On Sat, Dec 15, 2012 at 11:09 PM, Paul Berry <stereotype...@gmail.com> wrote:
> Previously, the i965 driver contained code to compute the maximum
> number of vertices that could be written without overflowing any
> transform feedback buffers. This code wasn't driver-specific, and for
> GLES3 support we're going to need to use it in core mesa. So this
> patch moves the code into a core mesa function,
> _mesa_compute_max_transform_feedback_vertices().
>
> Reviewed-by: Ian Romanick <ian.d.roman...@intel.com>
>
> v2: Eliminate C++-style variable declarations, since these won't work
> with MSVC.
> ---
> src/mesa/drivers/dri/i965/gen6_sol.c | 16 ++++------------
> src/mesa/main/transformfeedback.c | 28 ++++++++++++++++++++++++++++
> src/mesa/main/transformfeedback.h | 5 +++++
> 3 files changed, 37 insertions(+), 12 deletions(-)
>
> diff --git a/src/mesa/drivers/dri/i965/gen6_sol.c
> b/src/mesa/drivers/dri/i965/gen6_sol.c
> index 07316c8..7aa6140 100644
> --- a/src/mesa/drivers/dri/i965/gen6_sol.c
> +++ b/src/mesa/drivers/dri/i965/gen6_sol.c
> @@ -31,6 +31,7 @@
> #include "intel_batchbuffer.h"
> #include "brw_defines.h"
> #include "brw_state.h"
> +#include "main/transformfeedback.h"
>
> static void
> gen6_update_sol_surfaces(struct brw_context *brw)
> @@ -165,21 +166,12 @@ brw_begin_transform_feedback(struct gl_context *ctx,
> GLenum mode,
> 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);
> - }
> + unsigned max_index
> + = _mesa_compute_max_transform_feedback_vertices(xfb_obj,
> + linked_xfb_info);
>
> /* Initialize the SVBI 0 register to zero and set the maximum index.
> * These values will be sent to the hardware on the next draw.
> diff --git a/src/mesa/main/transformfeedback.c
> b/src/mesa/main/transformfeedback.c
> index 22060c3..bf161bb 100644
> --- a/src/mesa/main/transformfeedback.c
> +++ b/src/mesa/main/transformfeedback.c
> @@ -34,6 +34,7 @@
> #include "bufferobj.h"
> #include "context.h"
> #include "hash.h"
> +#include "macros.h"
> #include "mfeatures.h"
> #include "mtypes.h"
> #include "transformfeedback.h"
> @@ -246,6 +247,33 @@ _mesa_init_transform_feedback_functions(struct
> dd_function_table *driver)
>
>
> /**
> + * Compute the maximum number of vertices that can be written to the
> currently
> + * enabled transform feedback buffers without overflowing any of them.
> + */
> +unsigned
> +_mesa_compute_max_transform_feedback_vertices(
> + const struct gl_transform_feedback_object *obj,
> + const struct gl_transform_feedback_info *info)
> +{
> + unsigned max_index = 0xffffffff;
> +
> + for (int i = 0; i < info->NumBuffers; ++i) {
You'll have to move the 'int i' decl before the loop. And it should
be unsigned.
> + unsigned stride = info->BufferStride[i];
> + unsigned max_for_this_buffer;
> +
> + /* Skip any inactive buffers, which have a stride of 0. */
> + if (stride == 0)
> + continue;
> +
> + max_for_this_buffer = obj->Size[i] / (4 * stride);
> + max_index = MIN2(max_index, max_for_this_buffer);
> + }
> +
> + return max_index;
> +}
> +
> +
> +/**
> ** Begin API functions
> **/
>
> diff --git a/src/mesa/main/transformfeedback.h
> b/src/mesa/main/transformfeedback.h
> index 01c2af3..3c03b7a 100644
> --- a/src/mesa/main/transformfeedback.h
> +++ b/src/mesa/main/transformfeedback.h
> @@ -46,6 +46,11 @@ _mesa_validate_transform_feedback_buffers(struct
> gl_context *ctx);
> extern void
> _mesa_init_transform_feedback_functions(struct dd_function_table *driver);
>
> +extern unsigned
> +_mesa_compute_max_transform_feedback_vertices(
> + const struct gl_transform_feedback_object *obj,
> + const struct gl_transform_feedback_info *info);
> +
>
> /*** GL_EXT_transform_feedback ***/
>
Reviewed-by: Brian Paul <bri...@vmware.com>
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