ref: 350fb1e60c6761d7171df663035846bacc2b8fde
dir: /src/hexen/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.
//
// HEADER FILES ------------------------------------------------------------
#include "h2def.h"
#include "i_system.h"
#include "r_local.h"
#include "p_spec.h"
// MACROS ------------------------------------------------------------------
// TYPES -------------------------------------------------------------------
// EXTERNAL FUNCTION PROTOTYPES --------------------------------------------
// PUBLIC FUNCTION PROTOTYPES ----------------------------------------------
// PRIVATE FUNCTION PROTOTYPES ---------------------------------------------
// EXTERNAL DATA DECLARATIONS ----------------------------------------------
// PUBLIC DATA DEFINITIONS -------------------------------------------------
int Sky1Texture;
int Sky2Texture;
fixed_t Sky1ColumnOffset;
fixed_t Sky2ColumnOffset;
int skyflatnum;
int skytexturemid;
fixed_t skyiscale;
boolean DoubleSky;
planefunction_t floorfunc, ceilingfunc;
// Opening
visplane_t visplanes[MAXVISPLANES], *lastvisplane;
visplane_t *floorplane, *ceilingplane;
short openings[MAXOPENINGS], *lastopening;
// Clip values are the solid pixel bounding the range.
// floorclip start out SCREENHEIGHT
// ceilingclip starts out -1
short floorclip[SCREENWIDTH];
short ceilingclip[SCREENWIDTH];
// spanstart holds the start of a plane span, initialized to 0
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];
// PRIVATE DATA DEFINITIONS ------------------------------------------------
// CODE --------------------------------------------------------------------
//==========================================================================
//
// R_InitSky
//
// Called at level load.
//
//==========================================================================
void R_InitSky(int map)
{
Sky1Texture = P_GetMapSky1Texture(map);
Sky2Texture = P_GetMapSky2Texture(map);
Sky1ScrollDelta = P_GetMapSky1ScrollDelta(map);
Sky2ScrollDelta = P_GetMapSky2ScrollDelta(map);
Sky1ColumnOffset = 0;
Sky2ColumnOffset = 0;
DoubleSky = P_GetMapDoubleSky(map);
}
//==========================================================================
//
// R_InitSkyMap
//
// Called whenever the view size changes.
//
//==========================================================================
void R_InitSkyMap(void)
{
skyflatnum = R_FlatNumForName("F_SKY");
skytexturemid = 200 * FRACUNIT;
skyiscale = FRACUNIT;
}
//==========================================================================
//
// R_InitPlanes
//
// Called at game startup.
//
//==========================================================================
void R_InitPlanes(void)
{
}
//==========================================================================
//
// R_MapPlane
//
// Globals used: planeheight, ds_source, basexscale, baseyscale,
// viewx, viewy.
//
//==========================================================================
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
//
// Called at the beginning of each 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 (special < 150)
{ // Don't let low specials affect search
special = 0;
}
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 visplane
}
// 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
//
//==========================================================================
#define SKYTEXTUREMIDSHIFTED 200
void R_DrawPlanes(void)
{
visplane_t *pl;
int light;
int x, stop;
int angle;
byte *tempSource;
byte *source;
byte *source2;
byte *dest;
int count;
int offset;
int skyTexture;
int offset2;
int skyTexture2;
int scrollOffset;
