dri: add __DRIimageLoaderExtension and __DRIimageDriverExtension

These provide an interface between the driver and the loader to allocate
color buffers through the DRIimage extension interface rather than through a
loader-specific extension (as is used by DRI2, for instance).

The driver uses the loader 'getBuffers' interface to allocate color buffers.

The loader uses the createNewScreen2, createNewDrawable, createNewContext,
getAPIMask and createContextAttribs APIS (mostly shared with DRI2).

This interface will work with the DRI3 loader, and should also work with GBM
and other loaders so that drivers need not be customized for each new loader
interface, as long as they provide this image interface.

v2: Fix build of i915 and i965 together (by anholt)

Signed-off-by: Keith Packard <[email protected]>
Reviewed-by: Kristian Høgsberg <[email protected]>
Reviewed-by: Eric Anholt <[email protected]>

11 files changed, 352 insertions, 11 deletions

diff --git a/src/mesa/drivers/dri/common/dri_util.c b/src/mesa/drivers/dri/common/dri_util.c
index 46a2da4cb59..86cf24cb881 100644
--- a/src/mesa/drivers/dri/common/dri_util.c
+++ b/src/mesa/drivers/dri/common/dri_util.c
@@ -78,6 +78,8 @@ setupLoaderExtensions(__DRIscreen *psp,
 	    psp->dri2.useInvalidate = (__DRIuseInvalidateExtension *) extensions[i];
 	if (strcmp(extensions[i]->name, __DRI_SWRAST_LOADER) == 0)
 	    psp->swrast_loader = (__DRIswrastLoaderExtension *) extensions[i];
+        if (strcmp(extensions[i]->name, __DRI_IMAGE_LOADER) == 0)
+           psp->image.loader = (__DRIimageLoaderExtension *) extensions[i];
     }
 }
 
@@ -859,3 +861,14 @@ driImageFormatToGLFormat(uint32_t image_format)
       return MESA_FORMAT_NONE;
    }
 }
+
+/** Image driver interface */
+const __DRIimageDriverExtension driImageDriverExtension = {
+    .base = { __DRI_IMAGE_DRIVER, __DRI_IMAGE_DRIVER_VERSION },
+
+    .createNewScreen2           = driCreateNewScreen2,
+    .createNewDrawable          = driCreateNewDrawable,
+    .createNewContext           = driCreateNewContext,
+    .getAPIMask                 = driGetAPIMask,
+    .createContextAttribs       = driCreateContextAttribs,
+};
diff --git a/src/mesa/drivers/dri/common/dri_util.h b/src/mesa/drivers/dri/common/dri_util.h
index 7fab3e5f720..79a8564ad51 100644
--- a/src/mesa/drivers/dri/common/dri_util.h
+++ b/src/mesa/drivers/dri/common/dri_util.h
@@ -176,6 +176,10 @@ struct __DRIscreenRec {
 	__DRIuseInvalidateExtension *useInvalidate;
     } dri2;
 
+    struct {
+        __DRIimageLoaderExtension *loader;
+    } image;
+
     driOptionCache optionInfo;
     driOptionCache optionCache;
 
@@ -285,4 +289,6 @@ dri2InvalidateDrawable(__DRIdrawable *drawable);
 extern void
 driUpdateFramebufferSize(struct gl_context *ctx, const __DRIdrawable *dPriv);
 
+extern const __DRIimageDriverExtension driImageDriverExtension;
+
 #endif /* _DRI_UTIL_H_ */
diff --git a/src/mesa/drivers/dri/i915/intel_context.c b/src/mesa/drivers/dri/i915/intel_context.c
index 1568a166485..36188934fca 100644
--- a/src/mesa/drivers/dri/i915/intel_context.c
+++ b/src/mesa/drivers/dri/i915/intel_context.c
@@ -99,6 +99,8 @@ intelGetString(struct gl_context * ctx, GLenum name)
    }
 }
 
+#define flushFront(screen)      ((screen)->image.loader ? (screen)->image.loader->flushFrontBuffer : (screen)->dri2.loader->flushFrontBuffer)
+
 static void
 intel_flush_front(struct gl_context *ctx)
 {
@@ -108,11 +110,10 @@ intel_flush_front(struct gl_context *ctx)
     __DRIscreen *const screen = intel->intelScreen->driScrnPriv;
 
     if (intel->front_buffer_dirty && _mesa_is_winsys_fbo(ctx->DrawBuffer)) {
-      if (screen->dri2.loader->flushFrontBuffer != NULL &&
+      if (flushFront(screen) && 
           driDrawable &&
           driDrawable->loaderPrivate) {
-         screen->dri2.loader->flushFrontBuffer(driDrawable,
-                                               driDrawable->loaderPrivate);
+         flushFront(screen)(driDrawable, driDrawable->loaderPrivate);
 
