shithub: riscv

ref: dc593372bfc4224c6cf91d2031d0ad0aeadaddfe
dir: /sys/src/games/doom/r_things.c/

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// Emacs style mode select   -*- C++ -*- 
//-----------------------------------------------------------------------------
//
// $Id:$
//
// Copyright (C) 1993-1996 by id Software, Inc.
//
// This source is available for distribution and/or modification
// only under the terms of the DOOM Source Code License as
// published by id Software. All rights reserved.
//
// The source is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// FITNESS FOR A PARTICULAR PURPOSE. See the DOOM Source Code License
// for more details.
//
// $Log:$
//
// DESCRIPTION:
//	Refresh of things, i.e. objects represented by sprites.
//
//-----------------------------------------------------------------------------


static const char
rcsid[] = "$Id: r_things.c,v 1.5 1997/02/03 16:47:56 b1 Exp $";

#include "doomdef.h"
#include "m_swap.h"

#include "i_system.h"
#include "z_zone.h"
#include "w_wad.h"

#include "r_local.h"

#include "doomstat.h"



#define MINZ				(FRACUNIT*4)
#define BASEYCENTER			100

//void R_DrawColumn (void);
//void R_DrawFuzzColumn (void);



typedef struct
{
	int	x1;
	int	x2;

	int	column;
	int	topclip;
	int	bottomclip;
} maskdraw_t;



//
// Sprite rotation 0 is facing the viewer,
//  rotation 1 is one angle turn CLOCKWISE around the axis.
// This is not the same as the angle,
//  which increases counter clockwise (protractor).
// There was a lot of stuff grabbed wrong, so I changed it...
//
fixed_t		pspritescale;
fixed_t		pspriteiscale;

lighttable_t**	spritelights;

// constant arrays
//  used for psprite clipping and initializing clipping
short		negonearray[SCREENWIDTH];
short		screenheightarray[SCREENWIDTH];


//
// INITIALIZATION FUNCTIONS
//

// variables used to look up
//  and range check thing_t sprites patches
spritedef_t*	sprites;
int		numsprites;

spriteframe_t	sprtemp[29];
int		maxframe;
char*		spritename;




//
// R_InstallSpriteLump
// Local function for R_InitSprites.
//
void
R_InstallSpriteLump
( int		lump,
  unsigned	frame,
  unsigned	rotation,
  boolean	flipped )
{
    int		r;
	
    if (frame >= 29 || rotation > 8)
	I_Error("R_InstallSpriteLump: "
		"Bad frame characters in lump %i", lump);
	
    if ((int)frame > maxframe)
	maxframe = frame;
		
    if (rotation == 0)
    {
	// the lump should be used for all rotations
	if (sprtemp[frame].rotate == false)
	    I_Error ("R_InitSprites: Sprite %s frame %c has "
		     "multip rot=0 lump", spritename, 'A'+frame);

	if (sprtemp[frame].rotate == true)
	    I_Error ("R_InitSprites: Sprite %s frame %c has rotations "
		     "and a rot=0 lump", spritename, 'A'+frame);
			
	sprtemp[frame].rotate = false;
	for (r=0 ; r<8 ; r++)
	{
	    sprtemp[frame].lump[r] = lump - firstspritelump;
	    sprtemp[frame].flip[r] = (byte)flipped;
	}
	return;
    }
	
    // the lump is only used for one rotation
    if (sprtemp[frame].rotate == false)
	I_Error ("R_InitSprites: Sprite %s frame %c has rotations "
		 "and a rot=0 lump", spritename, 'A'+frame);
		
    sprtemp[frame].rotate = true;

    // make 0 based
    rotation--;		
    if (sprtemp[frame].lump[rotation] != -1)
	I_Error ("R_InitSprites: Sprite %s : %c : %c "
		 "has two lumps mapped to it",
		 spritename, 'A'+frame, '1'+rotation);
		
    sprtemp[frame].lump[rotation] = lump - firstspritelump;
    sprtemp[frame].flip[rotation] = (byte)flipped;
}




//
// R_InitSpriteDefs
// Pass a null terminated list of sprite names
//  (4 chars exactly) to be used.
// Builds the sprite rotation matrixes to account
//  for horizontally flipped sprites.
// Will report an error if the lumps are inconsistant. 
// Only called at startup.
//
// Sprite lump names are 4 characters for the actor,
//  a letter for the frame, and a number for the rotation.
// A sprite that is flippable will have an additional
//  letter/number appended.
// The rotation character can be 0 to signify no rotations.
//
void R_InitSpriteDefs (char** namelist) 
{ 
/*    char**	check; */
    int		i;
    int		l;
    int		frame;
    int		rotation;
    int		start;
    int		end;
    int		patched;
    char*	name;

/* BUG
   This would work if the namelist was NULL terminated which it is not.
   The array comes from info.c which is limited to NUMSPRITES, so simply
   use NUMSPRITES for numsprites.. simple.

