mesa: support GL_NV_representative_fragment test

Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/37081>

docs/gallium/screen.rst

@@ -653,6 +653,7 @@ Capability about the features and limits of the driver/GPU.
 * ``pipe_caps.shader_subgroup_quad_all_stages``: Whether shader subgroup quad operations are supported by shader stages other than fragment shader.
 * ``pipe_caps.multiview``: Whether multiview rendering of array textures is supported. A return of ``1`` indicates support for OVR_multiview, and ``2`` additionally supports OVR_multiview2. 
 * ``pipe_caps.call_finalize_nir_in_linker``: Whether ``pipe_screen::finalize_nir`` can be called in the GLSL linker before the NIR is stored in the shader cache. It's always called again after st/mesa adds code for shader variants. It must be 1 if the driver wants to report compile failures to the GLSL linker. It must be 0 if two consecutive ``finalize_nir`` calls on the same shader can break it, or if ``finalize_nir`` can't handle NIR that isn't fully lowered for the driver, or if ``finalize_nir`` breaks passes that st/mesa runs after it. Setting it to 1 is generally safe for drivers that expose nir_io_has_intrinsics and that don't enable any optional shader variants in st/mesa. Since it's difficult to support, any future refactoring can change it to 0.
+* ``pipe_caps.representative_fragment_test``: Support for GL_NV_representative_fragment_test.
 * ``pipe_caps.min_line_width``: The minimum width of a regular line.
 * ``pipe_caps.min_line_width_aa``: The minimum width of a smoothed line.
 * ``pipe_caps.max_line_width``: The maximum width of a regular line.

src/gallium/include/pipe/p_defines.h

@@ -1043,6 +1043,7 @@ struct pipe_caps {
    bool shader_subgroup_quad_all_stages;
    bool call_finalize_nir_in_linker;
    bool mesh_shader;
+   bool representative_fragment_test;
 
    int accelerated;
    int min_texel_offset;

src/gallium/include/pipe/p_state.h

@@ -203,6 +203,8 @@ struct pipe_rasterizer_state
     */
    unsigned clip_plane_enable:PIPE_MAX_CLIP_PLANES;
 
+   unsigned representative_fragment_test:1;
+
    unsigned line_stipple_factor:8;  /**< [1..256] actually */
    unsigned line_stipple_pattern:16;
 

src/mesa/glapi/glapi/gen/gl_API.xml

@@ -9310,6 +9310,10 @@
     <function name="ResolveDepthValuesNV" es2="3.1" alias="EvaluateDepthValuesARB"/>
 </category>
 
+<category name="GL_NV_representative_fragment_test">
+    <enum name="REPRESENTATIVE_FRAGMENT_TEST_NV" value="0x937F"/>
+</category>
+
 <category name="GL_SUN_convolution_border_modes" number="182">
     <enum name="WRAP_BORDER_SUN"                          value="0x81D4"/>
 </category>

src/mesa/main/consts_exts.h

@@ -288,6 +288,7 @@ struct gl_extensions
    GLboolean NV_viewport_array2;
    GLboolean NV_viewport_swizzle;
    GLboolean NV_timeline_semaphore;
+   GLboolean NV_representative_fragment_test;
    GLboolean NVX_gpu_memory_info;
    GLboolean TDFX_texture_compression_FXT1;
    GLboolean OES_EGL_image;

src/mesa/main/enable.c

@@ -616,6 +616,15 @@ _mesa_set_enable(struct gl_context *ctx, GLenum cap, GLboolean state)
          ST_SET_STATE(ctx->NewDriverState, ST_NEW_RASTERIZER);
          ctx->ConservativeRasterization = state;
          break;
+      case GL_REPRESENTATIVE_FRAGMENT_TEST_NV:
+         if (!_mesa_has_NV_representative_fragment_test(ctx))
+            goto invalid_enum_error;
+         if (ctx->RepresentativeFragmentTest == state)
+            return;
+         FLUSH_VERTICES(ctx, 0, GL_ENABLE_BIT);
+         ST_SET_STATE(ctx->NewDriverState, ST_NEW_RASTERIZER);
+         ctx->RepresentativeFragmentTest = state;
+         break;
       case GL_COLOR_LOGIC_OP:
          if (!_mesa_is_desktop_gl(ctx) && ctx->API != API_OPENGLES)
             goto invalid_enum_error;
@@ -1983,6 +1992,11 @@ _mesa_IsEnabled( GLenum cap )
             goto invalid_enum_error;
          return ctx->ConservativeRasterization;
 
