Add clamped/unclamped xform to GrColorSpaceXform

Use that in analytic gradient setup for future-proofing. Also fixed
several out-of-date comments in gradient code.

Bug: skia:
Change-Id: I79726cad786c22f80e08cdc2b7a1e15ae27ecd5a
Reviewed-on: https://skia-review.googlesource.com/62320
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Brian Osman <brianosman@google.com>

3 files changed, 10 insertions, 4 deletions

diff --git a/src/gpu/GrColorSpaceXform.cpp b/src/gpu/GrColorSpaceXform.cpp
index 0e98a87f6c..e43ccdc14d 100644
--- a/src/gpu/GrColorSpaceXform.cpp
+++ b/src/gpu/GrColorSpaceXform.cpp
@@ -121,11 +121,16 @@ bool GrColorSpaceXform::Equals(const GrColorSpaceXform* a, const GrColorSpaceXfo
     return a->fSrcToDst == b->fSrcToDst;
 }
 
-GrColor4f GrColorSpaceXform::apply(const GrColor4f& srcColor) {
+GrColor4f GrColorSpaceXform::unclampedXform(const GrColor4f& srcColor) {
     GrColor4f result;
     fSrcToDst.mapScalars(srcColor.fRGBA, result.fRGBA);
-    // We always operate on unpremul colors, so clamp to [0,1].
+    return result;
+}
+
+GrColor4f GrColorSpaceXform::clampedXform(const GrColor4f& srcColor) {
+    GrColor4f result = this->unclampedXform(srcColor);
     for (int i = 0; i < 4; ++i) {
+        // We always operate on unpremul colors, so clamp to [0,1].
         result.fRGBA[i] = SkTPin(result.fRGBA[i], 0.0f, 1.0f);
     }
     return result;
diff --git a/src/gpu/GrColorSpaceXform.h b/src/gpu/GrColorSpaceXform.h
index b871563387..3f03e5652d 100644
--- a/src/gpu/GrColorSpaceXform.h
+++ b/src/gpu/GrColorSpaceXform.h
@@ -37,7 +37,8 @@ public:
 
     static bool Equals(const GrColorSpaceXform* a, const GrColorSpaceXform* b);
 
-    GrColor4f apply(const GrColor4f& srcColor);
+    GrColor4f unclampedXform(const GrColor4f& srcColor);
+    GrColor4f clampedXform(const GrColor4f& srcColor);
 
 private:
     SkMatrix44 fSrcToDst;
diff --git a/src/gpu/SkGr.cpp b/src/gpu/SkGr.cpp
index 0c065f9c74..2d09f00719 100644
--- a/src/gpu/SkGr.cpp
+++ b/src/gpu/SkGr.cpp
@@ -342,7 +342,7 @@ GrColor4f SkColorToUnpremulGrColor4f(SkColor c, SkColorSpace* dstColorSpace,
     }
 
     if (gamutXform) {
-        color = gamutXform->apply(color);
+        color = gamutXform->clampedXform(color);
     }
 
     return color;