Add BlitRect to SkTCompressedAlphaBlitter

src/utils/SkTextureCompressor_ASTC.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkTextureCompressor_ASTC.h"
 #include "SkTextureCompressor_Blitter.h"
 
@@ skipping 1982 matching lines @@
     dst += data.fDimY * dstRowBytes;
     for (int y = 0; y < data.fDimY; ++y) {
         dst -= dstRowBytes;
         SkColor* colorPtr = reinterpret_cast<SkColor*>(dst);
         for (int x = 0; x < data.fDimX; ++x) {
             colorPtr[x] = data.getTexel(endpoints, texelWeights, x, y);
         }
     }
 }
 
+////////////////////////////////////////////////////////////////////////////////
+//
+// ASTC Comrpession Struct
+//
+////////////////////////////////////////////////////////////////////////////////
+
 // This is the type passed as the CompressorType argument of the compressed
 // blitter for the ASTC format. The static functions required to be in this
 // struct are documented in SkTextureCompressor_Blitter.h
 struct CompressorASTC {
     static inline void CompressA8Vertical(uint8_t* dst, const uint8_t* src) {
         compress_a8_astc_block<GetAlphaTranspose>(&dst, src, 12);
     }
 
     static inline void CompressA8Horizontal(uint8_t* dst, const uint8_t* src,
                                             int srcRowBytes) {
         compress_a8_astc_block<GetAlpha>(&dst, src, srcRowBytes);
     }
 
-    static inline void UpdateBlock(uint8_t* dst, const uint8_t* src) {
+#if PEDANTIC_BLIT_RECT
+    static inline void UpdateBlock(uint8_t* dst, const uint8_t* src, int srcRowBytes,
+                                   const uint8_t* mask) {
+        // TODO: krajcevski
+        // This is kind of difficult for ASTC because the weight values are calculated
+        // as an average of the actual weights. The best we can do is decompress the
+        // weights and recalculate them based on the new texel values. This should
+        // be "not too bad" since we know that anytime we hit this function, we're
+        // compressing 12x12 block dimension alpha-only, and we know the layout
+        // of the block
+        SkFAIL("Implement me!");
     }
+#endif
 };
 
 ////////////////////////////////////////////////////////////////////////////////
 
 namespace SkTextureCompressor {
 
 bool CompressA8To12x12ASTC(uint8_t* dst, const uint8_t* src,
                            int width, int height, int rowBytes) {
     if (width < 0 || ((width % 12) != 0) || height < 0 || ((height % 12) != 0)) {
         return false;
@@ skipping 47 matching lines @@
             read_astc_block(&data, src);
             decompress_astc_block(reinterpret_cast<uint8_t*>(colorPtr + x), dstRowBytes, data);
 
             // ASTC encoded blocks are 16 bytes (128 bits) large.
             src += 16;
         }
     }
 }
 
 }  // SkTextureCompressor