rockbox/apps/plugins/doom/r_bsp.c
Karl Kurbjun b47a43aa28 Doom for the Gigabeat and some code reduction
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@12051 a1c6a512-1295-4272-9138-f99709370657
2007-01-17 18:52:24 +00:00

600 lines
19 KiB
C

/* Emacs style mode select -*- C++ -*-
*-----------------------------------------------------------------------------
*
*
* PrBoom a Doom port merged with LxDoom and LSDLDoom
* based on BOOM, a modified and improved DOOM engine
* Copyright (C) 1999 by
* id Software, Chi Hoang, Lee Killough, Jim Flynn, Rand Phares, Ty Halderman
* Copyright (C) 1999-2000 by
* Jess Haas, Nicolas Kalkhof, Colin Phipps, Florian Schulze
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
* 02111-1307, USA.
*
* DESCRIPTION:
* BSP traversal, handling of LineSegs for rendering.
*
*-----------------------------------------------------------------------------*/
#include "doomstat.h"
#include "m_bbox.h"
#include "i_system.h"
#include "r_main.h"
#include "r_segs.h"
#include "r_plane.h"
#include "r_things.h"
#include "r_bsp.h" // cph - sanity checking
seg_t *curline;
side_t *sidedef;
line_t *linedef;
sector_t *frontsector;
sector_t *backsector;
drawseg_t *ds_p;
// killough 4/7/98: indicates doors closed wrt automap bugfix:
// cph - replaced by linedef rendering flags - int doorclosed;
// killough: New code which removes 2s linedef limit
drawseg_t *drawsegs;
unsigned maxdrawsegs;
// drawseg_t drawsegs[MAXDRAWSEGS]; // old code -- killough
//
// R_ClearDrawSegs
//
void R_ClearDrawSegs(void)
{
ds_p = drawsegs;
}
// CPhipps -
// Instead of clipsegs, let's try using an array with one entry for each column,
// indicating whether it's blocked by a solid wall yet or not.
byte solidcol[MAX_SCREENWIDTH] IBSS_ATTR;
// CPhipps -
// R_ClipWallSegment
//
// Replaces the old R_Clip*WallSegment functions. It draws bits of walls in those
// columns which aren't solid, and updates the solidcol[] array appropriately
void R_ClipWallSegment(int first, int last, boolean solid)
{
byte *p;
while (first < last)
{
if (solidcol[first])
{
if (!(p = memchr(solidcol+first, 0, last-first)))
return; // All solid
first = p - solidcol;
}
else
{
int to;
if (!(p = memchr(solidcol+first, 1, last-first)))
to = last;
else
to = p - solidcol;
R_StoreWallRange(first, to-1);
if (solid)
{
memset(solidcol+first,1,to-first);
}
first = to;
}
}
}
//
// R_ClearClipSegs
//
void R_ClearClipSegs (void)
{
memset(solidcol, 0, SCREENWIDTH);
}
// killough 1/18/98 -- This function is used to fix the automap bug which
// showed lines behind closed doors simply because the door had a dropoff.
//
// cph - converted to R_RecalcLineFlags. This recalculates all the flags for
// a line, including closure and texture tiling.
static void R_RecalcLineFlags(void)
{
linedef->r_validcount = gametic;
/* First decide if the line is closed, normal, or invisible */
if (!(linedef->flags & ML_TWOSIDED)
|| backsector->ceilingheight <= frontsector->floorheight
|| backsector->floorheight >= frontsector->ceilingheight
|| (
// if door is closed because back is shut:
backsector->ceilingheight <= backsector->floorheight
// preserve a kind of transparent door/lift special effect:
&& (backsector->ceilingheight >= frontsector->ceilingheight ||
curline->sidedef->toptexture)
&& (backsector->floorheight <= frontsector->floorheight ||
curline->sidedef->bottomtexture)
// properly render skies (consider door "open" if both ceilings are sky):
&& (backsector->ceilingpic !=skyflatnum ||
frontsector->ceilingpic!=skyflatnum)
)
)
linedef->r_flags = RF_CLOSED;
else
{
// Reject empty lines used for triggers
// and special events.
// Identical floor and ceiling on both sides,
// identical light levels on both sides,
// and no middle texture.
// CPhipps - recode for speed, not certain if this is portable though
if (backsector->ceilingheight != frontsector->ceilingheight
|| backsector->floorheight != frontsector->floorheight
|| curline->sidedef->midtexture
|| memcmp(&backsector->floor_xoffs, &frontsector->floor_xoffs,
sizeof(frontsector->floor_xoffs) + sizeof(frontsector->floor_yoffs) +
sizeof(frontsector->ceiling_xoffs) + sizeof(frontsector->ceiling_yoffs) +
sizeof(frontsector->ceilingpic) + sizeof(frontsector->floorpic) +
sizeof(frontsector->lightlevel) + sizeof(frontsector->floorlightsec) +
sizeof(frontsector->ceilinglightsec)))
{
linedef->r_flags = 0;
return;
}
else
linedef->r_flags = RF_IGNORE;
}
/* cph - I'm too lazy to try and work with offsets in this */
if (curline->sidedef->rowoffset)
return;
/* Now decide on texture tiling */
if (linedef->flags & ML_TWOSIDED)
{
int c;
/* Does top texture need tiling */
if ((c = frontsector->ceilingheight - backsector->ceilingheight) > 0 &&
(textureheight[texturetranslation[curline->sidedef->toptexture]] > c))
linedef->r_flags |= RF_TOP_TILE;
/* Does bottom texture need tiling */
if ((c = frontsector->floorheight - backsector->floorheight) > 0 &&
(textureheight[texturetranslation[curline->sidedef->bottomtexture]] > c))
linedef->r_flags |= RF_BOT_TILE;
}
else
{
int c;
/* Does middle texture need tiling */
if ((c = frontsector->ceilingheight - frontsector->floorheight) > 0 &&
(textureheight[texturetranslation[curline->sidedef->midtexture]] > c))
linedef->r_flags |= RF_MID_TILE;
}
}
//
// killough 3/7/98: Hack floor/ceiling heights for deep water etc.
