From 5320a72a882f505682f47978d2e38778113900fa Mon Sep 17 00:00:00 2001
From: Matt Sarett <msarett@google.com>
Date: Mon, 20 Mar 2017 13:51:29 -0400
Subject: [PATCH] Support Alpha8->RGBA bitmap copying

Skia recently dropped support for this conversion.  So this adds
an implementation to the framework.

This also unifies framework behavior to treat Alpha8 as
implicitly black when it must be converted to a color.

Test: CTS

BUG:36202415

Change-Id: Ia141733387e80f7e61bae472e632cdfbac67b2e0
---
 core/jni/android/graphics/Bitmap.cpp | 50 ++++++++++++++++++++++++++--
 1 file changed, 47 insertions(+), 3 deletions(-)

diff --git a/core/jni/android/graphics/Bitmap.cpp b/core/jni/android/graphics/Bitmap.cpp
index a8d683028c13f..de5e505af3daa 100755
--- a/core/jni/android/graphics/Bitmap.cpp
+++ b/core/jni/android/graphics/Bitmap.cpp
@@ -621,7 +621,7 @@ static void ToColor_SA8(SkColor dst[], const void* src, int width, SkColorTable*
     const uint8_t* s = (const uint8_t*)src;
     do {
         uint8_t c = *s++;
-        *dst++ = SkColorSetARGB(c, c, c, c);
+        *dst++ = SkColorSetARGB(c, 0, 0, 0);
     } while (--width != 0);
 }
 
@@ -727,6 +727,50 @@ static jobject Bitmap_creator(JNIEnv* env, jobject, jintArray jColors,
     return createBitmap(env, nativeBitmap.release(), getPremulBitmapCreateFlags(isMutable));
 }
 
+static bool bitmapCopyTo(SkBitmap* dst, SkColorType dstCT, const SkBitmap& src,
+        SkBitmap::Allocator* alloc) {
+    // Skia does not support copying from kAlpha8 to types that are not alpha only.
+    // We will handle this case here.
+    if (kAlpha_8_SkColorType == src.colorType() && kAlpha_8_SkColorType != dstCT) {
+        SkAutoPixmapUnlock srcUnlocker;
+        if (!src.requestLock(&srcUnlocker)) {
+            return false;
+        }
+        SkPixmap srcPixmap = srcUnlocker.pixmap();
+
+        SkImageInfo dstInfo = src.info().makeColorType(dstCT);
+        if (!dst->setInfo(dstInfo)) {
+            return false;
+        }
+        if (!dst->tryAllocPixels(alloc, nullptr)) {
+            return false;
+        }
+
+        switch (dstCT) {
+            case kRGBA_8888_SkColorType:
+            case kBGRA_8888_SkColorType: {
+                for (int y = 0; y < src.height(); y++) {
+                    const uint8_t* srcRow = srcPixmap.addr8(0, y);
+                    uint32_t* dstRow = dst->getAddr32(0, y);
+                    ToColor_SA8(dstRow, srcRow, src.width(), nullptr);
+                }
+                return true;
+            }
+            case kRGB_565_SkColorType: {
+                for (int y = 0; y < src.height(); y++) {
+                    uint16_t* dstRow = dst->getAddr16(0, y);
+                    memset(dstRow, 0, sizeof(uint16_t) * src.width());
+                }
+                return true;
+            }
+            default:
+                return false;
+        }
+    }
+
+    return src.copyTo(dst, dstCT, alloc);
+}
+
 static jobject Bitmap_copy(JNIEnv* env, jobject, jlong srcHandle,
                            jint dstConfigHandle, jboolean isMutable) {
     SkBitmap src;
@@ -743,7 +787,7 @@ static jobject Bitmap_copy(JNIEnv* env, jobject, jlong srcHandle,
     SkBitmap result;
     HeapAllocator allocator;
 
-    if (!src.copyTo(&result, dstCT, &allocator)) {
+    if (!bitmapCopyTo(&result, dstCT, src, &allocator)) {
         return NULL;
     }
     auto bitmap = allocator.getStorageObjAndReset();
@@ -754,7 +798,7 @@ static Bitmap* Bitmap_copyAshmemImpl(JNIEnv* env, SkBitmap& src, SkColorType& ds
     SkBitmap result;
 
     AshmemPixelAllocator allocator(env);
-    if (!src.copyTo(&result, dstCT, &allocator)) {
+    if (!bitmapCopyTo(&result, dstCT, src, &allocator)) {
         return NULL;
     }
     auto bitmap = allocator.getStorageObjAndReset();