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doom3-bfg/doomclassic/doom/r_plane.cpp
2022-09-05 22:25:33 +02:00

458 lines
8.9 KiB
C++

/*
===========================================================================
Doom 3 BFG Edition GPL Source Code
Copyright (C) 1993-2012 id Software LLC, a ZeniMax Media company.
This file is part of the Doom 3 BFG Edition GPL Source Code ("Doom 3 BFG Edition Source Code").
Doom 3 BFG Edition Source Code is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Doom 3 BFG Edition Source Code is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with Doom 3 BFG Edition Source Code. If not, see <http://www.gnu.org/licenses/>.
In addition, the Doom 3 BFG Edition Source Code is also subject to certain additional terms. You should have received a copy of these additional terms immediately following the terms and conditions of the GNU General Public License which accompanied the Doom 3 BFG Edition Source Code. If not, please request a copy in writing from id Software at the address below.
If you have questions concerning this license or the applicable additional terms, you may contact in writing id Software LLC, c/o ZeniMax Media Inc., Suite 120, Rockville, Maryland 20850 USA.
===========================================================================
*/
#include "Precompiled.h"
#include "globaldata.h"
#include <stdlib.h>
#include "i_system.h"
#include "z_zone.h"
#include "w_wad.h"
#include "doomdef.h"
#include "doomstat.h"
#include "r_local.h"
#include "r_sky.h"
//
// opening
//
// Here comes the obnoxious "visplane".
//
// Clip values are the solid pixel bounding the range.
// ::g->floorclip starts out SCREENHEIGHT
// ::g->ceilingclip starts out -1
//
//
// ::g->spanstart holds the start of a plane span
// initialized to 0 at start
//
//
// texture mapping
//
//
// R_InitPlanes
// Only at game startup.
//
void R_InitPlanes( void )
{
// Doh!
}
//
// R_MapPlane
//
// Uses global vars:
// ::g->planeheight
// ::g->ds_source
// ::g->basexscale
// ::g->baseyscale
// ::g->viewx
// ::g->viewy
//
// BASIC PRIMITIVE
//
void
R_MapPlane
( int y,
int x1,
int x2 )
{
angle_t angle;
fixed_t distance;
fixed_t length;
unsigned index;
//#ifdef RANGECHECK
if( x2 < x1 || x1 < 0 || x2 >=::g->viewwidth || y >::g->viewheight )
{
//I_Error ("R_MapPlane: %i, %i at %i",x1,x2,y);
return;
}
//#endif
if( ::g->planeheight != ::g->cachedheight[y] )
{
::g->cachedheight[y] = ::g->planeheight;
distance = ::g->cacheddistance[y] = FixedMul( ::g->planeheight, ::g->yslope[y] );
::g->ds_xstep = ::g->cachedxstep[y] = FixedMul( distance, ::g->basexscale );
::g->ds_ystep = ::g->cachedystep[y] = FixedMul( distance, ::g->baseyscale );
}
else
{
distance = ::g->cacheddistance[y];
::g->ds_xstep = ::g->cachedxstep[y];
::g->ds_ystep = ::g->cachedystep[y];
}
extern angle_t GetViewAngle();
length = FixedMul( distance, ::g->distscale[x1] );
angle = ( GetViewAngle() + ::g->xtoviewangle[x1] ) >> ANGLETOFINESHIFT;
extern fixed_t GetViewX();
extern fixed_t GetViewY();
::g->ds_xfrac = GetViewX() + FixedMul( finecosine[angle], length );
::g->ds_yfrac = -GetViewY() - FixedMul( finesine[angle], length );
if( ::g->fixedcolormap )
{
::g->ds_colormap = ::g->fixedcolormap;
}
else
{
index = distance >> LIGHTZSHIFT;
if( index >= MAXLIGHTZ )
{
index = MAXLIGHTZ - 1;
}
::g->ds_colormap = ::g->planezlight[index];
}
::g->ds_y = y;
::g->ds_x1 = x1;
::g->ds_x2 = x2;
// high or low detail
spanfunc(
::g->ds_xfrac,
::g->ds_yfrac,
::g->ds_y,
::g->ds_x1,
::g->ds_x2,
::g->ds_xstep,
::g->ds_ystep,
::g->ds_colormap,
::g->ds_source );
}
//
// R_ClearPlanes
// At begining of frame.
