[Mesa-dev] [PATCH 5/8] radeonsi: implement SAMPLEPOS fragment shader input

Ilia Mirkin imirkin at alum.mit.edu
Wed May 7 08:00:25 PDT 2014


On Wed, May 7, 2014 at 10:00 AM, Marek Olšák <maraeo at gmail.com> wrote:
> From: Marek Olšák <marek.olsak at amd.com>
>
> The sample positions are read from a constant buffer.

FWIW I had to do the same thing in both nv50 and nvc0. I had proposed
that this should actually be done directly by the state tracker, but I
think claims were made to the effect that there might be hw which can
look up the positions directly. I figured radeon was such hw, but I
guess not.

Anyways, seems like a nice refactor would be to have mesa/st (or
mesa/main) supply the constbufs and rip out the extra logic from
nv50/nvc0/radeonsi. [Certainly don't have to do it now, esp now that
you've done it this way.] The sample count is already handled this way
by mesa core.

  -ilia

> ---
>  src/gallium/drivers/radeon/cayman_msaa.c      | 17 +++++++++++++++++
>  src/gallium/drivers/radeon/r600_pipe_common.c |  1 +
>  src/gallium/drivers/radeon/r600_pipe_common.h | 10 ++++++++++
>  src/gallium/drivers/radeonsi/si_shader.c      | 23 +++++++++++++++++++++++
>  src/gallium/drivers/radeonsi/si_state.c       | 25 +++++++++++++++++++++++++
>  5 files changed, 76 insertions(+)
>
> diff --git a/src/gallium/drivers/radeon/cayman_msaa.c b/src/gallium/drivers/radeon/cayman_msaa.c
> index 8727f3e..47fc5c4 100644
> --- a/src/gallium/drivers/radeon/cayman_msaa.c
> +++ b/src/gallium/drivers/radeon/cayman_msaa.c
> @@ -123,6 +123,23 @@ void cayman_get_sample_position(struct pipe_context *ctx, unsigned sample_count,
>         }
>  }
>
> +void cayman_init_msaa(struct pipe_context *ctx)
> +{
> +       struct r600_common_context *rctx = (struct r600_common_context*)ctx;
> +       int i;
> +
> +       cayman_get_sample_position(ctx, 1, 0, rctx->sample_locations_1x[0]);
> +
> +       for (i = 0; i < 2; i++)
> +               cayman_get_sample_position(ctx, 2, i, rctx->sample_locations_2x[i]);
> +       for (i = 0; i < 4; i++)
> +               cayman_get_sample_position(ctx, 4, i, rctx->sample_locations_4x[i]);
> +       for (i = 0; i < 8; i++)
> +               cayman_get_sample_position(ctx, 8, i, rctx->sample_locations_8x[i]);
> +       for (i = 0; i < 16; i++)
> +               cayman_get_sample_position(ctx, 16, i, rctx->sample_locations_16x[i]);
> +}
> +
>  void cayman_emit_msaa_sample_locs(struct radeon_winsys_cs *cs, int nr_samples)
>  {
>         switch (nr_samples) {
> diff --git a/src/gallium/drivers/radeon/r600_pipe_common.c b/src/gallium/drivers/radeon/r600_pipe_common.c
> index 70c4d1a..4c6cf0e 100644
> --- a/src/gallium/drivers/radeon/r600_pipe_common.c
> +++ b/src/gallium/drivers/radeon/r600_pipe_common.c
> @@ -154,6 +154,7 @@ bool r600_common_context_init(struct r600_common_context *rctx,
>         r600_init_context_texture_functions(rctx);
>         r600_streamout_init(rctx);
>         r600_query_init(rctx);
> +       cayman_init_msaa(&rctx->b);
>
>         rctx->allocator_so_filled_size = u_suballocator_create(&rctx->b, 4096, 4,
>                                                                0, PIPE_USAGE_DEFAULT, TRUE);
> diff --git a/src/gallium/drivers/radeon/r600_pipe_common.h b/src/gallium/drivers/radeon/r600_pipe_common.h
> index 4c3e9ce..8862d31 100644
> --- a/src/gallium/drivers/radeon/r600_pipe_common.h
> +++ b/src/gallium/drivers/radeon/r600_pipe_common.h
> @@ -357,6 +357,15 @@ struct r600_common_context {
>         boolean                         saved_render_cond_cond;
>         unsigned                        saved_render_cond_mode;
>
> +       /* MSAA sample locations.
> +        * The first index is the sample index.
> +        * The second index is the coordinate: X, Y. */
> +       float                           sample_locations_1x[1][2];
> +       float                           sample_locations_2x[2][2];
> +       float                           sample_locations_4x[4][2];
> +       float                           sample_locations_8x[8][2];
> +       float                           sample_locations_16x[16][2];
> +
>         /* Copy one resource to another using async DMA. */
>         void (*dma_copy)(struct pipe_context *ctx,
>                          struct pipe_resource *dst,
> @@ -472,6 +481,7 @@ extern const uint32_t eg_sample_locs_4x[4];
>  extern const unsigned eg_max_dist_4x;
>  void cayman_get_sample_position(struct pipe_context *ctx, unsigned sample_count,
