[Mesa-dev] [PATCH 4/6] mesa/st: wire up DiscardSubFramebuffer

[Rob Clark]

Signed-off-by: Rob Clark <robdclark at gmail.com>
---
 src/gallium/include/pipe/p_context.h | 11 +++++++++++
 src/mesa/state_tracker/st_cb_fbo.c   | 26 ++++++++++++++++++++++++++
 2 files changed, 37 insertions(+)

diff --git a/src/gallium/include/pipe/p_context.h b/src/gallium/include/pipe/p_context.h
index d4e9179b78a..eb52c7e9a4e 100644
--- a/src/gallium/include/pipe/p_context.h
+++ b/src/gallium/include/pipe/p_context.h
@@ -811,6 +811,17 @@ struct pipe_context {
    void (*invalidate_surface)(struct pipe_context *ctx,
                               struct pipe_surface *surf);
 
+   /**
+    * Invalidate a portion of a surface.  This is used to
+    *
+    * (1) implement glInvalidateSubFramebuffer() and friends
+    * (2) as a hint before a scissored clear (which is turned into draw_vbo()
+    *     that the cleared rect can be discarded
+    */
+   void (*invalidate_sub_surface)(struct pipe_context *ctx,
+                                  struct pipe_surface *surf,
+                                  const struct pipe_scissor_state *rect);
+
    /**
     * Return information about unexpected device resets.
     */
diff --git a/src/mesa/state_tracker/st_cb_fbo.c b/src/mesa/state_tracker/st_cb_fbo.c
index 3ece1d4a9de..50c27ea51d9 100644
--- a/src/mesa/state_tracker/st_cb_fbo.c
+++ b/src/mesa/state_tracker/st_cb_fbo.c
@@ -774,6 +774,31 @@ st_discard_framebuffer(struct gl_context *ctx, struct gl_framebuffer *fb,
       st->pipe->invalidate_surface(st->pipe, psurf);
 }
 
+static void
+st_discard_sub_framebuffer(struct gl_context *ctx, struct gl_framebuffer *fb,
+                           struct gl_renderbuffer_attachment *att, GLint x,
+                           GLint y, GLsizei width, GLsizei height)
+{
+   struct st_context *st = st_context(ctx);
+   struct pipe_surface *psurf;
+
+   if (!att->Renderbuffer)
+      return;
+
+   psurf = st_renderbuffer(att->Renderbuffer)->surface;
+
+   if (st->pipe->invalidate_sub_surface) {
+      struct pipe_scissor_state rect;
+
+      rect.minx = x;
+      rect.maxx = x + width - 1;
+      rect.miny = y;
+      rect.maxy = y + height - 1;
+
+      st->pipe->invalidate_sub_surface(st->pipe, psurf, &rect);
+   }
+}
+
 /**
  * Called via glDrawBuffer.  We only provide this driver function so that we
  * can check if we need to allocate a new renderbuffer.  Specifically, we
@@ -952,6 +977,7 @@ st_init_fbo_functions(struct dd_function_table *functions)
    functions->FinishRenderTexture = st_finish_render_texture;
    functions->ValidateFramebuffer = st_validate_framebuffer;
    functions->DiscardFramebuffer = st_discard_framebuffer;
+   functions->DiscardSubFramebuffer = st_discard_sub_framebuffer;
 
    functions->DrawBufferAllocate = st_DrawBufferAllocate;
    functions->ReadBuffer = st_ReadBuffer;
-- 
2.19.2