Merge "Decode images to sRGB, premultiply based on framework define"

2 files changed, 50 insertions, 3 deletions

diff --git a/core/jni/Android.mk b/core/jni/Android.mk
index a13ebaf55cf4..252f168040df 100644
--- a/core/jni/Android.mk
+++ b/core/jni/Android.mk
@@ -215,6 +215,7 @@ LOCAL_C_INCLUDES += \
     external/skia/src/effects \
     external/skia/src/image \
     external/skia/src/images \
+    external/skia/src/utils \
     external/sqlite/dist \
     external/sqlite/android \
     external/tremor/Tremor \
diff --git a/core/jni/android/graphics/BitmapFactory.cpp b/core/jni/android/graphics/BitmapFactory.cpp
index 1165a45c1535..19d4848e1656 100644
--- a/core/jni/android/graphics/BitmapFactory.cpp
+++ b/core/jni/android/graphics/BitmapFactory.cpp
@@ -8,6 +8,7 @@
 #include "SkBRDAllocator.h"
 #include "SkFrontBufferedStream.h"
 #include "SkMath.h"
+#include "SkOpts.h"
 #include "SkPixelRef.h"
 #include "SkStream.h"
 #include "SkUtils.h"
@@ -224,6 +225,45 @@ static bool needsFineScale(const SkISize fullSize, const SkISize decodedSize,
            needsFineScale(fullSize.height(), decodedSize.height(), sampleSize);
 }
 
+static inline SkAlphaType computeDecodeAlphaType(SkColorType colorType, SkAlphaType alphaType) {
+#ifndef ANDROID_ENABLE_LINEAR_BLENDING
+    // Skia premultiplies linearly.  Until the framework enables linear blending,
+    // it expects a legacy premultiply.
+    if (kPremul_SkAlphaType == alphaType && kRGBA_F16_SkColorType != colorType) {
+        return kUnpremul_SkAlphaType;
+    }
+#endif
+
+    return alphaType;
+}
+
+static inline void premultiplyIfNecessary(SkBitmap* bitmap, SkPMColor* colorPtr, int* colorCount,
+        SkAlphaType alphaType, bool requireUnpremultiplied) {
+#ifndef ANDROID_ENABLE_LINEAR_BLENDING
+    if (kUnpremul_SkAlphaType != alphaType || requireUnpremultiplied) {
+        return;
+    }
+
+    switch (bitmap->colorType()) {
+        case kN32_SkColorType:
+            for (int y = 0; y < bitmap->height(); y++) {
+                SkOpts::RGBA_to_rgbA(bitmap->getAddr32(0, y), bitmap->getAddr32(0, y),
+                    bitmap->width());
+            }
+
+            return;
+        case kIndex_8_SkColorType:
+            SkOpts::RGBA_to_rgbA(colorPtr, colorPtr, *colorCount);
+            return;
+        default:
+            // kRGBA_F16 will be premultiplied by the codec if necessary.
+            // kGray_8 (alias kAlpha_8) and k565 are opaque.
+            LOG_ALWAYS_FATAL("Should be unreachable - no need for legacy premultiply.");
+            return;
+    }
+#endif
+}
+
 static jobject doDecode(JNIEnv* env, SkStreamRewindable* stream, jobject padding, jobject options) {
     // This function takes ownership of the input stream.  Since the SkAndroidCodec
     // will take ownership of the stream, we don't necessarily need to take ownership
@@ -391,13 +431,17 @@ static jobject doDecode(JNIEnv* env, SkStreamRewindable* stream, jobject padding
         colorCount = &maxColors;
     }
 
-    // Set the alpha type for the decode.
     SkAlphaType alphaType = codec->computeOutputAlphaType(requireUnpremultiplied);
+    SkAlphaType decodeAlphaType = computeDecodeAlphaType(decodeColorType, alphaType);
 
     const SkImageInfo decodeInfo = SkImageInfo::Make(size.width(), size.height(),
-            decodeColorType, alphaType, GraphicsJNI::colorSpaceForType(decodeColorType));
+            decodeColorType, decodeAlphaType, codec->computeOutputColorSpace(decodeColorType));
+
+    // When supported by the colorType, we will decode to sRGB (or linear sRGB).  However,
+    // we only want to mark the bitmap as sRGB when linear blending is enabled.
+    SkImageInfo bitmapInfo = decodeInfo.makeAlphaType(alphaType)
+            .makeColorSpace(GraphicsJNI::colorSpaceForType(decodeColorType));
 
-    SkImageInfo bitmapInfo = decodeInfo;
     if (decodeColorType == kGray_8_SkColorType) {
         // The legacy implementation of BitmapFactory used kAlpha8 for
         // grayscale images (before kGray8 existed).  While the codec
@@ -433,6 +477,8 @@ static jobject doDecode(JNIEnv* env, SkStreamRewindable* stream, jobject padding
         default:
             return nullObjectReturn("codec->getAndroidPixels() failed.");
     }
+    premultiplyIfNecessary(&decodingBitmap, colorPtr, colorCount, decodeAlphaType,
+            requireUnpremultiplied);
 
     jbyteArray ninePatchChunk = NULL;
     if (peeker.mPatch != NULL) {