/*************************************************************************/
/*  openxr_extension_wrapper.h                                           */
/*************************************************************************/
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#ifndef OPENXR_EXTENSION_WRAPPER_H
#define OPENXR_EXTENSION_WRAPPER_H

#include "core/error/error_macros.h"
#include "core/math/camera_matrix.h"
#include "core/templates/map.h"
#include "core/templates/rid.h"

#include "thirdparty/openxr/src/common/xr_linear.h"
#include <openxr/openxr.h>

class OpenXRAPI;

class OpenXRExtensionWrapper {
protected:
	OpenXRAPI *openxr_api = nullptr;

	// Store extension we require.
	// If bool pointer is a nullptr this means this extension is mandatory and initialisation will fail if it is not available
	// If bool pointer is set, value will be set to true or false depending on whether extension is available
	Map<const char *, bool *> request_extensions;

public:
	virtual Map<const char *, bool *> get_request_extensions() {
		return request_extensions;
	}

	// These functions allow an extension to add entries to a struct chain.
	// `p_next_pointer` points to the last struct that was created for this chain
	// and should be used as the value for the `pNext` pointer in the first struct you add.
	// You should return the pointer to the last struct you define as your result.
	// If you are not adding any structs, just return `p_next_pointer`.
	// See existing extensions for examples of this implementation.
	virtual void *set_system_properties_and_get_next_pointer(void *p_next_pointer) { return p_next_pointer; }
	virtual void *set_session_create_and_get_next_pointer(void *p_next_pointer) { return p_next_pointer; }
	virtual void *set_swapchain_create_info_and_get_next_pointer(void *p_next_pointer) { return p_next_pointer; }

	virtual void on_instance_created(const XrInstance p_instance) {}
	virtual void on_instance_destroyed() {}
	virtual void on_session_created(const XrSession p_instance) {}
	virtual void on_process() {}
	virtual void on_pre_render() {}
	virtual void on_session_destroyed() {}

	virtual void on_state_idle() {}
	virtual void on_state_ready() {}
	virtual void on_state_synchronized() {}
	virtual void on_state_visible() {}
	virtual void on_state_focused() {}
	virtual void on_state_stopping() {}
	virtual void on_state_loss_pending() {}
	virtual void on_state_exiting() {}

	// Returns true if the event was handled, false otherwise.
	virtual bool on_event_polled(const XrEventDataBuffer &event) {
		return false;
	}

	OpenXRExtensionWrapper(OpenXRAPI *p_openxr_api) { openxr_api = p_openxr_api; };
	virtual ~OpenXRExtensionWrapper() = default;
};

class OpenXRGraphicsExtensionWrapper : public OpenXRExtensionWrapper {
public:
	virtual void get_usable_swapchain_formats(Vector<int64_t> &p_usable_swap_chains) = 0;
	virtual String get_swapchain_format_name(int64_t p_swapchain_format) const = 0;
	virtual bool get_swapchain_image_data(XrSwapchain p_swapchain, int64_t p_swapchain_format, uint32_t p_width, uint32_t p_height, uint32_t p_sample_count, uint32_t p_array_size, void **r_swapchain_graphics_data) = 0;
	virtual void cleanup_swapchain_graphics_data(void **p_swapchain_graphics_data) = 0;
	virtual bool create_projection_fov(const XrFovf p_fov, double p_z_near, double p_z_far, CameraMatrix &r_camera_matrix) = 0;
	virtual bool copy_render_target_to_image(RID p_from_render_target, void *p_swapchain_graphics_data, int p_image_index) = 0;

	OpenXRGraphicsExtensionWrapper(OpenXRAPI *p_openxr_api) :
			OpenXRExtensionWrapper(p_openxr_api){};
};

#endif // ~OPENXR_EXTENSION_WRAPPER_H