diff options
Diffstat (limited to 'src/mesa/drivers/dri/i965/gen6_sol.c')
| -rw-r--r-- | src/mesa/drivers/dri/i965/gen6_sol.c | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/src/mesa/drivers/dri/i965/gen6_sol.c b/src/mesa/drivers/dri/i965/gen6_sol.c index 38aedcc4297..2f2051bc613 100644 --- a/src/mesa/drivers/dri/i965/gen6_sol.c +++ b/src/mesa/drivers/dri/i965/gen6_sol.c @@ -26,6 +26,7 @@ * Code to initialize the binding table entries used by transform feedback. */ +#include "main/macros.h" #include "brw_context.h" #include "intel_batchbuffer.h" #include "brw_defines.h" @@ -72,6 +73,43 @@ const struct brw_tracked_state gen6_sol_surface = { }; void +brw_begin_transform_feedback(struct gl_context *ctx, GLenum mode, + struct gl_transform_feedback_object *obj) +{ + struct intel_context *intel = intel_context(ctx); + const struct gl_shader_program *vs_prog = + ctx->Shader.CurrentVertexProgram; + const struct gl_transform_feedback_info *linked_xfb_info = + &vs_prog->LinkedTransformFeedback; + struct gl_transform_feedback_object *xfb_obj = + ctx->TransformFeedback.CurrentObject; + + unsigned max_index = 0xffffffff; + + /* Compute the maximum number of vertices that we can write without + * overflowing any of the buffers currently being used for feedback. + */ + for (int i = 0; i < BRW_MAX_SOL_BUFFERS; ++i) { + unsigned stride = linked_xfb_info->BufferStride[i]; + + /* Skip any inactive buffers, which have a stride of 0. */ + if (stride == 0) + continue; + + unsigned max_for_this_buffer = xfb_obj->Size[i] / (4 * stride); + max_index = MIN2(max_index, max_for_this_buffer); + } + + /* Initialize the SVBI 0 register to zero and set the maximum index. */ + BEGIN_BATCH(4); + OUT_BATCH(_3DSTATE_GS_SVB_INDEX << 16 | (4 - 2)); + OUT_BATCH(0); /* SVBI 0 */ + OUT_BATCH(0); + OUT_BATCH(max_index); + ADVANCE_BATCH(); +} + +void brw_end_transform_feedback(struct gl_context *ctx, struct gl_transform_feedback_object *obj) { |