 	 /* We set the dirty bit in intel_prepare_render() if we're
 	  * front buffer rendering once we get there.
@@ -122,6 +123,9 @@ intel_flush_front(struct gl_context *ctx)
    }
 }
 
+static void
+intel_update_image_buffers(struct intel_context *intel, __DRIdrawable *drawable);
+
 static unsigned
 intel_bits_per_pixel(const struct intel_renderbuffer *rb)
 {
@@ -202,7 +206,10 @@ intel_update_renderbuffers(__DRIcontext *context, __DRIdrawable *drawable)
    if (unlikely(INTEL_DEBUG & DEBUG_DRI))
       fprintf(stderr, "enter %s, drawable %p\n", __func__, drawable);
 
-   intel_update_dri2_buffers(intel, drawable);
+   if (screen->image.loader)
+      intel_update_image_buffers(intel, drawable);
+   else
+      intel_update_dri2_buffers(intel, drawable);
 
    driUpdateFramebufferSize(&intel->ctx, drawable);
 }
@@ -811,3 +818,101 @@ intel_process_dri2_buffer(struct intel_context *intel,
                                                  region);
    intel_region_release(&region);
 }
+
+/**
+ * \brief Query DRI Image loader to obtain a DRIdrawable's buffers.
+ *
+ * To determine which DRI buffers to request, examine the renderbuffers
+ * attached to the drawable's framebuffer. Then request the buffers with
+ * dri3
+ *
+ * This is called from intel_update_renderbuffers().
+ *
+ * \param drawable      Drawable whose buffers are queried.
+ * \param buffers       [out] List of buffers returned by DRI2 query.
+ * \param buffer_count  [out] Number of buffers returned.
+ *
+ * \see intel_update_renderbuffers()
+ */
+
+static void
+intel_update_image_buffer(struct intel_context *intel,
+                          __DRIdrawable *drawable,
+                          struct intel_renderbuffer *rb,
+                          __DRIimage *buffer,
+                          enum __DRIimageBufferMask buffer_type)
+{
+   struct intel_region *region = buffer->region;
+
+   if (!rb || !region)
+      return;
+
+   unsigned num_samples = rb->Base.Base.NumSamples;
+
+   if (rb->mt &&
+       rb->mt->region &&
+       rb->mt->region == region)
+      return;
+
+   intel_miptree_release(&rb->mt);
+   rb->mt = intel_miptree_create_for_image_buffer(intel,
+                                                  buffer_type,
+                                                  intel_rb_format(rb),
+                                                  num_samples,
+                                                  region);
+}
+
+
+static void
+intel_update_image_buffers(struct intel_context *intel, __DRIdrawable *drawable)
+{
+   struct gl_framebuffer *fb = drawable->driverPrivate;
+   __DRIscreen *screen = intel->intelScreen->driScrnPriv;
+   struct intel_renderbuffer *front_rb;
+   struct intel_renderbuffer *back_rb;
+   struct __DRIimageList images;
+   unsigned int format;
+   uint32_t buffer_mask = 0;
+
+   front_rb = intel_get_renderbuffer(fb, BUFFER_FRONT_LEFT);
+   back_rb = intel_get_renderbuffer(fb, BUFFER_BACK_LEFT);
+
+   if (back_rb)
+      format = intel_rb_format(back_rb);
+   else if (front_rb)
+      format = intel_rb_format(front_rb);
+   else
+      return;
+
+   if ((intel->is_front_buffer_rendering || intel->is_front_buffer_reading || !back_rb) && front_rb)
+      buffer_mask |= __DRI_IMAGE_BUFFER_FRONT;
+
+   if (back_rb)
+      buffer_mask |= __DRI_IMAGE_BUFFER_BACK;
+
+   (*screen->image.loader->getBuffers) (drawable,
+                                        driGLFormatToImageFormat(format),
+                                        &drawable->dri2.stamp,
+                                        drawable->loaderPrivate,
+                                        buffer_mask,
+                                        &images);
+
+   if (images.image_mask & __DRI_IMAGE_BUFFER_FRONT) {
+      drawable->w = images.front->width;
+      drawable->h = images.front->height;
+      intel_update_image_buffer(intel,
+                                drawable,
+                                front_rb,
+                                images.front,
+                                __DRI_IMAGE_BUFFER_FRONT);
+   }
+   if (images.image_mask & __DRI_IMAGE_BUFFER_BACK) {
+      drawable->w = images.back->width;
+      drawable->h = images.back->height;
+      intel_update_image_buffer(intel,
+                                drawable,
+                                back_rb,
+                                images.back,
+                                __DRI_IMAGE_BUFFER_BACK);
+   }
+}
diff --git a/src/mesa/drivers/dri/i915/intel_mipmap_tree.c b/src/mesa/drivers/dri/i915/intel_mipmap_tree.c
index 8432b6dc53f..66a7a92dc05 100644
--- a/src/mesa/drivers/dri/i915/intel_mipmap_tree.c
+++ b/src/mesa/drivers/dri/i915/intel_mipmap_tree.c
@@ -322,6 +322,39 @@ intel_miptree_create_for_dri2_buffer(struct intel_context *intel,
    return mt;
 }
 
