[vulkan] Implemented active color output tracking in runtime info and update fragment color handling

src/shader_recompiler/backend/spirv/emit_spirv_context_get_set.cpp

@@ -491,6 +491,9 @@ void EmitSetPatch(EmitContext& ctx, IR::Patch patch, Id value) {
 }
 
 void EmitSetFragColor(EmitContext& ctx, u32 index, u32 component, Id value) {
+    if (!ctx.runtime_info.active_color_outputs[index]) {
+        return;
+    }
     const Id component_id{ctx.Const(component)};
     const AttributeType type{ctx.runtime_info.color_output_types[index]};
     if (type == AttributeType::Float) {

src/shader_recompiler/backend/spirv/spirv_emit_context.cpp

@@ -1688,8 +1688,10 @@ void EmitContext::DefineOutputs(const IR::Program& program) {
     case Stage::Fragment:
         for (u32 index = 0; index < 8; ++index) {
             const bool need_dual_source = runtime_info.dual_source_blend && index <= 1;
-            if (!need_dual_source && !info.stores_frag_color[index] &&
-                !profile.need_declared_frag_colors) {
+            const bool should_declare = runtime_info.active_color_outputs[index] &&
+                                        (info.stores_frag_color[index] ||
+                                         profile.need_declared_frag_colors);
+            if (!need_dual_source && !should_declare) {
                 continue;
             }
             const Id type{GetAttributeType(*this, runtime_info.color_output_types[index])};

src/shader_recompiler/runtime_info.h

@@ -111,6 +111,9 @@ struct RuntimeInfo {
     /// Output types for each color attachment
     std::array<AttributeType, 8> color_output_types{};
 
+    /// Fragment color outputs that are active for the current pipeline.
+    std::array<bool, 8> active_color_outputs{true, true, true, true, true, true, true, true};
+
     /// Dual source blending
     bool dual_source_blend{};
 };

src/video_core/renderer_vulkan/vk_pipeline_cache.cpp

@@ -249,6 +249,17 @@ Shader::RuntimeInfo MakeRuntimeInfo(std::span<const Shader::IR::Program> program
                 dst_a == F::Source1Alpha_GL || dst_a == F::OneMinusSource1Alpha_GL;
         }
 
+        for (size_t i = 0; i < info.active_color_outputs.size(); ++i) {
+            const auto format = static_cast<Tegra::RenderTargetFormat>(key.state.color_formats[i]);
+            info.active_color_outputs[i] = format != Tegra::RenderTargetFormat::NONE;
+        }
+        if (info.dual_source_blend && info.active_color_outputs[0]) {
+            info.active_color_outputs[1] = true;
+        }
+        if (info.alpha_test_func && *info.alpha_test_func != Shader::CompareFunction::Always) {
+            info.active_color_outputs[0] = true;
+        }
+
         if (device.IsMoltenVK()) {
             for (size_t i = 0; i < 8; ++i) {
                 const auto format = static_cast<Tegra::RenderTargetFormat>(key.state.color_formats[i]);