mesa/st: add support for ARB_sample_shading

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Reviewed-by: Roland Scheidegger <sroland@vmware.com>

src/gallium/auxiliary/cso_cache/cso_context.c

@@ -120,6 +120,7 @@ struct cso_context {
    struct pipe_viewport_state vp, vp_saved;
    struct pipe_blend_color blend_color;
    unsigned sample_mask, sample_mask_saved;
+   unsigned min_samples, min_samples_saved;
    struct pipe_stencil_ref stencil_ref, stencil_ref_saved;
 };
 
@@ -716,6 +717,24 @@ void cso_restore_sample_mask(struct cso_context *ctx)
    cso_set_sample_mask(ctx, ctx->sample_mask_saved);
 }
 
+void cso_set_min_samples(struct cso_context *ctx, unsigned min_samples)
+{
+   if (ctx->min_samples != min_samples && ctx->pipe->set_min_samples) {
+      ctx->min_samples = min_samples;
+      ctx->pipe->set_min_samples(ctx->pipe, min_samples);
+   }
+}
+
+void cso_save_min_samples(struct cso_context *ctx)
+{
+   ctx->min_samples_saved = ctx->min_samples;
+}
+
+void cso_restore_min_samples(struct cso_context *ctx)
+{
+   cso_set_min_samples(ctx, ctx->min_samples_saved);
+}
+
 void cso_set_stencil_ref(struct cso_context *ctx,
                          const struct pipe_stencil_ref *sr)
 {

src/gallium/auxiliary/cso_cache/cso_context.h

@@ -164,6 +164,10 @@ void cso_set_sample_mask(struct cso_context *cso, unsigned stencil_mask);
 void cso_save_sample_mask(struct cso_context *ctx);
 void cso_restore_sample_mask(struct cso_context *ctx);
 
+void cso_set_min_samples(struct cso_context *cso, unsigned min_samples);
+void cso_save_min_samples(struct cso_context *ctx);
+void cso_restore_min_samples(struct cso_context *ctx);
+
 void cso_set_stencil_ref(struct cso_context *cso,
                          const struct pipe_stencil_ref *sr);
 void cso_save_stencil_ref(struct cso_context *cso);

src/gallium/auxiliary/hud/hud_context.c

@@ -412,6 +412,7 @@ hud_draw(struct hud_context *hud, struct pipe_resource *tex)
 
    cso_save_framebuffer(cso);
    cso_save_sample_mask(cso);
+   cso_save_min_samples(cso);
    cso_save_blend(cso);
    cso_save_depth_stencil_alpha(cso);
    cso_save_fragment_shader(cso);
@@ -450,6 +451,7 @@ hud_draw(struct hud_context *hud, struct pipe_resource *tex)
 
    cso_set_framebuffer(cso, &fb);
    cso_set_sample_mask(cso, ~0);
+   cso_set_min_samples(cso, 1);
    cso_set_blend(cso, &hud->alpha_blend);
    cso_set_depth_stencil_alpha(cso, &hud->dsa);
    cso_set_rasterizer(cso, &hud->rasterizer);
@@ -538,6 +540,7 @@ hud_draw(struct hud_context *hud, struct pipe_resource *tex)
    /* restore states */
    cso_restore_framebuffer(cso);
    cso_restore_sample_mask(cso);
+   cso_restore_min_samples(cso);
    cso_restore_blend(cso);
    cso_restore_depth_stencil_alpha(cso);
    cso_restore_fragment_shader(cso);

src/gallium/auxiliary/postprocess/pp_run.c

@@ -122,6 +122,7 @@ pp_run(struct pp_queue_t *ppq, struct pipe_resource *in,
    cso_save_geometry_shader(cso);
    cso_save_rasterizer(cso);
    cso_save_sample_mask(cso);
+   cso_save_min_samples(cso);
    cso_save_samplers(cso, PIPE_SHADER_FRAGMENT);
    cso_save_sampler_views(cso, PIPE_SHADER_FRAGMENT);
    cso_save_stencil_ref(cso);
@@ -136,6 +137,7 @@ pp_run(struct pp_queue_t *ppq, struct pipe_resource *in,
 
    /* set default state */
    cso_set_sample_mask(cso, ~0);
+   cso_set_min_samples(cso, 1);
    cso_set_stream_outputs(cso, 0, NULL, NULL);
    cso_set_geometry_shader_handle(cso, NULL);
    cso_set_render_condition(cso, NULL, FALSE, 0);
@@ -187,6 +189,7 @@ pp_run(struct pp_queue_t *ppq, struct pipe_resource *in,
    cso_restore_geometry_shader(cso);
    cso_restore_rasterizer(cso);
    cso_restore_sample_mask(cso);
+   cso_restore_min_samples(cso);
    cso_restore_samplers(cso, PIPE_SHADER_FRAGMENT);
    cso_restore_sampler_views(cso, PIPE_SHADER_FRAGMENT);
    cso_restore_stencil_ref(cso);