+/**
+ * For a singlesample image buffer, this simply wraps the given region with a miptree.
+ *
+ * For a multisample image buffer, this wraps the given region with
+ * a singlesample miptree, then creates a multisample miptree into which the
+ * singlesample miptree is embedded as a child.
+ */
+struct intel_mipmap_tree*
+intel_miptree_create_for_image_buffer(struct intel_context *intel,
+                                      enum __DRIimageBufferMask buffer_type,
+                                      gl_format format,
+                                      uint32_t num_samples,
+                                      struct intel_region *region)
+{
+   struct intel_mipmap_tree *mt = NULL;
+
+   /* Only the front and back buffers, which are color buffers, are allocated
+    * through the image loader.
+    */
+   assert(_mesa_get_format_base_format(format) == GL_RGB ||
+          _mesa_get_format_base_format(format) == GL_RGBA);
+
+   mt = intel_miptree_create_for_bo(intel,
+                                    region->bo,
+                                    format,
+                                    0,
+                                    region->width,
+                                    region->height,
+                                    region->pitch,
+                                    region->tiling);
+   return mt;
+}
+
 struct intel_mipmap_tree*
 intel_miptree_create_for_renderbuffer(struct intel_context *intel,
                                       gl_format format,
diff --git a/src/mesa/drivers/dri/i915/intel_mipmap_tree.h b/src/mesa/drivers/dri/i915/intel_mipmap_tree.h
index 1142af60bb7..35cad6dfcc6 100644
--- a/src/mesa/drivers/dri/i915/intel_mipmap_tree.h
+++ b/src/mesa/drivers/dri/i915/intel_mipmap_tree.h
@@ -32,6 +32,7 @@
 
 #include "intel_screen.h"
 #include "intel_regions.h"
+#include "GL/internal/dri_interface.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -258,6 +259,13 @@ intel_miptree_create_for_dri2_buffer(struct intel_context *intel,
                                      gl_format format,
                                      struct intel_region *region);
 
+struct intel_mipmap_tree*
+intel_miptree_create_for_image_buffer(struct intel_context *intel,
+                                      enum __DRIimageBufferMask buffer_type,
+                                      gl_format format,
+                                      uint32_t num_samples,
+                                      struct intel_region *region);
+
 /**
  * Create a miptree appropriate as the storage for a non-texture renderbuffer.
  * The miptree has the following properties:
diff --git a/src/mesa/drivers/dri/i915/intel_screen.c b/src/mesa/drivers/dri/i915/intel_screen.c
index d93bd9be59e..2c309ed4a16 100644
--- a/src/mesa/drivers/dri/i915/intel_screen.c
+++ b/src/mesa/drivers/dri/i915/intel_screen.c
@@ -1258,6 +1258,7 @@ static const struct __DRIDriverVtableExtensionRec i915_vtable = {
 /* This is the table of extensions that the loader will dlsym() for. */
 static const __DRIextension *i915_driver_extensions[] = {
     &driCoreExtension.base,
+    &driImageDriverExtension.base,
     &driDRI2Extension.base,
     &i915_vtable.base,
     &i915_config_options.base,
diff --git a/src/mesa/drivers/dri/i915/intel_screen.h b/src/mesa/drivers/dri/i915/intel_screen.h
index 4ae259cccdf..faa4c205d36 100644
--- a/src/mesa/drivers/dri/i915/intel_screen.h
+++ b/src/mesa/drivers/dri/i915/intel_screen.h
@@ -155,6 +155,7 @@ struct intel_screen
 #define intel_fbo_init                      old_intel_fbo_init
 #define intel_get_rb_region                 old_intel_get_rb_region
 #define intel_renderbuffer_set_draw_offset  old_intel_renderbuffer_set_draw_offset
+#define intel_miptree_create_for_image_buffer old_intel_miptree_create_for_image_buffer
 
