ref: a0e667de8678b045f8f08a7d87ba86239e33fa6b
dir: /src/heretic/r_plane.c/
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 1993-2008 Raven Software
// Copyright(C) 2005-2014 Simon Howard
//
// This program 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 2
// of the License, or (at your option) any later version.
//
// This program 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.
//
// R_planes.c
#include <stdlib.h>
#include "doomdef.h"
#include "deh_str.h"
#include "i_system.h"
#include "r_local.h"
planefunction_t floorfunc, ceilingfunc;
//
// sky mapping
//
int skyflatnum;
int skytexture;
int skytexturemid;
fixed_t skyiscale;
//
// opening
//
visplane_t visplanes[MAXVISPLANES], *lastvisplane;
visplane_t *floorplane, *ceilingplane;
short openings[MAXOPENINGS], *lastopening;
//
// clip values are the solid pixel bounding the range
// floorclip starts out SCREENHEIGHT
// ceilingclip starts out -1
//
short floorclip[SCREENWIDTH];
short ceilingclip[SCREENWIDTH];
//
// spanstart holds the start of a plane span
// initialized to 0 at start
//
int spanstart[SCREENHEIGHT];
int spanstop[SCREENHEIGHT];
//
// texture mapping
//
lighttable_t **planezlight;
fixed_t planeheight;
fixed_t yslope[SCREENHEIGHT];
fixed_t distscale[SCREENWIDTH];
fixed_t basexscale, baseyscale;
fixed_t cachedheight[SCREENHEIGHT];
fixed_t cacheddistance[SCREENHEIGHT];
fixed_t cachedxstep[SCREENHEIGHT];
fixed_t cachedystep[SCREENHEIGHT];
/*
================
=
= R_InitSkyMap
=
= Called whenever the view size changes
=
================
*/
void R_InitSkyMap(void)
{
skyflatnum = R_FlatNumForName(DEH_String("F_SKY1"));
skytexturemid = 200 * FRACUNIT;
skyiscale = FRACUNIT;
}
/*
====================
=
= R_InitPlanes
=
= Only at game startup
====================
*/
void R_InitPlanes(void)
{
}
/*
================
=
= R_MapPlane
=
global vars:
planeheight
ds_source
basexscale
baseyscale
viewx
viewy
BASIC PRIMITIVE
================
*/
void R_MapPlane(int y, int x1, int x2)
{
angle_t angle;
fixed_t distance, length;
unsigned index;
#ifdef RANGECHECK
if (x2 < x1 || x1 < 0 || x2 >= viewwidth || (unsigned) y > viewheight)
I_Error("R_MapPlane: %i, %i at %i", x1, x2, y);
#endif
if (planeheight != cachedheight[y])
{
cachedheight[y] = planeheight;
distance = cacheddistance[y] = FixedMul(planeheight, yslope[y]);
ds_xstep = cachedxstep[y] = FixedMul(distance, basexscale);
ds_ystep = cachedystep[y] = FixedMul(distance, baseyscale);
}
else
{
distance = cacheddistance[y];
ds_xstep = cachedxstep[y];
ds_ystep = cachedystep[y];
}
length = FixedMul(distance, distscale[x1]);
angle = (viewangle + xtoviewangle[x1]) >> ANGLETOFINESHIFT;
ds_xfrac = viewx + FixedMul(finecosine[angle], length);
ds_yfrac = -viewy - FixedMul(finesine[angle], length);
if (fixedcolormap)
ds_colormap = fixedcolormap;
else
{
index = distance >> LIGHTZSHIFT;
if (index >= MAXLIGHTZ)
index = MAXLIGHTZ - 1;
ds_colormap = planezlight[index];
}
ds_y = y;
ds_x1 = x1;
ds_x2 = x2;
spanfunc(); // high or low detail
}
//=============================================================================
/*
====================
=
= R_ClearPlanes
=
= At begining of frame
====================
*/
void R_ClearPlanes(void)
{
int i;
angle_t angle;
//
// opening / clipping determination
//
for (i = 0; i < viewwidth; i++)
{
floorclip[i] = viewheight;
ceilingclip[i] = -1;
}
lastvisplane = visplanes;
lastopening = openings;
//
// texture calculation
//
memset(cachedheight, 0, sizeof(cachedheight));
angle = (viewangle - ANG90) >> ANGLETOFINESHIFT; // left to right mapping
// scale will be unit scale at SCREENWIDTH/2 distance
basexscale = FixedDiv(finecosine[angle], centerxfrac);
baseyscale = -FixedDiv(finesine[angle], centerxfrac);
}
/*
===============
=
= R_FindPlane
=
===============
*/
visplane_t *R_FindPlane(fixed_t height, int picnum,
int lightlevel, int special)
{
visplane_t *check;
if (picnum == skyflatnum)
{
