r_things.c

使用Doom引擎开发的著名游戏《毁灭巫师》的源代码。

		rot = (ang-thing->angle+(unsigned)(ANG45/2)*9)>>29;
		lump = sprframe->lump[rot];
		flip = (boolean)sprframe->flip[rot];
	}
	else
	{	// use single rotation for all views
		lump = sprframe->lump[0];
		flip = (boolean)sprframe->flip[0];
	}

//
// calculate edges of the shape
//
	tx -= spriteoffset[lump];
	x1 = (centerxfrac + FixedMul (tx,xscale) ) >>FRACBITS;
	if (x1 > viewwidth)
		return;		// off the right side
	tx +=  spritewidth[lump];
	x2 = ((centerxfrac + FixedMul (tx,xscale) ) >>FRACBITS) - 1;
	if (x2 < 0)
		return;		// off the left side


//
// store information in a vissprite
//
	vis = R_NewVisSprite ();
	vis->mobjflags = thing->flags;
	vis->psprite = false;
	vis->scale = xscale<<detailshift;
	vis->gx = thing->x;
	vis->gy = thing->y;
	vis->gz = thing->z;
	vis->gzt = thing->z + spritetopoffset[lump];
	if(thing->flags&MF_TRANSLATION)
	{
		if(thing->player)
		{
			vis->class = thing->player->class;
		}
		else
		{
			vis->class = thing->special1;
		}
		if(vis->class > 2)
		{
			vis->class = 0;
		}
	}
	// foot clipping
	vis->floorclip = thing->floorclip;
	vis->texturemid = vis->gzt-viewz-vis->floorclip;

	vis->x1 = x1 < 0 ? 0 : x1;
	vis->x2 = x2 >= viewwidth ? viewwidth-1 : x2;
	iscale = FixedDiv (FRACUNIT, xscale);
	if (flip)
	{
		vis->startfrac = spritewidth[lump]-1;
		vis->xiscale = -iscale;
	}
	else
	{
		vis->startfrac = 0;
		vis->xiscale = iscale;
	}
	if (vis->x1 > x1)
		vis->startfrac += vis->xiscale*(vis->x1-x1);
	vis->patch = lump;
//
// get light level
//

//	if (thing->flags & MF_SHADOW)
//		vis->colormap = NULL;			// shadow draw
//	else ...

	if (fixedcolormap)
		vis->colormap = fixedcolormap;	// fixed map
	else if(LevelUseFullBright && thing->frame&FF_FULLBRIGHT)
		vis->colormap = colormaps;		// full bright
	else
	{									// diminished light
		index = xscale>>(LIGHTSCALESHIFT-detailshift);
		if (index >= MAXLIGHTSCALE)
			index = MAXLIGHTSCALE-1;
		vis->colormap = spritelights[index];
	}
}




/*
========================
=
= R_AddSprites
=
========================
*/

void R_AddSprites (sector_t *sec)
{
	mobj_t		*thing;
	int			lightnum;

	if (sec->validcount == validcount)
		return;		// already added

	sec->validcount = validcount;

	lightnum = (sec->lightlevel >> LIGHTSEGSHIFT)+extralight;
	if (lightnum < 0)
		spritelights = scalelight[0];
	else if (lightnum >= LIGHTLEVELS)
		spritelights = scalelight[LIGHTLEVELS-1];
	else
		spritelights = scalelight[lightnum];


	for (thing = sec->thinglist ; thing ; thing = thing->snext)
		R_ProjectSprite (thing);
}


/*
========================
=
= R_DrawPSprite
=
========================
*/

// Y-adjustment values for full screen (4 weapons)
int PSpriteSY[NUMCLASSES][NUMWEAPONS] =
{
	{ 0, -12*FRACUNIT, -10*FRACUNIT, 10*FRACUNIT }, // Fighter
	{ -8*FRACUNIT, 10*FRACUNIT, 10*FRACUNIT, 0 }, // Cleric
	{ 9*FRACUNIT, 20*FRACUNIT, 20*FRACUNIT, 20*FRACUNIT }, // Mage 
	{ 10*FRACUNIT, 10*FRACUNIT, 10*FRACUNIT, 10*FRACUNIT } // Pig
};

void R_DrawPSprite (pspdef_t *psp)
{
	fixed_t		tx;
	int			x1, x2;
	spritedef_t	*sprdef;
	spriteframe_t	*sprframe;
	int			lump;
	boolean		flip;
	vissprite_t	*vis, avis;

	int tempangle;

//
// decide which patch to use
//
#ifdef RANGECHECK
	if ( (unsigned)psp->state->sprite >= numsprites)
		I_Error ("R_ProjectSprite: invalid sprite number %i "
		, psp->state->sprite);
#endif
	sprdef = &sprites[psp->state->sprite];
#ifdef RANGECHECK
	if ( (psp->state->frame & FF_FRAMEMASK)  >= sprdef->numframes)
		I_Error ("R_ProjectSprite: invalid sprite frame %i : %i "
		, psp->state->sprite, psp->state->frame);
#endif
	sprframe = &sprdef->spriteframes[ psp->state->frame & FF_FRAMEMASK ];

	lump = sprframe->lump[0];
	flip = (boolean)sprframe->flip[0];

