On 3 January 2012 12:57, Ian Romanick <<a href="mailto:idr@freedesktop.org">idr@freedesktop.org</a>> wrote: <div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> <div class="HOEnZb"><div class="h5">On 01/02/2012 09:37 PM, Paul Berry wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> From the EXT_transform_feedback spec: The error INVALID_OPERATION is generated by BeginTransformFeedbackEXT if any transform feedback buffer object binding point used in transform feedback mode does not have a buffer object bound. This required adding a new NumBuffers field to the gl_transform_feedback_info struct, to keep track of how many transform feedback buffers are required by the current program. Fixes Piglit tests: - EXT_transform_feedback/api-errors interleaved_unbound - EXT_transform_feedback/api-errors separate_unbound_0_1 - EXT_transform_feedback/api-errors separate_unbound_0_2 - EXT_transform_feedback/api-errors separate_unbound_1_2 --- src/glsl/linker.cpp | 7 +++++-- src/mesa/main/mtypes.h | 5 +++++ src/mesa/main/transformfeedback.c | 12 ++++++++++++ 3 files changed, 22 insertions(+), 2 deletions(-) diff --git a/src/glsl/linker.cpp b/src/glsl/linker.cpp index ed9a5d7..43be205 100644 --- a/src/glsl/linker.cpp +++ b/src/glsl/linker.cpp @@ -1889,11 +1889,14 @@ store_tfeedback_info(struct gl_context *ctx, struct gl_shader_program *prog, tfeedback_decl *tfeedback_decls) { unsigned total_tfeedback_components = 0; + bool separate_attribs_mode = + prog->TransformFeedback.BufferMode == GL_SEPARATE_ATTRIBS; memset(&prog->LinkedTransformFeedback, 0, sizeof(prog->LinkedTransformFeedback)); + prog->LinkedTransformFeedback.NumBuffers = + separate_attribs_mode ? num_tfeedback_decls : 1; for (unsigned i = 0; i< num_tfeedback_decls; ++i) { - unsigned buffer = - prog->TransformFeedback.BufferMode == GL_SEPARATE_ATTRIBS ? i : 0; + unsigned buffer = separate_attribs_mode ? i : 0; </blockquote> </div></div> Is this actually necessary? If separate_attribs_mode is false, num_tfeedback_decls is 1, and i can only ever be 0. Right? </blockquote><div> No, num_tfeedback_decls is the value of "count" that was passed to TransformFeedbackVaryings--it indicates the number of varyings that should be captured. So if separate_attribs_mode is false, and more than one varying is being interleaved, then num_tfeedback_decls will be greater than 1. </div></div>