// all skies map together
height = 0;
lightlevel = 0;
}
for (check = visplanes; check < lastvisplane; check++)
{
if (height == check->height
&& picnum == check->picnum
&& lightlevel == check->lightlevel && special == check->special)
break;
}
if (check < lastvisplane)
{
return (check);
}
if (lastvisplane - visplanes == MAXVISPLANES)
{
I_Error("R_FindPlane: no more visplanes");
}
lastvisplane++;
check->height = height;
check->picnum = picnum;
check->lightlevel = lightlevel;
check->special = special;
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, intrh;
int unionl, 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] != 0xff)
break;
if (x > intrh)
{
pl->minx = unionl;
pl->maxx = unionh;
return pl; // use the same one
}
// make a new visplane
lastvisplane->height = pl->height;
lastvisplane->picnum = pl->picnum;
lastvisplane->lightlevel = pl->lightlevel;
lastvisplane->special = pl->special;
pl = 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, spanstart[t1], x - 1);
t1++;
}
while (b1 > b2 && b1 >= t1)
{
R_MapPlane(b1, spanstart[b1], x - 1);
b1--;
}
while (t2 < t1 && t2 <= b2)
{
spanstart[t2] = x;
t2++;
}
while (b2 > b1 && b2 >= t2)
{
spanstart[b2] = x;
b2--;
}
}
/*
================
=
= R_DrawPlanes
=
= At the end of each frame
================
*/
void R_DrawPlanes(void)
{
visplane_t *pl;
int light;
int x, stop;
int lumpnum;
int angle;
byte *tempSource;
byte *dest;
int count;
fixed_t frac, fracstep;
extern byte *ylookup[MAXHEIGHT];
extern int columnofs[MAXWIDTH];
#ifdef RANGECHECK
if (ds_p - drawsegs > MAXDRAWSEGS)
I_Error("R_DrawPlanes: drawsegs overflow (%" PRIiPTR ")",
ds_p - drawsegs);
if (lastvisplane - visplanes > MAXVISPLANES)
I_Error("R_DrawPlanes: visplane overflow (%" PRIiPTR ")",
lastvisplane - visplanes);
if (lastopening - openings > MAXOPENINGS)
I_Error("R_DrawPlanes: opening overflow (%" PRIiPTR ")",
lastopening - openings);
#endif
for (pl = visplanes; pl < lastvisplane; pl++)
{
if (pl->minx > pl->maxx)
continue;
//
// sky flat
//
if (pl->picnum == skyflatnum)
{
dc_iscale = skyiscale;
dc_colormap = colormaps; // sky is allways drawn full bright
dc_texturemid = skytexturemid;
for (x = pl->minx; x <= pl->maxx; x++)
{
dc_yl = pl->top[x];
dc_yh = pl->bottom[x];
if (dc_yl <= dc_yh)
{
angle = (viewangle + xtoviewangle[x]) >> ANGLETOSKYSHIFT;
dc_x = x;
dc_source = R_GetColumn(skytexture, angle);
count = dc_yh - dc_yl;
if (count < 0)
return;
#ifdef RANGECHECK
if ((unsigned) dc_x >= SCREENWIDTH || dc_yl < 0
|| dc_yh >= SCREENHEIGHT)
I_Error("R_DrawColumn: %i to %i at %i", dc_yl, dc_yh,
dc_x);
#endif
dest = ylookup[dc_yl] + columnofs[dc_x];
fracstep = 1;
frac = (dc_texturemid >> FRACBITS) + (dc_yl - centery);
do
{
*dest = dc_source[frac];
dest += SCREENWIDTH;
frac += fracstep;
}
while (count--);
// colfunc ();
}
}
continue;
}
//
// regular flat
//
lumpnum = firstflat + flattranslation[pl->picnum];
tempSource = W_CacheLumpNum(lumpnum, PU_STATIC);
switch (pl->special)
{
case 25:
case 26:
case 27:
case 28:
case 29: // Scroll_North
ds_source = tempSource;
break;
case 20:
case 21:
case 22:
case 23:
case 24: // Scroll_East
ds_source = tempSource + ((63 - ((leveltime >> 1) & 63)) <<
(pl->special - 20) & 63);
//ds_source = tempSource+((leveltime>>1)&63);
break;
case 30:
case 31:
case 32:
case 33:
case 34: // Scroll_South
ds_source = tempSource;
break;
case 35:
case 36:
case 37:
case 38:
case 39: // Scroll_West
ds_source = tempSource;
break;
case 4: // Scroll_EastLavaDamage
ds_source =
tempSource + (((63 - ((leveltime >> 1) & 63)) << 3) & 63);
break;
default:
ds_source = tempSource;
}
planeheight = abs(pl->height - viewz);
light = (pl->lightlevel >> LIGHTSEGSHIFT) + extralight;
if (light >= LIGHTLEVELS)
light = LIGHTLEVELS - 1;
if (light < 0)
light = 0;
planezlight = zlight[light];
pl->top[pl->maxx + 1] = 0xff;
pl->top[pl->minx - 1] = 0xff;
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]);
W_ReleaseLumpNum(lumpnum);
}
}