[Mesa-dev] [PATCH 3/3] anv/pipeline: make FragCoord include sample positions when sample shading

[Iago Toral Quiroga]

Because this setting affects the code we generate for the shader, we also
need to include it in the WM prog key. Notice we don't need to alter the
OpenGL code because it doesn't ever use this behavior, so they key's
value is always false (the default).

Fixes:
dEQP-VK.glsl.builtin_var.fragcoord_msaa.*
---
 src/intel/compiler/brw_compiler.h |  1 +
 src/intel/vulkan/anv_pipeline.c   | 23 +++++++++++++++--------
 2 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/src/intel/compiler/brw_compiler.h b/src/intel/compiler/brw_compiler.h
index d4128bc..9228413 100644
--- a/src/intel/compiler/brw_compiler.h
+++ b/src/intel/compiler/brw_compiler.h
@@ -292,6 +292,7 @@ struct brw_wm_prog_key {
    bool clamp_fragment_color:1;
    bool persample_interp:1;
    bool multisample_fbo:1;
+   bool frag_coord_adds_sample_pos:1;
    enum brw_wm_aa_enable line_aa:2;
    bool high_quality_derivatives:1;
    bool force_dual_color_blend:1;
diff --git a/src/intel/vulkan/anv_pipeline.c b/src/intel/vulkan/anv_pipeline.c
index ce9c889..9d0dc69 100644
--- a/src/intel/vulkan/anv_pipeline.c
+++ b/src/intel/vulkan/anv_pipeline.c
@@ -87,12 +87,14 @@ void anv_DestroyShaderModule(
  * we can't do that yet because we don't have the ability to copy nir.
  */
 static nir_shader *
-anv_shader_compile_to_nir(struct anv_device *device,
+anv_shader_compile_to_nir(struct anv_pipeline *pipeline,
                           struct anv_shader_module *module,
                           const char *entrypoint_name,
                           gl_shader_stage stage,
                           const VkSpecializationInfo *spec_info)
 {
+   const struct anv_device *device = pipeline->device;
+
    const struct brw_compiler *compiler =
       device->instance->physicalDevice.compiler;
    const nir_shader_compiler_options *nir_options =
@@ -158,7 +160,7 @@ anv_shader_compile_to_nir(struct anv_device *device,
               nir_var_shader_in | nir_var_shader_out | nir_var_system_value);
 
    if (stage == MESA_SHADER_FRAGMENT)
-      NIR_PASS_V(nir, nir_lower_wpos_center, false);
+      NIR_PASS_V(nir, nir_lower_wpos_center, pipeline->sample_shading_enable);
 
    /* Now that we've deleted all but the main function, we can go ahead and
     * lower the rest of the constant initializers.
@@ -304,14 +306,19 @@ populate_wm_prog_key(const struct anv_pipeline *pipeline,
                           info->pMultisampleState &&
                           info->pMultisampleState->alphaToCoverageEnable;
 
-   if (info->pMultisampleState && info->pMultisampleState->rasterizationSamples > 1) {
+   if (info->pMultisampleState) {
       /* We should probably pull this out of the shader, but it's fairly
        * harmless to compute it and then let dead-code take care of it.
        */
-      key->persample_interp =
-         (info->pMultisampleState->minSampleShading *
-          info->pMultisampleState->rasterizationSamples) > 1;
-      key->multisample_fbo = true;
+      if (info->pMultisampleState->rasterizationSamples > 1) {
+         key->persample_interp =
+            (info->pMultisampleState->minSampleShading *
+             info->pMultisampleState->rasterizationSamples) > 1;
+         key->multisample_fbo = true;
+      }
+
+      key->frag_coord_adds_sample_pos =
+         info->pMultisampleState->sampleShadingEnable;
    }
 }
 
@@ -333,7 +340,7 @@ anv_pipeline_compile(struct anv_pipeline *pipeline,
                      struct brw_stage_prog_data *prog_data,
                      struct anv_pipeline_bind_map *map)
 {
-   nir_shader *nir = anv_shader_compile_to_nir(pipeline->device,
+   nir_shader *nir = anv_shader_compile_to_nir(pipeline,
                                                module, entrypoint, stage,
                                                spec_info);
    if (nir == NULL)
-- 
2.7.4