[Mesa-dev] [PATCH 5/5] draw: implement distance culling
Brian Paul
brianp at vmware.com
Tue Jun 11 08:16:34 PDT 2013
On 06/10/2013 08:31 AM, Zack Rusin wrote:
> Works similarly to clip distance. If the cull distance is negative
> for all vertices against a specific plane then the primitive
> is culled.
>
> Signed-off-by: Zack Rusin <zackr at vmware.com>
> ---
> src/gallium/auxiliary/draw/draw_context.c | 17 ++++
> src/gallium/auxiliary/draw/draw_gs.c | 6 ++
> src/gallium/auxiliary/draw/draw_gs.h | 1 +
> src/gallium/auxiliary/draw/draw_pipe_cull.c | 124 ++++++++++++++++++-----
> src/gallium/auxiliary/draw/draw_pipe_validate.c | 11 +-
> src/gallium/auxiliary/draw/draw_private.h | 2 +
> src/gallium/auxiliary/draw/draw_vs.c | 5 +
> src/gallium/auxiliary/draw/draw_vs.h | 1 +
> 8 files changed, 137 insertions(+), 30 deletions(-)
>
> diff --git a/src/gallium/auxiliary/draw/draw_context.c b/src/gallium/auxiliary/draw/draw_context.c
> index e8480f6..470e7ac 100644
> --- a/src/gallium/auxiliary/draw/draw_context.c
> +++ b/src/gallium/auxiliary/draw/draw_context.c
> @@ -751,6 +751,23 @@ draw_current_shader_num_written_clipdistances(const struct draw_context *draw)
> return draw->vs.vertex_shader->info.num_written_clipdistance;
> }
>
> +
> +uint
> +draw_current_shader_culldistance_output(const struct draw_context *draw, int index)
> +{
> + if (draw->gs.geometry_shader)
> + return draw->gs.geometry_shader->culldistance_output[index];
> + return draw->vs.vertex_shader->culldistance_output[index];
> +}
> +
> +uint
> +draw_current_shader_num_written_culldistances(const struct draw_context *draw)
> +{
> + if (draw->gs.geometry_shader)
> + return draw->gs.geometry_shader->info.num_written_culldistance;
> + return draw->vs.vertex_shader->info.num_written_culldistance;
> +}
> +
> /**
> * Return a pointer/handle for a driver/CSO rasterizer object which
> * disabled culling, stippling, unfilled tris, etc.
> diff --git a/src/gallium/auxiliary/draw/draw_gs.c b/src/gallium/auxiliary/draw/draw_gs.c
> index 74c6279..dc1298d 100644
> --- a/src/gallium/auxiliary/draw/draw_gs.c
> +++ b/src/gallium/auxiliary/draw/draw_gs.c
> @@ -797,6 +797,12 @@ draw_create_geometry_shader(struct draw_context *draw,
> else
> gs->clipdistance_output[1] = i;
> }
> + if (gs->info.output_semantic_name[i] == TGSI_SEMANTIC_CULLDIST) {
> + if (gs->info.output_semantic_index[i] == 0)
> + gs->culldistance_output[0] = i;
> + else
> + gs->culldistance_output[1] = i;
> + }
> }
>
> gs->machine = draw->gs.tgsi.machine;
> diff --git a/src/gallium/auxiliary/draw/draw_gs.h b/src/gallium/auxiliary/draw/draw_gs.h
> index 543b32d..05d666d 100644
> --- a/src/gallium/auxiliary/draw/draw_gs.h
> +++ b/src/gallium/auxiliary/draw/draw_gs.h
> @@ -68,6 +68,7 @@ struct draw_geometry_shader {
> unsigned position_output;
> unsigned viewport_index_output;
> unsigned clipdistance_output[2];
> + unsigned culldistance_output[2];
>
> unsigned max_output_vertices;
> unsigned primitive_boundary;
> diff --git a/src/gallium/auxiliary/draw/draw_pipe_cull.c b/src/gallium/auxiliary/draw/draw_pipe_cull.c
> index 2f4d01d..2636ffb 100644
> --- a/src/gallium/auxiliary/draw/draw_pipe_cull.c
> +++ b/src/gallium/auxiliary/draw/draw_pipe_cull.c
> @@ -33,6 +33,7 @@
> */
>
>
> +#include "util/u_math.h"
> #include "util/u_memory.h"
> #include "pipe/p_defines.h"
> #include "draw_pipe.h"
> @@ -51,42 +52,109 @@ static INLINE struct cull_stage *cull_stage( struct draw_stage *stage )
> }
>
>
> +
Could you put a comment on this function explaining that it implements
the culldistance feature?
