On Monday 20 September 2010 15:21:40 Luca Barbieri wrote: > >> 2. How do you pass to Gallium the id parameter to DrawTransformFeedback? > > > > You bind the buffer with the given id before issuing draw_stream_output. > > Bind to what?
As the vbo. > Note that the id parameter to DrawTransformFeedback is _not_ the place > to write to stream output to, but the place to take the count of > primitives to draw from. Which is size of the buffer / pipe_stream_output_state::num_outputs. > >> 3. How do you handle pause/resume in ARB_transform_feedback2? (it must > >> _not_ reset the count) > > > > You just append to the buffer. > > You do not append to the buffer =) > > OK, but how do you tell the GPU to start writing from 0 and reset the > count in some cases, and to append and not reset the count in the > others? SO will always append and if the state tracker wants a reset it should simply create a new pipe_resource and use that. > > The question is "how much data is in this pipe_buffer" so you hold that > > in the pipe_buffer itself. > > No, the question is "how many primitives were streamed out when that > transform feedback object was bound to GL and not paused between the > last Begin and End GL calls?". No, that's a question that's asked by a query and it should stay in the query. > Anyway, trying to implement ARB_transform_feedback2 (or, better, > ARB_transform_feedback3) will quickly show the requirements for the > Gallium interface. Cool, then lets worry about it when we'll be crossing that bridge. z _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
