[Mesa-dev] [PATCH 2/2] mesa: Implement glGet*(GL_PRIMITIVE_RESTART_FOR_PATCHES_SUPPORTED).

[Ilia Mirkin]

On Sat, May 21, 2016 at 1:31 AM, Kenneth Graunke <kenneth at whitecape.org> wrote:
> Technically, this was introduced with GL 4.4.  However, I believe it
> was intended to be retroactive.  As far as I know, AMD has never
> supported primitive restart with patches, while NVidia and Intel do.
> This necessitated the need for a query which would allow applications
> to figure out whether this was usable or not.
>
> I decided to expose it everywhere ARB_tessellation_shader is exposed.
> (It's also in both OES and EXT_tessellation_shader.)
>
> Enable this for i965 and Gallium drivers which expose the capability.
>
> Bugzilla: https://cvs.khronos.org/bugzilla/show_bug.cgi?id=10364
> Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
> ---
>  src/mapi/glapi/gen/ARB_tessellation_shader.xml | 1 +
>  src/mesa/drivers/dri/i965/brw_context.c        | 1 +
>  src/mesa/main/context.c                        | 1 +
>  src/mesa/main/get_hash_params.py               | 1 +
>  src/mesa/main/mtypes.h                         | 1 +
>  src/mesa/state_tracker/st_extensions.c         | 3 +++
>  6 files changed, 8 insertions(+)
>
> I'm working on a branch to add OES_tessellation_shader support, and I
> noticed this query that we didn't implement.  I tested the query on
> i965 with the dEQP-GLES31.functional.tessellation.state_query.
> primitive_restart_for_patches_supported test.  It passed.
>
> diff --git a/src/mapi/glapi/gen/ARB_tessellation_shader.xml b/src/mapi/glapi/gen/ARB_tessellation_shader.xml
> index 77f2228..5ffc2ba 100644
> --- a/src/mapi/glapi/gen/ARB_tessellation_shader.xml
> +++ b/src/mapi/glapi/gen/ARB_tessellation_shader.xml
> @@ -48,6 +48,7 @@
>      <enum value="0x8E88" name="TESS_CONTROL_SHADER"/>
>      <enum value="0x8E89" name="MAX_TESS_CONTROL_UNIFORM_BLOCKS"/>
>      <enum value="0x8E8A" name="MAX_TESS_EVALUATION_UNIFORM_BLOCKS"/>
> +    <enum value="0x8221" name="PRIMITIVE_RESTART_FOR_PATCHES_SUPPORTED"/>
>
>      <function name="PatchParameteri">
>          <param name="pname" type="GLenum"/>
> diff --git a/src/mesa/drivers/dri/i965/brw_context.c b/src/mesa/drivers/dri/i965/brw_context.c
> index 1ab02ae..552e5ec 100644
> --- a/src/mesa/drivers/dri/i965/brw_context.c
> +++ b/src/mesa/drivers/dri/i965/brw_context.c
> @@ -565,6 +565,7 @@ brw_initialize_context_constants(struct brw_context *brw)
>        ctx->Const.MaxClipPlanes = 8;
>
>     ctx->Const.LowerTessLevel = true;
> +   ctx->Const.PrimitiveRestartForPatches = true;
>
>     ctx->Const.Program[MESA_SHADER_VERTEX].MaxNativeInstructions = 16 * 1024;
>     ctx->Const.Program[MESA_SHADER_VERTEX].MaxAluInstructions = 0;
> diff --git a/src/mesa/main/context.c b/src/mesa/main/context.c
> index f690799..7c0a6ef 100644
> --- a/src/mesa/main/context.c
> +++ b/src/mesa/main/context.c
