use from/to_srgb

Change-Id: I256dd98e1e918943195772954bc114e54b9325cd
Reviewed-on: https://skia-review.googlesource.com/140564
Commit-Queue: Mike Klein <mtklein@chromium.org>
Commit-Queue: Brian Osman <brianosman@google.com>
Auto-Submit: Mike Klein <mtklein@chromium.org>
Reviewed-by: Brian Osman <brianosman@google.com>

1 files changed, 18 insertions, 10 deletions

diff --git a/src/core/SkColorSpaceXformSteps.cpp b/src/core/SkColorSpaceXformSteps.cpp
index 4dfe56383a..d2f3881a1d 100644
--- a/src/core/SkColorSpaceXformSteps.cpp
+++ b/src/core/SkColorSpaceXformSteps.cpp
@@ -41,8 +41,10 @@ SkColorSpaceXformSteps::SkColorSpaceXformSteps(SkColorSpace* src, SkAlphaType sr
     SkColorSpaceTransferFn srcTF, dstTF;
     SkAssertResult(src->isNumericalTransferFn(&srcTF));
     SkAssertResult(dst->isNumericalTransferFn(&dstTF));
-    this->srcTF    = srcTF;
-    this->dstTFInv = dstTF.invert();
+    this->srcTF         = srcTF;
+    this->dstTFInv      = dstTF.invert();
+    this->srcTF_is_sRGB = src->gammaCloseToSRGB();
+    this->dstTF_is_sRGB = dst->gammaCloseToSRGB();
 
     // If we linearize then immediately reencode with the same transfer function, skip both.
     if ( this->flags.linearize       &&
@@ -103,19 +105,25 @@ void SkColorSpaceXformSteps::apply(float* rgba) const {
 void SkColorSpaceXformSteps::apply(SkRasterPipeline* p) const {
     if (flags.unpremul) { p->append(SkRasterPipeline::unpremul); }
     if (flags.linearize) {
-        // TODO: missing an opportunity to use from_srgb here.
-        p->append(SkRasterPipeline::parametric_r, &srcTF);
-        p->append(SkRasterPipeline::parametric_g, &srcTF);
-        p->append(SkRasterPipeline::parametric_b, &srcTF);
+        if (srcTF_is_sRGB) {
+            p->append(SkRasterPipeline::from_srgb);
+        } else {
+            p->append(SkRasterPipeline::parametric_r, &srcTF);
+            p->append(SkRasterPipeline::parametric_g, &srcTF);
+            p->append(SkRasterPipeline::parametric_b, &srcTF);
+        }
     }
     if (flags.gamut_transform) {
         p->append(SkRasterPipeline::matrix_3x3, &src_to_dst_matrix);
     }
     if (flags.encode) {
-        // TODO: missing an opportunity to use to_srgb here.
-        p->append(SkRasterPipeline::parametric_r, &dstTFInv);
-        p->append(SkRasterPipeline::parametric_g, &dstTFInv);
-        p->append(SkRasterPipeline::parametric_b, &dstTFInv);
+        if (dstTF_is_sRGB) {
+            p->append(SkRasterPipeline::to_srgb);
+        } else {
+            p->append(SkRasterPipeline::parametric_r, &dstTFInv);
+            p->append(SkRasterPipeline::parametric_g, &dstTFInv);
+            p->append(SkRasterPipeline::parametric_b, &dstTFInv);
+        }
     }
     if (flags.premul) { p->append(SkRasterPipeline::premul); }
 }