunk@6510 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 108 insertions, 0 deletions

diff --git a/gm/strokerect.cpp b/gm/strokerect.cpp
new file mode 100644
index 0000000000..f075600e47
--- /dev/null
+++ b/gm/strokerect.cpp
@@ -0,0 +1,108 @@
+/*
+ * Copyright 2012 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 "SkPath.h"
+
+#define STROKE_WIDTH    SkIntToScalar(20)
+
+static void draw_path(SkCanvas* canvas, const SkPath& path, const SkRect& rect, SkPaint::Join join) {
+    SkPaint paint;
+    paint.setAntiAlias(true);
+    paint.setStyle(SkPaint::kStroke_Style);
+
+    paint.setColor(SK_ColorGRAY);
+    paint.setStrokeWidth(STROKE_WIDTH);
+    paint.setStrokeJoin(join);
+    canvas->drawRect(rect, paint);
+
+    paint.setStrokeWidth(0);
+    paint.setColor(SK_ColorRED);
+    canvas->drawPath(path, paint);
+
+    paint.setStrokeWidth(3);
+    paint.setStrokeJoin(SkPaint::kMiter_Join);
+    int n = path.countPoints();
+    SkAutoTArray<SkPoint> points(n);
+    path.getPoints(points.get(), n);
+    canvas->drawPoints(SkCanvas::kPoints_PointMode, n, points.get(), paint);
+}
+
+/*
+ *  Test calling SkStroker for rectangles. Cases to cover:
+ *
+ *  geometry: normal, small (smaller than stroke-width), empty, inverted
+ *  joint-type for the corners
+ */
+class StrokeRectGM : public skiagm::GM {
+public:
+    StrokeRectGM() {}
+
+protected:
+    virtual SkString onShortName() {
+        return SkString("strokerect");
+    }
+
+    virtual SkISize onISize() {
+        return SkISize::Make(1024, 480);
+    }
+
+    virtual void onDraw(SkCanvas* canvas) {
+        canvas->drawColor(SK_ColorWHITE);
+        canvas->translate(STROKE_WIDTH*3/2, STROKE_WIDTH*3/2);
+
+        SkPaint paint;
+        paint.setStyle(SkPaint::kStroke_Style);
+        paint.setStrokeWidth(STROKE_WIDTH);
+
+        static const SkPaint::Join gJoins[] = {
+            SkPaint::kMiter_Join, SkPaint::kRound_Join, SkPaint::kBevel_Join
+        };
+
+        static const SkScalar W = 80;
+        static const SkScalar H = 110;
+        static const SkRect gRects[] = {
+            { 0, 0, W, H },
+            { W, 0, 0, H },
+            { 0, H, W, 0 },
+            { 0, 0, STROKE_WIDTH, H },
+            { 0, 0, W, STROKE_WIDTH },
+            { 0, 0, STROKE_WIDTH/2, STROKE_WIDTH/2 },
+            { 0, 0, W, 0 },
+            { 0, 0, 0, H },
+            { 0, 0, 0, 0 },
+        };
+            
+        for (size_t i = 0; i < SK_ARRAY_COUNT(gJoins); ++i) {
+            SkPaint::Join join = gJoins[i];
+            paint.setStrokeJoin(join);
+
+            SkAutoCanvasRestore acr(canvas, true);
+            for (size_t j = 0; j < SK_ARRAY_COUNT(gRects); ++j) {
+                const SkRect& r = gRects[j];
+
+                SkPath path, fillPath;
+                path.addRect(r);
+                paint.getFillPath(path, &fillPath);
+                draw_path(canvas, fillPath, r, join);
+
+                canvas->translate(W + 2 * STROKE_WIDTH, 0);
+            }
+            acr.restore();
+            canvas->translate(0, H + 2 * STROKE_WIDTH);
+        }
+    }
+
+private:
+    typedef GM INHERITED;
+};
+
+///////////////////////////////////////////////////////////////////////////////////////////////////
+
+DEF_GM(return new StrokeRectGM;)
+