gallium: Add new PIPE_CAP_SURFACE_SAMPLE_COUNT

This new pipe cap and the new nr_samples field in pipe_surface lets a
state tracker bind a render target with a different sample count than
the resource. This allows for implementing
EXT_multisampled_render_to_texture and
EXT_multisampled_render_to_texture2.

Reviewed-by: Eric Anholt <[email protected]>
Signed-off-by: Kristian H. Kristensen <[email protected]>

2 files changed, 8 insertions, 0 deletions

diff --git a/src/gallium/include/pipe/p_defines.h b/src/gallium/include/pipe/p_defines.h
index e99895d30d8..6d96f1ccb5b 100644
--- a/src/gallium/include/pipe/p_defines.h
+++ b/src/gallium/include/pipe/p_defines.h
@@ -832,6 +832,7 @@ enum pipe_cap
    PIPE_CAP_MAX_COMBINED_HW_ATOMIC_COUNTER_BUFFERS,
    PIPE_CAP_MAX_TEXTURE_UPLOAD_MEMORY_BUDGET,
    PIPE_CAP_MAX_VERTEX_ELEMENT_SRC_OFFSET,
+   PIPE_CAP_SURFACE_SAMPLE_COUNT,
 };
 
 /**
diff --git a/src/gallium/include/pipe/p_state.h b/src/gallium/include/pipe/p_state.h
index fd670345aad..38052e5fd3d 100644
--- a/src/gallium/include/pipe/p_state.h
+++ b/src/gallium/include/pipe/p_state.h
@@ -443,6 +443,13 @@ struct pipe_surface
    uint16_t width;               /**< logical width in pixels */
    uint16_t height;              /**< logical height in pixels */
 
+   /**
+    * Number of samples for the surface.  This will be 0 if rendering
+    * should use the resource's nr_samples, or another value if the resource
+    * is bound using FramebufferTexture2DMultisampleEXT.
+    */
+   unsigned nr_samples:8;
+
    union pipe_surface_desc u;
 };