zink: handle point sprite

this needs custom yinvert handling and also prim mode detection, which
gallium can't do on its own

Reviewed-by: Dave Airlie <airlied@redhat.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/9115>

src/gallium/drivers/zink/zink_compiler.c

@@ -469,6 +469,12 @@ zink_shader_compile(struct zink_screen *screen, struct zink_shader *zs, struct z
             nir = nir_shader_clone(NULL, zs->nir);
          NIR_PASS_V(nir, lower_dual_blend);
       }
+      if (zink_fs_key(key)->coord_replace_bits) {
+         if (nir == zs->nir)
+            nir = nir_shader_clone(NULL, zs->nir);
+         NIR_PASS_V(nir, nir_lower_texcoord_replace, zink_fs_key(key)->coord_replace_bits,
+                    false, zink_fs_key(key)->coord_replace_yinvert);
+      }
    }
    struct spirv_shader *spirv = nir_to_spirv(nir, streamout, shader_slot_map, shader_slots_reserved);
    assert(spirv);

src/gallium/drivers/zink/zink_draw.c

@@ -664,6 +664,11 @@ zink_draw_vbo(struct pipe_context *pctx,
    if (drawid_broken != ctx->drawid_broken)
       ctx->dirty_shader_stages |= BITFIELD_BIT(PIPE_SHADER_VERTEX);
    ctx->gfx_pipeline_state.vertices_per_patch = dinfo->vertices_per_patch;
+   if (ctx->rast_state->base.point_quad_rasterization &&
+       ctx->gfx_prim_mode != dinfo->mode) {
+      if (ctx->gfx_prim_mode == PIPE_PRIM_POINTS || dinfo->mode == PIPE_PRIM_POINTS)
+         ctx->dirty_shader_stages |= BITFIELD_BIT(PIPE_SHADER_FRAGMENT);
+   }
    ctx->gfx_prim_mode = dinfo->mode;
    struct zink_gfx_program *gfx_program = get_gfx_program(ctx);
    if (!gfx_program)

src/gallium/drivers/zink/zink_program.c

@@ -246,6 +246,11 @@ shader_key_fs_gen(struct zink_context *ctx, struct zink_shader *zs,
    fs_key->force_dual_color_blend = screen->driconf.dual_color_blend_by_location &&
                                     ctx->gfx_pipeline_state.blend_state->dual_src_blend &&
                                     ctx->gfx_pipeline_state.blend_state->attachments[1].blendEnable;
+   if (((shaders[PIPE_SHADER_GEOMETRY] && shaders[PIPE_SHADER_GEOMETRY]->nir->info.gs.output_primitive == GL_POINTS) ||
+       ctx->gfx_prim_mode == PIPE_PRIM_POINTS) && ctx->rast_state->base.point_quad_rasterization && ctx->rast_state->base.sprite_coord_enable) {
+      fs_key->coord_replace_bits = ctx->rast_state->base.sprite_coord_enable;
+      fs_key->coord_replace_yinvert = !!ctx->rast_state->base.sprite_coord_mode;
+   }
 }
 
 static void

src/gallium/drivers/zink/zink_screen.c

@@ -264,6 +264,9 @@ zink_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
    case PIPE_CAP_TEXTURE_MULTISAMPLE:
       return 1;
 
+   case PIPE_CAP_POINT_SPRITE:
+      return 1;
+
    case PIPE_CAP_SAMPLE_SHADING:
       return screen->info.feats.features.sampleRateShading;
 

src/gallium/drivers/zink/zink_shader_keys.h

@@ -35,6 +35,8 @@ struct zink_vs_key {
 
 struct zink_fs_key {
    unsigned shader_id;
+   uint8_t coord_replace_bits;
+   bool coord_replace_yinvert;
    //bool flat_shade;
    bool samples;
    bool force_dual_color_blend;

src/gallium/drivers/zink/zink_state.c

@@ -468,6 +468,7 @@ zink_bind_rasterizer_state(struct pipe_context *pctx, void *cso)
 {
    struct zink_context *ctx = zink_context(pctx);
    bool clip_halfz = ctx->rast_state ? ctx->rast_state->base.clip_halfz : false;
+   bool point_quad_rasterization = ctx->rast_state ? ctx->rast_state->base.point_quad_rasterization : false;
    ctx->rast_state = cso;
 
    if (ctx->rast_state) {
@@ -483,6 +484,8 @@ zink_bind_rasterizer_state(struct pipe_context *pctx, void *cso)
          ctx->line_width = ctx->rast_state->line_width;
          ctx->gfx_pipeline_state.dirty = true;
       }
+      if (ctx->rast_state->base.point_quad_rasterization != point_quad_rasterization)
+         ctx->dirty_shader_stages |= BITFIELD_BIT(PIPE_SHADER_FRAGMENT);
    }
 }