 extern void intelDestroyContext(__DRIcontext * driContextPriv);
 
diff --git a/src/mesa/drivers/dri/i965/brw_context.c b/src/mesa/drivers/dri/i965/brw_context.c
index f9623bb2a7d..a33e993f281 100644
--- a/src/mesa/drivers/dri/i965/brw_context.c
+++ b/src/mesa/drivers/dri/i965/brw_context.c
@@ -162,6 +162,8 @@ intelInvalidateState(struct gl_context * ctx, GLuint new_state)
    brw->NewGLState |= new_state;
 }
 
+#define flushFront(screen)      ((screen)->image.loader ? (screen)->image.loader->flushFrontBuffer : (screen)->dri2.loader->flushFrontBuffer)
+
 static void
 intel_flush_front(struct gl_context *ctx)
 {
@@ -171,8 +173,7 @@ intel_flush_front(struct gl_context *ctx)
    __DRIscreen *const screen = brw->intelScreen->driScrnPriv;
 
    if (brw->front_buffer_dirty && _mesa_is_winsys_fbo(ctx->DrawBuffer)) {
-      if (screen->dri2.loader->flushFrontBuffer != NULL &&
-          driDrawable &&
+      if (flushFront(screen) && driDrawable &&
           driDrawable->loaderPrivate) {
 
          /* Resolve before flushing FAKE_FRONT_LEFT to FRONT_LEFT.
@@ -185,8 +186,7 @@ intel_flush_front(struct gl_context *ctx)
          intel_resolve_for_dri2_flush(brw, driDrawable);
          intel_batchbuffer_flush(brw);
 
-         screen->dri2.loader->flushFrontBuffer(driDrawable,
-                                               driDrawable->loaderPrivate);
+         flushFront(screen)(driDrawable, driDrawable->loaderPrivate);
 
          /* We set the dirty bit in intel_prepare_render() if we're
           * front buffer rendering once we get there.
@@ -1029,6 +1029,9 @@ intel_process_dri2_buffer(struct brw_context *brw,
                           const char *buffer_name);
 
 static void
+intel_update_image_buffers(struct brw_context *brw, __DRIdrawable *drawable);
+
+static void
 intel_update_dri2_buffers(struct brw_context *brw, __DRIdrawable *drawable)
 {
    struct gl_framebuffer *fb = drawable->driverPrivate;
@@ -1088,6 +1091,7 @@ void
 intel_update_renderbuffers(__DRIcontext *context, __DRIdrawable *drawable)
 {
    struct brw_context *brw = context->driverPrivate;
+   __DRIscreen *screen = brw->intelScreen->driScrnPriv;
 
    /* Set this up front, so that in case our buffers get invalidated
     * while we're getting new buffers, we don't clobber the stamp and
@@ -1097,7 +1101,10 @@ intel_update_renderbuffers(__DRIcontext *context, __DRIdrawable *drawable)
    if (unlikely(INTEL_DEBUG & DEBUG_DRI))
       fprintf(stderr, "enter %s, drawable %p\n", __func__, drawable);
 
-   intel_update_dri2_buffers(brw, drawable);
+   if (screen->image.loader)
+      intel_update_image_buffers(brw, drawable);
+   else
+      intel_update_dri2_buffers(brw, drawable);
 
