support colortables in cacherator

src/core/SkImageCacherator.cpp

Index: src/core/SkImageCacherator.cpp
diff --git a/src/core/SkImageCacherator.cpp b/src/core/SkImageCacherator.cpp
index 82f36edfb378724757de4700f957396a8720886d..8c0e415770fb7539c50370f4541708c99bc9a519 100644
--- a/src/core/SkImageCacherator.cpp
+++ b/src/core/SkImageCacherator.cpp
@@ -70,36 +70,63 @@ static bool check_output_bitmap(const SkBitmap& bitmap, uint32_t expectedID) {
     return true;
 }
 
-bool SkImageCacherator::generateBitmap(SkBitmap* bitmap) {
-    const size_t rowBytes = fInfo.minRowBytes();
-    if (!bitmap->tryAllocPixels(fInfo, rowBytes)) {
+static void release_malloc_proc(void* pixels, void* ctx) {
+    sk_free(pixels);
+}
+
+static bool generate_a_bitmap(SkBitmap* bitmap, SkImageGenerator* gen, const SkImageInfo& info) {
+    const size_t rowBytes = info.minRowBytes();
+    const size_t pixelSize = info.getSafeSize(rowBytes);
+    if (0 == pixelSize) {
+        return false;
+    }
+
+    SkAutoFree pixelStorage(sk_malloc_flags(pixelSize, 0));
+    void* pixels = pixelStorage.get();
+    if (!pixels) {
+        return false;
+    }
+
+    SkPMColor ctStorage[256];
+    int ctCount = 0;
+
+    if (!gen->getPixels(info, pixels, rowBytes, ctStorage, &ctCount)) {
         return false;
     }
-    SkASSERT(bitmap->rowBytes() == rowBytes);
 
+    SkAutoTUnref<SkColorTable> ctable;
+    if (ctCount > 0) {
+        SkASSERT(kIndex_8_SkColorType == info.colorType());
+        ctable.reset(new SkColorTable(ctStorage, ctCount));
+    } else {
+        SkASSERT(kIndex_8_SkColorType != info.colorType());
+    }
+
+    return bitmap->installPixels(info, pixelStorage.detach(), rowBytes, ctable,
+                                 release_malloc_proc, nullptr);
+}
+
+bool SkImageCacherator::generateBitmap(SkBitmap* bitmap) {
     ScopedGenerator generator(this);
     const SkImageInfo& genInfo = generator->getInfo();
     if (fInfo.dimensions() == genInfo.dimensions()) {
         SkASSERT(fOrigin.x() == 0 && fOrigin.y() == 0);
         // fast-case, no copy needed
-        if (!generator->getPixels(bitmap->info(), bitmap->getPixels(), rowBytes)) {
-            bitmap->reset();
-            return false;
-        }
+        return generate_a_bitmap(bitmap, generator, fInfo);
     } else {
-        // need to handle subsetting
+        // need to handle subsetting, so we first generate the full size version, and then
+        // "read" from it to get our subset. See skbug.com/4213
+
         SkBitmap full;
-        if (!full.tryAllocPixels(genInfo)) {
+        if (!generate_a_bitmap(&full, generator, genInfo)) {
             return false;
         }
-        if (!generator->getPixels(full.info(), full.getPixels(), full.rowBytes())) {
-            bitmap->reset();
+        if (!bitmap->tryAllocPixels(fInfo, nullptr, full.getColorTable())) {
             return false;
         }
-        full.readPixels(bitmap->info(), bitmap->getPixels(), bitmap->rowBytes(),
-                        fOrigin.x(), fOrigin.y());
+        return full.readPixels(bitmap->info(), bitmap->getPixels(), bitmap->rowBytes(),
+                               fOrigin.x(), fOrigin.y());
     }
-    return true;
 }
 
 //////////////////////////////////////////////////////////////////////////////////////////////////