Merge pull request #99041 from mrsaturnsan/metal_frame_pacing

Use afterMinimumDuration to correct frame pacing

drivers/metal/rendering_context_driver_metal.h

@@ -107,6 +107,7 @@ public:
 		uint32_t height = 0;
 		DisplayServer::VSyncMode vsync_mode = DisplayServer::VSYNC_ENABLED;
 		bool needs_resize = false;
+		double present_minimum_duration = 0.0;
 
 		Surface(
 #ifdef __OBJC__
@@ -123,6 +124,7 @@ public:
 		virtual Error resize(uint32_t p_desired_framebuffer_count) = 0;
 		virtual RDD::FramebufferID acquire_next_frame_buffer() = 0;
 		virtual void present(MDCommandBuffer *p_cmd_buffer) = 0;
+		void set_max_fps(int p_max_fps) { present_minimum_duration = p_max_fps ? 1.0 / p_max_fps : 0.0; }
 	};
 
 #ifdef __OBJC__

drivers/metal/rendering_context_driver_metal.mm

@@ -172,7 +172,7 @@ public:
 		count--;
 		front = (front + 1) % frame_buffers.size();
 
-		[p_cmd_buffer->get_command_buffer() presentDrawable:drawable];
+		[p_cmd_buffer->get_command_buffer() presentDrawable:drawable afterMinimumDuration:present_minimum_duration];
 	}
 };
 

drivers/metal/rendering_device_driver_metal.h

@@ -220,6 +220,7 @@ public:
 	virtual FramebufferID swap_chain_acquire_framebuffer(CommandQueueID p_cmd_queue, SwapChainID p_swap_chain, bool &r_resize_required) override final;
 	virtual RenderPassID swap_chain_get_render_pass(SwapChainID p_swap_chain) override final;
 	virtual DataFormat swap_chain_get_format(SwapChainID p_swap_chain) override final;
+	virtual void swap_chain_set_max_fps(SwapChainID p_swap_chain, int p_max_fps) override final;
 	virtual void swap_chain_free(SwapChainID p_swap_chain) override final;
 
 #pragma mark - Frame Buffer

drivers/metal/rendering_device_driver_metal.mm

@@ -982,6 +982,12 @@ RDD::DataFormat RenderingDeviceDriverMetal::swap_chain_get_format(SwapChainID p_
 	return swap_chain->data_format;
 }
 
+void RenderingDeviceDriverMetal::swap_chain_set_max_fps(SwapChainID p_swap_chain, int p_max_fps) {
+	SwapChain *swap_chain = (SwapChain *)(p_swap_chain.id);
+	RenderingContextDriverMetal::Surface *metal_surface = (RenderingContextDriverMetal::Surface *)(swap_chain->surface);
+	metal_surface->set_max_fps(p_max_fps);
+}
+
 void RenderingDeviceDriverMetal::swap_chain_free(SwapChainID p_swap_chain) {
 	SwapChain *swap_chain = (SwapChain *)(p_swap_chain.id);
 	_swap_chain_release(swap_chain);