type PFN_vkCmdTraceRaysNV = Option<unsafe extern "system" fn(commandBuffer: VkCommandBuffer, raygenShaderBindingTableBuffer: VkBuffer, raygenShaderBindingOffset: VkDeviceSize, missShaderBindingTableBuffer: VkBuffer, missShaderBindingOffset: VkDeviceSize, missShaderBindingStride: VkDeviceSize, hitShaderBindingTableBuffer: VkBuffer, hitShaderBindingOffset: VkDeviceSize, hitShaderBindingStride: VkDeviceSize, callableShaderBindingTableBuffer: VkBuffer, callableShaderBindingOffset: VkDeviceSize, callableShaderBindingStride: VkDeviceSize, width: u32, height: u32, depth: u32)>;