//
// calculate edges of the shape
//
	tx = psp->sx-160*FRACUNIT;

	tx -= spriteoffset[lump];
	if(viewangleoffset)
	{
		tempangle = ((centerxfrac/1024)*(viewangleoffset>>ANGLETOFINESHIFT));
	}
	else
	{
		tempangle = 0;
	}
	x1 = (centerxfrac + FixedMul (tx,pspritescale)+tempangle ) >>FRACBITS;
	if (x1 > viewwidth)
		return;		// off the right side
	tx +=  spritewidth[lump];
	x2 = ((centerxfrac + FixedMul (tx, pspritescale)+tempangle ) >>FRACBITS) - 1;
	if (x2 < 0)
		return;		// off the left side

//
// store information in a vissprite
//
	vis = &avis;
	vis->mobjflags = 0;
	vis->class = 0;
	vis->psprite = true;
	vis->texturemid = (BASEYCENTER<<FRACBITS)+FRACUNIT/2
		-(psp->sy-spritetopoffset[lump]);
	if(viewheight == SCREENHEIGHT)
	{
		vis->texturemid -= PSpriteSY[viewplayer->class]
			[players[consoleplayer].readyweapon];
	}
	vis->x1 = x1 < 0 ? 0 : x1;
	vis->x2 = x2 >= viewwidth ? viewwidth-1 : x2;
	vis->scale = pspritescale<<detailshift;
	if (flip)
	{
		vis->xiscale = -pspriteiscale;
		vis->startfrac = spritewidth[lump]-1;
	}
	else
	{
		vis->xiscale = pspriteiscale;
		vis->startfrac = 0;
	}
	if (vis->x1 > x1)
		vis->startfrac += vis->xiscale*(vis->x1-x1);
	vis->patch = lump;

	if(viewplayer->powers[pw_invulnerability] && viewplayer->class
		== PCLASS_CLERIC)
	{
		vis->colormap = spritelights[MAXLIGHTSCALE-1];
		if(viewplayer->powers[pw_invulnerability] > 4*32)
		{
			if(viewplayer->mo->flags2&MF2_DONTDRAW)
			{ // don't draw the psprite
				vis->mobjflags |= MF_SHADOW;
			}
			else if(viewplayer->mo->flags&MF_SHADOW)
			{
				vis->mobjflags |= MF_ALTSHADOW;
			}
		}
		else if(viewplayer->powers[pw_invulnerability]&8)
		{
			vis->mobjflags |= MF_SHADOW;
		}
	}	
	else if(fixedcolormap)
	{
		// Fixed color
		vis->colormap = fixedcolormap;
	}
	else if(psp->state->frame & FF_FULLBRIGHT)
	{
		// Full bright
		vis->colormap = colormaps;
	}
	else
	{
		// local light
		vis->colormap = spritelights[MAXLIGHTSCALE-1];
	}
	R_DrawVisSprite(vis, vis->x1, vis->x2);
}

/*
========================
=
= R_DrawPlayerSprites
=
========================
*/

void R_DrawPlayerSprites (void)
{
	int			i, lightnum;
	pspdef_t	*psp;

//
// get light level
//
	lightnum = (viewplayer->mo->subsector->sector->lightlevel >> LIGHTSEGSHIFT)
		+extralight;
	if (lightnum < 0)
		spritelights = scalelight[0];
	else if (lightnum >= LIGHTLEVELS)
		spritelights = scalelight[LIGHTLEVELS-1];
	else
		spritelights = scalelight[lightnum];
//
// clip to screen bounds
//
	mfloorclip = screenheightarray;
	mceilingclip = negonearray;

//
// add all active psprites
//
	for (i=0, psp=viewplayer->psprites ; i<NUMPSPRITES ; i++,psp++)
		if (psp->state)
			R_DrawPSprite (psp);

}


/*
========================
=
= R_SortVisSprites
=
========================
*/

vissprite_t	vsprsortedhead;

void R_SortVisSprites (void)
{
	int			i, count;
	vissprite_t	*ds, *best;
	vissprite_t	unsorted;
	fixed_t		bestscale;

	count = vissprite_p - vissprites;

	unsorted.next = unsorted.prev = &unsorted;
	if (!count)
		return;

	for (ds=vissprites ; ds<vissprite_p ; ds++)
	{
		ds->next = ds+1;
		ds->prev = ds-1;
	}
	vissprites[0].prev = &unsorted;
	unsorted.next = &vissprites[0];
	(vissprite_p-1)->next = &unsorted;
	unsorted.prev = vissprite_p-1;

