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, 4 insertions, 2 deletions

diff --git a/src/mesa/state_tracker/st_cb_drawpixels.c b/src/mesa/state_tracker/st_cb_drawpixels.c
index 9ae53c95f8..8c775ad886 100644
--- a/src/mesa/state_tracker/st_cb_drawpixels.c
+++ b/src/mesa/state_tracker/st_cb_drawpixels.c
@@ -346,7 +346,8 @@ make_texture(struct st_context *st,
       return NULL;
 
    pt = st_texture_create(st, PIPE_TEXTURE_2D, pipeFormat, 0, width, height,
-			  1, 0);
+			  1, 0,
+                          PIPE_TEXTURE_USAGE_SAMPLER);
    if (!pt) {
       _mesa_unmap_drawpix_pbo(ctx, unpack);
       return NULL;
@@ -994,7 +995,8 @@ st_CopyPixels(GLcontext *ctx, GLint srcx, GLint srcy,
    }
 
    pt = st_texture_create(ctx->st, PIPE_TEXTURE_2D, texFormat, 0,
-                          width, height, 1, 0);
+                          width, height, 1, 0,
+                          PIPE_TEXTURE_USAGE_SAMPLER);
    if (!pt)
       return;