Initial work to get ETC1 data up to the GPU

Committed: http://code.google.com/p/skia/source/detail?r=15001

R=bsalomon@google.com, robertphillips@google.com

Author: krajcevski@google.com

Review URL: https://codereview.chromium.org/302783002

2 files changed, 23 insertions, 3 deletions

diff --git a/include/gpu/GrContext.h b/include/gpu/GrContext.h
index 5b7ef25ced..c54f2e6b23 100644
--- a/include/gpu/GrContext.h
+++ b/include/gpu/GrContext.h
@@ -204,10 +204,11 @@ public:
      *                  for different wrap modes on GPUs with limited NPOT
      *                  texture support). NULL implies clamp wrap modes.
      * @param desc      Description of the texture properties.
-     * @param cacheID Cache-specific properties (e.g., texture gen ID)
+     * @param cacheID   Cache-specific properties (e.g., texture gen ID)
      * @param srcData   Pointer to the pixel values.
      * @param rowBytes  The number of bytes between rows of the texture. Zero
-     *                  implies tightly packed rows.
+     *                  implies tightly packed rows. For compressed pixel configs, this
+     *                  field is ignored.
      * @param cacheKey  (optional) If non-NULL, we'll write the cache key we used to cacheKey.
      */
     GrTexture* createTexture(const GrTextureParams* params,
@@ -216,7 +217,6 @@ public:
                              const void* srcData,
                              size_t rowBytes,
                              GrResourceKey* cacheKey = NULL);
-
     /**
      * Search for an entry based on key and dimensions. If found, ref it and return it. The return
      * value will be NULL if not found. The caller must balance with a call to unref.
diff --git a/include/gpu/GrTypes.h b/include/gpu/GrTypes.h
index 53e633da57..34f4e2827d 100644
--- a/include/gpu/GrTypes.h
+++ b/include/gpu/GrTypes.h
@@ -641,6 +641,26 @@ enum GrGLBackendState {
 };
 
 /**
+ * Returns the data size for the given compressed pixel config
+ */ 
+static inline size_t GrCompressedFormatDataSize(GrPixelConfig config,
+                                                int width, int height) {
+    SkASSERT(GrPixelConfigIsCompressed(config));
+
+    switch (config) {
+        case kLATC_GrPixelConfig:
+        case kETC1_GrPixelConfig:
+            SkASSERT((width & 3) == 0);
+            SkASSERT((height & 3) == 0);
+            return (width >> 2) * (height >> 2) * 8;
+
+        default:
+            SkFAIL("Unknown compressed pixel config");
+            return 4 * width * height;
+    }
+}
+
+/**
  * This value translates to reseting all the context state for any backend.
  */
 static const uint32_t kAll_GrBackendState = 0xffffffff;