src/gallium/auxiliary/util/u_blit.c

@@ -520,6 +520,7 @@ util_blit_pixels_tex(struct blit_state *ctx,
    cso_save_depth_stencil_alpha(ctx->cso);
    cso_save_rasterizer(ctx->cso);
    cso_save_sample_mask(ctx->cso);
+   cso_save_min_samples(ctx->cso);
    cso_save_samplers(ctx->cso, PIPE_SHADER_FRAGMENT);
    cso_save_sampler_views(ctx->cso, PIPE_SHADER_FRAGMENT);
    cso_save_stream_outputs(ctx->cso);
@@ -535,6 +536,7 @@ util_blit_pixels_tex(struct blit_state *ctx,
    cso_set_blend(ctx->cso, &ctx->blend_write_color);
    cso_set_depth_stencil_alpha(ctx->cso, &ctx->dsa_keep_depthstencil);
    cso_set_sample_mask(ctx->cso, ~0);
+   cso_set_min_samples(ctx->cso, 1);
    cso_set_rasterizer(ctx->cso, &ctx->rasterizer);
    cso_set_vertex_elements(ctx->cso, 2, ctx->velem);
    cso_set_stream_outputs(ctx->cso, 0, NULL, NULL);
@@ -597,6 +599,7 @@ util_blit_pixels_tex(struct blit_state *ctx,
    cso_restore_depth_stencil_alpha(ctx->cso);
    cso_restore_rasterizer(ctx->cso);
    cso_restore_sample_mask(ctx->cso);
+   cso_restore_min_samples(ctx->cso);
    cso_restore_samplers(ctx->cso, PIPE_SHADER_FRAGMENT);
    cso_restore_sampler_views(ctx->cso, PIPE_SHADER_FRAGMENT);
    cso_restore_viewport(ctx->cso);

src/mesa/state_tracker/st_atom.c

@@ -61,6 +61,7 @@ static const struct st_tracked_state *atoms[] =
    &st_update_sampler, /* depends on update_*_texture for swizzle */
    &st_update_framebuffer,
    &st_update_msaa,
+   &st_update_sample_shading,
    &st_update_vs_constants,
    &st_update_gs_constants,
    &st_update_fs_constants,

src/mesa/state_tracker/st_atom.h

@@ -59,6 +59,7 @@ extern const struct st_tracked_state st_update_viewport;
 extern const struct st_tracked_state st_update_scissor;
 extern const struct st_tracked_state st_update_blend;
 extern const struct st_tracked_state st_update_msaa;
+extern const struct st_tracked_state st_update_sample_shading;
 extern const struct st_tracked_state st_update_sampler;
 extern const struct st_tracked_state st_update_fragment_texture;
 extern const struct st_tracked_state st_update_vertex_texture;

src/mesa/state_tracker/st_atom_msaa.c

@@ -27,8 +27,10 @@
 
 
 #include "st_context.h"
+#include "pipe/p_screen.h"
 #include "pipe/p_context.h"
 #include "st_atom.h"
+#include "st_program.h"
 
 #include "cso_cache/cso_context.h"
 #include "util/u_framebuffer.h"
@@ -70,6 +72,18 @@ static void update_sample_mask( struct st_context *st )
    }
 }
 
+static void update_sample_shading( struct st_context *st )
+{
+   if (!st->fp)
+      return;
+
+   if (!st->ctx->Extensions.ARB_sample_shading)
+      return;
+
+   cso_set_min_samples(
+	 st->cso_context,
+         _mesa_get_min_invocations_per_fragment(st->ctx, &st->fp->Base, false));
+}
 
 const struct st_tracked_state st_update_msaa = {
    "st_update_msaa",					/* name */
@@ -79,3 +93,12 @@ const struct st_tracked_state st_update_msaa = {
    },
    update_sample_mask					/* update */
 };
+
+const struct st_tracked_state st_update_sample_shading = {
+   "st_update_sample_shading",				/* name */
+   {							/* dirty */
+      (_NEW_MULTISAMPLE | _NEW_PROGRAM | _NEW_BUFFERS),	/* mesa */
+      ST_NEW_FRAGMENT_PROGRAM | ST_NEW_FRAMEBUFFER,	/* st */
+   },
+   update_sample_shading				/* update */
+};

src/mesa/state_tracker/st_cb_clear.c

@@ -240,6 +240,7 @@ clear_with_quad(struct gl_context *ctx, unsigned clear_buffers)
    cso_save_depth_stencil_alpha(st->cso_context);
    cso_save_rasterizer(st->cso_context);
    cso_save_sample_mask(st->cso_context);
+   cso_save_min_samples(st->cso_context);
    cso_save_viewport(st->cso_context);
    cso_save_fragment_shader(st->cso_context);
    cso_save_stream_outputs(st->cso_context);
@@ -309,6 +310,7 @@ clear_with_quad(struct gl_context *ctx, unsigned clear_buffers)
    cso_set_vertex_elements(st->cso_context, 2, st->velems_util_draw);
    cso_set_stream_outputs(st->cso_context, 0, NULL, NULL);
    cso_set_sample_mask(st->cso_context, ~0);
+   cso_set_min_samples(st->cso_context, 1);
    cso_set_rasterizer(st->cso_context, &st->clear.raster);
 
