[Mesa-dev] [PATCH] mesa: fix transform feedback when a geometry shader is active.

[Paul Berry]

From: Bryan Cain <bryancain3 at gmail.com>

When a geometry shader is active, the transform feedback primitive
type ("mode") needs to be validated against the geometry shader output
primitive type, not the primitive type passed to the glDraw*()
function.

Fixes the following piglit tests:
- glsl-1.50-geometry-primitive-types GL_LINES
- glsl-1.50-geometry-primitive-types GL_LINES_ADJACENCY
- glsl-1.50-geometry-primitive-types GL_LINE_STRIP
- glsl-1.50-geometry-primitive-types GL_LINE_STRIP_ADJACENCY
- glsl-1.50-geometry-primitive-types GL_TRIANGLES
- glsl-1.50-geometry-primitive-types GL_TRIANGLES_ADJACENCY
- glsl-1.50-geometry-primitive-types GL_TRIANGLE_FAN

Exposes previously hidden failures in the following piglit tests:
- glsl-1.50-geometry-primitive-id-restart GL_LINES other
- glsl-1.50-geometry-primitive-id-restart GL_LINES_ADJACENCY other
- glsl-1.50-geometry-primitive-id-restart GL_LINE_LOOP ffs
- glsl-1.50-geometry-primitive-id-restart GL_LINE_LOOP other
- glsl-1.50-geometry-primitive-id-restart GL_LINE_STRIP other
- glsl-1.50-geometry-primitive-id-restart GL_LINE_STRIP_ADJACENCY other
- glsl-1.50-geometry-primitive-id-restart GL_TRIANGLES other
- glsl-1.50-geometry-primitive-id-restart GL_TRIANGLES_ADJACENCY other
- glsl-1.50-geometry-primitive-id-restart GL_TRIANGLE_FAN ffs
- glsl-1.50-geometry-primitive-id-restart GL_TRIANGLE_FAN other
- glsl-1.50-geometry-primitive-id-restart GL_TRIANGLE_STRIP other
- glsl-1.50-geometry-primitive-id-restart GL_TRIANGLE_STRIP_ADJACENCY other

(These failures were previously hidden due to a flaw in the test: it
doesn't check for GL errors.  I'll fix the test shortly).
---
 src/mesa/main/api_validate.c | 53 +++++++++++++++++++++++++++++---------------
 1 file changed, 35 insertions(+), 18 deletions(-)

diff --git a/src/mesa/main/api_validate.c b/src/mesa/main/api_validate.c
index 0029921..f285c97 100644
--- a/src/mesa/main/api_validate.c
+++ b/src/mesa/main/api_validate.c
@@ -330,26 +330,43 @@ _mesa_valid_prim_mode(struct gl_context *ctx, GLenum mode, const char *name)
    if (_mesa_is_xfb_active_and_unpaused(ctx)) {
       GLboolean pass = GL_TRUE;
 
-      switch (mode) {
-      case GL_POINTS:
-         pass = ctx->TransformFeedback.Mode == GL_POINTS;
-	 break;
-      case GL_LINES:
-      case GL_LINE_STRIP:
-      case GL_LINE_LOOP:
-         pass = ctx->TransformFeedback.Mode == GL_LINES;
-	 break;
-      default:
-         pass = ctx->TransformFeedback.Mode == GL_TRIANGLES;
-	 break;
+      if(ctx->Shader.CurrentGeometryProgram) {
+         switch (ctx->Shader.CurrentGeometryProgram->Geom.OutputType) {
+         case GL_POINTS:
+            pass = ctx->TransformFeedback.Mode == GL_POINTS;
+            break;
+         case GL_LINE_STRIP:
+            pass = ctx->TransformFeedback.Mode == GL_LINES;
+            break;
+         case GL_TRIANGLE_STRIP:
+            pass = ctx->TransformFeedback.Mode == GL_TRIANGLES;
+            break;
+         default:
+            pass = GL_FALSE;
+         }
+      }
+      else {
+         switch (mode) {
+         case GL_POINTS:
+            pass = ctx->TransformFeedback.Mode == GL_POINTS;
+            break;
+         case GL_LINES:
+         case GL_LINE_STRIP:
+         case GL_LINE_LOOP:
+            pass = ctx->TransformFeedback.Mode == GL_LINES;
+            break;
+         default:
+            pass = ctx->TransformFeedback.Mode == GL_TRIANGLES;
+            break;
+         }
       }
       if (!pass) {
-	 _mesa_error(ctx, GL_INVALID_OPERATION,
-		     "%s(mode=%s vs transform feedback %s)",
-		     name,
-		     _mesa_lookup_prim_by_nr(mode),
-		     _mesa_lookup_prim_by_nr(ctx->TransformFeedback.Mode));
-	 return GL_FALSE;
+         _mesa_error(ctx, GL_INVALID_OPERATION,
+	                 "%s(mode=%s vs transform feedback %s)",
+	                 name,
+	                 _mesa_lookup_prim_by_nr(mode),
+	                 _mesa_lookup_prim_by_nr(ctx->TransformFeedback.Mode));
+         return GL_FALSE;
       }
    }
 
-- 
1.8.4