    driUpdateFramebufferSize(&brw->ctx, drawable);
 }
@@ -1303,3 +1310,100 @@ intel_process_dri2_buffer(struct brw_context *brw,
                                                  region);
    intel_region_release(&region);
 }
+
+/**
+ * \brief Query DRI image loader to obtain a DRIdrawable's buffers.
+ *
+ * To determine which DRI buffers to request, examine the renderbuffers
+ * attached to the drawable's framebuffer. Then request the buffers from
+ * the image loader
+ *
+ * This is called from intel_update_renderbuffers().
+ *
+ * \param drawable      Drawable whose buffers are queried.
+ * \param buffers       [out] List of buffers returned by DRI2 query.
+ * \param buffer_count  [out] Number of buffers returned.
+ *
+ * \see intel_update_renderbuffers()
+ */
+
+static void
+intel_update_image_buffer(struct brw_context *intel,
+                          __DRIdrawable *drawable,
+                          struct intel_renderbuffer *rb,
+                          __DRIimage *buffer,
+                          enum __DRIimageBufferMask buffer_type)
+{
+   struct intel_region *region = buffer->region;
+
+   if (!rb || !region)
+      return;
+
+   unsigned num_samples = rb->Base.Base.NumSamples;
+
+   if (rb->mt &&
+       rb->mt->region &&
+       rb->mt->region == region)
+      return;
+
+   intel_miptree_release(&rb->mt);
+   rb->mt = intel_miptree_create_for_image_buffer(intel,
+                                                  buffer_type,
+                                                  intel_rb_format(rb),
+                                                  num_samples,
+                                                  region);
+}
+
+static void
+intel_update_image_buffers(struct brw_context *brw, __DRIdrawable *drawable)
+{
+   struct gl_framebuffer *fb = drawable->driverPrivate;
+   __DRIscreen *screen = brw->intelScreen->driScrnPriv;
+   struct intel_renderbuffer *front_rb;
+   struct intel_renderbuffer *back_rb;
+   struct __DRIimageList images;
+   unsigned int format;
+   uint32_t buffer_mask = 0;
+
+   front_rb = intel_get_renderbuffer(fb, BUFFER_FRONT_LEFT);
+   back_rb = intel_get_renderbuffer(fb, BUFFER_BACK_LEFT);
+
+   if (back_rb)
+      format = intel_rb_format(back_rb);
+   else if (front_rb)
+      format = intel_rb_format(front_rb);
+   else
+      return;
+
+   if ((brw->is_front_buffer_rendering || brw->is_front_buffer_reading || !back_rb) && front_rb)
+      buffer_mask |= __DRI_IMAGE_BUFFER_FRONT;
+
+   if (back_rb)
+      buffer_mask |= __DRI_IMAGE_BUFFER_BACK;
+
+   (*screen->image.loader->getBuffers) (drawable,
+                                        driGLFormatToImageFormat(format),
+                                        &drawable->dri2.stamp,
+                                        drawable->loaderPrivate,
+                                        buffer_mask,
+                                        &images);
+
+   if (images.image_mask & __DRI_IMAGE_BUFFER_FRONT) {
+      drawable->w = images.front->width;
+      drawable->h = images.front->height;
+      intel_update_image_buffer(brw,
+                                drawable,
+                                front_rb,
+                                images.front,
+                                __DRI_IMAGE_BUFFER_FRONT);
+   }
+   if (images.image_mask & __DRI_IMAGE_BUFFER_BACK) {
+      drawable->w = images.back->width;
+      drawable->h = images.back->height;
+      intel_update_image_buffer(brw,
+                                drawable,
+                                back_rb,
+                                images.back,
+                                __DRI_IMAGE_BUFFER_BACK);
+   }
+}
diff --git a/src/mesa/drivers/dri/i965/intel_mipmap_tree.c b/src/mesa/drivers/dri/i965/intel_mipmap_tree.c
index f690ac1aca1..3f5608601ec 100644
--- a/src/mesa/drivers/dri/i965/intel_mipmap_tree.c
+++ b/src/mesa/drivers/dri/i965/intel_mipmap_tree.c
@@ -726,6 +726,67 @@ intel_miptree_create_for_dri2_buffer(struct brw_context *brw,
    return multisample_mt;
 }
 