   This is left here in case a decision is made to make it NULL terminated.

    // count the number of sprite names
    check = namelist;
    while (*check != NULL)
	check++;

    numsprites = check-namelist;

    if (!numsprites)
	return;
*/
numsprites = NUMSPRITES;
		
    sprites = Z_Malloc(numsprites *sizeof(*sprites), PU_STATIC, NULL);
	
    start = firstspritelump-1;
    end = lastspritelump+1;
	
    // scan all the lump names for each of the names,
    //  noting the highest frame letter.
    // Just compare 4 characters as ints
    for (i=0 ; i<numsprites ; i++)
    {
	spritename = namelist[i];
	memset (sprtemp,-1, sizeof(sprtemp));
		
	maxframe = -1;
	name = namelist[i];
	
	// scan the lumps,
	//  filling in the frames for whatever is found
	for (l=start+1 ; l<end ; l++)
	{
	    if (memcmp(lumpinfo[l].name, name, 4) == 0)
	    {
		frame = lumpinfo[l].name[4] - 'A';
		rotation = lumpinfo[l].name[5] - '0';

		if (modifiedgame)
		    patched = W_GetNumForName (lumpinfo[l].name);
		else
		    patched = l;

		R_InstallSpriteLump (patched, frame, rotation, false);

		if (lumpinfo[l].name[6])
		{
		    frame = lumpinfo[l].name[6] - 'A';
		    rotation = lumpinfo[l].name[7] - '0';
		    R_InstallSpriteLump (l, frame, rotation, true);
		}
	    }
	}
	
	// check the frames that were found for completeness
	if (maxframe == -1)
	{
	    sprites[i].numframes = 0;
	    continue;
	}
		
	maxframe++;
	
	for (frame = 0 ; frame < maxframe ; frame++)
	{
	    switch ((int)sprtemp[frame].rotate)
	    {
	      case -1:
		// no rotations were found for that frame at all
		I_Error ("R_InitSprites: No patches found "
			 "for %s frame %c", namelist[i], frame+'A');
		break;
		
	      case 0:
		// only the first rotation is needed
		break;
			
	      case 1:
		// must have all 8 frames
		for (rotation=0 ; rotation<8 ; rotation++)
		    if (sprtemp[frame].lump[rotation] == -1)
			I_Error ("R_InitSprites: Sprite %s frame %c "
				 "is missing rotations",
				 namelist[i], frame+'A');
		break;
	    }
	}
	
	// allocate space for the frames present and copy sprtemp to it
	sprites[i].numframes = maxframe;
	sprites[i].spriteframes = 
	    Z_Malloc (maxframe * sizeof(spriteframe_t), PU_STATIC, NULL);
	memcpy (sprites[i].spriteframes, sprtemp, maxframe*sizeof(spriteframe_t));
    }

}




//
// GAME FUNCTIONS
//
vissprite_t	vissprites[MAXVISSPRITES];
vissprite_t*	vissprite_p;
int		newvissprite;



//
// R_InitSprites
// Called at program start.
//
void R_InitSprites (char** namelist)
{
    int		i;
	
    for (i=0 ; i<SCREENWIDTH ; i++)
    {
	negonearray[i] = -1;
    }
	
    R_InitSpriteDefs (namelist);
}



//
// R_ClearSprites
// Called at frame start.
//
void R_ClearSprites (void)
{
    vissprite_p = vissprites;
}