> +static void cull_line( struct draw_stage *stage,
> + struct prim_header *header )
> +{
> + const unsigned num_written_culldistances =
> + draw_current_shader_num_written_culldistances(stage->draw);
> +
> + if (num_written_culldistances) {
> + unsigned i;
> + boolean culled = FALSE;
> + for (i = 0; i < num_written_culldistances; ++i) {
> + unsigned cull_idx = (i >= 4) ? 1 : 0;
In case there's ever more cull distances, could that be
unsigned cull_idx = i / 4;
> + unsigned out_idx =
> + draw_current_shader_culldistance_output(stage->draw, cull_idx);
> + unsigned idx = i % 4;
> + float cull1 = header->v[0]->data[out_idx][idx];
> + float cull2 = header->v[1]->data[out_idx][idx];
> + boolean vert1_out = (cull1 < 0) || util_is_inf_or_nan(cull1);
> + boolean vert2_out = (cull2 < 0) || util_is_inf_or_nan(cull2);
s/0/0.0f/ to silence potential MSVC warnings.
> + if (vert1_out && vert2_out)
> + culled = TRUE;
> + }
> + if (!culled)
> + stage->next->line( stage->next, header );
> + }
> +}
> +
Any a comment for this function saying it does conventional
front/back-face culling plus culldistance?
> static void cull_tri( struct draw_stage *stage,
> struct prim_header *header )
> {
> - const unsigned pos = draw_current_shader_position_output(stage->draw);
> -
> - /* Window coords: */
> - const float *v0 = header->v[0]->data[pos];
> - const float *v1 = header->v[1]->data[pos];
> - const float *v2 = header->v[2]->data[pos];
> -
> - /* edge vectors: e = v0 - v2, f = v1 - v2 */
> - const float ex = v0[0] - v2[0];
> - const float ey = v0[1] - v2[1];
> - const float fx = v1[0] - v2[0];
> - const float fy = v1[1] - v2[1];
> + const unsigned num_written_culldistances =
> + draw_current_shader_num_written_culldistances(stage->draw);
> +
> + if (num_written_culldistances) {
> + unsigned i;
> + boolean culled = FALSE;
> + for (i = 0; i < num_written_culldistances; ++i) {
> + unsigned cull_idx = (i >= 4) ? 1 : 0;
Same as above.
> + unsigned out_idx =
> + draw_current_shader_culldistance_output(stage->draw, cull_idx);
> + unsigned idx = i % 4;
> + float cull1 = header->v[0]->data[out_idx][idx];
> + float cull2 = header->v[1]->data[out_idx][idx];
> + float cull3 = header->v[2]->data[out_idx][idx];
> + boolean vert1_out = (cull1 < 0) || util_is_inf_or_nan(cull1);
> + boolean vert2_out = (cull2 < 0) || util_is_inf_or_nan(cull2);
> + boolean vert3_out = (cull3 < 0) || util_is_inf_or_nan(cull3);
0.0f
> + if (vert1_out && vert2_out && vert3_out)
> + culled = TRUE;
> + }
> + if (!culled)
> + stage->next->line( stage->next, header );
> + } else {
> + const unsigned pos = draw_current_shader_position_output(stage->draw);
> + /* Window coords: */
> + const float *v0 = header->v[0]->data[pos];
> + const float *v1 = header->v[1]->data[pos];
> + const float *v2 = header->v[2]->data[pos];
> +
> + /* edge vectors: e = v0 - v2, f = v1 - v2 */
> + const float ex = v0[0] - v2[0];
> + const float ey = v0[1] - v2[1];
> + const float fx = v1[0] - v2[0];
> + const float fy = v1[1] - v2[1];
> +
>
> - /* det = cross(e,f).z */
> - header->det = ex * fy - ey * fx;
> -
> - if (header->det != 0) {
> - /* if det < 0 then Z points toward the camera and the triangle is
> - * counter-clockwise winding.
> - */
> - unsigned ccw = (header->det < 0);
> - unsigned face = ((ccw == cull_stage(stage)->front_ccw) ?
> - PIPE_FACE_FRONT :
> - PIPE_FACE_BACK);
> -
> - if ((face & cull_stage(stage)->cull_face) == 0) {
> - /* triangle is not culled, pass to next stage */
> - stage->next->tri( stage->next, header );
> + /* det = cross(e,f).z */
> + header->det = ex * fy - ey * fx;
> +
> + if (header->det != 0) {
> + /* if det < 0 then Z points toward the camera and the triangle is
> + * counter-clockwise winding.
> + */
> + unsigned ccw = (header->det < 0);
> + unsigned face = ((ccw == cull_stage(stage)->front_ccw) ?
