devilutionX/Source/engine/render/cel_render.cpp

/**
 * @file cel_render.cpp
 *
 * CEL rendering.
 */
#include "engine/render/cel_render.hpp"

#include <cstdint>
#include <cstring>

#include "engine/cel_header.hpp"
#include "engine/palette.h"
#include "engine/render/common_impl.h"
#include "engine/render/scrollrt.h"
#include "engine/trn.hpp"
#include "options.h"
#include "utils/attributes.h"

namespace devilution {

namespace {

constexpr bool IsCelTransparent(uint8_t control)
{
	constexpr uint8_t CelTransparentMin = 0x80;
	return control >= CelTransparentMin;
}

constexpr uint8_t GetCelTransparentWidth(uint8_t control)
{
	return -static_cast<std::int8_t>(control);
}

DVL_ALWAYS_INLINE DVL_ATTRIBUTE_HOT BlitCommand CelGetBlitCommand(const uint8_t *src)
{
	const uint8_t control = *src++;
	if (IsCelTransparent(control))
		return BlitCommand { BlitType::Transparent, src, GetCelTransparentWidth(control), 0 };
	return BlitCommand { BlitType::Pixels, src + control, control, 0 };
}

template <bool North, bool West, bool South, bool East, bool SkipColorIndexZero>
uint8_t *RenderCelOutlinePixelsCheckFirstColumn(
    uint8_t *dst, int dstPitch, int dstX,
    const uint8_t *src, uint8_t width, uint8_t color)
{
	if (dstX == -1) {
		RenderOutlineForPixel</*North=*/false, /*West=*/false, /*South=*/false, East, SkipColorIndexZero>(
		    dst++, dstPitch, *src++, color);
		--width;
	}
	if (width > 0) {
		RenderOutlineForPixel<North, /*West=*/false, South, East, SkipColorIndexZero>(dst++, dstPitch, *src++, color);
		--width;
	}
	if (width > 0) {
		RenderOutlineForPixels<North, West, South, East, SkipColorIndexZero>(dst, dstPitch, width, src, color);
		dst += width;
	}
	return dst;
}

template <bool North, bool West, bool South, bool East, bool SkipColorIndexZero>
uint8_t *RenderCelOutlinePixelsCheckLastColumn(
    uint8_t *dst, int dstPitch, int dstX, int dstW,
    const uint8_t *src, uint8_t width, uint8_t color)
{
	const bool lastPixel = dstX < dstW && width >= 1;
	const bool oobPixel = dstX + width > dstW;
	const int numSpecialPixels = (lastPixel ? 1 : 0) + (oobPixel ? 1 : 0);
	if (width > numSpecialPixels) {
		width -= numSpecialPixels;
		RenderOutlineForPixels<North, West, South, East, SkipColorIndexZero>(dst, dstPitch, width, src, color);
		src += width;
		dst += width;
	}
	if (lastPixel)
		RenderOutlineForPixel<North, West, South, /*East=*/false, SkipColorIndexZero>(dst++, dstPitch, *src++, color);
	if (oobPixel)
		RenderOutlineForPixel</*North=*/false, West, /*South=*/false, /*East=*/false, SkipColorIndexZero>(dst++, dstPitch, *src++, color);
	return dst;
}

template <bool SkipColorIndexZero, bool North, bool West, bool South, bool East, bool CheckFirstColumn, bool CheckLastColumn>
uint8_t *RenderCelOutlinePixels(
    uint8_t *dst, int dstPitch, int dstX, int dstW,
    const uint8_t *src, uint8_t width, uint8_t color)
{
	if (CheckFirstColumn && dstX <= 0) {
		return RenderCelOutlinePixelsCheckFirstColumn<North, West, South, East, SkipColorIndexZero>(
		    dst, dstPitch, dstX, src, width, color);
	}
	if (CheckLastColumn && dstX + width >= dstW) {
		return RenderCelOutlinePixelsCheckLastColumn<North, West, South, East, SkipColorIndexZero>(
		    dst, dstPitch, dstX, dstW, src, width, color);
	}
	RenderOutlineForPixels<North, West, South, East, SkipColorIndexZero>(dst, dstPitch, width, src, color);
	return dst + width;
}

