commit ff174b39474df20945fc7cc5c9d5bb68916f39a8
author senorblanco@chromium.org <senorblanco@chromium.org@2bbb7eff-a529-9590-31e7-b0007b416f81> Mon May 16 16:59:57 2011 +0000
committer senorblanco@chromium.org <senorblanco@chromium.org@2bbb7eff-a529-9590-31e7-b0007b416f81> Mon May 16 16:59:57 2011 +0000
tree cf98f97ae75289ffb686a71d35b07eb913f20671
parent b54455e440e66e0b1c30954d226226f49aac26d6

Fix winding order check for negative scale in tesselated path rendering.  The
isCCW() code in GrTesselatedPathRenderer was using untransformed vertices,
which fails for transforms with negative scale.  Doing the check after
transformation fixes it.  This was causing some missing geometry in the
PolyToPoly and Shapes tests in SampleApp.

Review URL:  http://codereview.appspot.com/4545049/



git-svn-id: http://skia.googlecode.com/svn/trunk@1334 2bbb7eff-a529-9590-31e7-b0007b416f81

gpu/src/GrTesselatedPathRenderer.cpp

diff --git a/gpu/src/GrTesselatedPathRenderer.cpp b/gpu/src/GrTesselatedPathRenderer.cpp
index 3993adb..19ee46d 100644
--- a/gpu/src/GrTesselatedPathRenderer.cpp
+++ b/gpu/src/GrTesselatedPathRenderer.cpp
@@ -97,10 +97,10 @@
 
 typedef GrTDArray<Edge> EdgeArray;
 
-bool isCCW(const GrPoint* v)
+bool isCCW(const GrPoint* pts)
 {
-    GrVec v1 = v[1] - v[0];
-    GrVec v2 = v[2] - v[1];
+    GrVec v1 = pts[1] - pts[0];
+    GrVec v2 = pts[2] - pts[1];
     return v1.cross(v2) < 0;
 }
 
@@ -110,12 +110,11 @@
                                             size_t numVertices,
                                             EdgeArray* edges)
 {
+    matrix.mapPoints(vertices, numVertices);
     GrPoint p = vertices[numVertices - 1];
-    matrix.mapPoints(&p, 1);
     float sign = isCCW(vertices) ? -1.0f : 1.0f;
     for (size_t i = 0; i < numVertices; ++i) {
         GrPoint q = vertices[i];
-        matrix.mapPoints(&q, 1);
         if (p == q) continue;
         GrVec tangent = GrVec::Make(p.fY - q.fY, q.fX - p.fX);
         float scale = sign / tangent.length();