Fix DRI2 accelerated EXT_texture_from_pixmap with GL_RGB format.

This requires upgrading the interface so that the argument to
glXBindTexImageEXT isn't just dropped on the floor.  Note that this only
fixes the accelerated path on Intel, as Mesa's texture format support is
missing x8r8g8b8 support (right now, GL_RGB textures get uploaded as a8r8gb8,
but in this case we're not doing the upload so we can't really work around it
that way).

Fixes bugs with compositors trying to use shaders that use alpha channels, on
windows without a valid alpha channel.  Bug #19910 and likely others as well.

Reviewed-by:	Ian Romanick <ian.d.romanick@intel.com>

3 files changed, 19 insertions, 2 deletions

diff --git a/src/mesa/drivers/dri/intel/intel_screen.c b/src/mesa/drivers/dri/intel/intel_screen.c
index e8c074712c..d20ea15187 100644
--- a/src/mesa/drivers/dri/intel/intel_screen.c
+++ b/src/mesa/drivers/dri/intel/intel_screen.c
@@ -211,6 +211,7 @@ static const __DRItexOffsetExtension intelTexOffsetExtension = {
 static const __DRItexBufferExtension intelTexBufferExtension = {
     { __DRI_TEX_BUFFER, __DRI_TEX_BUFFER_VERSION },
    intelSetTexBuffer,
+   intelSetTexBuffer2,
 };
 
 static const __DRIextension *intelScreenExtensions[] = {
diff --git a/src/mesa/drivers/dri/intel/intel_tex.h b/src/mesa/drivers/dri/intel/intel_tex.h
index 742ccc043a..f5372d82fb 100644
--- a/src/mesa/drivers/dri/intel/intel_tex.h
+++ b/src/mesa/drivers/dri/intel/intel_tex.h
@@ -149,6 +149,8 @@ void intelSetTexOffset(__DRIcontext *pDRICtx, GLint texname,
 		       unsigned long long offset, GLint depth, GLuint pitch);
 void intelSetTexBuffer(__DRIcontext *pDRICtx,
 		       GLint target, __DRIdrawable *pDraw);
+void intelSetTexBuffer2(__DRIcontext *pDRICtx,
+			GLint target, GLint format, __DRIdrawable *pDraw);
 
 GLuint intel_finalize_mipmap_tree(struct intel_context *intel, GLuint unit);
 
diff --git a/src/mesa/drivers/dri/intel/intel_tex_image.c b/src/mesa/drivers/dri/intel/intel_tex_image.c
index 943636c37b..e902187637 100644
--- a/src/mesa/drivers/dri/intel/intel_tex_image.c
+++ b/src/mesa/drivers/dri/intel/intel_tex_image.c
@@ -714,7 +714,9 @@ intelSetTexOffset(__DRIcontext *pDRICtx, GLint texname,
 }
 
 void
-intelSetTexBuffer(__DRIcontext *pDRICtx, GLint target, __DRIdrawable *dPriv)
+intelSetTexBuffer2(__DRIcontext *pDRICtx, GLint target,
+		   GLint glx_texture_format,
+		   __DRIdrawable *dPriv)
 {
    struct intel_framebuffer *intel_fb = dPriv->driverPrivate;
    struct intel_context *intel = pDRICtx->driverPrivate;
@@ -745,7 +747,10 @@ intelSetTexBuffer(__DRIcontext *pDRICtx, GLint target, __DRIdrawable *dPriv)
 
    type = GL_BGRA;
    format = GL_UNSIGNED_BYTE;
-   internalFormat = (rb->region->cpp == 3 ? 3 : 4);
+   if (glx_texture_format == GLX_TEXTURE_FORMAT_RGB_EXT)
+      internalFormat = GL_RGB;
+   else
+      internalFormat = GL_RGBA;
 
    mt = intel_miptree_create_for_region(intel, target,
 					internalFormat,
@@ -785,3 +790,12 @@ intelSetTexBuffer(__DRIcontext *pDRICtx, GLint target, __DRIdrawable *dPriv)
 
    _mesa_unlock_texture(&intel->ctx, texObj);
 }
+
+void
+intelSetTexBuffer(__DRIcontext *pDRICtx, GLint target, __DRIdrawable *dPriv)
+{
+   /* The old interface didn't have the format argument, so copy our
+    * implementation's behavior at the time.
+    */
+   intelSetTexBuffer2(pDRICtx, target, GLX_TEXTURE_FORMAT_RGBA_EXT, dPriv);
+}