    /* viewport state: viewport matching window dims */
@@ -348,6 +350,7 @@ clear_with_quad(struct gl_context *ctx, unsigned clear_buffers)
    cso_restore_depth_stencil_alpha(st->cso_context);
    cso_restore_rasterizer(st->cso_context);
    cso_restore_sample_mask(st->cso_context);
+   cso_restore_min_samples(st->cso_context);
    cso_restore_viewport(st->cso_context);
    cso_restore_fragment_shader(st->cso_context);
    cso_restore_vertex_shader(st->cso_context);

src/mesa/state_tracker/st_extensions.c

@@ -425,7 +425,8 @@ void st_init_extensions(struct st_context *st)
       { o(OES_standard_derivatives),         PIPE_CAP_SM3                              },
       { o(ARB_texture_cube_map_array),       PIPE_CAP_CUBE_MAP_ARRAY                   },
       { o(ARB_texture_multisample),          PIPE_CAP_TEXTURE_MULTISAMPLE              },
-      { o(ARB_texture_query_lod),            PIPE_CAP_TEXTURE_QUERY_LOD                }
+      { o(ARB_texture_query_lod),            PIPE_CAP_TEXTURE_QUERY_LOD                },
+      { o(ARB_sample_shading),               PIPE_CAP_SAMPLE_SHADING                   },
    };
 
    /* Required: render target and sampler support */

src/mesa/state_tracker/st_glsl_to_tgsi.cpp

@@ -4163,7 +4163,9 @@ struct st_translate {
 static unsigned mesa_sysval_to_semantic[SYSTEM_VALUE_MAX] = {
    TGSI_SEMANTIC_FACE,
    TGSI_SEMANTIC_VERTEXID,
-   TGSI_SEMANTIC_INSTANCEID
+   TGSI_SEMANTIC_INSTANCEID,
+   TGSI_SEMANTIC_SAMPLEID,
+   TGSI_SEMANTIC_SAMPLEPOS,
 };
 
 /**
@@ -4381,7 +4383,8 @@ translate_dst(struct st_translate *t,
          break;
 
       case TGSI_PROCESSOR_FRAGMENT:
-         if (dst_reg->index >= FRAG_RESULT_COLOR) {
+         if (dst_reg->index == FRAG_RESULT_COLOR ||
+             dst_reg->index >= FRAG_RESULT_DATA0) {
             dst = ureg_saturate(dst);
          }
          break;
@@ -4876,6 +4879,15 @@ st_translate_program(
                                              TGSI_SEMANTIC_COLOR,
                                              outputSemanticIndex[i]);
             break;
+         case TGSI_SEMANTIC_SAMPLEMASK:
+            t->outputs[i] = ureg_DECL_output(ureg,
+                                             TGSI_SEMANTIC_SAMPLEMASK,
+                                             outputSemanticIndex[i]);
+            /* TODO: If we ever support more than 32 samples, this will have
+             * to become an array.
+             */
+            t->outputs[i] = ureg_writemask(t->outputs[i], TGSI_WRITEMASK_X);
+            break;
          default:
             assert(!"fragment shader outputs must be POSITION/STENCIL/COLOR");
             ret = PIPE_ERROR_BAD_INPUT;

src/mesa/state_tracker/st_program.c

@@ -682,6 +682,7 @@ st_translate_fragment_program(struct st_context *st,
       /* handle remaining outputs (color) */
       for (attr = 0; attr < FRAG_RESULT_MAX; attr++) {
          if (outputsWritten & BITFIELD64_BIT(attr)) {
+            int semantic = TGSI_SEMANTIC_COLOR;
             switch (attr) {
             case FRAG_RESULT_DEPTH:
             case FRAG_RESULT_STENCIL:
@@ -689,16 +690,20 @@ st_translate_fragment_program(struct st_context *st,
                assert(0);
                break;
             case FRAG_RESULT_COLOR:
-               write_all = GL_TRUE; /* fallthrough */
+               write_all = GL_TRUE;
-            default:
+               break;
+            case FRAG_RESULT_SAMPLE_MASK:
+               semantic = TGSI_SEMANTIC_SAMPLEMASK;
+               break;
+            }
+
             assert(attr == FRAG_RESULT_COLOR ||
+                   attr == FRAG_RESULT_SAMPLE_MASK ||
                    (FRAG_RESULT_DATA0 <= attr && attr < FRAG_RESULT_MAX));
-               fs_output_semantic_name[fs_num_outputs] = TGSI_SEMANTIC_COLOR;
+            fs_output_semantic_name[fs_num_outputs] = semantic;
             fs_output_semantic_index[fs_num_outputs] = numColors;
             outputMapping[attr] = fs_num_outputs;
             numColors++;
-               break;
-            }
 
             fs_num_outputs++;
          }