template <bool SkipColorIndexZero, bool North, bool West, bool South, bool East,
    bool ClipWidth = false, bool CheckFirstColumn = false, bool CheckLastColumn = false>
const uint8_t *RenderCelOutlineRowClipped( // NOLINT(readability-function-cognitive-complexity,misc-no-recursion)
    const Surface &out, Point position, const uint8_t *src, ClipX clipX, uint8_t color)
{
	int_fast16_t remainingWidth = clipX.width;
	uint8_t v;

	auto *dst = &out[position];
	const auto dstPitch = out.pitch();
	const auto dstW = out.w();

	if (ClipWidth) {
		auto remainingLeftClip = clipX.left;
		while (remainingLeftClip > 0) {
			v = static_cast<uint8_t>(*src++);
			if (!IsCelTransparent(v)) {
				if (v > remainingLeftClip) {
					RenderCelOutlinePixels<SkipColorIndexZero, North, West, South, East, CheckFirstColumn, CheckLastColumn>(
					    dst, dstPitch, position.x, dstW, src, v - remainingLeftClip, color);
				}
				src += v;
			} else {
				v = GetCelTransparentWidth(v);
			}
			remainingLeftClip -= v;
		}
		dst -= static_cast<int>(remainingLeftClip);
		position.x -= static_cast<int>(remainingLeftClip);
		remainingWidth += remainingLeftClip;
	}

	while (remainingWidth > 0) {
		v = static_cast<uint8_t>(*src++);
		if (!IsCelTransparent(v)) {
			dst = RenderCelOutlinePixels<SkipColorIndexZero, North, West, South, East, CheckFirstColumn, CheckLastColumn>(
			    dst, dstPitch, position.x, dstW, src,
			    std::min(remainingWidth, static_cast<int_fast16_t>(v)), color);
			src += v;
		} else {
			v = GetCelTransparentWidth(v);
			dst += v;
		}
		remainingWidth -= v;
		position.x += v;
	}

	src = SkipRestOfLine<CelGetBlitCommand>(src, clipX.right + remainingWidth);

	return src;
}

template <bool SkipColorIndexZero>
void RenderCelOutlineClippedY(const Surface &out, Point position, RenderSrcBackwards src, uint8_t color) // NOLINT(readability-function-cognitive-complexity)
{
	// Skip the bottom clipped lines.
	const auto dstHeight = out.h();
	SkipLinesForRenderBackwards<CelGetBlitCommand>(position, src, dstHeight);
	if (src.begin == src.end)
		return;

	const ClipX clipX = { 0, 0, static_cast<decltype(ClipX {}.width)>(src.width) };

	if (position.y == dstHeight) {
		// After-bottom line - can only draw north.
		src.begin = RenderCelOutlineRowClipped<SkipColorIndexZero, /*North=*/true, /*West=*/false, /*South=*/false, /*East=*/false>(
		    out, position, src.begin, clipX, color);
		--position.y;
	}
	if (src.begin == src.end)
		return;

	if (position.y + 1 == dstHeight) {
		// Bottom line - cannot draw south.
		src.begin = RenderCelOutlineRowClipped<SkipColorIndexZero, /*North=*/true, /*West=*/true, /*South=*/false, /*East=*/true>(
		    out, position, src.begin, clipX, color);
		--position.y;
	}

	while (position.y > 0 && src.begin != src.end) {
		src.begin = RenderCelOutlineRowClipped<SkipColorIndexZero, /*North=*/true, /*West=*/true, /*South=*/true, /*East=*/true>(
		    out, position, src.begin, clipX, color);
		--position.y;
	}
	if (src.begin == src.end)
		return;

	if (position.y == 0) {
		src.begin = RenderCelOutlineRowClipped<SkipColorIndexZero, /*North=*/false, /*West=*/true, /*South=*/true, /*East=*/true>(
		    out, position, src.begin, clipX, color);
		--position.y;
	}
	if (src.begin == src.end)
		return;

	if (position.y == -1) {
		// Special case: the top of the sprite is 1px below the last line, render just the outline above.
		RenderCelOutlineRowClipped<SkipColorIndexZero, /*North=*/false, /*West=*/false, /*South=*/true, /*East=*/false>(
		    out, position, src.begin, clipX, color);
	}
}

template <bool SkipColorIndexZero>
void RenderCelOutlineClippedXY(const Surface &out, Point position, RenderSrcBackwards src, uint8_t color) // NOLINT(readability-function-cognitive-complexity)
{
	// Skip the bottom clipped lines.
	const auto dstHeight = out.h();
	SkipLinesForRenderBackwards<CelGetBlitCommand>(position, src, dstHeight);
	if (src.begin == src.end)
		return;