//
void R_ClearPlanes( void )
{
int i;
angle_t angle;
// opening / clipping determination
for( i = 0 ; i < ::g->viewwidth ; i++ )
{
::g->floorclip[i] = ::g->viewheight;
::g->ceilingclip[i] = -1;
}
::g->lastvisplane = ::g->visplanes;
::g->lastopening = ::g->openings;
// texture calculation
memset( ::g->cachedheight, 0, sizeof( ::g->cachedheight ) );
// left to right mapping
extern angle_t GetViewAngle();
angle = ( GetViewAngle() - ANG90 ) >> ANGLETOFINESHIFT;
// scale will be unit scale at SCREENWIDTH/2 distance
::g->basexscale = FixedDiv( finecosine[angle], ::g->centerxfrac );
::g->baseyscale = -FixedDiv( finesine[angle], ::g->centerxfrac );
}
//
// R_FindPlane
//
visplane_t* R_FindPlane( fixed_t height, int picnum, int lightlevel )
{
visplane_t* check;
if( picnum == ::g->skyflatnum )
{
height = 0; // all skys map together
lightlevel = 0;
}
for( check =::g->visplanes; check < ::g->lastvisplane; check++ )
{
if( height == check->height && picnum == check->picnum && lightlevel == check->lightlevel )
{
break;
}
}
if( check < ::g->lastvisplane )
{
return check;
}
//if (::g->lastvisplane - ::g->visplanes == MAXVISPLANES)
//I_Error ("R_FindPlane: no more visplanes");
if( ::g->lastvisplane - ::g->visplanes == MAXVISPLANES )
{
check = ::g->visplanes;
return check;
}
::g->lastvisplane++;
check->height = height;
check->picnum = picnum;
check->lightlevel = lightlevel;
check->minx = SCREENWIDTH;
check->maxx = -1;
memset( check->top, 0xff, sizeof( check->top ) );
return check;
}
//
// R_CheckPlane
//
visplane_t*
R_CheckPlane
( visplane_t* pl,
int start,
int stop )
{
int intrl;
int intrh;
int unionl;
int unionh;
int x;
if( start < pl->minx )
{
intrl = pl->minx;
unionl = start;
}
else
{
unionl = pl->minx;
intrl = start;
}
if( stop > pl->maxx )
{
intrh = pl->maxx;
unionh = stop;
}
else
{
unionh = pl->maxx;
intrh = stop;
}
for( x = intrl ; x <= intrh ; x++ )
if( pl->top[x] != 0xffff )
{
break;
}
if( x > intrh )
{
pl->minx = unionl;
pl->maxx = unionh;
// use the same one
return pl;
}
if( ::g->lastvisplane - ::g->visplanes == MAXVISPLANES )
{
return pl;
}
// make a new visplane
::g->lastvisplane->height = pl->height;
::g->lastvisplane->picnum = pl->picnum;
::g->lastvisplane->lightlevel = pl->lightlevel;
pl = ::g->lastvisplane++;
pl->minx = start;
pl->maxx = stop;
memset( pl->top, 0xff, sizeof( pl->top ) );
return pl;
}
//
// R_MakeSpans
//
void
R_MakeSpans
( int x,
int t1,
int b1,
int t2,
int b2 )
{
while( t1 < t2 && t1 <= b1 )
{
R_MapPlane( t1, ::g->spanstart[t1], x - 1 );
t1++;
}
while( b1 > b2 && b1 >= t1 )
{
R_MapPlane( b1, ::g->spanstart[b1], x - 1 );
b1--;
}
while( t2 < t1 && t2 <= b2 )
{
::g->spanstart[t2] = x;
t2++;
}
while( b2 > b1 && b2 >= t2 )
{
::g->spanstart[b2] = x;
b2--;
}
}
//
// R_DrawPlanes
// At the end of each frame.
//
void R_DrawPlanes( void )
{
visplane_t* pl;
int light;
int x;
int stop;
int angle;
#ifdef RANGECHECK
if( ::g->ds_p - ::g->drawsegs > MAXDRAWSEGS )
I_Error( "R_DrawPlanes: ::g->drawsegs overflow (%i)",
::g->ds_p - ::g->drawsegs );
if( ::g->lastvisplane - ::g->visplanes > MAXVISPLANES )
I_Error( "R_DrawPlanes: visplane overflow (%i)",
::g->lastvisplane - ::g->visplanes );
if( ::g->lastopening - ::g->openings > MAXOPENINGS )
I_Error( "R_DrawPlanes: opening overflow (%i)",
::g->lastopening - ::g->openings );
#endif
for( pl = ::g->visplanes ; pl < ::g->lastvisplane ; pl++ )
{
if( pl->minx > pl->maxx )
{
continue;
}
// sky flat
if( pl->picnum == ::g->skyflatnum )
{
::g->dc_iscale = ::g->pspriteiscale >>::g->detailshift;
// Sky is allways drawn full bright,
// i.e. ::g->colormaps[0] is used.
// Because of this hack, sky is not affected
// by INVUL inverse mapping.
::g->dc_colormap = ::g->colormaps;
::g->dc_texturemid = ::g->skytexturemid;
for( x = pl->minx ; x <= pl->maxx ; x++ )
{
::g->dc_yl = pl->top[x];
::g->dc_yh = pl->bottom[x];
if( ::g->dc_yl <= ::g->dc_yh )
{
extern angle_t GetViewAngle();
angle = ( GetViewAngle() + ::g->xtoviewangle[x] ) >> ANGLETOSKYSHIFT;
::g->dc_x = x;
::g->dc_source = R_GetColumn( ::g->skytexture, angle );
colfunc( ::g->dc_colormap, ::g->dc_source );
}
}
continue;
}
// regular flat
::g->ds_source = ( byte* )W_CacheLumpNum( ::g->firstflat +
::g->flattranslation[pl->picnum],
PU_CACHE_SHARED );
::g->planeheight = abs( pl->height -::g->viewz );
light = ( pl->lightlevel >> LIGHTSEGSHIFT ) +::g->extralight;
if( light >= LIGHTLEVELS )
{
light = LIGHTLEVELS - 1;
}
if( light < 0 )
{
light = 0;
}
::g->planezlight = ::g->zlight[light];
pl->top[pl->maxx + 1] = 0xffff;
pl->top[pl->minx - 1] = 0xffff;
stop = pl->maxx + 1;
for( x = pl->minx ; x <= stop ; x++ )
{
R_MakeSpans( x, pl->top[x - 1],
pl->bottom[x - 1],
pl->top[x],
pl->bottom[x] );
}
}
}