454 lines
8.1 KiB
C
Executable File
454 lines
8.1 KiB
C
Executable File
// Emacs style mode select -*- C++ -*-
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//-----------------------------------------------------------------------------
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//
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// $Id:$
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//
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// Copyright (C) 1993-1996 by id Software, Inc.
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//
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// This source is available for distribution and/or modification
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// only under the terms of the DOOM Source Code License as
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// published by id Software. All rights reserved.
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//
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// The source is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// FITNESS FOR A PARTICULAR PURPOSE. See the DOOM Source Code License
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// for more details.
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//
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// $Log:$
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//
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// DESCRIPTION:
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// Here is a core component: drawing the floors and ceilings,
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// while maintaining a per column clipping list only.
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// Moreover, the sky areas have to be determined.
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//
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//-----------------------------------------------------------------------------
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static const char
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rcsid[] = "$Id: r_plane.c,v 1.4 1997/02/03 16:47:55 b1 Exp $";
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#include <stdlib.h>
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#include "i_system.h"
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#include "z_zone.h"
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#include "w_wad.h"
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#include "doomdef.h"
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#include "doomstat.h"
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#include "r_local.h"
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#include "r_sky.h"
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planefunction_t floorfunc;
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planefunction_t ceilingfunc;
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//
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// opening
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//
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// Here comes the obnoxious "visplane".
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#define MAXVISPLANES 128
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visplane_t visplanes[MAXVISPLANES];
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visplane_t* lastvisplane;
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visplane_t* floorplane;
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visplane_t* ceilingplane;
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// ?
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#define MAXOPENINGS SCREENWIDTH*64
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short openings[MAXOPENINGS];
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short* lastopening;
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//
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// Clip values are the solid pixel bounding the range.
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// floorclip starts out SCREENHEIGHT
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// ceilingclip starts out -1
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//
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short floorclip[SCREENWIDTH];
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short ceilingclip[SCREENWIDTH];
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//
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// spanstart holds the start of a plane span
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// initialized to 0 at start
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//
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int spanstart[SCREENHEIGHT];
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int spanstop[SCREENHEIGHT];
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//
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// texture mapping
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//
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lighttable_t** planezlight;
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fixed_t planeheight;
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fixed_t yslope[SCREENHEIGHT];
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fixed_t distscale[SCREENWIDTH];
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fixed_t basexscale;
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fixed_t baseyscale;
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fixed_t cachedheight[SCREENHEIGHT];
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fixed_t cacheddistance[SCREENHEIGHT];
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fixed_t cachedxstep[SCREENHEIGHT];
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fixed_t cachedystep[SCREENHEIGHT];
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//
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// R_InitPlanes
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// Only at game startup.
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//
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void R_InitPlanes (void)
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{
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// Doh!
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}
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//
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// R_MapPlane
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//
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// Uses global vars:
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// planeheight
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// ds_source
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// basexscale
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// baseyscale
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// viewx
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// viewy
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//
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// BASIC PRIMITIVE
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//
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void
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R_MapPlane
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( int y,
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int x1,
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int x2 )
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{
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angle_t angle;
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fixed_t distance;
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fixed_t length;
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unsigned index;
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#ifdef RANGECHECK
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if (x2 < x1
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|| x1<0
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|| x2>=viewwidth
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|| (unsigned)y>viewheight)
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{
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I_Error ("R_MapPlane: %i, %i at %i",x1,x2,y);
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}
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#endif
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if (planeheight != cachedheight[y])
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{
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cachedheight[y] = planeheight;
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distance = cacheddistance[y] = FixedMul (planeheight, yslope[y]);
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ds_xstep = cachedxstep[y] = FixedMul (distance,basexscale);
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ds_ystep = cachedystep[y] = FixedMul (distance,baseyscale);
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}
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else
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{
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distance = cacheddistance[y];
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ds_xstep = cachedxstep[y];
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ds_ystep = cachedystep[y];
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}
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length = FixedMul (distance,distscale[x1]);
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angle = (viewangle + xtoviewangle[x1])>>ANGLETOFINESHIFT;
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ds_xfrac = viewx + FixedMul(finecosine[angle], length);
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ds_yfrac = -viewy - FixedMul(finesine[angle], length);
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if (fixedcolormap)
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ds_colormap = fixedcolormap;
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else
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{
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index = distance >> LIGHTZSHIFT;
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if (index >= MAXLIGHTZ )
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index = MAXLIGHTZ-1;
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ds_colormap = planezlight[index];
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}
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ds_y = y;
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ds_x1 = x1;
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ds_x2 = x2;
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// high or low detail
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spanfunc ();
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}
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//
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// R_ClearPlanes
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// At begining of frame.