> + PIPE_FACE_FRONT :
> + PIPE_FACE_BACK);
> +
> + if ((face & cull_stage(stage)->cull_face) == 0) {
> + /* triangle is not culled, pass to next stage */
> + stage->next->tri( stage->next, header );
> + }
> }
> }
> }
>
>
> +
> +static void cull_first_line( struct draw_stage *stage,
> + struct prim_header *header )
> +{
> + const unsigned num_written_culldistances =
> + draw_current_shader_num_written_culldistances(stage->draw);
> +
> + if (num_written_culldistances) {
> + stage->line = cull_line;
> + stage->line( stage, header );
> + } else {
> + stage->line = draw_pipe_passthrough_line;
> + stage->line( stage, header );
> + }
> +}
> +
> static void cull_first_tri( struct draw_stage *stage,
> struct prim_header *header )
> {
> @@ -133,7 +201,7 @@ struct draw_stage *draw_cull_stage( struct draw_context *draw )
> cull->stage.name = "cull";
> cull->stage.next = NULL;
> cull->stage.point = draw_pipe_passthrough_point;
> - cull->stage.line = draw_pipe_passthrough_line;
> + cull->stage.line = cull_first_line;
> cull->stage.tri = cull_first_tri;
> cull->stage.flush = cull_flush;
> cull->stage.reset_stipple_counter = cull_reset_stipple_counter;
> diff --git a/src/gallium/auxiliary/draw/draw_pipe_validate.c b/src/gallium/auxiliary/draw/draw_pipe_validate.c
> index 4b0ed14..2dbb95c 100644
> --- a/src/gallium/auxiliary/draw/draw_pipe_validate.c
> +++ b/src/gallium/auxiliary/draw/draw_pipe_validate.c
> @@ -93,6 +93,9 @@ draw_need_pipeline(const struct draw_context *draw,
> /* AA lines */
> if (rasterizer->line_smooth && draw->pipeline.aaline)
> return TRUE;
> +
> + if (draw_current_shader_num_written_culldistances(draw))
> + return TRUE;
> }
>
> if (points(prim))
> @@ -136,6 +139,9 @@ draw_need_pipeline(const struct draw_context *draw,
> /* two-side lighting */
> if (rasterizer->light_twoside)
> return TRUE;
> +
> + if (draw_current_shader_num_written_culldistances(draw))
> + return TRUE;
> }
>
> /* polygon cull - this is difficult - hardware can cull just fine
> @@ -145,7 +151,7 @@ draw_need_pipeline(const struct draw_context *draw,
> *
> if (rasterizer->cull_mode)
> return TRUE;
> - */
> + */
>
> return FALSE;
> }
> @@ -260,7 +266,8 @@ static struct draw_stage *validate_pipeline( struct draw_stage *stage )
> * to less work emitting vertices, smaller vertex buffers, etc.
> * It's difficult to say whether this will be true in general.
> */
> - if (need_det || rast->cull_face != PIPE_FACE_NONE) {
> + if (need_det || rast->cull_face != PIPE_FACE_NONE ||
> + draw_current_shader_num_written_culldistances(draw)) {
> draw->pipeline.cull->next = next;
> next = draw->pipeline.cull;
> }
> diff --git a/src/gallium/auxiliary/draw/draw_private.h b/src/gallium/auxiliary/draw/draw_private.h
> index fa0b19b..351bd2b 100644
> --- a/src/gallium/auxiliary/draw/draw_private.h
> +++ b/src/gallium/auxiliary/draw/draw_private.h
> @@ -390,6 +390,8 @@ uint draw_current_shader_viewport_index_output(const struct draw_context *draw);
> uint draw_current_shader_clipvertex_output(const struct draw_context *draw);
> uint draw_current_shader_clipdistance_output(const struct draw_context *draw, int index);
> uint draw_current_shader_num_written_clipdistances(const struct draw_context *draw);
> +uint draw_current_shader_culldistance_output(const struct draw_context *draw, int index);
> +uint draw_current_shader_num_written_culldistances(const struct draw_context *draw);
> int draw_alloc_extra_vertex_attrib(struct draw_context *draw,
> uint semantic_name, uint semantic_index);
> void draw_remove_extra_vertex_attribs(struct draw_context *draw);
> diff --git a/src/gallium/auxiliary/draw/draw_vs.c b/src/gallium/auxiliary/draw/draw_vs.c
> index 95f678a..44845ff 100644
> --- a/src/gallium/auxiliary/draw/draw_vs.c
> +++ b/src/gallium/auxiliary/draw/draw_vs.c
> @@ -90,6 +90,11 @@ draw_create_vertex_shader(struct draw_context *draw,
> vs->clipdistance_output[0] = i;
> else
> vs->clipdistance_output[1] = i;
> + } else if (vs->info.output_semantic_name[i] == TGSI_SEMANTIC_CULLDIST) {
> + if (vs->info.output_semantic_index[i] == 0)
> + vs->culldistance_output[0] = i;
> + else
> + vs->culldistance_output[1] = i;
> }
> }
> if (!found_clipvertex)
> diff --git a/src/gallium/auxiliary/draw/draw_vs.h b/src/gallium/auxiliary/draw/draw_vs.h
> index 798b004..7635aba 100644
> --- a/src/gallium/auxiliary/draw/draw_vs.h
> +++ b/src/gallium/auxiliary/draw/draw_vs.h
> @@ -113,6 +113,7 @@ struct draw_vertex_shader {
> unsigned edgeflag_output;
> unsigned clipvertex_output;
> unsigned clipdistance_output[2];
> + unsigned culldistance_output[2];
> /* Extracted from shader:
> */
> const float (*immediates)[4];
>
Reviewed-by: Brian Paul <brianp at vmware.com>
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