gl_rasterizer: Track how many vertex attributes have been written to.

src/video_core/engines/maxwell_3d.cpp

@@ -102,6 +102,26 @@ void Maxwell3D::WriteReg(u32 method, u32 value, u32 remaining_params) {
         ProcessCBData(value);
         break;
     }
+    case MAXWELL3D_REG_INDEX(vertex_attrib_format[0]):
+    case MAXWELL3D_REG_INDEX(vertex_attrib_format[1]):
+    case MAXWELL3D_REG_INDEX(vertex_attrib_format[2]):
+    case MAXWELL3D_REG_INDEX(vertex_attrib_format[3]):
+    case MAXWELL3D_REG_INDEX(vertex_attrib_format[4]):
+    case MAXWELL3D_REG_INDEX(vertex_attrib_format[5]):
+    case MAXWELL3D_REG_INDEX(vertex_attrib_format[6]):
+    case MAXWELL3D_REG_INDEX(vertex_attrib_format[7]):
+    case MAXWELL3D_REG_INDEX(vertex_attrib_format[8]):
+    case MAXWELL3D_REG_INDEX(vertex_attrib_format[9]):
+    case MAXWELL3D_REG_INDEX(vertex_attrib_format[10]):
+    case MAXWELL3D_REG_INDEX(vertex_attrib_format[11]):
+    case MAXWELL3D_REG_INDEX(vertex_attrib_format[12]):
+    case MAXWELL3D_REG_INDEX(vertex_attrib_format[13]):
+    case MAXWELL3D_REG_INDEX(vertex_attrib_format[14]):
+    case MAXWELL3D_REG_INDEX(vertex_attrib_format[15]): {
+        state.MaxAttribs =
+            std::max(state.MaxAttribs, method - MAXWELL3D_REG_INDEX(vertex_attrib_format[0]) + 1);
+        break;
+    }
     case MAXWELL3D_REG_INDEX(cb_bind[0].raw_config): {
         ProcessCBBind(Regs::ShaderStage::Vertex);
         break;

src/video_core/engines/maxwell_3d.h

@@ -800,6 +800,7 @@ public:
         };
 
         std::array<ShaderStageInfo, Regs::MaxShaderStage> shader_stages;
+        size_t MaxAttribs;
     };
 
     State state{};

src/video_core/renderer_opengl/gl_rasterizer.cpp

@@ -128,6 +128,7 @@ RasterizerOpenGL::~RasterizerOpenGL() {
 std::pair<u8*, GLintptr> RasterizerOpenGL::SetupVertexArrays(u8* array_ptr,
                                                              GLintptr buffer_offset) {
     MICROPROFILE_SCOPE(OpenGL_VAO);
+
     const auto& regs = Core::System::GetInstance().GPU().Maxwell3D().regs;
     const auto& memory_manager = Core::System::GetInstance().GPU().memory_manager;
 
@@ -160,12 +161,12 @@ std::pair<u8*, GLintptr> RasterizerOpenGL::SetupVertexArrays(u8* array_ptr,
     }
 
     // Use the vertex array as-is, assumes that the data is formatted correctly for OpenGL.
-    // Enables the first 16 vertex attributes always, as we don't know which ones are actually used
+    // Enables the all vertex attributes that have been written to, as we don't know which ones are
-    // until shader time. Note, Tegra technically supports 32, but we're capping this to 16 for now
+    // actually used until shader time. Note: Tegra technically supports 32.
-    // to avoid OpenGL errors.
     // TODO(Subv): Analyze the shader to identify which attributes are actually used and don't
     // assume every shader uses them all.
-    for (unsigned index = 0; index < 16; ++index) {
+    const auto& max_attribs = Core::System::GetInstance().GPU().Maxwell3D().state.MaxAttribs;
+    for (unsigned index = 0; index < max_attribs; ++index) {
         auto& attrib = regs.vertex_attrib_format[index];
         LOG_DEBUG(HW_GPU, "vertex attrib {}, count={}, size={}, type={}, offset={}, normalize={}",
                   index, attrib.ComponentCount(), attrib.SizeString(), attrib.TypeString(),