/**************************************************************************/
/*  openxr_frame_synthesis_extension.h                                    */
/**************************************************************************/
/*                         This file is part of:                          */
/*                             GODOT ENGINE                               */
/*                        https://godotengine.org                         */
/**************************************************************************/
/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
/*                                                                        */
/* Permission is hereby granted, free of charge, to any person obtaining  */
/* a copy of this software and associated documentation files (the        */
/* "Software"), to deal in the Software without restriction, including    */
/* without limitation the rights to use, copy, modify, merge, publish,    */
/* distribute, sublicense, and/or sell copies of the Software, and to     */
/* permit persons to whom the Software is furnished to do so, subject to  */
/* the following conditions:                                              */
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/* The above copyright notice and this permission notice shall be         */
/* included in all copies or substantial portions of the Software.        */
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/**************************************************************************/

#pragma once

#include "../openxr_api.h"
#include "openxr_extension_wrapper.h"

#include <openxr/openxr.h>

class OpenXRFrameSynthesisExtension : public OpenXRExtensionWrapper {
	GDCLASS(OpenXRFrameSynthesisExtension, OpenXRExtensionWrapper);

public:
	static OpenXRFrameSynthesisExtension *get_singleton();

	OpenXRFrameSynthesisExtension();
	virtual ~OpenXRFrameSynthesisExtension() override;

	virtual HashMap<String, bool *> get_requested_extensions() override;

	virtual void on_instance_created(const XrInstance p_instance) override;
	virtual void on_instance_destroyed() override;

	virtual void prepare_view_configuration(uint32_t p_view_count) override;
	virtual void *set_view_configuration_and_get_next_pointer(uint32_t p_view, void *p_next_pointer) override;
	virtual void print_view_configuration_info(uint32_t p_view) const override;

	virtual void on_session_destroyed() override;

	virtual void on_main_swapchains_created() override;
	virtual void on_pre_render() override;
	virtual void on_post_draw_viewport(RID p_render_target) override;
	virtual void *set_projection_views_and_get_next_pointer(int p_view_index, void *p_next_pointer) override;

	bool is_available() const;

	bool is_enabled() const;
	void set_enabled(bool p_enabled);

	bool get_relax_frame_interval() const;
	void set_relax_frame_interval(bool p_relax_frame_interval);

	void skip_next_frame();

protected:
	static void _bind_methods();

	void _set_render_state_enabled_rt(bool p_enabled);
	void _set_relax_frame_interval_rt(bool p_relax_frame_interval);
	void _set_skip_next_frame_rt();

private:
	enum SwapchainTypes {
		SWAPCHAIN_MOTION_VECTOR,
		SWAPCHAIN_DEPTH,
		SWAPCHAIN_MAX
	};
	void free_swapchains();

	static OpenXRFrameSynthesisExtension *singleton;

	bool frame_synthesis_ext = false;
	bool enabled = true;
	bool relax_frame_interval = false;

	// Frame synthesis render state, only accessible on render thread
	struct RenderState {
		bool enabled = true;
		bool relax_frame_interval = false;
		bool skip_next_frame = false;

		LocalVector<XrFrameSynthesisConfigViewEXT> config_views;
		OpenXRAPI::OpenXRSwapChainInfo swapchains[SWAPCHAIN_MAX];
		LocalVector<XrFrameSynthesisInfoEXT> frame_synthesis_info;
		Transform3D previous_transform;
	} render_state;
};