>                                 unsigned sample_index, float *out_value);
> +void cayman_init_msaa(struct pipe_context *ctx);
>  void cayman_emit_msaa_sample_locs(struct radeon_winsys_cs *cs, int nr_samples);
>  void cayman_emit_msaa_config(struct radeon_winsys_cs *cs, int nr_samples,
>                              int ps_iter_samples);
> diff --git a/src/gallium/drivers/radeonsi/si_shader.c b/src/gallium/drivers/radeonsi/si_shader.c
> index 0195e54..d8b7b9c 100644
> --- a/src/gallium/drivers/radeonsi/si_shader.c
> +++ b/src/gallium/drivers/radeonsi/si_shader.c
> @@ -559,6 +559,8 @@ static void declare_system_value(
>  {
>         struct si_shader_context *si_shader_ctx =
>                 si_shader_context(&radeon_bld->soa.bld_base);
> +       struct lp_build_context *uint_bld = &radeon_bld->soa.bld_base.uint_bld;
> +       struct gallivm_state *gallivm = &radeon_bld->gallivm;
>         LLVMValueRef value = 0;
>
>         switch (decl->Semantic.Name) {
> @@ -576,6 +578,27 @@ static void declare_system_value(
>                 value = get_sample_id(radeon_bld);
>                 break;
>
> +       case TGSI_SEMANTIC_SAMPLEPOS:
> +       {
> +               LLVMBuilderRef builder = gallivm->builder;
> +               LLVMValueRef desc = LLVMGetParam(si_shader_ctx->radeon_bld.main_fn, SI_PARAM_CONST);
> +               LLVMValueRef buf_index = lp_build_const_int32(gallivm, NUM_PIPE_CONST_BUFFERS);
> +               LLVMValueRef resource = build_indexed_load(si_shader_ctx, desc, buf_index);
> +
> +               /* offset = sample_id * 8  (8 = 2 floats containing samplepos.xy) */
> +               LLVMValueRef offset0 = lp_build_mul_imm(uint_bld, get_sample_id(radeon_bld), 8);
> +               LLVMValueRef offset1 = LLVMBuildAdd(builder, offset0, lp_build_const_int32(gallivm, 4), "");
> +
> +               LLVMValueRef pos[4] = {
> +                       load_const(builder, resource, offset0, radeon_bld->soa.bld_base.base.elem_type),
> +                       load_const(builder, resource, offset1, radeon_bld->soa.bld_base.base.elem_type),
> +                       lp_build_const_float(gallivm, 0),
> +                       lp_build_const_float(gallivm, 0)
> +               };
> +               value = lp_build_gather_values(gallivm, pos, 4);
> +               break;
> +       }
> +
>         default:
>                 assert(!"unknown system value");
>                 return;
> diff --git a/src/gallium/drivers/radeonsi/si_state.c b/src/gallium/drivers/radeonsi/si_state.c
> index fd9de05..3c1af06 100644
> --- a/src/gallium/drivers/radeonsi/si_state.c
> +++ b/src/gallium/drivers/radeonsi/si_state.c
> @@ -1859,6 +1859,7 @@ static void si_set_framebuffer_state(struct pipe_context *ctx,
>                                      const struct pipe_framebuffer_state *state)
>  {
>         struct si_context *sctx = (struct si_context *)ctx;
> +       struct pipe_constant_buffer constbuf = {0};
>         struct r600_surface *surf = NULL;
>         struct r600_texture *rtex;
>         int i;
> @@ -1924,6 +1925,30 @@ static void si_set_framebuffer_state(struct pipe_context *ctx,
>         sctx->framebuffer.atom.num_dw += 18; /* MSAA sample locations */
>         sctx->framebuffer.atom.dirty = true;
>         sctx->msaa_config.dirty = true;
> +
> +       /* Set sample locations as fragment shader constants. */
> +       switch (sctx->framebuffer.nr_samples) {
> +       case 1:
> +               constbuf.user_buffer = sctx->b.sample_locations_1x;
> +               break;
> +       case 2:
> +               constbuf.user_buffer = sctx->b.sample_locations_2x;
> +               break;
> +       case 4:
> +               constbuf.user_buffer = sctx->b.sample_locations_4x;
> +               break;
> +       case 8:
> +               constbuf.user_buffer = sctx->b.sample_locations_8x;
> +               break;
> +       case 16:
> +               constbuf.user_buffer = sctx->b.sample_locations_16x;
> +               break;
> +       default:
> +               assert(0);
> +       }
> +       constbuf.buffer_size = sctx->framebuffer.nr_samples * 2 * 4;
> +       ctx->set_constant_buffer(ctx, PIPE_SHADER_FRAGMENT,
> +                                NUM_PIPE_CONST_BUFFERS, &constbuf);
>  }
>
>  static void si_emit_framebuffer_state(struct si_context *sctx, struct r600_atom *atom)
> --
> 1.9.1
>
> _______________________________________________
> mesa-dev mailing list
> mesa-dev at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/mesa-dev


More information about the mesa-dev mailing list