[Mesa-dev] [RFC] gallium: add support for rectangle primitives

[Roland Scheidegger]

Am 21.08.2014 18:44, schrieb Marek Olšák:
> From: Marek Olšák <marek.olsak at amd.com>
> 
> This is already supported by r600g and radeonsi.
> Alex suggested this could be useful for video acceleration state trackers.
> ---
>  src/gallium/auxiliary/tgsi/tgsi_strings.c     | 3 ++-
>  src/gallium/auxiliary/util/u_prim.h           | 1 +
>  src/gallium/docs/source/screen.rst            | 6 ++++++
>  src/gallium/drivers/r600/r600_pipe.c          | 1 +
>  src/gallium/drivers/radeon/r600_pipe_common.h | 2 +-
>  src/gallium/drivers/radeonsi/si_pipe.c        | 1 +
>  src/gallium/include/pipe/p_defines.h          | 4 +++-
>  7 files changed, 15 insertions(+), 3 deletions(-)
> 
> diff --git a/src/gallium/auxiliary/tgsi/tgsi_strings.c b/src/gallium/auxiliary/tgsi/tgsi_strings.c
> index 3c108a8..ddc23c1 100644
> --- a/src/gallium/auxiliary/tgsi/tgsi_strings.c
> +++ b/src/gallium/auxiliary/tgsi/tgsi_strings.c
> @@ -164,7 +164,8 @@ const char *tgsi_primitive_names[PIPE_PRIM_MAX] =
>     "LINES_ADJACENCY",
>     "LINE_STRIP_ADJACENCY",
>     "TRIANGLES_ADJACENCY",
> -   "TRIANGLE_STRIP_ADJACENCY"
> +   "TRIANGLE_STRIP_ADJACENCY",
> +   "RECTANGLES"
>  };
>  
>  const char *tgsi_fs_coord_origin_names[2] =
> diff --git a/src/gallium/auxiliary/util/u_prim.h b/src/gallium/auxiliary/util/u_prim.h
> index cf1a18f..d631dc1 100644
> --- a/src/gallium/auxiliary/util/u_prim.h
> +++ b/src/gallium/auxiliary/util/u_prim.h
> @@ -131,6 +131,7 @@ u_prim_vertex_count(unsigned prim)
>        { 4, 1 }, /* PIPE_PRIM_LINE_STRIP_ADJACENCY */
>        { 6, 6 }, /* PIPE_PRIM_TRIANGLES_ADJACENCY */
>        { 6, 2 }, /* PIPE_PRIM_TRIANGLE_STRIP_ADJACENCY */
> +      { 3, 3 }  /* PIPE_PRIM_RECTANGLES */
>     };
>  
>     return (likely(prim < PIPE_PRIM_MAX)) ? &prim_table[prim] : NULL;
> diff --git a/src/gallium/docs/source/screen.rst b/src/gallium/docs/source/screen.rst
> index eee254e..f162ec0 100644
> --- a/src/gallium/docs/source/screen.rst
> +++ b/src/gallium/docs/source/screen.rst
> @@ -26,6 +26,12 @@ The integer capabilities:
>    normalized coordinates, and mipmaps.
>  * ``PIPE_CAP_TWO_SIDED_STENCIL``: Whether the stencil test can also affect back-facing
>    polygons.
> +* ``PIPE_CAP_PRIM_TYPE_RECTANGLES``: Whether rectangle primitives are supported.
> +  Rectangles are like quads, but they are only specified by the first 3 vertices.
> +  The 4th vertex is computed from the first three by hardware. Rectangles must
> +  be parallel with screen borders, which means they can only be rotated with
> +  90-degree increments. Rectangles bypass clipping and therefore can be specified
> +  in screen coordinates.
Do they also need to be planar (same z for each vertex)?
Also, the implicit bypass clip / screen coordinate specification makes
them quite an outlier among all the primitives. Hmm...