	ClipX clipX = CalculateClipX(position.x, src.width, out);
	if (clipX.width < 0)
		return;
	if (clipX.left > 0) {
		--clipX.left, ++clipX.width;
	} else if (clipX.right > 0) {
		--clipX.right, ++clipX.width;
	}
	position.x += static_cast<int>(clipX.left);

	if (position.y == dstHeight) {
		// After-bottom line - can only draw north.
		if (position.x <= 0) {
			src.begin = RenderCelOutlineRowClipped<SkipColorIndexZero, /*North=*/true, /*West=*/false, /*South=*/false, /*East=*/false,
			    /*ClipWidth=*/true, /*CheckFirstColumn=*/true, /*CheckLastColumn=*/false>(out, position, src.begin, clipX, color);
		} else if (position.x + clipX.width >= out.w()) {
			src.begin = RenderCelOutlineRowClipped<SkipColorIndexZero, /*North=*/true, /*West=*/false, /*South=*/false, /*East=*/false,
			    /*ClipWidth=*/true, /*CheckFirstColumn=*/false, /*CheckLastColumn=*/true>(out, position, src.begin, clipX, color);
		} else {
			src.begin = RenderCelOutlineRowClipped<SkipColorIndexZero, /*North=*/true, /*West=*/false, /*South=*/false, /*East=*/false,
			    /*ClipWidth=*/true>(out, position, src.begin, clipX, color);
		}

		--position.y;
	}
	if (src.begin == src.end)
		return;

	if (position.y + 1 == dstHeight) {
		// Bottom line - cannot draw south.
		if (position.x <= 0) {
			src.begin = RenderCelOutlineRowClipped<SkipColorIndexZero, /*North=*/true, /*West=*/true, /*South=*/false, /*East=*/true,
			    /*ClipWidth=*/true, /*CheckFirstColumn=*/true, /*CheckLastColumn=*/false>(
			    out, position, src.begin, clipX, color);
		} else if (position.x + clipX.width >= out.w()) {
			src.begin = RenderCelOutlineRowClipped<SkipColorIndexZero, /*North=*/true, /*West=*/true, /*South=*/false, /*East=*/true,
			    /*ClipWidth=*/true, /*CheckFirstColumn=*/false, /*CheckLastColumn=*/true>(
			    out, position, src.begin, clipX, color);
		} else {
			src.begin = RenderCelOutlineRowClipped<SkipColorIndexZero, /*North=*/true, /*West=*/true, /*South=*/false, /*East=*/true,
			    /*ClipWidth=*/true>(
			    out, position, src.begin, clipX, color);
		}
		--position.y;
	}

	if (position.x <= 0) {
		while (position.y > 0 && src.begin != src.end) {
			src.begin = RenderCelOutlineRowClipped<SkipColorIndexZero, /*North=*/true, /*West=*/true, /*South=*/true, /*East=*/true,
			    /*ClipWidth=*/true, /*CheckFirstColumn=*/true, /*CheckLastColumn=*/false>(
			    out, position, src.begin, clipX, color);
			--position.y;
		}
	} else if (position.x + clipX.width >= out.w()) {
		while (position.y > 0 && src.begin != src.end) {
			src.begin = RenderCelOutlineRowClipped<SkipColorIndexZero, /*North=*/true, /*West=*/true, /*South=*/true, /*East=*/true,
			    /*ClipWidth=*/true, /*CheckFirstColumn=*/false, /*CheckLastColumn=*/true>(
			    out, position, src.begin, clipX, color);
			--position.y;
		}
	} else {
		while (position.y > 0 && src.begin != src.end) {
			src.begin = RenderCelOutlineRowClipped<SkipColorIndexZero, /*North=*/true, /*West=*/true, /*South=*/true, /*East=*/true,
			    /*ClipWidth=*/true>(
			    out, position, src.begin, clipX, color);
			--position.y;
		}
	}
	if (src.begin == src.end)
		return;

