// Code based on DOSBox-0.65

#ifndef ZMBVENCODER_HH

#define ZMBVENCODER_HH

#include "MemBuffer.hh"

#include "aligned.hh"

#include <cstdint>

#include <span>

#include <string_view>

#include <zlib.h>

namespace openmsx {

class FrameSource;

class ZMBVEncoder

{

public:

	static constexpr std::string_view CODEC_4CC = "ZMBV";

	using Pixel = uint32_t;

	ZMBVEncoder(unsigned width, unsigned height);

	ZMBVEncoder(const ZMBVEncoder&) = delete;

	ZMBVEncoder(ZMBVEncoder&&) = delete;

	ZMBVEncoder& operator=(const ZMBVEncoder&) = delete;

	ZMBVEncoder& operator=(ZMBVEncoder&&) = delete;

	~ZMBVEncoder() = default;

	[[nodiscard]] std::span<const uint8_t> compressFrame(bool keyFrame, const FrameSource* frame);

private:

	void setupBuffers();

	[[nodiscard]] unsigned neededSize() const;

	void addFullFrame(unsigned& workUsed);

	void addXorFrame (unsigned& workUsed);

	[[nodiscard]] unsigned possibleBlock(int vx, int vy, size_t offset);

	[[nodiscard]] unsigned compareBlock(int vx, int vy, size_t offset);

	void addXorBlock(int vx, int vy, size_t offset, unsigned& workUsed);

	[[nodiscard]] const Pixel* getScaledLine(const FrameSource* frame, unsigned y, Pixel* workBuf) const;

private:

	MemBuffer<uint8_t, SSE_ALIGNMENT> oldFrame;

	MemBuffer<uint8_t, SSE_ALIGNMENT> newFrame;

	MemBuffer<uint8_t, SSE_ALIGNMENT> work;

	MemBuffer<uint8_t> output;

	MemBuffer<size_t> blockOffsets;

	unsigned outputSize;

	z_stream zstream;

	unsigned width;

	unsigned height;

	size_t pitch;

};

} // namespace openmsx

#endif