maxwell_to_vk: Use VK_EXT_index_type_uint8 when available

src/video_core/renderer_vulkan/maxwell_to_vk.cpp

@@ -308,11 +308,14 @@ vk::CompareOp ComparisonOp(Maxwell::ComparisonOp comparison) {
     return {};
 }
 
-vk::IndexType IndexFormat(Maxwell::IndexFormat index_format) {
+vk::IndexType IndexFormat(const VKDevice& device, Maxwell::IndexFormat index_format) {
     switch (index_format) {
     case Maxwell::IndexFormat::UnsignedByte:
-        UNIMPLEMENTED_MSG("Vulkan does not support native u8 index format");
-        return vk::IndexType::eUint16;
+        if (!device.IsExtIndexTypeUint8Supported()) {
+            UNIMPLEMENTED_MSG("Native uint8 indices are not supported on this device");
+            return vk::IndexType::eUint16;
+        }
+        return vk::IndexType::eUint8EXT;
     case Maxwell::IndexFormat::UnsignedShort:
         return vk::IndexType::eUint16;
     case Maxwell::IndexFormat::UnsignedInt:

src/video_core/renderer_vulkan/maxwell_to_vk.h

@@ -40,7 +40,7 @@ vk::Format VertexFormat(Maxwell::VertexAttribute::Type type, Maxwell::VertexAttr
 
 vk::CompareOp ComparisonOp(Maxwell::ComparisonOp comparison);
 
-vk::IndexType IndexFormat(Maxwell::IndexFormat index_format);
+vk::IndexType IndexFormat(const VKDevice& device, Maxwell::IndexFormat index_format);
 
 vk::StencilOp StencilOp(Maxwell::StencilOp stencil_op);