3 files changed, 73 insertions, 1 deletions

diff --git a/src/mesa/drivers/dri/intel/intel_extensions.c b/src/mesa/drivers/dri/intel/intel_extensions.c
index 953b98389c3..844125dc8a5 100755
--- a/src/mesa/drivers/dri/intel/intel_extensions.c
+++ b/src/mesa/drivers/dri/intel/intel_extensions.c
@@ -91,6 +91,7 @@ intelInitExtensions(struct gl_context *ctx)
    ctx->Extensions.OES_EGL_image = true;
 #endif
    ctx->Extensions.OES_draw_texture = true;
+   ctx->Extensions.OES_compressed_ETC1_RGB8_texture = true;
 
    if (intel->gen >= 6)
       ctx->Const.GLSLVersion = 130;
diff --git a/src/mesa/drivers/dri/intel/intel_mipmap_tree.c b/src/mesa/drivers/dri/intel/intel_mipmap_tree.c
index 4e892b27fd1..d6572cd90f1 100644
--- a/src/mesa/drivers/dri/intel/intel_mipmap_tree.c
+++ b/src/mesa/drivers/dri/intel/intel_mipmap_tree.c
@@ -38,6 +38,7 @@
 #include "main/enums.h"
 #include "main/formats.h"
 #include "main/image.h"
+#include "main/texcompress_etc.h"
 #include "main/teximage.h"
 
 #define FILE_DEBUG_FLAG DEBUG_MIPTREE
@@ -190,7 +191,15 @@ intel_miptree_create(struct intel_context *intel,
 {
    struct intel_mipmap_tree *mt;
    uint32_t tiling = I915_TILING_NONE;
-   GLenum base_format = _mesa_get_format_base_format(format);
+   GLenum base_format;
+   bool wraps_etc1 = false;
+
+   if (format == MESA_FORMAT_ETC1_RGB8) {
+      format = MESA_FORMAT_RGBX8888_REV;
+      wraps_etc1 = true;
+   }
+
+   base_format = _mesa_get_format_base_format(format);
 
    if (intel->use_texture_tiling && !_mesa_is_format_compressed(format)) {
       if (intel->gen >= 4 &&
@@ -237,6 +246,7 @@ intel_miptree_create(struct intel_context *intel,
       return NULL;
    }
 
+   mt->wraps_etc1 = wraps_etc1;
    mt->region = intel_region_alloc(intel->intelScreen,
 				   tiling,
 				   mt->cpp,
@@ -1049,6 +1059,60 @@ intel_miptree_unmap_s8(struct intel_context *intel,
    free(map->buffer);
 }
 
+static void
+intel_miptree_map_etc1(struct intel_context *intel,
+                       struct intel_mipmap_tree *mt,
+                       struct intel_miptree_map *map,
+                       unsigned int level,
+                       unsigned int slice)
+{
+   /* For justification of these invariants,
+    * see intel_mipmap_tree:wraps_etc1.
+    */
+   assert(mt->wraps_etc1);
+   assert(mt->format == MESA_FORMAT_RGBX8888_REV);
+
+   /* From the GL_OES_compressed_ETC1_RGB8_texture spec:
+    *   INVALID_OPERATION is generated by CompressedTexSubImage2D,
+    *   TexSubImage2D, or CopyTexSubImage2D if the texture image <level>
+    *   bound to <target> has internal format ETC1_RGB8_OES.
+    *
+    * This implies that intel_miptree_map_etc1() can only be called from
+    * glCompressedTexImage2D, and hence the assertions below hold.
+    */
+   assert(map->mode & GL_MAP_WRITE_BIT);
+   assert(map->mode & GL_MAP_INVALIDATE_RANGE_BIT);
+   assert(map->x == 0);
+   assert(map->y == 0);
+
+   /* Each ETC1 block contains 4x4 pixels in 8 bytes. */
+   map->stride = 2 * map->w;
+   map->buffer = map->ptr = malloc(map->stride * map->h);
+}
+
+static void
+intel_miptree_unmap_etc1(struct intel_context *intel,
+                         struct intel_mipmap_tree *mt,
+                         struct intel_miptree_map *map,
+                         unsigned int level,
+                         unsigned int slice)
+{
+   uint32_t image_x;
+   uint32_t image_y;
+   intel_miptree_get_image_offset(mt, level, 0, slice, &image_x, &image_y);
+
+   uint8_t *xbgr = intel_region_map(intel, mt->region, map->mode)
+                 + image_y * mt->region->pitch * mt->region->cpp
+                 + image_x * mt->region->cpp;
+
+   _mesa_etc1_unpack_rgba8888(xbgr, mt->region->pitch * mt->region->cpp,
+                              map->ptr, map->stride,
+                              map->w, map->h);
+
+   intel_region_unmap(intel, mt->region);
+   free(map->buffer);
+}
+
 /**
  * Mapping function for packed depth/stencil miptrees backed by real separate
  * miptrees for depth and stencil.
@@ -1225,6 +1289,8 @@ intel_miptree_map(struct intel_context *intel,
 
    if (mt->format == MESA_FORMAT_S8) {
       intel_miptree_map_s8(intel, mt, map, level, slice);
+   } else if (mt->wraps_etc1) {
+      intel_miptree_map_etc1(intel, mt, map, level, slice);
    } else if (mt->stencil_mt) {
       intel_miptree_map_depthstencil(intel, mt, map, level, slice);
    } else if (intel->has_llc &&
@@ -1261,6 +1327,8 @@ intel_miptree_unmap(struct intel_context *intel,
 
    if (mt->format == MESA_FORMAT_S8) {
       intel_miptree_unmap_s8(intel, mt, map, level, slice);
+   } else if (mt->wraps_etc1) {
+      intel_miptree_unmap_etc1(intel, mt, map, level, slice);
    } else if (mt->stencil_mt) {
       intel_miptree_unmap_depthstencil(intel, mt, map, level, slice);
    } else if (map->bo) {
diff --git a/src/mesa/drivers/dri/intel/intel_mipmap_tree.h b/src/mesa/drivers/dri/intel/intel_mipmap_tree.h
index 74fcc796cf5..2fb5775c02f 100644
--- a/src/mesa/drivers/dri/intel/intel_mipmap_tree.h
+++ b/src/mesa/drivers/dri/intel/intel_mipmap_tree.h
@@ -190,6 +190,9 @@ struct intel_mipmap_tree
     * MESA_FORMAT_Z32_FLOAT_X24S8, then mt->format will be
     * MESA_FORMAT_Z32_FLOAT, otherwise for MESA_FORMAT_S8_Z24 objects it will be
     * MESA_FORMAT_X8_Z24.
+    *
+    * For ETC1 textures, this is MESA_FORMAT_RGBX8888_REV if the hardware
+    * lacks support for ETC1. See @ref wraps_etc1.
     */
    gl_format format;