//
// R_NewVisSprite
//
vissprite_t	overflowsprite;

vissprite_t* R_NewVisSprite (void)
{
    if (vissprite_p == &vissprites[MAXVISSPRITES])
	return &overflowsprite;
    
    vissprite_p++;
    return vissprite_p-1;
}



//
// R_DrawMaskedColumn
// Used for sprites and masked mid textures.
// Masked means: partly transparent, i.e. stored
//  in posts/runs of opaque pixels.
//
short*		mfloorclip;
short*		mceilingclip;

fixed_t		spryscale;
fixed_t		sprtopscreen;

void R_DrawMaskedColumn (column_t* column)
{
    int		topscreen;
    int 	bottomscreen;
    fixed_t	basetexturemid;
	
    basetexturemid = dc_texturemid;
	
    for ( ; column->topdelta != 0xff ; ) 
    {
	// calculate unclipped screen coordinates
	//  for post
	topscreen = sprtopscreen + spryscale*column->topdelta;
	bottomscreen = topscreen + spryscale*column->length;

	dc_yl = (topscreen+FRACUNIT-1)>>FRACBITS;
	dc_yh = (bottomscreen-1)>>FRACBITS;
		
	if (dc_yh >= mfloorclip[dc_x])
	    dc_yh = mfloorclip[dc_x]-1;
	if (dc_yl <= mceilingclip[dc_x])
	    dc_yl = mceilingclip[dc_x]+1;

	if (dc_yl <= dc_yh)
	{
	    dc_source = (byte *)column + 3;
	    dc_texturemid = basetexturemid - (column->topdelta<<FRACBITS);
	    // dc_source = (byte *)column + 3 - column->topdelta;

	    // Drawn by either R_DrawColumn
	    //  or (SHADOW) R_DrawFuzzColumn.
	    colfunc ();	
	}
	column = (column_t *)(  (byte *)column + column->length + 4);
    }
	
    dc_texturemid = basetexturemid;
}



//
// R_DrawVisSprite
//  mfloorclip and mceilingclip should also be set.
//
void
R_DrawVisSprite
( vissprite_t*		vis,
  int			/*x1*/,
  int			/*x2*/ )
{
    column_t*		column;
    int			texturecolumn;
    fixed_t		frac;
    patch_t*		patch;
	
	
    patch = W_CacheLumpNum (vis->patch+firstspritelump, PU_CACHE);

    dc_colormap = vis->colormap;
    
    if (!dc_colormap)
    {
	// NULL colormap = shadow draw
	colfunc = fuzzcolfunc;
    }
    else if (vis->mobjflags & MF_TRANSLATION)
    {
	colfunc = R_DrawTranslatedColumn;
	dc_translation = translationtables - 256 +
	    ( (vis->mobjflags & MF_TRANSLATION) >> (MF_TRANSSHIFT-8) );
    }
	
    dc_iscale = abs(vis->xiscale)>>detailshift;
    dc_texturemid = vis->texturemid;
    frac = vis->startfrac;
    spryscale = vis->scale;
    sprtopscreen = centeryfrac - FixedMul(dc_texturemid,spryscale);
	
    for (dc_x=vis->x1 ; dc_x<=vis->x2 ; dc_x++, frac += vis->xiscale)
    {
	texturecolumn = frac>>FRACBITS;
#ifdef RANGECHECK
	if (texturecolumn < 0 || texturecolumn >= SHORT(patch->width))
	    I_Error ("R_DrawSpriteRange: bad texturecolumn");
#endif
	column = (column_t *) ((byte *)patch +
			       LONG(patch->columnofs[texturecolumn]));
	R_DrawMaskedColumn (column);
    }

    colfunc = basecolfunc;
}



//
// R_ProjectSprite
// Generates a vissprite for a thing
//  if it might be visible.
//
void R_ProjectSprite (mobj_t* thing)
{
    fixed_t		tr_x;
    fixed_t		tr_y;
    
    fixed_t		gxt;
    fixed_t		gyt;
    
    fixed_t		tx;
    fixed_t		tz;

    fixed_t		xscale;
    
    int			x1;
    int			x2;

    spritedef_t*	sprdef;
    spriteframe_t*	sprframe;
    int			lump;
    
    unsigned		rot;
    boolean		flip;
    
    int			index;

    vissprite_t*	vis;
    
    angle_t		ang;
    fixed_t		iscale;
    
    // transform the origin point
    tr_x = thing->x - viewx;
    tr_y = thing->y - viewy;
	
    gxt = FixedMul(tr_x,viewcos); 
    gyt = -FixedMul(tr_y,viewsin);
    
    tz = gxt-gyt; 

    // thing is behind view plane?
    if (tz < MINZ)
	return;
    
    xscale = FixedDiv(projection, tz);
	
    gxt = -FixedMul(tr_x,viewsin); 
    gyt = FixedMul(tr_y,viewcos); 
    tx = -(gyt+gxt); 

    // too far off the side?
    if (abs(tx)>(tz<<2))
	return;
    