	if (position.y == 0) {
		if (position.x <= 0) {
			src.begin = RenderCelOutlineRowClipped<SkipColorIndexZero, /*North=*/false, /*West=*/true, /*South=*/true, /*East=*/true,
			    /*ClipWidth=*/true, /*CheckFirstColumn=*/true, /*CheckLastColumn=*/false>(
			    out, position, src.begin, clipX, color);
		} else if (position.x + clipX.width >= out.w()) {
			src.begin = RenderCelOutlineRowClipped<SkipColorIndexZero, /*North=*/false, /*West=*/true, /*South=*/true, /*East=*/true,
			    /*ClipWidth=*/true, /*CheckFirstColumn=*/false, /*CheckLastColumn=*/true>(
			    out, position, src.begin, clipX, color);
		} else {
			src.begin = RenderCelOutlineRowClipped<SkipColorIndexZero, /*North=*/false, /*West=*/true, /*South=*/true, /*East=*/true,
			    /*ClipWidth=*/true>(
			    out, position, src.begin, clipX, color);
		}
		--position.y;
	}
	if (src.begin == src.end)
		return;

	if (position.y == -1) {
		// After-bottom line - can only draw south.
		if (position.x <= 0) {
			src.begin = RenderCelOutlineRowClipped<SkipColorIndexZero, /*North=*/false, /*West=*/false, /*South=*/true, /*East=*/false,
			    /*ClipWidth=*/true, /*CheckFirstColumn=*/true, /*CheckLastColumn=*/false>(out, position, src.begin, clipX, color);
		} else if (position.x + clipX.width >= out.w()) {
			src.begin = RenderCelOutlineRowClipped<SkipColorIndexZero, /*North=*/false, /*West=*/false, /*South=*/true, /*East=*/false,
			    /*ClipWidth=*/true, /*CheckFirstColumn=*/false, /*CheckLastColumn=*/true>(out, position, src.begin, clipX, color);
		} else {
			src.begin = RenderCelOutlineRowClipped<SkipColorIndexZero, /*North=*/false, /*West=*/false, /*South=*/true, /*East=*/false,
			    /*ClipWidth=*/true>(out, position, src.begin, clipX, color);
		}
	}
}

template <bool SkipColorIndexZero>
void RenderCelOutline(const Surface &out, Point position, const uint8_t *src, std::size_t srcSize,
    std::size_t srcWidth, uint8_t color)
{
	RenderSrcBackwards srcForBackwards { src, src + srcSize, static_cast<uint_fast16_t>(srcWidth) };
	if (position.x > 0 && position.x + static_cast<int>(srcWidth) < static_cast<int>(out.w())) {
		RenderCelOutlineClippedY<SkipColorIndexZero>(out, position, srcForBackwards, color);
	} else {
		RenderCelOutlineClippedXY<SkipColorIndexZero>(out, position, srcForBackwards, color);
	}
}

/**
 * @brief Blit CEL sprite to the given buffer, checks for drawing outside the buffer.
 * @param out Target buffer
 * @param position Target buffer coordinate
 * @param pRLEBytes CEL pixel stream (run-length encoded)
 * @param nDataSize Size of CEL in bytes
 * @param nWidth Width of sprite in pixels
 */
void CelBlitSafeTo(const Surface &out, Point position, const byte *pRLEBytes, int nDataSize, int nWidth)
{
	assert(pRLEBytes != nullptr);
	DoRenderBackwards</*TransparentCommandCanCrossLines=*/false, CelGetBlitCommand>(
	    out, position, reinterpret_cast<const uint8_t *>(pRLEBytes), nDataSize, nWidth, BlitDirect {});
}

