/**
 * @file engine.h
 *
 *  of basic engine helper functions:
 * - Sprite blitting
 * - Drawing
 * - Angle calculation
 * - RNG
 * - Memory allocation
 * - File loading
 * - Video playback
 */
#ifndef __ENGINE_H__
#define __ENGINE_H__

DEVILUTION_BEGIN_NAMESPACE

#ifdef __cplusplus
extern "C" {
#endif

//offset 0
//pCelBuff->pFrameTable[0]

/** automap pixel color 8-bit (palette entry) */
extern char gbPixelCol;
/** flip - if y < x */
extern BOOL gbRotateMap;
/** Seed value before the most recent call to SetRndSeed() */
extern int orgseed;
/** Track number of calls to GetRndSeed() since last call to SetRndSeed() */
extern int SeedCount;
/** valid - if x/y are in bounds */
extern BOOL gbNotInView;

inline BYTE *CelGetFrameStart(BYTE *pCelBuff, int nCel)
{
	DWORD *pFrameTable;

	pFrameTable = (DWORD *)pCelBuff;

	return pCelBuff + SwapLE32(pFrameTable[nCel]);
}

#define LOAD_LE32(b) (((DWORD)(b)[3] << 24) | ((DWORD)(b)[2] << 16) | ((DWORD)(b)[1] << 8) | (DWORD)(b)[0])
inline BYTE *CelGetFrame(BYTE *pCelBuff, int nCel, int *nDataSize)
{
	DWORD nCellStart;

	nCellStart = LOAD_LE32(&pCelBuff[nCel * 4]);
	*nDataSize = LOAD_LE32(&pCelBuff[(nCel + 1) * 4]) - nCellStart;
	return pCelBuff + nCellStart;
}

inline BYTE *CelGetFrameClipped(BYTE *pCelBuff, int nCel, int *nDataSize)
{
	DWORD nDataStart;
	BYTE *pRLEBytes = CelGetFrame(pCelBuff, nCel, nDataSize);

	nDataStart = pRLEBytes[1] << 8 | pRLEBytes[0];
	*nDataSize -= nDataStart;

	return pRLEBytes + nDataStart;
}

void CelDraw(int sx, int sy, BYTE *pCelBuff, int nCel, int nWidth);
void CelBlitFrame(BYTE *pBuff, BYTE *pCelBuff, int nCel, int nWidth);
void CelClippedDraw(int sx, int sy, BYTE *pCelBuff, int nCel, int nWidth);
void CelDrawLight(int sx, int sy, BYTE *pCelBuff, int nCel, int nWidth, BYTE *tbl);
void CelClippedDrawLight(int sx, int sy, BYTE *pCelBuff, int nCel, int nWidth);
void CelClippedBlitLightTrans(BYTE *pBuff, BYTE *pCelBuff, int nCel, int nWidth);
void CelDrawLightRed(int sx, int sy, BYTE *pCelBuff, int nCel, int nWidth, char light);
void CelBlitSafe(BYTE *pDecodeTo, BYTE *pRLEBytes, int nDataSize, int nWidth);
void CelClippedDrawSafe(int sx, int sy, BYTE *pCelBuff, int nCel, int nWidth);
void CelBlitLightSafe(BYTE *pDecodeTo, BYTE *pRLEBytes, int nDataSize, int nWidth, BYTE *tbl);
void CelBlitLightTransSafe(BYTE *pDecodeTo, BYTE *pRLEBytes, int nDataSize, int nWidth);
void CelDrawLightRedSafe(int sx, int sy, BYTE *pCelBuff, int nCel, int nWidth, char light);
void CelBlitWidth(BYTE *pBuff, int x, int y, int wdt, BYTE *pCelBuff, int nCel, int nWidth);
void CelBlitOutline(char col, int sx, int sy, BYTE *pCelBuff, int nCel, int nWidth);
void ENG_set_pixel(int sx, int sy, BYTE col);
void engine_draw_pixel(int sx, int sy);
void DrawLine(int x0, int y0, int x1, int y1, BYTE col);
int GetDirection(int x1, int y1, int x2, int y2);
void SetRndSeed(int s);
int GetRndSeed();
int random_(BYTE idx, int v);
void engine_debug_trap(BOOL show_cursor);
BYTE *DiabloAllocPtr(DWORD dwBytes);
void mem_free_dbg(void *p);
BYTE *LoadFileInMem(char *pszName, DWORD *pdwFileLen);
DWORD LoadFileWithMem(const char *pszName, BYTE *p);
void Cl2ApplyTrans(BYTE *p, BYTE *ttbl, int nCel);
void Cl2Draw(int sx, int sy, BYTE *pCelBuff, int nCel, int nWidth);
void Cl2DrawOutline(char col, int sx, int sy, BYTE *pCelBuff, int nCel, int nWidth);
void Cl2DrawLightTbl(int sx, int sy, BYTE *pCelBuff, int nCel, int nWidth, char light);
void Cl2DrawLight(int sx, int sy, BYTE *pCelBuff, int nCel, int nWidth);
void Cl2BlitSafe(BYTE *pDecodeTo, BYTE *pRLEBytes, int nDataSize, int nWidth);
void Cl2BlitOutlineSafe(BYTE *pDecodeTo, BYTE *pRLEBytes, int nDataSize, int nWidth, char col);
void Cl2BlitLightSafe(BYTE *pDecodeTo, BYTE *pRLEBytes, int nDataSize, int nWidth, BYTE *pTable);
void PlayInGameMovie(char *pszMovie);

/* rdata */

extern const int RndInc;
extern const int RndMult;

#ifdef __cplusplus
}
#endif

DEVILUTION_END_NAMESPACE

#endif /* __ENGINE_H__ */