+/**
+ * For a singlesample image buffer, this simply wraps the given region with a miptree.
+ *
+ * For a multisample image buffer, this wraps the given region with
+ * a singlesample miptree, then creates a multisample miptree into which the
+ * singlesample miptree is embedded as a child.
+ */
+struct intel_mipmap_tree*
+intel_miptree_create_for_image_buffer(struct brw_context *intel,
+                                      enum __DRIimageBufferMask buffer_type,
+                                      gl_format format,
+                                      uint32_t num_samples,
+                                      struct intel_region *region)
+{
+   struct intel_mipmap_tree *singlesample_mt = NULL;
+   struct intel_mipmap_tree *multisample_mt = NULL;
+
+   /* Only the front and back buffers, which are color buffers, are allocated
+    * through the image loader.
+    */
+   assert(_mesa_get_format_base_format(format) == GL_RGB ||
+          _mesa_get_format_base_format(format) == GL_RGBA);
+
+   singlesample_mt = intel_miptree_create_for_bo(intel,
+                                                 region->bo,
+                                                 format,
+                                                 0,
+                                                 region->width,
+                                                 region->height,
+                                                 region->pitch,
+                                                 region->tiling);
+   if (!singlesample_mt)
+      return NULL;
+
+   intel_region_reference(&singlesample_mt->region, region);
+
+   if (num_samples == 0)
+      return singlesample_mt;
+
+   multisample_mt = intel_miptree_create_for_renderbuffer(intel,
+                                                          format,
+                                                          region->width,
+                                                          region->height,
+                                                          num_samples);
+   if (!multisample_mt) {
+      intel_miptree_release(&singlesample_mt);
+      return NULL;
+   }
+
+   multisample_mt->singlesample_mt = singlesample_mt;
+   multisample_mt->need_downsample = false;
+
+   intel_region_reference(&multisample_mt->region, region);
+
+   if (intel->is_front_buffer_rendering && buffer_type == __DRI_IMAGE_BUFFER_FRONT) {
+      intel_miptree_upsample(intel, multisample_mt);
+   }
+
+   return multisample_mt;
+}
+
 struct intel_mipmap_tree*
 intel_miptree_create_for_renderbuffer(struct brw_context *brw,
                                       gl_format format,
diff --git a/src/mesa/drivers/dri/i965/intel_mipmap_tree.h b/src/mesa/drivers/dri/i965/intel_mipmap_tree.h
index d7181255edb..8777a8c605c 100644
--- a/src/mesa/drivers/dri/i965/intel_mipmap_tree.h
+++ b/src/mesa/drivers/dri/i965/intel_mipmap_tree.h
@@ -32,6 +32,7 @@
 
 #include "intel_regions.h"
 #include "intel_resolve_map.h"
+#include <GL/internal/dri_interface.h>
 
 #ifdef __cplusplus
 extern "C" {
@@ -529,6 +530,13 @@ intel_miptree_create_for_dri2_buffer(struct brw_context *brw,
                                      uint32_t num_samples,
                                      struct intel_region *region);
 
+struct intel_mipmap_tree*
+intel_miptree_create_for_image_buffer(struct brw_context *intel,
+                                     enum __DRIimageBufferMask buffer_type,
+                                     gl_format format,
+                                     uint32_t num_samples,
+                                     struct intel_region *region);
+
 /**
  * Create a miptree appropriate as the storage for a non-texture renderbuffer.
  * The miptree has the following properties:
diff --git a/src/mesa/drivers/dri/i965/intel_screen.c b/src/mesa/drivers/dri/i965/intel_screen.c
index 099cabfb9d0..e39d6545970 100644
--- a/src/mesa/drivers/dri/i965/intel_screen.c
+++ b/src/mesa/drivers/dri/i965/intel_screen.c
@@ -1264,7 +1264,8 @@ __DRIconfig **intelInitScreen2(__DRIscreen *psp)
 {
    struct intel_screen *intelScreen;
 
-   if (psp->dri2.loader->base.version <= 2 ||
+   if (psp->image.loader) {
+   } else if (psp->dri2.loader->base.version <= 2 ||
        psp->dri2.loader->getBuffersWithFormat == NULL) {
       fprintf(stderr,
 	      "\nERROR!  DRI2 loader with getBuffersWithFormat() "
@@ -1352,7 +1353,6 @@ intelReleaseBuffer(__DRIscreen *screen, __DRIbuffer *buffer)
    free(intelBuffer);
 }
 
-
 static const struct __DriverAPIRec brw_driver_api = {
    .InitScreen		 = intelInitScreen2,
    .DestroyScreen	 = intelDestroyScreen,
@@ -1373,6 +1373,7 @@ static const struct __DRIDriverVtableExtensionRec brw_vtable = {
 
 static const __DRIextension *brw_driver_extensions[] = {
     &driCoreExtension.base,
+    &driImageDriverExtension.base,
     &driDRI2Extension.base,
     &brw_vtable.base,
     &brw_config_options.base,