Reject horizontal edges in FDot6 precision

This simplifies the slope computation because we don't have to check dy != 0. BUG=skia: Change-Id: I5c09a9217ceed65f81f9d82cb045e33a70218077 Reviewed-on: https://skia-review.googlesource.com/7180 Commit-Queue: Yuqian Li <[email protected]> Reviewed-by: Cary Clark <[email protected]>
jasonborn · Jan 18, 2017 · ce7e18f · ce7e18f
1 parent 8461506
commit ce7e18f
Showing 1 changed file with 8 additions and 6 deletions.
diff --git a/src/core/SkAnalyticEdge.h b/src/core/SkAnalyticEdge.h
@@ -147,11  147,6 @@ bool SkAnalyticEdge::setLine(const SkPoint& p0, const SkPoint& p1) {
     SkFixed x1 = SkFDot6ToFixed(SkScalarToFDot6(p1.fX * multiplier)) >> accuracy;
     SkFixed y1 = SnapY(SkFDot6ToFixed(SkScalarToFDot6(p1.fY * multiplier)) >> accuracy);
 
-    // are we a zero-height line?
-    if (y0 == y1) {
-        return false;
-    }
-
     int winding = 1;
 
     if (y0 > y1) {
@@ -160,12  155,19 @@ bool SkAnalyticEdge::setLine(const SkPoint& p0, const SkPoint& p1) {
         winding = -1;
     }
 
     // are we a zero-height line?
 #ifdef SK_SUPPORT_LEGACY_AAA
     if (y0 == y1) {
         return false;
     }
     SkFixed slope = SkFixedDiv(x1 - x0, y1 - y0);
 #else
     SkFDot6 dy = SkFixedToFDot6(y1 - y0);
     if (dy == 0) {
         return false;
     }
     SkFDot6 dx = SkFixedToFDot6(x1 - x0);
-    SkFixed slope = dy ? QuickSkFDot6Div(dx, dy) : SK_MaxS32;
     SkFixed slope = QuickSkFDot6Div(dx, dy);
     SkFixed absSlope = SkAbs32(slope);
 #endif