#ifdef RANGECHECK
if (ds_p - drawsegs > MAXDRAWSEGS)
{
I_Error("R_DrawPlanes: drawsegs overflow (%td)",
ds_p - drawsegs);
}
if (lastvisplane - visplanes > MAXVISPLANES)
{
I_Error("R_DrawPlanes: visplane overflow (%td)",
lastvisplane - visplanes);
}
if (lastopening - openings > MAXOPENINGS)
{
I_Error("R_DrawPlanes: opening overflow (%td)",
lastopening - openings);
}
#endif
for (pl = visplanes; pl < lastvisplane; pl++)
{
if (pl->minx > pl->maxx)
{
continue;
}
if (pl->picnum == skyflatnum)
{ // Sky flat
if (DoubleSky)
{ // Render 2 layers, sky 1 in front
offset = Sky1ColumnOffset >> 16;
skyTexture = texturetranslation[Sky1Texture];
offset2 = Sky2ColumnOffset >> 16;
skyTexture2 = texturetranslation[Sky2Texture];
for (x = pl->minx; x <= pl->maxx; x++)
{
dc_yl = pl->top[x];
dc_yh = pl->bottom[x];
if (dc_yl <= dc_yh)
{
count = dc_yh - dc_yl;
if (count < 0)
{
return;
}
angle = (viewangle + xtoviewangle[x])
>> ANGLETOSKYSHIFT;
source = R_GetColumn(skyTexture, angle + offset)
+ SKYTEXTUREMIDSHIFTED + (dc_yl - centery);
source2 = R_GetColumn(skyTexture2, angle + offset2)
+ SKYTEXTUREMIDSHIFTED + (dc_yl - centery);
dest = ylookup[dc_yl] + columnofs[x];
do
{
if (*source)
{
*dest = *source++;
source2++;
}
else
{
*dest = *source2++;
source++;
}
dest += SCREENWIDTH;
}
while (count--);
}
}
continue; // Next visplane
}
else
{ // Render single layer
if (pl->special == 200)
{ // Use sky 2
offset = Sky2ColumnOffset >> 16;
skyTexture = texturetranslation[Sky2Texture];
}
else
{ // Use sky 1
offset = Sky1ColumnOffset >> 16;
skyTexture = texturetranslation[Sky1Texture];
}
for (x = pl->minx; x <= pl->maxx; x++)
{
dc_yl = pl->top[x];
dc_yh = pl->bottom[x];
if (dc_yl <= dc_yh)
{
count = dc_yh - dc_yl;
if (count < 0)
{
return;
}
angle = (viewangle + xtoviewangle[x])
>> ANGLETOSKYSHIFT;
source = R_GetColumn(skyTexture, angle + offset)
+ SKYTEXTUREMIDSHIFTED + (dc_yl - centery);
dest = ylookup[dc_yl] + columnofs[x];
do
{
*dest = *source++;
dest += SCREENWIDTH;
}
while (count--);
}
}
continue; // Next visplane
}
}
// Regular flat
tempSource = W_CacheLumpNum(firstflat +
flattranslation[pl->picnum], PU_STATIC);
scrollOffset = leveltime >> 1 & 63;
switch (pl->special)
{ // Handle scrolling flats
case 201:
case 202:
case 203: // Scroll_North_xxx
ds_source = tempSource + ((scrollOffset
<< (pl->special - 201) & 63) << 6);
break;
case 204:
case 205:
case 206: // Scroll_East_xxx
ds_source = tempSource + ((63 - scrollOffset)
<< (pl->special - 204) & 63);
break;
case 207:
case 208:
case 209: // Scroll_South_xxx
ds_source = tempSource + (((63 - scrollOffset)
<< (pl->special - 207) & 63) << 6);
break;
case 210:
case 211:
case 212: // Scroll_West_xxx
ds_source = tempSource + (scrollOffset
<< (pl->special - 210) & 63);
break;
case 213:
case 214:
case 215: // Scroll_NorthWest_xxx
ds_source = tempSource + (scrollOffset
<< (pl->special - 213) & 63) +
((scrollOffset << (pl->special - 213) & 63) << 6);
break;
case 216:
case 217:
case 218: // Scroll_NorthEast_xxx
ds_source = tempSource + ((63 - scrollOffset)
<< (pl->special - 216) & 63) +
((scrollOffset << (pl->special - 216) & 63) << 6);
break;
case 219:
case 220:
case 221: // Scroll_SouthEast_xxx
ds_source = tempSource + ((63 - scrollOffset)
<< (pl->special - 219) & 63) +
(((63 - scrollOffset) << (pl->special - 219) & 63) << 6);
break;
case 222:
case 223:
case 224: // Scroll_SouthWest_xxx
ds_source = tempSource + (scrollOffset
<< (pl->special - 222) & 63) +
(((63 - scrollOffset) << (pl->special - 222) & 63) << 6);
break;
default:
ds_source = tempSource;
break;
}
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(firstflat + flattranslation[pl->picnum]);
}
}