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//
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void R_ClearPlanes (void)
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{
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int i;
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angle_t angle;
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// opening / clipping determination
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for (i=0 ; i<viewwidth ; i++)
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{
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floorclip[i] = viewheight;
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ceilingclip[i] = -1;
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}
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lastvisplane = visplanes;
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lastopening = openings;
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// texture calculation
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memset (cachedheight, 0, sizeof(cachedheight));
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// left to right mapping
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angle = (viewangle-ANG90)>>ANGLETOFINESHIFT;
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// scale will be unit scale at SCREENWIDTH/2 distance
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basexscale = FixedDiv (finecosine[angle],centerxfrac);
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baseyscale = -FixedDiv (finesine[angle],centerxfrac);
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}
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//
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// R_FindPlane
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//
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visplane_t*
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R_FindPlane
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( fixed_t height,
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int picnum,
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int lightlevel )
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{
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visplane_t* check;
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if (picnum == skyflatnum)
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{
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height = 0; // all skys map together
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lightlevel = 0;
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}
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for (check=visplanes; check<lastvisplane; check++)
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{
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if (height == check->height
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&& picnum == check->picnum
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&& lightlevel == check->lightlevel)
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{
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break;
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}
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}
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if (check < lastvisplane)
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return check;
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if (lastvisplane - visplanes == MAXVISPLANES)
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I_Error ("R_FindPlane: no more visplanes");
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lastvisplane++;
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check->height = height;
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check->picnum = picnum;
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check->lightlevel = lightlevel;
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check->minx = SCREENWIDTH;
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check->maxx = -1;
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memset (check->top,0xff,sizeof(check->top));
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return check;
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}
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//
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// R_CheckPlane
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//
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visplane_t*
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R_CheckPlane
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( visplane_t* pl,
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int start,
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int stop )
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{
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int intrl;
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int intrh;
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int unionl;
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int unionh;
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int x;
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if (start < pl->minx)
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{
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intrl = pl->minx;
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unionl = start;
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}
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else
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{
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unionl = pl->minx;
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intrl = start;
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}
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if (stop > pl->maxx)
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{
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intrh = pl->maxx;
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unionh = stop;
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}
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else
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{
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unionh = pl->maxx;
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intrh = stop;
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}
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for (x=intrl ; x<= intrh ; x++)
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if (pl->top[x] != 0xff)
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break;
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if (x > intrh)
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{
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pl->minx = unionl;
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pl->maxx = unionh;
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// use the same one
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return pl;
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}
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// make a new visplane
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lastvisplane->height = pl->height;
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lastvisplane->picnum = pl->picnum;
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lastvisplane->lightlevel = pl->lightlevel;
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pl = lastvisplane++;
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pl->minx = start;
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pl->maxx = stop;
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memset (pl->top,0xff,sizeof(pl->top));
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return pl;
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}
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//
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// R_MakeSpans
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//
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void
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R_MakeSpans
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( int x,
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int t1,
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int b1,
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int t2,
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int b2 )
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{
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while (t1 < t2 && t1<=b1)
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{
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R_MapPlane (t1,spanstart[t1],x-1);
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t1++;
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}
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while (b1 > b2 && b1>=t1)
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{
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R_MapPlane (b1,spanstart[b1],x-1);
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b1--;
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}
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while (t2 < t1 && t2<=b2)
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{
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spanstart[t2] = x;
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t2++;
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}
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while (b2 > b1 && b2>=t2)
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{
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spanstart[b2] = x;
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b2--;
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}
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}
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//
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// R_DrawPlanes
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// At the end of each frame.
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//
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void R_DrawPlanes (void)
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{
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visplane_t* pl;
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int light;
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int x;
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int stop;
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int angle;
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#ifdef RANGECHECK
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if (ds_p - drawsegs > MAXDRAWSEGS)
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I_Error ("R_DrawPlanes: drawsegs overflow (%i)",
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ds_p - drawsegs);
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if (lastvisplane - visplanes > MAXVISPLANES)
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I_Error ("R_DrawPlanes: visplane overflow (%i)",
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lastvisplane - visplanes);
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if (lastopening - openings > MAXOPENINGS)
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I_Error ("R_DrawPlanes: opening overflow (%i)",
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lastopening - openings);
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#endif
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for (pl = visplanes ; pl < lastvisplane ; pl++)
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{
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if (pl->minx > pl->maxx)
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continue;
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// sky flat
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if (pl->picnum == skyflatnum)
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{
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dc_iscale = pspriteiscale>>detailshift;
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// Sky is allways drawn full bright,
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// i.e. colormaps[0] is used.
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// Because of this hack, sky is not affected
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// by INVUL inverse mapping.
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dc_colormap = colormaps;
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dc_texturemid = skytexturemid;
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for (x=pl->minx ; x <= pl->maxx ; x++)
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{
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dc_yl = pl->top[x];
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dc_yh = pl->bottom[x];
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if (dc_yl <= dc_yh)
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{
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angle = (viewangle + xtoviewangle[x])>>ANGLETOSKYSHIFT;
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dc_x = x;
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dc_source = R_GetColumn(skytexture, angle);
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colfunc ();
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}
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}
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continue;
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}
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// regular flat
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ds_source = W_CacheLumpNum(firstflat +
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flattranslation[pl->picnum],
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PU_STATIC);
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planeheight = abs(pl->height-viewz);
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light = (pl->lightlevel >> LIGHTSEGSHIFT)+extralight;
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if (light >= LIGHTLEVELS)
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light = LIGHTLEVELS-1;
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if (light < 0)
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light = 0;
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planezlight = zlight[light];
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pl->top[pl->maxx+1] = 0xff;
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pl->top[pl->minx-1] = 0xff;
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stop = pl->maxx + 1;
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for (x=pl->minx ; x<= stop ; x++)
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{
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R_MakeSpans(x,pl->top[x-1],
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pl->bottom[x-1],
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pl->top[x],
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pl->bottom[x]);
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}
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Z_ChangeTag (ds_source, PU_CACHE);
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}
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}
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