+      case GL_REPRESENTATIVE_FRAGMENT_TEST_NV:
+         if (!_mesa_has_NV_representative_fragment_test(ctx))
+            goto invalid_enum_error;
+         return ctx->RepresentativeFragmentTest;
+
       case GL_TILE_RASTER_ORDER_FIXED_MESA:
          if (!_mesa_has_MESA_tile_raster_order(ctx))
             goto invalid_enum_error;

src/mesa/main/extensions_table.h

@@ -434,6 +434,7 @@ EXT(NV_read_buffer                          , dummy_true
 EXT(NV_read_depth                           , dummy_true                             ,  x ,  x ,  x , ES2, 2011)
 EXT(NV_read_depth_stencil                   , dummy_true                             ,  x ,  x ,  x , ES2, 2011)
 EXT(NV_read_stencil                         , dummy_true                             ,  x ,  x ,  x , ES2, 2011)
+EXT(NV_representative_fragment_test         , NV_representative_fragment_test        , GLL, GLC,  x ,  32, 2019)
 EXT(NV_sample_locations                     , ARB_sample_locations                   , GLL, GLC,  x , ES2, 2015)
 EXT(NV_shader_atomic_float                  , NV_shader_atomic_float                 , GLL, GLC,  x ,  x , 2012)
 EXT(NV_shader_atomic_int64                  , NV_shader_atomic_int64                 , GLL, GLC,  x ,  x , 2014)

src/mesa/main/get_hash_params.py

@@ -895,6 +895,9 @@ descriptor=[
   [ "EDGE_FLAG_ARRAY_STRIDE", "ARRAY_SHORT(VertexAttrib[VERT_ATTRIB_EDGEFLAG].Stride), NO_EXTRA" ],
   [ "EDGE_FLAG_ARRAY_COUNT_EXT", "CONST(0), NO_EXTRA" ],
 
+# GL_NV_representative_fragment_test
+  [ "REPRESENTATIVE_FRAGMENT_TEST_NV", "CONTEXT_BOOL(RepresentativeFragmentTest), NO_EXTRA" ],
+
 # GL_ARB_texture_compression
   [ "TEXTURE_COMPRESSION_HINT_ARB", "CONTEXT_ENUM16(Hint.TextureCompression), NO_EXTRA" ],
 

src/mesa/main/mtypes.h

@@ -3589,6 +3589,8 @@ struct gl_context
    GLfloat ConservativeRasterDilate;
    GLenum16 ConservativeRasterMode;
 
+   GLboolean RepresentativeFragmentTest; /**< GL_REPRESENTATIVE_FRAGMENT_TEST_NV */
+
    GLboolean IntelBlackholeRender; /**< GL_INTEL_blackhole_render */
 
    /** Does glVertexAttrib(0) alias glVertex()? */

src/mesa/state_tracker/st_atom_rasterizer.c

@@ -165,6 +165,8 @@ st_update_rasterizer(struct st_context *st)
 
    raster->poly_stipple_enable = ctx->Polygon.StippleFlag;
 
+   raster->representative_fragment_test = ctx->RepresentativeFragmentTest;
+
    /* Multisampling disables point, line, and polygon smoothing.
     *
     * GL_ARB_multisample says:

src/mesa/state_tracker/st_extensions.c

@@ -1146,6 +1146,7 @@ void st_init_extensions(struct pipe_screen *screen,
    EXT_CAP(NV_conditional_render,            conditional_render);
    EXT_CAP(NV_fill_rectangle,                polygon_mode_fill_rectangle);
    EXT_CAP(NV_primitive_restart,             primitive_restart);
+   EXT_CAP(NV_representative_fragment_test,  representative_fragment_test);
    EXT_CAP(NV_shader_atomic_float,           image_atomic_float_add);
    EXT_CAP(NV_shader_atomic_int64,           shader_atomic_int64);
    EXT_CAP(NV_texture_barrier,               texture_barrier);