Add preliminary ASTC encoder

src/utils/SkTextureCompressor.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.h"
+#include "SkTextureCompressor_ASTC.h"
+#include "SkTextureCompressor_LATC.h"
 #include "SkTextureCompressor_R11EAC.h"
-#include "SkTextureCompressor_LATC.h"
 
 #include "SkBitmap.h"
 #include "SkData.h"
 #include "SkEndian.h"
 
 #include "SkTextureCompression_opts.h"
 
 ////////////////////////////////////////////////////////////////////////////////
 
 namespace SkTextureCompressor {
 
 int GetCompressedDataSize(Format fmt, int width, int height) {
+    int blockDimension = 0;
+    int encodedBlockSize = 0;
+            
     switch (fmt) {
         // These formats are 64 bits per 4x4 block.
         case kR11_EAC_Format:
         case kLATC_Format:
-        {
-            static const int kBlockDimension = 4;
-            static const int kEncodedBlockSize = 8;
+            blockDimension = 4;
+            encodedBlockSize = 8;
+            break;
 
-            if(((width % kBlockDimension) == 0) && ((height % kBlockDimension) == 0)) {
-
-                const int blocksX = width / kBlockDimension;
-                const int blocksY = height / kBlockDimension;
-
-                return blocksX * blocksY * kEncodedBlockSize;
-            }
-
-            return -1;
-        }
+        // This format is 12x12 blocks to 128 bits.
+        case kASTC_12x12_Format:
+            blockDimension = 12;
+            encodedBlockSize = 16;
+            break;
 
         default:
             SkFAIL("Unknown compressed format!");
             return -1;
     }
+
+    if(((width % blockDimension) == 0) && ((height % blockDimension) == 0)) {
+        const int blocksX = width / blockDimension;
+        const int blocksY = height / blockDimension;
+
+        return blocksX * blocksY * encodedBlockSize;
+    }
+
+    return -1;
 }
 
 bool CompressBufferToFormat(uint8_t* dst, const uint8_t* src, SkColorType srcColorType,
                             int width, int height, int rowBytes, Format format, bool opt) {
     CompressionProc proc = NULL;
     if (opt) {
         proc = SkTextureCompressorGetPlatformProc(srcColorType, format);
     }
 
     if (NULL == proc) {
         switch (srcColorType) {
             case kAlpha_8_SkColorType:
             {
                 switch (format) {
                     case kLATC_Format:
                         proc = CompressA8ToLATC;
                         break;
                     case kR11_EAC_Format:
                         proc = CompressA8ToR11EAC;
                         break;
+                    case kASTC_12x12_Format:
+                        proc = CompressA8To12x12ASTC;
+                        break;
                     default:
                         // Do nothing...
                         break;
                 }
             }
             break;
 
             default:
                 // Do nothing...
                 break;
@@ skipping 36 matching lines @@
             return CreateR11EACBlitter(width, height, compressedBuffer);
 
         default:
             return NULL;
     }
 
     return NULL;
 }
 
 }  // namespace SkTextureCompressor