mesa: gl_NumSamples should always be at least one

From ARB_sample_shading:

    "gl_NumSamples is the total number of samples in the framebuffer,
     or one if rendering to a non-multisample framebuffer"

So make sure to always pass in at least 1.

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
Reviewed-by: Edward O`Callaghan <eocallaghan@alterapraxis.com>
Reviewed-by: Neil Roberts <neil@linux.intel.com>

diff --git a/src/mesa/program/prog_statevars.c b/src/mesa/program/prog_statevars.c
index eed2412..489f75f 100644 (file)
--- a/src/mesa/program/prog_statevars.c
+++ b/src/mesa/program/prog_statevars.c
@@ -353,7 +353,7 @@ _mesa_fetch_state(struct gl_context *ctx, const gl_state_index state[],
       }
       return;
    case STATE_NUM_SAMPLES:
-      ((int *)value)[0] = _mesa_geometric_samples(ctx->DrawBuffer);
+      ((int *)value)[0] = MAX2(1, _mesa_geometric_samples(ctx->DrawBuffer));
       return;
    case STATE_DEPTH_RANGE:
       value[0] = ctx->ViewportArray[0].Near;                /* near       */