/**
 * @brief Same as CelBlitLightSafe, with blended transparency applied
 * @param out Target buffer
 * @param position Target buffer coordinate
 * @param pRLEBytes CEL pixel stream (run-length encoded)
 * @param nDataSize Size of CEL in bytes
 * @param nWidth Width of sprite in pixels
 * @param tbl Palette translation table
 */
void CelBlitLightBlendedSafeTo(const Surface &out, Point position, const byte *pRLEBytes, int nDataSize, int nWidth, const uint8_t *tbl)
{
	assert(pRLEBytes != nullptr);
	if (tbl == nullptr)
		tbl = &LightTables[LightTableIndex * 256];

	DoRenderBackwards</*TransparentCommandCanCrossLines=*/false, CelGetBlitCommand>(
	    out, position, reinterpret_cast<const uint8_t *>(pRLEBytes), nDataSize, nWidth, BlitBlendedWithMap { tbl });
}

void RenderCelWithLightTable(const Surface &out, Point position, const byte *src, std::size_t srcSize, std::size_t srcWidth, const uint8_t *tbl)
{
	DoRenderBackwards</*TransparentCommandCanCrossLines=*/false, CelGetBlitCommand>(
	    out, position, reinterpret_cast<const uint8_t *>(src), srcSize, srcWidth, BlitWithMap { tbl });
}

/**
 * @brief Blit CEL sprite, and apply lighting, to the given buffer, checks for drawing outside the buffer
 * @param out Target buffer
 * @param position Target buffer coordinate
 * @param pRLEBytes CEL pixel stream (run-length encoded)
 * @param nDataSize Size of CEL in bytes
 * @param nWidth Width of sprite in pixels
 * @param tbl Palette translation table
 */
void CelBlitLightSafeTo(const Surface &out, Point position, const byte *pRLEBytes, int nDataSize, int nWidth, uint8_t *tbl)
{
	assert(pRLEBytes != nullptr);
	if (tbl == nullptr)
		tbl = &LightTables[LightTableIndex * 256];
	RenderCelWithLightTable(out, position, pRLEBytes, nDataSize, nWidth, tbl);
}

} // namespace

void CelDrawTo(const Surface &out, Point position, CelSprite cel, int frame)
{
	int nDataSize;
	const auto *pRLEBytes = CelGetFrame(cel.Data(), frame, &nDataSize);
	CelBlitSafeTo(out, position, pRLEBytes, nDataSize, cel.Width(frame));
}

void CelClippedDrawTo(const Surface &out, Point position, CelSprite cel, int frame)
{
	int nDataSize;
	const auto *pRLEBytes = CelGetFrameClipped(cel.Data(), frame, &nDataSize);

	CelBlitSafeTo(out, position, pRLEBytes, nDataSize, cel.Width(frame));
}

void CelDrawLightTo(const Surface &out, Point position, CelSprite cel, int frame, uint8_t *tbl)
{
	int nDataSize;
	const auto *pRLEBytes = CelGetFrame(cel.Data(), frame, &nDataSize);

	if (LightTableIndex != 0 || tbl != nullptr)
		CelBlitLightSafeTo(out, position, pRLEBytes, nDataSize, cel.Width(frame), tbl);
	else
		CelBlitSafeTo(out, position, pRLEBytes, nDataSize, cel.Width(frame));
}

void CelClippedDrawLightTo(const Surface &out, Point position, CelSprite cel, int frame)
{
	int nDataSize;
	const auto *pRLEBytes = CelGetFrameClipped(cel.Data(), frame, &nDataSize);

	if (LightTableIndex != 0)
		CelBlitLightSafeTo(out, position, pRLEBytes, nDataSize, cel.Width(frame), nullptr);
	else
		CelBlitSafeTo(out, position, pRLEBytes, nDataSize, cel.Width(frame));
}

void CelDrawLightRedTo(const Surface &out, Point position, CelSprite cel, int frame)
{
	int nDataSize;
	const auto *pRLEBytes = CelGetFrameClipped(cel.Data(), frame, &nDataSize);
	RenderCelWithLightTable(out, position, pRLEBytes, nDataSize, cel.Width(frame), GetInfravisionTRN());
}