//
// pull the vissprites out by scale
//
	best = 0;		// shut up the compiler warning
	vsprsortedhead.next = vsprsortedhead.prev = &vsprsortedhead;
	for (i=0 ; i<count ; i++)
	{
		bestscale = MAXINT;
		for (ds=unsorted.next ; ds!= &unsorted ; ds=ds->next)
		{
			if (ds->scale < bestscale)
			{
				bestscale = ds->scale;
				best = ds;
			}
		}
		best->next->prev = best->prev;
		best->prev->next = best->next;
		best->next = &vsprsortedhead;
		best->prev = vsprsortedhead.prev;
		vsprsortedhead.prev->next = best;
		vsprsortedhead.prev = best;
	}
}



/*
========================
=
= R_DrawSprite
=
========================
*/

void R_DrawSprite (vissprite_t *spr)
{
	drawseg_t		*ds;
	short			clipbot[SCREENWIDTH], cliptop[SCREENWIDTH];
	int				x, r1, r2;
	fixed_t			scale, lowscale;
	int				silhouette;

	for (x = spr->x1 ; x<=spr->x2 ; x++)
		clipbot[x] = cliptop[x] = -2;

//
// scan drawsegs from end to start for obscuring segs
// the first drawseg that has a greater scale is the clip seg
//
	for (ds=ds_p-1 ; ds >= drawsegs ; ds--)
	{
		//
		// determine if the drawseg obscures the sprite
		//
		if (ds->x1 > spr->x2 || ds->x2 < spr->x1 ||
		(!ds->silhouette && !ds->maskedtexturecol) )
			continue;			// doesn't cover sprite

		r1 = ds->x1 < spr->x1 ? spr->x1 : ds->x1;
		r2 = ds->x2 > spr->x2 ? spr->x2 : ds->x2;
		if (ds->scale1 > ds->scale2)
		{
			lowscale = ds->scale2;
			scale = ds->scale1;
		}
		else
		{
			lowscale = ds->scale1;
			scale = ds->scale2;
		}

		if (scale < spr->scale || ( lowscale < spr->scale
		&& !R_PointOnSegSide (spr->gx, spr->gy, ds->curline) ) )
		{
			if (ds->maskedtexturecol)	// masked mid texture
				R_RenderMaskedSegRange (ds, r1, r2);
			continue;			// seg is behind sprite
		}

//
// clip this piece of the sprite
//
		silhouette = ds->silhouette;
		if (spr->gz >= ds->bsilheight)
			silhouette &= ~SIL_BOTTOM;
		if (spr->gzt <= ds->tsilheight)
			silhouette &= ~SIL_TOP;

		if (silhouette == 1)
		{	// bottom sil
			for (x=r1 ; x<=r2 ; x++)
				if (clipbot[x] == -2)
					clipbot[x] = ds->sprbottomclip[x];
		}
		else if (silhouette == 2)
		{	// top sil
			for (x=r1 ; x<=r2 ; x++)
				if (cliptop[x] == -2)
					cliptop[x] = ds->sprtopclip[x];
		}
		else if (silhouette == 3)
		{	// both
			for (x=r1 ; x<=r2 ; x++)
			{
				if (clipbot[x] == -2)
					clipbot[x] = ds->sprbottomclip[x];
				if (cliptop[x] == -2)
					cliptop[x] = ds->sprtopclip[x];
			}
		}

	}

//
// all clipping has been performed, so draw the sprite
//

// check for unclipped columns
	for (x = spr->x1 ; x<=spr->x2 ; x++)
	{
		if (clipbot[x] == -2)
			clipbot[x] = viewheight;
		if (cliptop[x] == -2)
			cliptop[x] = -1;
	}

	mfloorclip = clipbot;
	mceilingclip = cliptop;
	R_DrawVisSprite (spr, spr->x1, spr->x2);
}


/*
========================
=
= R_DrawMasked
=
========================
*/

void R_DrawMasked (void)
{
	vissprite_t		*spr;
	drawseg_t		*ds;

	R_SortVisSprites ();

	if (vissprite_p > vissprites)
	{
	// draw all vissprites back to front

		for (spr = vsprsortedhead.next ; spr != &vsprsortedhead
		; spr=spr->next)
			R_DrawSprite (spr);
	}

//
// render any remaining masked mid textures
//
	for (ds=ds_p-1 ; ds >= drawsegs ; ds--)
		if (ds->maskedtexturecol)
			R_RenderMaskedSegRange (ds, ds->x1, ds->x2);

//
// draw the psprites on top of everything
//
// Added for the sideviewing with an external device
	if (viewangleoffset <= 1024<<ANGLETOFINESHIFT || viewangleoffset >=
			-1024<<ANGLETOFINESHIFT)
  	{	// don't draw on side views
		R_DrawPlayerSprites ();
	}

//	if (!viewangleoffset)		// don't draw on side views
//		R_DrawPlayerSprites ();
}