[Mesa-dev] [PATCH 2/4] st/mesa: Add support for EXT_multisampled_render_to_texture

[Kristian H. Kristensen]

In gallium, we model the attachment sample count as a new nr_samples
field in pipe_surface. A driver can indicate support for the extension
using the new pipe cap, PIPE_CAP_MULTISAMPLED_RENDER_TO_TEXTURE.

Signed-off-by: Kristian H. Kristensen <hoegsberg at chromium.org>
---
 src/gallium/include/pipe/p_defines.h   | 1 +
 src/gallium/include/pipe/p_state.h     | 6 ++++++
 src/mesa/state_tracker/st_cb_fbo.c     | 3 +++
 src/mesa/state_tracker/st_cb_fbo.h     | 1 +
 src/mesa/state_tracker/st_extensions.c | 1 +
 5 files changed, 12 insertions(+)

diff --git a/src/gallium/include/pipe/p_defines.h b/src/gallium/include/pipe/p_defines.h
index dacedf5b936..0ecfaf3ba5e 100644
--- a/src/gallium/include/pipe/p_defines.h
+++ b/src/gallium/include/pipe/p_defines.h
@@ -823,6 +823,7 @@ 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_MULTISAMPLED_RENDER_TO_TEXTURE,
 };
 
 /**
diff --git a/src/gallium/include/pipe/p_state.h b/src/gallium/include/pipe/p_state.h
index fd670345aad..89cffb15bd8 100644
--- a/src/gallium/include/pipe/p_state.h
+++ b/src/gallium/include/pipe/p_state.h
@@ -443,6 +443,12 @@ struct pipe_surface
    uint16_t width;               /**< logical width in pixels */
    uint16_t height;              /**< logical height in pixels */
 
+   /** Number of samples for the surface.  This can be different from the
+    * resource nr_samples when the resource is bound using
+    * FramebufferTexture2DMultisampleEXT.
+    */
+   unsigned nr_samples:8;
+
    union pipe_surface_desc u;
 };
 
diff --git a/src/mesa/state_tracker/st_cb_fbo.c b/src/mesa/state_tracker/st_cb_fbo.c
index 0e535257cb4..8901a8680ef 100644
--- a/src/mesa/state_tracker/st_cb_fbo.c
+++ b/src/mesa/state_tracker/st_cb_fbo.c
@@ -516,6 +516,7 @@ st_update_renderbuffer_surface(struct st_context *st,
        surf->texture != resource ||
        surf->width != rtt_width ||
        surf->height != rtt_height ||
+       surf->nr_samples != strb->rtt_nr_samples ||
        surf->u.tex.level != level ||
        surf->u.tex.first_layer != first_layer ||
        surf->u.tex.last_layer != last_layer) {
@@ -523,6 +524,7 @@ st_update_renderbuffer_surface(struct st_context *st,
       struct pipe_surface surf_tmpl;
       memset(&surf_tmpl, 0, sizeof(surf_tmpl));
       surf_tmpl.format = format;
+      surf_tmpl.nr_samples = strb->rtt_nr_samples;
       surf_tmpl.u.tex.level = level;
       surf_tmpl.u.tex.first_layer = first_layer;
       surf_tmpl.u.tex.last_layer = last_layer;
@@ -572,6 +574,7 @@ st_render_texture(struct gl_context *ctx,
    strb->rtt_face = att->CubeMapFace;
    strb->rtt_slice = att->Zoffset;
    strb->rtt_layered = att->Layered;
+   strb->rtt_nr_samples = att->NumSamples;
    pipe_resource_reference(&strb->texture, pt);
 
    st_update_renderbuffer_surface(st, strb);
diff --git a/src/mesa/state_tracker/st_cb_fbo.h b/src/mesa/state_tracker/st_cb_fbo.h
index 345c11442c6..046f01713ce 100644
--- a/src/mesa/state_tracker/st_cb_fbo.h
+++ b/src/mesa/state_tracker/st_cb_fbo.h
@@ -69,6 +69,7 @@ struct st_renderbuffer
    boolean is_rtt; /**< whether Driver.RenderTexture was called */
    unsigned rtt_face, rtt_slice;
    boolean rtt_layered; /**< whether glFramebufferTexture was called */
+   unsigned rtt_nr_samples; /**< from FramebufferTexture2DMultisampleEXT */
 };
 
 
diff --git a/src/mesa/state_tracker/st_extensions.c b/src/mesa/state_tracker/st_extensions.c
index 16889074f66..9a1594212dd 100644
--- a/src/mesa/state_tracker/st_extensions.c
+++ b/src/mesa/state_tracker/st_extensions.c
@@ -740,6 +740,7 @@ void st_init_extensions(struct pipe_screen *screen,
       { o(EXT_draw_buffers2),                PIPE_CAP_INDEP_BLEND_ENABLE               },
       { o(EXT_memory_object),                PIPE_CAP_MEMOBJ                           },
       { o(EXT_memory_object_fd),             PIPE_CAP_MEMOBJ                           },
+      { o(EXT_multisampled_render_to_texture), PIPE_CAP_MULTISAMPLED_RENDER_TO_TEXTURE },
       { o(EXT_semaphore),                    PIPE_CAP_FENCE_SIGNAL                     },
       { o(EXT_semaphore_fd),                 PIPE_CAP_FENCE_SIGNAL                     },
       { o(EXT_texture_array),                PIPE_CAP_MAX_TEXTURE_ARRAY_LAYERS         },
-- 
2.19.1.930.g4563a0d9d0-goog