void CelDrawItem(const Item &item, const Surface &out, Point position, CelSprite cel, int frame)
{
	bool usable = item._iStatFlag;
	if (!usable) {
		CelDrawLightRedTo(out, position, cel, frame);
	} else {
		CelClippedDrawTo(out, position, cel, frame);
	}
}

void CelClippedBlitLightTransTo(const Surface &out, Point position, CelSprite cel, int frame)
{
	int nDataSize;
	const byte *pRLEBytes = CelGetFrameClipped(cel.Data(), frame, &nDataSize);

	if (cel_transparency_active) {
		CelBlitLightBlendedSafeTo(out, position, pRLEBytes, nDataSize, cel.Width(frame), nullptr);
	} else if (LightTableIndex != 0)
		CelBlitLightSafeTo(out, position, pRLEBytes, nDataSize, cel.Width(frame), nullptr);
	else
		CelBlitSafeTo(out, position, pRLEBytes, nDataSize, cel.Width(frame));
}

void CelDrawUnsafeTo(const Surface &out, Point position, CelSprite cel, int frame)
{
	int srcSize;
	const auto *srcBegin = reinterpret_cast<const uint8_t *>(CelGetFrame(cel.Data(), frame, &srcSize));
	RenderSrcBackwards src { srcBegin, srcBegin + srcSize, cel.Width(frame) };
	DoRenderBackwardsClipY</*TransparentCommandCanCrossLines=*/false, &CelGetBlitCommand>(
	    out, position, src, BlitDirect {});
}

void CelBlitOutlineTo(const Surface &out, uint8_t col, Point position, CelSprite cel, int frame, bool skipColorIndexZero)
{
	int nDataSize;
	const uint8_t *src = reinterpret_cast<const uint8_t *>(CelGetFrameClipped(cel.Data(), frame, &nDataSize));
	if (skipColorIndexZero)
		RenderCelOutline<true>(out, position, src, nDataSize, cel.Width(frame), col);
	else
		RenderCelOutline<false>(out, position, src, nDataSize, cel.Width(frame), col);
}

std::pair<int, int> MeasureSolidHorizontalBounds(CelSprite cel, int frame)
{
	int nDataSize;
	const byte *src = CelGetFrameClipped(cel.Data(), frame, &nDataSize);
	const auto *end = &src[nDataSize];
	const int celWidth = cel.Width(frame);

	int xBegin = celWidth;
	int xEnd = 0;
	while (src < end) {
		int xCur = 0;
		while (xCur < celWidth) {
			const auto val = static_cast<uint8_t>(*src++);
			if (IsCelTransparent(val)) {
				const int width = GetCelTransparentWidth(val);
				xCur += width;
			} else {
				xBegin = std::min(xBegin, xCur);
				xCur += val;
				xEnd = std::max(xEnd, xCur);
				src += val;
			}
		}
		if (xBegin == 0 && xEnd == celWidth)
			break;
	}
	return { xBegin, xEnd };
}

void CelApplyTrans(byte *p, const std::array<uint8_t, 256> &translation)
{
	assert(p != nullptr);
	const uint32_t numFrames = LoadLE32(p);
	const byte *frameOffsets = p + 4;
	p += 4 * (2 + static_cast<size_t>(numFrames));

	uint32_t frameEnd = LoadLE32(&frameOffsets[0]);
	for (uint32_t i = 0; i < numFrames; ++i) {
		const uint32_t frameBegin = frameEnd;
		frameEnd = LoadLE32(&frameOffsets[4 * (static_cast<size_t>(i) + 1)]);

		const byte *end = p + (frameEnd - frameBegin);
		const bool frameHasHeader = static_cast<uint8_t>(*p) == 0;
		if (frameHasHeader) {
			constexpr uint32_t FrameHeaderSize = 5 * 2;
			p += FrameHeaderSize;
		}
		while (p != end) {
			const auto val = static_cast<uint8_t>(*p++);
			if (IsCelTransparent(val)) {
				continue;
			}
			for (unsigned i = 0; i < val; ++i) {
				const auto color = static_cast<uint8_t>(*p);
				*p++ = static_cast<byte>(translation[color]);
			}
		}
	}
}

} // namespace devilution