> @@ -725,6 +725,7 @@ _mesa_init_constants(struct gl_constants *consts, gl_api api)
>     consts->Program[MESA_SHADER_TESS_EVAL].MaxTextureImageUnits = MAX_TEXTURE_IMAGE_UNITS;
>     consts->MaxTessPatchComponents = MAX_TESS_PATCH_COMPONENTS;
>     consts->MaxTessControlTotalOutputComponents = MAX_TESS_CONTROL_TOTAL_OUTPUT_COMPONENTS;
> +   consts->PrimitiveRestartForPatches = false;
>  }
>
>
> diff --git a/src/mesa/main/get_hash_params.py b/src/mesa/main/get_hash_params.py
> index 8f693ac..2124072 100644
> --- a/src/mesa/main/get_hash_params.py
> +++ b/src/mesa/main/get_hash_params.py
> @@ -912,6 +912,7 @@ descriptor=[
>    [ "MAX_TESS_EVALUATION_UNIFORM_BLOCKS", "CONTEXT_INT(Const.Program[MESA_SHADER_TESS_EVAL].MaxUniformBlocks), extra_ARB_tessellation_shader" ],
>    [ "MAX_COMBINED_TESS_CONTROL_UNIFORM_COMPONENTS", "CONTEXT_INT(Const.Program[MESA_SHADER_TESS_CTRL].MaxCombinedUniformComponents), extra_ARB_tessellation_shader" ],
>    [ "MAX_COMBINED_TESS_EVALUATION_UNIFORM_COMPONENTS", "CONTEXT_INT(Const.Program[MESA_SHADER_TESS_EVAL].MaxCombinedUniformComponents), extra_ARB_tessellation_shader" ],
> +  [ "PRIMITIVE_RESTART_FOR_PATCHES_SUPPORTED", "CONTEXT_BOOL(Const.PrimitiveRestartForPatches), extra_ARB_tessellation_shader" ],
>  # Dependencies on GL_ARB_tessellation_shader
>    [ "MAX_TESS_CONTROL_ATOMIC_COUNTER_BUFFERS", "CONTEXT_INT(Const.Program[MESA_SHADER_TESS_CTRL].MaxAtomicBuffers), extra_ARB_shader_atomic_counters_and_tessellation" ],
>    [ "MAX_TESS_CONTROL_ATOMIC_COUNTERS", "CONTEXT_INT(Const.Program[MESA_SHADER_TESS_CTRL].MaxAtomicCounters), extra_ARB_shader_atomic_counters_and_tessellation" ],
> diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
> index 569e0ac..feab1a1 100644
> --- a/src/mesa/main/mtypes.h
> +++ b/src/mesa/main/mtypes.h
> @@ -3725,6 +3725,7 @@ struct gl_constants
>     GLuint MaxTessPatchComponents;
>     GLuint MaxTessControlTotalOutputComponents;
>     bool LowerTessLevel; /**< Lower gl_TessLevel* from float[n] to vecn? */
> +   bool PrimitiveRestartForPatches;
>  };
>
>
> diff --git a/src/mesa/state_tracker/st_extensions.c b/src/mesa/state_tracker/st_extensions.c
> index ea60e41..eeb80dd 100644
> --- a/src/mesa/state_tracker/st_extensions.c
> +++ b/src/mesa/state_tracker/st_extensions.c
> @@ -314,6 +314,9 @@ void st_init_limits(struct pipe_screen *screen,
>     }
>
>     c->LowerTessLevel = true;
> +   c->PrimitiveRestartForPatches =
> +      screen->get_shader_param(screen, sh,
> +                               PIPE_CAP_PRIMITIVE_RESTART_FOR_PATCHES);

I think you want ->get_param(screen, PIPE_CAP_FOO). shader_param is
for PIPE_SHADER_CAP, which are per-shader stage. (What is "sh" here?)

Otherwise this series is

Reviewed-by: Ilia Mirkin <imirkin at alum.mit.edu>

>
>     c->MaxCombinedTextureImageUnits =
>           _min(c->Program[MESA_SHADER_VERTEX].MaxTextureImageUnits +
> --
> 2.8.2
>