gallium: Add texture usage flags, special-case allocation of display targets

For many envirionments it's necessary to allocate display targets
in a window-system friendly manner.  Add facilities so that a driver
can tell if a texture is likely to be used to generate a display surface
and if use special allocation paths if necessary.

Hook up softpipe to call into the winsys->surface_alloc_storage()
routine in this case, though we probably want to change that interface
slightly also.

1 files changed, 2 insertions, 1 deletions

diff --git a/src/mesa/state_tracker/st_atom_pixeltransfer.c b/src/mesa/state_tracker/st_atom_pixeltransfer.c
index 0c32d53c4a..e500ac8684 100644
--- a/src/mesa/state_tracker/st_atom_pixeltransfer.c
+++ b/src/mesa/state_tracker/st_atom_pixeltransfer.c
@@ -126,7 +126,8 @@ create_color_map_texture(GLcontext *ctx)
 
    /* create texture for color map/table */
    pt = st_texture_create(ctx->st, PIPE_TEXTURE_2D, format, 0,
-                          texSize, texSize, 1, 0);
+                          texSize, texSize, 1, 0,
+                          PIPE_TEXTURE_USAGE_SAMPLER);
    return pt;
 }