Fix bogus span mask in s_atifragshader.c leading to trouble when the pixel was later discarded by z test (this fixes doom3 r200 renderpath with swrast). Fix calling _swrast_alpha_test potentially leading to bogus results when Alpha Test might not be enabled. While here, don't disable deferred_texture (early z) when ATI_fragment_shader is active, as it is not necessary (for the record, this boosts doom3 swrast performance by roughly a factor of 2 (4 seconds per frame now...) with the r200 render path, might be a worthwile optimization for fragment programs which don't write z).

2 files changed, 8 insertions, 6 deletions

diff --git a/src/mesa/swrast/s_atifragshader.c b/src/mesa/swrast/s_atifragshader.c
index 36ada5fa304..08640e146b5 100644
--- a/src/mesa/swrast/s_atifragshader.c
+++ b/src/mesa/swrast/s_atifragshader.c
@@ -593,10 +593,11 @@ _swrast_exec_fragment_shader(GLcontext * ctx, struct sw_span *span)
       if (span->array->mask[i]) {
 	 init_machine(ctx, &ctx->ATIFragmentShader.Machine,
 		      ctx->ATIFragmentShader.Current, span, i);
-
-	 if (execute_shader(ctx, shader, ~0,
+	 /* can't really happen... */
+	 if (!execute_shader(ctx, shader, ~0,
 			    &ctx->ATIFragmentShader.Machine, span, i)) {
 	    span->array->mask[i] = GL_FALSE;
+            span->writeAll = GL_FALSE;
 	 }
 
 	 {
diff --git a/src/mesa/swrast/s_span.c b/src/mesa/swrast/s_span.c
index 0856b801ed2..c4a725fa197 100644
--- a/src/mesa/swrast/s_span.c
+++ b/src/mesa/swrast/s_span.c
@@ -1084,7 +1084,6 @@ _swrast_write_rgba_span( GLcontext *ctx, struct sw_span *span)
    const GLbitfield origArrayMask = span->arrayMask;
    const GLboolean deferredTexture = !(ctx->Color.AlphaEnabled ||
                                        ctx->FragmentProgram._Active ||
-                                       ctx->ATIFragmentShader._Enabled ||
                                        ctx->ShaderObjects.CurrentProgram);
 
    ASSERT(span->primitive == GL_POINT  ||  span->primitive == GL_LINE ||
@@ -1174,9 +1173,11 @@ _swrast_write_rgba_span( GLcontext *ctx, struct sw_span *span)
          _swrast_texture_span( ctx, span );
 
       /* Do the alpha test */
-      if (!_swrast_alpha_test(ctx, span)) {
-         span->arrayMask = origArrayMask;
-	 return;
+      if (ctx->Color.AlphaEnabled) {
+         if (!_swrast_alpha_test(ctx, span)) {
+            span->arrayMask = origArrayMask;
+	    return;
+	 }
       }
    }