Initial work to get ETC1 data up to the GPU

include/gpu/GrTypes.h

Index: include/gpu/GrTypes.h
diff --git a/include/gpu/GrTypes.h b/include/gpu/GrTypes.h
index 5868a39e7d22add6a914351a166d6d28e0d08188..ba40718a06d3c3a07e15b36e5a74941e60e8bba2 100644
--- a/include/gpu/GrTypes.h
+++ b/include/gpu/GrTypes.h
@@ -634,6 +634,37 @@ enum GrCompressedFormat {
 static const int kGrCompressedFormatCount = kLast_GrCompressedFormat + 1;
 
 /**
+ * This structure contains relevant information for the various kinds of
+ * compressed texture formats. The information is used when determining
+ * data size of compressed textures for a given width and height, along
+ * with how to properly index into compressed textures for a given pixel
+ * location.
+ */
+struct GrCompressedFormatDesc {
+    int fBlockSizeX;
+    int fBlockSizeY;
+    int fBytesPerBlock;
+};
+
+static inline GrCompressedFormatDesc
+GrGetCompressedFormatDesc(GrCompressedFormat fmt) {
+    GrCompressedFormatDesc desc;
+    switch (fmt) {
+        case kETC1_GrCompressedFormat:
+        case kETC2_GrCompressedFormat:
+        case kDXT1_GrCompressedFormat:
+            desc.fBlockSizeX = 4;
+            desc.fBlockSizeY = 4;
+            desc.fBytesPerBlock = 4;

[robertphillips, 2014/05/27 22:01:50]

break; ?

[krajcevski, 2014/05/27 22:19:29]

Done.

+            
+        default:
+            SkASSERT(!"Unknown compressed format!");
+            break;
+    }
+    return desc;
+}
+
+/**
  * This value translates to reseting all the context state for any backend.
  */
 static const uint32_t kAll_GrBackendState = 0xffffffff;