    // decide which patch to use for sprite relative to player
#ifdef RANGECHECK
    if ((unsigned)thing->sprite >= numsprites)
	I_Error ("R_ProjectSprite: invalid sprite number %i ",
		 thing->sprite);
#endif
    sprdef = &sprites[thing->sprite];
#ifdef RANGECHECK
    if ( (thing->frame&FF_FRAMEMASK) >= sprdef->numframes )
	I_Error ("R_ProjectSprite: invalid sprite frame %i : %i ",
		 thing->sprite, thing->frame);
#endif
    sprframe = &sprdef->spriteframes[ thing->frame & FF_FRAMEMASK];

    if (sprframe->rotate)
    {
	// choose a different rotation based on player view
	ang = R_PointToAngle (thing->x, thing->y);
	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;

    // off the right side?
    if (x1 > viewwidth)
	return;
    
    tx +=  spritewidth[lump];
    x2 = ((centerxfrac + FixedMul (tx,xscale) ) >>FRACBITS) - 1;

    // off the left side
    if (x2 < 0)
	return;
    
    // store information in a vissprite
    vis = R_NewVisSprite ();
    vis->mobjflags = thing->flags;
    vis->scale = xscale<<detailshift;
    vis->gx = thing->x;
    vis->gy = thing->y;
    vis->gz = thing->z;
    vis->gzt = thing->z + spritetopoffset[lump];
    vis->texturemid = vis->gzt - viewz;
    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)
    {
	// shadow draw
	vis->colormap = NULL;
    }
    else if (fixedcolormap)
    {
	// fixed map
	vis->colormap = fixedcolormap;
    }
    else if (thing->frame & FF_FULLBRIGHT)
    {
	// full bright
	vis->colormap = colormaps;
    }
    
    else
    {
	// diminished light
	index = xscale>>(LIGHTSCALESHIFT-detailshift);

	if (index >= MAXLIGHTSCALE) 
	    index = MAXLIGHTSCALE-1;

	vis->colormap = spritelights[index];
    }	
}




//
// R_AddSprites
// During BSP traversal, this adds sprites by sector.
//
void R_AddSprites (sector_t* sec)
{
    mobj_t*		thing;
    int			lightnum;

    // BSP is traversed by subsector.
    // A sector might have been split into several
    //  subsectors during BSP building.
    // Thus we check whether its already added.
    if (sec->validcount == validcount)
	return;		

    // Well, now it will be done.
    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];

    // Handle all things in sector.
    for (thing = sec->thinglist ; thing ; thing = thing->snext)
	R_ProjectSprite (thing);
}


//
// R_DrawPSprite
//
void R_DrawPSprite (pspdef_t* psp)
{
    fixed_t		tx;
    int			x1;
    int			x2;
    spritedef_t*	sprdef;
    spriteframe_t*	sprframe;
    int			lump;
    boolean		flip;
    vissprite_t*	vis;
    vissprite_t		avis;
    
    // 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];	
    x1 = (centerxfrac + FixedMul (tx,pspritescale) ) >>FRACBITS;

    // off the right side
    if (x1 > viewwidth)
	return;		

    tx +=  spritewidth[lump];
    x2 = ((centerxfrac + FixedMul (tx, pspritescale) ) >>FRACBITS) - 1;

    // off the left side
    if (x2 < 0)
	return;
    
    // store information in a vissprite
    vis = &avis;
    vis->mobjflags = 0;
    vis->texturemid = (BASEYCENTER<<FRACBITS)+FRACUNIT/2-(psp->sy-spritetopoffset[lump]);
    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_invisibility] > 4*32
	|| viewplayer->powers[pw_invisibility] & 8)
    {
	// shadow draw
	vis->colormap = NULL;
    }
    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;
    int		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;
    int			count;
    vissprite_t*	ds;
    vissprite_t*	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
    vsprsortedhead.next = vsprsortedhead.prev = &vsprsortedhead;
    for (best=nil,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];
    short		cliptop[SCREENWIDTH];
    int			x;
    int			r1;
    int			r2;
    fixed_t		scale;
    fixed_t		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) )
	{
	    // does not cover sprite
	    continue;
	}
			
	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) ) )
	{
	    // masked mid texture?
	    if (ds->maskedtexturecol)	
		R_RenderMaskedSegRange (ds, r1, r2);
	    // seg is behind sprite
	    continue;			
	}

	
	// 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
    //  but does not draw on side views
    if (!viewangleoffset)		
	R_DrawPlayerSprites ();
}