Module: Mesa
Branch: master
Commit: 7314007925a25f65d178345dfc6d086c82e9a71e
URL:
http://cgit.freedesktop.org/mesa/mesa/commit/?id=7314007925a25f65d178345dfc6d086c82e9a71e
Author: Kenneth Graunke <kenn...@whitecape.org>
Date: Thu Oct 29 00:21:18 2015 -0700
mesa: Skip ES 3.0/3.1 transform feedback primitive counting error.
This error condition is not implementable when using tessellation or
geometry shaders. The text was also removed from the ES 3.2 spec.
I believe the intended behavior is to remove the error condition
when either OES_geometry_shader or OES_tessellation_shader are
exposed.
v2: Quote a better part of issue 13 (suggested by Ian).
Signed-off-by: Kenneth Graunke <kenn...@whitecape.org>
Reviewed-by: Ian Romanick <ian.d.roman...@intel.com>
---
src/mesa/main/api_validate.c | 18 +++++++++++++++++-
1 file changed, 17 insertions(+), 1 deletion(-)
diff --git a/src/mesa/main/api_validate.c b/src/mesa/main/api_validate.c
index 2ee2cd8..ec3cc1b 100644
--- a/src/mesa/main/api_validate.c
+++ b/src/mesa/main/api_validate.c
@@ -546,8 +546,24 @@ validate_draw_arrays(struct gl_context *ctx, const char
*func,
*
* This is in contrast to the behaviour of desktop GL, where the extra
* primitives are silently dropped from the transform feedback buffer.
+ *
+ * This text is removed in ES 3.2, presumably because it's not really
+ * implementable with geometry and tessellation shaders. In fact,
+ * the OES_geometry_shader spec says:
+ *
+ * "(13) Does this extension change how transform feedback operates
+ * compared to unextended OpenGL ES 3.0 or 3.1?
+ *
+ * RESOLVED: Yes. Because dynamic geometry amplification in a geometry
+ * shader can make it difficult if not impossible to predict the amount
+ * of geometry that may be generated in advance of executing the shader,
+ * the draw-time error for transform feedback buffer overflow conditions
+ * is removed and replaced with the GL behavior (primitives are not
+ * written and the corresponding counter is not updated)..."
*/
- if (_mesa_is_gles3(ctx) && _mesa_is_xfb_active_and_unpaused(ctx)) {
+ if (_mesa_is_gles3(ctx) && _mesa_is_xfb_active_and_unpaused(ctx) &&
+ !_mesa_has_OES_geometry_shader(ctx) &&
+ !_mesa_has_OES_tessellation_shader(ctx)) {
size_t prim_count = vbo_count_tessellated_primitives(mode, count, 1);
if (xfb_obj->GlesRemainingPrims < prim_count) {
_mesa_error(ctx, GL_INVALID_OPERATION,
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