svga: disable rasterization if rasterizer_discard is set or FS undefined

With this patch, rasterization will be disabled if the
rasterizer_discard flag is set or the fragment shader
is undefined due to missing position output from the
vertex/geometry shader.

Tested with piglit test glsl-1.50-geometry-primitive-id-restart.
Also tested with full MTT glretrace and piglit.

v2: As suggested by Roland, to properly disable rasterization, besides
    setting FS to NULL, we will also need to disable depth and stencil test.

v3: As suggested by Brian, set SVGA_NEW_DEPTH_STENCIL_ALPHA dirty bit
    in svga_bind_rasterizer_state() if the rasterizer_discard flag is
    changed.

Reviewed-by: Brian Paul <[email protected]>

1 files changed, 7 insertions, 0 deletions

diff --git a/src/gallium/drivers/svga/svga_context.c b/src/gallium/drivers/svga/svga_context.c
index ec86073ccc9..04466fb7dee 100644
--- a/src/gallium/drivers/svga/svga_context.c
+++ b/src/gallium/drivers/svga/svga_context.c
@@ -67,6 +67,11 @@ svga_destroy(struct pipe_context *pipe)
       }
    }
 
+   /* free depthstencil_disable state */
+   if (svga->depthstencil_disable) {
+      pipe->delete_depth_stencil_alpha_state(pipe, svga->depthstencil_disable);
+   }
+
    /* free HW constant buffers */
    for (shader = 0; shader < ARRAY_SIZE(svga->state.hw_draw.constbuf); shader++) {
       pipe_resource_reference(&svga->state.hw_draw.constbuf[shader], NULL);
@@ -248,6 +253,7 @@ svga_context_create(struct pipe_screen *screen, void *priv, unsigned flags)
    svga->state.hw_draw.num_views = 0;
    svga->state.hw_draw.num_rendertargets = 0;
    svga->state.hw_draw.dsv = NULL;
+   svga->state.hw_draw.rasterizer_discard = FALSE;
 
    /* Initialize the shader pointers */
    svga->state.hw_draw.vs = NULL;
@@ -289,6 +295,7 @@ svga_context_create(struct pipe_screen *screen, void *priv, unsigned flags)
 
    svga->dirty = ~0;
    svga->pred.query_id = SVGA3D_INVALID_ID;
+   svga->disable_rasterizer = FALSE;
 
    return &svga->pipe;