devilutionX/Source/engine/render/blit_impl.hpp

#pragma once

#include <cstdint>
#include <cstring>

#ifdef __has_include
#if __has_include(<version>)
#include <version>
#endif

#if __cpp_lib_execution >= 201902L
#include <execution>
#endif
#endif

#include "engine/palette.h"
#include "utils/attributes.h"

namespace devilution {

#if __cpp_lib_execution >= 201902L
#define DEVILUTIONX_BLIT_EXECUTION_POLICY std::execution::unseq,
#else
#define DEVILUTIONX_BLIT_EXECUTION_POLICY
#endif

DVL_ALWAYS_INLINE DVL_ATTRIBUTE_HOT void BlitFillDirect(uint8_t *dst, unsigned length, uint8_t color)
{
	DVL_ASSUME(length != 0);
	std::memset(dst, color, length);
}

DVL_ALWAYS_INLINE DVL_ATTRIBUTE_HOT void BlitPixelsDirect(uint8_t *DVL_RESTRICT dst, const uint8_t *DVL_RESTRICT src, unsigned length)
{
	DVL_ASSUME(length != 0);
	std::memcpy(dst, src, length);
}

struct BlitDirect {
	DVL_ALWAYS_INLINE DVL_ATTRIBUTE_HOT void operator()(unsigned length, uint8_t *DVL_RESTRICT dst, const uint8_t *DVL_RESTRICT src) const
	{
		BlitPixelsDirect(dst, src, length);
	}
	DVL_ALWAYS_INLINE DVL_ATTRIBUTE_HOT void operator()(unsigned length, uint8_t color, uint8_t *DVL_RESTRICT dst) const
	{
		BlitFillDirect(dst, length, color);
	}
};

DVL_ALWAYS_INLINE DVL_ATTRIBUTE_HOT void BlitFillWithMap(uint8_t *dst, unsigned length, uint8_t color, const uint8_t *DVL_RESTRICT colorMap)
{
	DVL_ASSUME(length != 0);
	std::memset(dst, colorMap[color], length);
}

DVL_ALWAYS_INLINE DVL_ATTRIBUTE_HOT void BlitPixelsWithMap(uint8_t *DVL_RESTRICT dst, const uint8_t *DVL_RESTRICT src, unsigned length, const uint8_t *DVL_RESTRICT colorMap)
{
	DVL_ASSUME(length != 0);
	std::transform(DEVILUTIONX_BLIT_EXECUTION_POLICY src, src + length, dst, [colorMap](uint8_t srcColor) { return colorMap[srcColor]; });
}

struct BlitWithMap {
	const uint8_t *DVL_RESTRICT colorMap;

	DVL_ALWAYS_INLINE DVL_ATTRIBUTE_HOT void operator()(unsigned length, uint8_t *DVL_RESTRICT dst, const uint8_t *DVL_RESTRICT src) const
	{
		BlitPixelsWithMap(dst, src, length, colorMap);
	}
	DVL_ALWAYS_INLINE DVL_ATTRIBUTE_HOT void operator()(unsigned length, uint8_t color, uint8_t *DVL_RESTRICT dst) const
	{
		BlitFillWithMap(dst, length, color, colorMap);
	}
};

DVL_ALWAYS_INLINE DVL_ATTRIBUTE_HOT void BlitFillBlended(uint8_t *dst, unsigned length, uint8_t color)
{
	DVL_ASSUME(length != 0);
	std::for_each(DEVILUTIONX_BLIT_EXECUTION_POLICY dst, dst + length, [tbl = paletteTransparencyLookup[color]](uint8_t &dstColor) {
		dstColor = tbl[dstColor];
	});
}

DVL_ALWAYS_INLINE DVL_ATTRIBUTE_HOT void BlitPixelsBlended(uint8_t *DVL_RESTRICT dst, const uint8_t *DVL_RESTRICT src, unsigned length)
{
	DVL_ASSUME(length != 0);
	std::transform(DEVILUTIONX_BLIT_EXECUTION_POLICY src, src + length, dst, dst, [pal = paletteTransparencyLookup](uint8_t srcColor, uint8_t dstColor) {
		return pal[srcColor][dstColor];
	});
}

struct BlitBlended {
	DVL_ALWAYS_INLINE DVL_ATTRIBUTE_HOT void operator()(unsigned length, uint8_t *DVL_RESTRICT dst, const uint8_t *DVL_RESTRICT src) const
	{
		BlitPixelsBlended(dst, src, length);
	}
	DVL_ALWAYS_INLINE DVL_ATTRIBUTE_HOT void operator()(unsigned length, uint8_t color, uint8_t *DVL_RESTRICT dst) const
	{
		BlitFillBlended(dst, length, color);
	}
};

DVL_ALWAYS_INLINE DVL_ATTRIBUTE_HOT void BlitPixelsBlendedWithMap(uint8_t *DVL_RESTRICT dst, const uint8_t *DVL_RESTRICT src, unsigned length, const uint8_t *DVL_RESTRICT colorMap)
{
	DVL_ASSUME(length != 0);
	std::transform(DEVILUTIONX_BLIT_EXECUTION_POLICY src, src + length, dst, dst, [colorMap, pal = paletteTransparencyLookup](uint8_t srcColor, uint8_t dstColor) {
		return pal[dstColor][colorMap[srcColor]];
	});
}

struct BlitBlendedWithMap {
	const uint8_t *DVL_RESTRICT colorMap;

	DVL_ALWAYS_INLINE DVL_ATTRIBUTE_HOT void operator()(unsigned length, uint8_t *DVL_RESTRICT dst, const uint8_t *DVL_RESTRICT src) const
	{
		BlitPixelsBlendedWithMap(dst, src, length, colorMap);
	}
	DVL_ALWAYS_INLINE DVL_ATTRIBUTE_HOT void operator()(unsigned length, uint8_t color, uint8_t *DVL_RESTRICT dst) const
	{
		BlitFillBlended(dst, length, colorMap[color]);
	}
};

} // namespace devilution