color-correct patch

Key work is to correctly convert SkColor corners into linear floats,
then interpolate, then (correctly) convert back to SkColors.

Bug: skia:6659
Change-Id: Iaf0ab842d7a4f8f3481e609903cec83814e5a749
Reviewed-on: https://skia-review.googlesource.com/17533
Commit-Queue: Mike Reed <reed@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>

1 files changed, 4 insertions, 2 deletions

diff --git a/src/core/SkDevice.cpp b/src/core/SkDevice.cpp
index 0b72eeb9e8..e210e3695e 100644
--- a/src/core/SkDevice.cpp
+++ b/src/core/SkDevice.cpp
@@ -125,9 +125,11 @@ void SkBaseDevice::drawDRRect(const SkRRect& outer,
 }
 
 void SkBaseDevice::drawPatch(const SkPoint cubics[12], const SkColor colors[4],
-                             const SkPoint texCoords[4], SkBlendMode bmode, const SkPaint& paint) {
+                             const SkPoint texCoords[4], SkBlendMode bmode,
+                             bool interpColorsLinearly, const SkPaint& paint) {
     SkISize lod = SkPatchUtils::GetLevelOfDetail(cubics, &this->ctm());
-    auto vertices = SkPatchUtils::MakeVertices(cubics, colors, texCoords, lod.width(), lod.height());
+    auto vertices = SkPatchUtils::MakeVertices(cubics, colors, texCoords, lod.width(), lod.height(),
+                                               interpColorsLinearly);
     if (vertices) {
         this->drawVertices(vertices.get(), bmode, paint);
     }