Add the ability to provide function pointers to SkPicture serialization

and deserialization for encoding and decoding bitmaps.

Remove kForceFlattenBitmapPixels_Flag, which is no longer used.

When an SkOrderedReadBuffer needs to read a bitmap, if it does not
have an image decoder, use a dummy bitmap.

In GM, add a tolerance option for color differences, used when
testing picture serialization, so it can assume two images are the
same even though PNG encoding/decoding may have resulted in small
differences.

Create dummy implementations for SkImageDecoder and SkImageEncoder
functions in SkImageDecoder_empty so that a project that does not
want to include the images project it can still build.

Allow ports to build without images project.

In Mac's image encoder, copy 4444 to 8888 before encoding.

Add SkWriter32::reservePad, to provide a pointer to write non 4 byte
aligned data, padded with zeroes.

In bench_ and render_ pictures, pass decode function to SkPicture
creation from a stream.

BUG=https://code.google.com/p/skia/issues/detail?id=842

Review URL: https://codereview.appspot.com/6551071

git-svn-id: http://skia.googlecode.com/svn/trunk@5818 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 10 insertions, 3 deletions

diff --git a/src/core/SkWriter32.cpp b/src/core/SkWriter32.cpp
index 3ae6a0775c..6a8492731b 100644
--- a/src/core/SkWriter32.cpp
+++ b/src/core/SkWriter32.cpp
@@ -226,14 +226,21 @@ void SkWriter32::flatten(void* dst) const {
     SkASSERT(total == fSize);
 }
 
-void SkWriter32::writePad(const void* src, size_t size) {
+uint32_t* SkWriter32::reservePad(size_t size) {
     if (size > 0) {
         size_t alignedSize = SkAlign4(size);
         char* dst = (char*)this->reserve(alignedSize);
-        // Pad the last four bytes with zeroes in one step. Some (or all) will
-        // be overwritten by the memcpy.
+        // Pad the last four bytes with zeroes in one step.
         uint32_t* padding = (uint32_t*)(dst + (alignedSize - 4));
         *padding = 0;
+        return (uint32_t*) dst;
+    }
+    return this->reserve(0);
+}
+
+void SkWriter32::writePad(const void* src, size_t size) {
+    if (size > 0) {
+        char* dst = (char*)this->reservePad(size);
         // Copy the actual data.
         memcpy(dst, src, size);
     }