/**************************************************************************/
/*  image_compress_betsy.h                                                */
/**************************************************************************/
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/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
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#ifndef IMAGE_COMPRESS_BETSY_H
#define IMAGE_COMPRESS_BETSY_H

#include "core/io/image.h"
#include "core/object/worker_thread_pool.h"
#include "core/os/thread.h"
#include "core/templates/command_queue_mt.h"

#include "servers/rendering/rendering_device_binds.h"
#include "servers/rendering/rendering_server_default.h"

#if defined(VULKAN_ENABLED)
#include "drivers/vulkan/rendering_context_driver_vulkan.h"
#endif
#if defined(METAL_ENABLED)
#include "drivers/metal/rendering_context_driver_metal.h"
#endif

enum BetsyFormat {
	BETSY_FORMAT_BC1,
	BETSY_FORMAT_BC1_DITHER,
	BETSY_FORMAT_BC3,
	BETSY_FORMAT_BC4_SIGNED,
	BETSY_FORMAT_BC4_UNSIGNED,
	BETSY_FORMAT_BC6_SIGNED,
	BETSY_FORMAT_BC6_UNSIGNED,
};

struct BC6PushConstant {
	float sizeX;
	float sizeY;
	uint32_t padding[2];
};

struct BC1PushConstant {
	uint32_t num_refines;
	uint32_t padding[3];
};

struct BC4PushConstant {
	uint32_t channel_idx;
	uint32_t padding[3];
};

void free_device();

Error _betsy_compress_bptc(Image *r_img, Image::UsedChannels p_channels);
Error _betsy_compress_s3tc(Image *r_img, Image::UsedChannels p_channels);

class BetsyCompressor : public Object {
	mutable CommandQueueMT command_queue;
	bool exit = false;
	WorkerThreadPool::TaskID task_id = WorkerThreadPool::INVALID_TASK_ID;

	struct BetsyShader {
		RID compiled;
		RID pipeline;
	};

	// Resources shared by all compression formats.
	RenderingDevice *compress_rd = nullptr;
	RenderingContextDriver *compress_rcd = nullptr;
	HashMap<String, BetsyShader> cached_shaders;
	RID src_sampler;

	// Format-specific resources.
	RID dxt1_encoding_table_buffer;

	void _init();
	void _assign_mt_ids(WorkerThreadPool::TaskID p_pump_task_id);
	void _thread_loop();
	void _thread_exit();

	Error _compress(BetsyFormat p_format, Image *r_img);

public:
	void init();
	void finish();

	Error compress(BetsyFormat p_format, Image *r_img) {
		Error err;
		command_queue.push_and_ret(this, &BetsyCompressor::_compress, p_format, r_img, &err);
		return err;
	}
};

#endif // IMAGE_COMPRESS_BETSY_H