commit 2e61b182dad86e592d12c8a73ffcc7555a6e11a2
author Matt Sarett <msarett@google.com> Tue May 09 12:46:50 2017 -0400
committer Skia Commit-Bot <skia-commit-bot@chromium.org> Tue May 09 18:32:04 2017 +0000
tree 323281b163e71f8058eab694c9562a2c1b007b67
parent ee2d9df087c5225c9f3ba0fb98d237905f2d650c

Add jpeg encoder alpha handling option

This instructs us on how to encode jpegs when the src
image has alpha.  The original behavior is to ignore
the alpha channel.  This CL adds the option to blend
the pixels onto opaque black.

Note that kBlendOnBlack and kIgnore are identical
unless the input alpha type is kUnpremul.

Bug: 713862
Bug: skia:1501
Change-Id: I4891c70bb0ccd83f7974c359bd40a2143b5c49ac
Reviewed-on: https://skia-review.googlesource.com/15817
Reviewed-by: Leon Scroggins <scroggo@google.com>
Commit-Queue: Matt Sarett <msarett@google.com>

src/images/SkImageEncoderFns.h

diff --git a/src/images/SkImageEncoderFns.h b/src/images/SkImageEncoderFns.h
index 5120570..af75ac9 100644
--- a/src/images/SkImageEncoderFns.h
+++ b/src/images/SkImageEncoderFns.h
@@ -16,6 +16,7 @@
 #include "SkColor.h"
 #include "SkColorPriv.h"
 #include "SkICC.h"
+#include "SkOpts.h"
 #include "SkPreConfig.h"
 #include "SkRasterPipeline.h"
 #include "SkUnPreMultiply.h"
@@ -165,6 +166,30 @@
 }
 
 /**
+ * Premultiply RGBA to rgbA.
+ */
+static inline void transform_scanline_to_premul_legacy(char* SK_RESTRICT dst,
+                                                       const char* SK_RESTRICT src,
+                                                       int width, int, const SkPMColor*) {
+    SkOpts::RGBA_to_rgbA((uint32_t*)dst, (const uint32_t*)src, width);
+}
+
+/**
+ * Premultiply RGBA to rgbA linearly.
+ */
+static inline void transform_scanline_to_premul_linear(char* SK_RESTRICT dst,
+                                                       const char* SK_RESTRICT src,
+                                                       int width, int, const SkPMColor*) {
+    SkRasterPipeline p;
+    p.append(SkRasterPipeline::load_8888, (const void**) &src);
+    p.append_from_srgb(kUnpremul_SkAlphaType);
+    p.append(SkRasterPipeline::premul);
+    p.append(SkRasterPipeline::to_srgb);
+    p.append(SkRasterPipeline::store_8888, (void**) &dst);
+    p.run(0, width);
+}
+
+/**
  * Transform from kPremul, kRGBA_8888_SkColorType to 4-bytes-per-pixel unpremultiplied RGBA.
  */
 static inline void transform_scanline_srgbA(char* SK_RESTRICT dst, const char* SK_RESTRICT src,
@@ -276,6 +301,19 @@
     p.run(0, width);
 }
 
+/**
+ * Transform from kUnpremul, kRGBA_F16 to premultiplied rgbA 8888.
+ */
+static inline void transform_scanline_F16_to_premul_8888(char* SK_RESTRICT dst,
+        const char* SK_RESTRICT src, int width, int, const SkPMColor*) {
+    SkRasterPipeline p;
+    p.append(SkRasterPipeline::load_f16, (const void**) &src);
+    p.append(SkRasterPipeline::premul);
+    p.append(SkRasterPipeline::to_srgb);
+    p.append(SkRasterPipeline::store_8888, (void**) &dst);
+    p.run(0, width);
+}
+
 static inline sk_sp<SkData> icc_from_color_space(const SkColorSpace& cs) {
     SkColorSpaceTransferFn fn;
     SkMatrix44 toXYZD50(SkMatrix44::kUninitialized_Constructor);