4 files changed, 26 insertions, 13 deletions

diff --git a/src/video_core/renderer_vulkan/vk_pipeline_cache.cpp b/src/video_core/renderer_vulkan/vk_pipeline_cache.cpp
index fe45ed269..890175d2d 100644
--- a/src/video_core/renderer_vulkan/vk_pipeline_cache.cpp
+++ b/src/video_core/renderer_vulkan/vk_pipeline_cache.cpp
@@ -312,7 +312,9 @@ VKPipelineCache::DecompileShaders(const GraphicsPipelineCacheKey& key) {
         ASSERT(point_size != 0.0f);
     }
     for (std::size_t i = 0; i < Maxwell::NumVertexAttributes; ++i) {
-        specialization.attribute_types[i] = fixed_state.vertex_input.attributes[i].Type();
+        const auto& attribute = fixed_state.vertex_input.attributes[i];
+        specialization.enabled_attributes[i] = attribute.enabled.Value() != 0;
+        specialization.attribute_types[i] = attribute.Type();
     }
     specialization.ndc_minus_one_to_one = fixed_state.rasterizer.ndc_minus_one_to_one;
 
diff --git a/src/video_core/renderer_vulkan/vk_rasterizer.cpp b/src/video_core/renderer_vulkan/vk_rasterizer.cpp
index 5af2a0d25..cf15e6d1c 100644
--- a/src/video_core/renderer_vulkan/vk_rasterizer.cpp
+++ b/src/video_core/renderer_vulkan/vk_rasterizer.cpp
@@ -875,7 +875,7 @@ void RasterizerVulkan::SetupVertexArrays(FixedPipelineState::VertexInput& vertex
 
     for (std::size_t index = 0; index < Maxwell::NumVertexAttributes; ++index) {
         const auto& attrib = regs.vertex_attrib_format[index];
-        if (!attrib.IsValid()) {
+        if (attrib.IsConstant()) {
             vertex_input.SetAttribute(index, false, 0, 0, {}, {});
             continue;
         }
diff --git a/src/video_core/renderer_vulkan/vk_shader_decompiler.cpp b/src/video_core/renderer_vulkan/vk_shader_decompiler.cpp
index 18678968c..6ce6bfcb5 100644
--- a/src/video_core/renderer_vulkan/vk_shader_decompiler.cpp
+++ b/src/video_core/renderer_vulkan/vk_shader_decompiler.cpp
@@ -731,8 +731,10 @@ private:
             if (!IsGenericAttribute(index)) {
                 continue;
             }
-
             const u32 location = GetGenericAttributeLocation(index);
+            if (!IsAttributeEnabled(location)) {
+                continue;
+            }
             const auto type_descriptor = GetAttributeType(location);
             Id type;
             if (IsInputAttributeArray()) {
@@ -976,6 +978,10 @@ private:
         return stage == ShaderType::TesselationControl;
     }
 
+    bool IsAttributeEnabled(u32 location) const {
+        return stage != ShaderType::Vertex || specialization.enabled_attributes[location];
+    }
+
     u32 GetNumInputVertices() const {
         switch (stage) {
         case ShaderType::Geometry:
@@ -1192,16 +1198,20 @@ private:
                 UNIMPLEMENTED_MSG("Unmanaged FrontFacing element={}", element);
                 return {v_float_zero, Type::Float};
             default:
-                if (IsGenericAttribute(attribute)) {
-                    const u32 location = GetGenericAttributeLocation(attribute);
-                    const auto type_descriptor = GetAttributeType(location);
-                    const Type type = type_descriptor.type;
-                    const Id attribute_id = input_attributes.at(attribute);
-                    const std::vector elements = {element};
-                    const Id pointer = ArrayPass(type_descriptor.scalar, attribute_id, elements);
-                    return {OpLoad(GetTypeDefinition(type), pointer), type};
+                if (!IsGenericAttribute(attribute)) {
+                    break;
                 }
-                break;
+                const u32 location = GetGenericAttributeLocation(attribute);
+                if (!IsAttributeEnabled(location)) {
+                    // Disabled attributes (also known as constant attributes) always return zero.
+                    return {v_float_zero, Type::Float};
+                }
+                const auto type_descriptor = GetAttributeType(location);
+                const Type type = type_descriptor.type;
+                const Id attribute_id = input_attributes.at(attribute);
+                const std::vector elements = {element};
+                const Id pointer = ArrayPass(type_descriptor.scalar, attribute_id, elements);
+                return {OpLoad(GetTypeDefinition(type), pointer), type};
             }
             UNIMPLEMENTED_MSG("Unhandled input attribute: {}", static_cast<u32>(attribute));
             return {v_float_zero, Type::Float};
diff --git a/src/video_core/renderer_vulkan/vk_shader_decompiler.h b/src/video_core/renderer_vulkan/vk_shader_decompiler.h
index f4c05ac3c..b7af26388 100644
--- a/src/video_core/renderer_vulkan/vk_shader_decompiler.h
+++ b/src/video_core/renderer_vulkan/vk_shader_decompiler.h
@@ -88,7 +88,8 @@ struct Specialization final {
     u32 shared_memory_size{};
 
     // Graphics specific
-    std::optional<float> point_size{};
+    std::optional<float> point_size;
+    std::bitset<Maxwell::NumVertexAttributes> enabled_attributes;
     std::array<Maxwell::VertexAttribute::Type, Maxwell::NumVertexAttributes> attribute_types{};
     bool ndc_minus_one_to_one{};
 };