Make GrShape recognize horizontal/vertical dashed lines with 0 off intervals as rrects.

Change-Id: Ic29b41911e0185d36093d5352f4494709e8124ba
Reviewed-on: https://skia-review.googlesource.com/88428
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>

1 files changed, 56 insertions, 47 deletions

diff --git a/src/gpu/GrShape.cpp b/src/gpu/GrShape.cpp
index 4c9338409c..b9bc00d1aa 100644
--- a/src/gpu/GrShape.cpp
+++ b/src/gpu/GrShape.cpp
@@ -579,6 +579,13 @@ void GrShape::attemptToSimplifyLine() {
     SkASSERT(Type::kLine == fType);
     SkASSERT(!fInheritedKey.count());
     if (fStyle.isDashed()) {
+        bool allOffsZero = true;
+        for (int i = 1; i < fStyle.dashIntervalCnt() && allOffsZero; i += 2) {
+            allOffsZero = !fStyle.dashIntervals()[i];
+        }
+        if (allOffsZero && this->attemptToSimplifyStrokedLineToRRect()) {
+            return;
+        }
         // Dashing ignores inverseness.
         fLineData.fInverted = false;
         return;
@@ -595,57 +602,59 @@ void GrShape::attemptToSimplifyLine() {
         this->changeType(fLineData.fInverted ? Type::kInvertedEmpty : Type::kEmpty);
         return;
     }
-    SkPoint* pts = fLineData.fPts;
-    if (fStyle.strokeRec().getStyle() == SkStrokeRec::kStroke_Style) {
-        // If it is horizontal or vertical we will turn it into a filled rrect.
-        SkRect rect;
-        rect.fLeft = SkTMin(pts[0].fX, pts[1].fX);
-        rect.fRight = SkTMax(pts[0].fX, pts[1].fX);
-        rect.fTop = SkTMin(pts[0].fY, pts[1].fY);
-        rect.fBottom = SkTMax(pts[0].fY, pts[1].fY);
-        bool eqX = rect.fLeft == rect.fRight;
-        bool eqY = rect.fTop == rect.fBottom;
-        if (eqX || eqY) {
-            SkScalar r = fStyle.strokeRec().getWidth() / 2;
-            bool inverted = fLineData.fInverted;
-            this->changeType(Type::kRRect);
-            switch (fStyle.strokeRec().getCap()) {
-                case SkPaint::kButt_Cap:
-                    if (eqX && eqY) {
-                        this->changeType(Type::kEmpty);
-                        return;
-                    }
-                    if (eqX) {
-                        rect.outset(r, 0);
-                    } else {
-                        rect.outset(0, r);
-                    }
-                    fRRectData.fRRect = SkRRect::MakeRect(rect);
-                    break;
-                case SkPaint::kSquare_Cap:
-                    rect.outset(r, r);
-                    fRRectData.fRRect = SkRRect::MakeRect(rect);
-                    break;
-                case SkPaint::kRound_Cap:
-                    rect.outset(r, r);
-                    fRRectData.fRRect = SkRRect::MakeRectXY(rect, r, r);
-                    break;
-            }
-            fRRectData.fInverted = inverted;
-            fRRectData.fDir = kDefaultRRectDir;
-            fRRectData.fStart = kDefaultRRectStart;
-            if (fRRectData.fRRect.isEmpty()) {
-                // This can happen when r is very small relative to the rect edges.
-                this->changeType(inverted ? Type::kInvertedEmpty : Type::kEmpty);
-                return;
-            }
-            fStyle = GrStyle::SimpleFill();
-            return;
-        }
+    if (fStyle.strokeRec().getStyle() == SkStrokeRec::kStroke_Style &&
+        this->attemptToSimplifyStrokedLineToRRect()) {
+        return;
     }
     // Only path effects could care about the order of the points. Otherwise canonicalize
     // the point order.
+    SkPoint* pts = fLineData.fPts;
     if (pts[1].fY < pts[0].fY || (pts[1].fY == pts[0].fY && pts[1].fX < pts[0].fX)) {
         SkTSwap(pts[0], pts[1]);
     }
 }
+
+bool GrShape::attemptToSimplifyStrokedLineToRRect() {
+    SkASSERT(Type::kLine == fType);
+    SkASSERT(fStyle.strokeRec().getStyle() == SkStrokeRec::kStroke_Style);
+
+    SkRect rect;
+    SkVector outset;
+    // If we allowed a rotation angle for rrects we could capture all cases here.
+    if (fLineData.fPts[0].fY == fLineData.fPts[1].fY) {
+        rect.fLeft = SkTMin(fLineData.fPts[0].fX, fLineData.fPts[1].fX);
+        rect.fRight = SkTMax(fLineData.fPts[0].fX, fLineData.fPts[1].fX);
+        rect.fTop = rect.fBottom = fLineData.fPts[0].fY;
+        outset.fY = fStyle.strokeRec().getWidth() / 2.f;
+        outset.fX = SkPaint::kButt_Cap == fStyle.strokeRec().getCap() ? 0.f : outset.fY;
+    } else if (fLineData.fPts[0].fX == fLineData.fPts[1].fX) {
+        rect.fTop = SkTMin(fLineData.fPts[0].fY, fLineData.fPts[1].fY);
+        rect.fBottom = SkTMax(fLineData.fPts[0].fY, fLineData.fPts[1].fY);
+        rect.fLeft = rect.fRight = fLineData.fPts[0].fX;
+        outset.fX = fStyle.strokeRec().getWidth() / 2.f;
+        outset.fY = SkPaint::kButt_Cap == fStyle.strokeRec().getCap() ? 0.f : outset.fX;
+    } else {
+        return false;
+    }
+    rect.outset(outset.fX, outset.fY);
+    if (rect.isEmpty()) {
+        this->changeType(Type::kEmpty);
+        fStyle = GrStyle::SimpleFill();
+        return true;
+    }
+    SkRRect rrect;
+    if (fStyle.strokeRec().getCap() == SkPaint::kRound_Cap) {
+        SkASSERT(outset.fX == outset.fY);
+        rrect = SkRRect::MakeRectXY(rect, outset.fX, outset.fY);
+    } else {
+        rrect = SkRRect::MakeRect(rect);
+    }
+    bool inverted = fLineData.fInverted && !fStyle.hasPathEffect();
+    this->changeType(Type::kRRect);
+    fRRectData.fRRect = rrect;
+    fRRectData.fInverted = inverted;
+    fRRectData.fDir = kDefaultRRectDir;
+    fRRectData.fStart = kDefaultRRectStart;
+    fStyle = GrStyle::SimpleFill();
+    return true;
+}