gallium: add PIPE_CAP_MAX_VARYINGS

Some NVIDIA hardware can accept 128 fragment shader input components,
but only have up to 124 varying-interpolated input components. We add a
new cap to express this cleanly. For most drivers, this will have the
same value as PIPE_SHADER_CAP_MAX_INPUTS for the fragment shader.

Fixes KHR-GL45.limits.max_fragment_input_components

Signed-off-by: Karol Herbst <[email protected]>
[imirkin: rebased, improved docs/commit message]
Signed-off-by: Ilia Mirkin <[email protected]>
Acked-by: Rob Clark <[email protected]>
Acked-by: Eric Anholt <[email protected]>
Reviewed-by: Marek Olšák <[email protected]>
Cc: 19.0 <[email protected]>

1 files changed, 1 insertions, 4 deletions

diff --git a/src/mesa/state_tracker/st_extensions.c b/src/mesa/state_tracker/st_extensions.c
index c1a528551cd..2dbda83ca10 100644
--- a/src/mesa/state_tracker/st_extensions.c
+++ b/src/mesa/state_tracker/st_extensions.c
@@ -365,10 +365,7 @@ void st_init_limits(struct pipe_screen *screen,
    c->Program[MESA_SHADER_VERTEX].MaxAttribs =
       MIN2(c->Program[MESA_SHADER_VERTEX].MaxAttribs, 16);
 
-   /* PIPE_SHADER_CAP_MAX_INPUTS for the FS specifies the maximum number
-    * of inputs. It's always 2 colors + N generic inputs. */
-   c->MaxVarying = screen->get_shader_param(screen, PIPE_SHADER_FRAGMENT,
-                                            PIPE_SHADER_CAP_MAX_INPUTS);
+   c->MaxVarying = screen->get_param(screen, PIPE_CAP_MAX_VARYINGS);
    c->MaxVarying = MIN2(c->MaxVarying, MAX_VARYING);
    c->MaxGeometryOutputVertices =
       screen->get_param(screen, PIPE_CAP_MAX_GEOMETRY_OUTPUT_VERTICES);