mesa: Check that all buffers are bound in BeginTransformFeedback.

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

Reviewed-by: Brian Paul <[email protected]>
Reviewed-by: Ian Romanick <[email protected]>
Reviewed-by: Eric Anholt <[email protected]>

0 files changed, 0 insertions, 0 deletions