Crop the fast path dashed lines to the cull rect

gm/dashing.cpp

Index: gm/dashing.cpp
diff --git a/gm/dashing.cpp b/gm/dashing.cpp
index 55addc8a66f3cba4086924ff90289e90c29ad938..0a3249c86584c706660c97fae02eab616cfae178 100644
--- a/gm/dashing.cpp
+++ b/gm/dashing.cpp
@@ -12,7 +12,8 @@
 
 static void drawline(SkCanvas* canvas, int on, int off, const SkPaint& paint,
                      SkScalar finalX = SkIntToScalar(600), SkScalar finalY = SkIntToScalar(0),
-                     SkScalar phase = SkIntToScalar(0)) {
+                     SkScalar phase = SkIntToScalar(0), 
+                     SkScalar startX = SkIntToScalar(0), SkScalar startY = SkIntToScalar(0)) {
     SkPaint p(paint);
 
     const SkScalar intervals[] = {
@@ -21,7 +22,7 @@ static void drawline(SkCanvas* canvas, int on, int off, const SkPaint& paint,
     };
 
     p.setPathEffect(SkDashPathEffect::Create(intervals, 2, phase))->unref();
-    canvas->drawLine(0, 0, finalX, finalY, p);
+    canvas->drawLine(startX, startY, finalX, finalY, p);
 }
 
 // earlier bug stopped us from drawing very long single-segment dashes, because
@@ -396,12 +397,53 @@ protected:
 
 //////////////////////////////////////////////////////////////////////////////
 
-static skiagm::GM* F0(void*) { return new DashingGM; }
-static skiagm::GM* F1(void*) { return new Dashing2GM; }
-static skiagm::GM* F2(void*) { return new Dashing3GM; }
-static skiagm::GM* F3(void*) { return new Dashing4GM; }
+class Dashing5GM : public skiagm::GM {
+public:
+    Dashing5GM(bool doAA) : fDoAA(doAA) {}
+
+protected:
+    virtual uint32_t onGetFlags() const SK_OVERRIDE { return kAsBench_Flag | kSkipTiled_Flag; }
+
+    virtual SkString onShortName() SK_OVERRIDE { 
+        if (fDoAA) {
+            return SkString("dashing5_aa");
+        } else {
+            return SkString("dashing5_bw");
+        }
+    }
+
+    virtual SkISize onISize() SK_OVERRIDE { return SkISize::Make(640, 300); }
+
+    virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
+        static const int kStrokeWidth = 8;
+
+        SkPaint paint;
+        paint.setStyle(SkPaint::kStroke_Style);
+
+        paint.setAntiAlias(fDoAA);
+        paint.setStrokeWidth(SkIntToScalar(kStrokeWidth));
+
+        for (int x = 0; x < 640; x += 10) {
+            drawline(canvas, 1, 1, paint, SkIntToScalar(x), -SkIntToScalar(10 * 1000), 0,
+                                          SkIntToScalar(x),  SkIntToScalar(10 * 1000));
+        }
+
+        for (int y = 0; y < 300; y += 10) {
+            drawline(canvas, 1, 1, paint, -SkIntToScalar(10 * 1000), SkIntToScalar(y), 0,
+                                           SkIntToScalar(10 * 1000), SkIntToScalar(y));
+        }
+    }
+
+private:
+    bool fDoAA;
+};
+
+//////////////////////////////////////////////////////////////////////////////
+
+DEF_GM(return SkNEW(DashingGM);)
+DEF_GM(return SkNEW(Dashing2GM);)
+DEF_GM(return SkNEW(Dashing3GM);)
+DEF_GM(return SkNEW(Dashing4GM);)
+DEF_GM(return SkNEW_ARGS(Dashing5GM, (true));)
+DEF_GM(return SkNEW_ARGS(Dashing5GM, (false));)
 
-static skiagm::GMRegistry gR0(F0);
-static skiagm::GMRegistry gR1(F1);
-static skiagm::GMRegistry gR2(F2);
-static skiagm::GMRegistry gR3(F3);