>  * ``PIPE_CAP_MAX_DUAL_SOURCE_RENDER_TARGETS``: How many dual-source blend RTs are support.
>    :ref:`Blend` for more information.
>  * ``PIPE_CAP_ANISOTROPIC_FILTER``: Whether textures can be filtered anisotropically.
> diff --git a/src/gallium/drivers/r600/r600_pipe.c b/src/gallium/drivers/r600/r600_pipe.c
> index 3d07864..7294c8c 100644
> --- a/src/gallium/drivers/r600/r600_pipe.c
> +++ b/src/gallium/drivers/r600/r600_pipe.c
> @@ -262,6 +262,7 @@ static int r600_get_param(struct pipe_screen* pscreen, enum pipe_cap param)
>  	case PIPE_CAP_BUFFER_MAP_PERSISTENT_COHERENT:
>  	case PIPE_CAP_TGSI_VS_WINDOW_SPACE_POSITION:
>  	case PIPE_CAP_TGSI_VS_LAYER_VIEWPORT:
> +	case PIPE_CAP_PRIM_TYPE_RECTANGLES:
>  		return 1;
>  
>  	case PIPE_CAP_COMPUTE:
> diff --git a/src/gallium/drivers/radeon/r600_pipe_common.h b/src/gallium/drivers/radeon/r600_pipe_common.h
> index ed16e1a..903395d 100644
> --- a/src/gallium/drivers/radeon/r600_pipe_common.h
> +++ b/src/gallium/drivers/radeon/r600_pipe_common.h
> @@ -76,7 +76,7 @@
>  #define R600_CONTEXT_VGT_STREAMOUT_SYNC		(1 << 20)
>  
>  /* special primitive types */
> -#define R600_PRIM_RECTANGLE_LIST	PIPE_PRIM_MAX
> +#define R600_PRIM_RECTANGLE_LIST	PIPE_PRIM_RECTANGLES
>  
>  /* Debug flags. */
>  /* logging */
> diff --git a/src/gallium/drivers/radeonsi/si_pipe.c b/src/gallium/drivers/radeonsi/si_pipe.c
> index ae1d043..9431ea4 100644
> --- a/src/gallium/drivers/radeonsi/si_pipe.c
> +++ b/src/gallium/drivers/radeonsi/si_pipe.c
> @@ -216,6 +216,7 @@ static int si_get_param(struct pipe_screen* pscreen, enum pipe_cap param)
>  	case PIPE_CAP_CUBE_MAP_ARRAY:
>  	case PIPE_CAP_SAMPLE_SHADING:
>  	case PIPE_CAP_DRAW_INDIRECT:
> +	case PIPE_CAP_PRIM_TYPE_RECTANGLES:
>  		return 1;
>  
>  	case PIPE_CAP_TEXTURE_MULTISAMPLE:
> diff --git a/src/gallium/include/pipe/p_defines.h b/src/gallium/include/pipe/p_defines.h
> index 04e4798..d92261c 100644
> --- a/src/gallium/include/pipe/p_defines.h
> +++ b/src/gallium/include/pipe/p_defines.h
> @@ -419,7 +419,8 @@ enum pipe_flush_flags {
>  #define PIPE_PRIM_LINE_STRIP_ADJACENCY    11
>  #define PIPE_PRIM_TRIANGLES_ADJACENCY      12
>  #define PIPE_PRIM_TRIANGLE_STRIP_ADJACENCY 13
> -#define PIPE_PRIM_MAX                      14
> +#define PIPE_PRIM_RECTANGLES               14
> +#define PIPE_PRIM_MAX                      15
>  
>  
>  /**
> @@ -479,6 +480,7 @@ enum pipe_flush_flags {
>  enum pipe_cap {
>     PIPE_CAP_NPOT_TEXTURES = 1,
>     PIPE_CAP_TWO_SIDED_STENCIL = 2,
> +   PIPE_CAP_PRIM_TYPE_RECTANGLES = 3,
>     PIPE_CAP_MAX_DUAL_SOURCE_RENDER_TARGETS = 4,
>     PIPE_CAP_ANISOTROPIC_FILTER = 5,
>     PIPE_CAP_POINT_SPRITE = 6,
>