//
// If player's view height is underneath fake floor, lower the
// drawn ceiling to be just under the floor height, and replace
// the drawn floor and ceiling textures, and light level, with
// the control sector's.
//
// Similar for ceiling, only reflected.
//
// killough 4/11/98, 4/13/98: fix bugs, add 'back' parameter
//
sector_t *R_FakeFlat(sector_t *sec, sector_t *tempsec,
int *floorlightlevel, int *ceilinglightlevel,
boolean back)
{
if (floorlightlevel)
*floorlightlevel = sec->floorlightsec == -1 ?
sec->lightlevel : sectors[sec->floorlightsec].lightlevel;
if (ceilinglightlevel)
*ceilinglightlevel = sec->ceilinglightsec == -1 ? // killough 4/11/98
sec->lightlevel : sectors[sec->ceilinglightsec].lightlevel;
if (sec->heightsec != -1)
{
const sector_t *s = &sectors[sec->heightsec];
int heightsec = viewplayer->mo->subsector->sector->heightsec;
int underwater = heightsec!=-1 && viewz<=sectors[heightsec].floorheight;
// Replace sector being drawn, with a copy to be hacked
*tempsec = *sec;
// Replace floor and ceiling height with other sector's heights.
tempsec->floorheight = s->floorheight;
tempsec->ceilingheight = s->ceilingheight;
// killough 11/98: prevent sudden light changes from non-water sectors:
if (underwater && (tempsec-> floorheight = sec->floorheight,
tempsec->ceilingheight = s->floorheight-1, !back))
{ // head-below-floor hack
tempsec->floorpic = s->floorpic;
tempsec->floor_xoffs = s->floor_xoffs;
tempsec->floor_yoffs = s->floor_yoffs;
if (underwater)
{
if (s->ceilingpic == skyflatnum)
{
tempsec->floorheight = tempsec->ceilingheight+1;
tempsec->ceilingpic = tempsec->floorpic;
tempsec->ceiling_xoffs = tempsec->floor_xoffs;
tempsec->ceiling_yoffs = tempsec->floor_yoffs;
}
else
{
tempsec->ceilingpic = s->ceilingpic;
tempsec->ceiling_xoffs = s->ceiling_xoffs;
tempsec->ceiling_yoffs = s->ceiling_yoffs;
}
}
tempsec->lightlevel = s->lightlevel;
if (floorlightlevel)
*floorlightlevel = s->floorlightsec == -1 ? s->lightlevel :
sectors[s->floorlightsec].lightlevel; // killough 3/16/98
if (ceilinglightlevel)
*ceilinglightlevel = s->ceilinglightsec == -1 ? s->lightlevel :
sectors[s->ceilinglightsec].lightlevel; // killough 4/11/98
}
else
if (heightsec != -1 && viewz >= sectors[heightsec].ceilingheight &&
sec->ceilingheight > s->ceilingheight)
{ // Above-ceiling hack
tempsec->ceilingheight = s->ceilingheight;
tempsec->floorheight = s->ceilingheight + 1;
tempsec->floorpic = tempsec->ceilingpic = s->ceilingpic;
tempsec->floor_xoffs = tempsec->ceiling_xoffs = s->ceiling_xoffs;
tempsec->floor_yoffs = tempsec->ceiling_yoffs = s->ceiling_yoffs;
if (s->floorpic != skyflatnum)
{
tempsec->ceilingheight = sec->ceilingheight;
tempsec->floorpic = s->floorpic;
tempsec->floor_xoffs = s->floor_xoffs;
tempsec->floor_yoffs = s->floor_yoffs;
}
tempsec->lightlevel = s->lightlevel;
if (floorlightlevel)
*floorlightlevel = s->floorlightsec == -1 ? s->lightlevel :
sectors[s->floorlightsec].lightlevel; // killough 3/16/98
if (ceilinglightlevel)
*ceilinglightlevel = s->ceilinglightsec == -1 ? s->lightlevel :
sectors[s->ceilinglightsec].lightlevel; // killough 4/11/98
}
sec = tempsec; // Use other sector
}
return sec;
}
//
// R_AddLine
// Clips the given segment
// and adds any visible pieces to the line list.
//
static void R_AddLine (seg_t *line)
{
int x1;
int x2;
angle_t angle1;
angle_t angle2;
angle_t span;
angle_t tspan;
static sector_t tempsec; // killough 3/8/98: ceiling/water hack
// boolean solid = true;
curline = line;
angle1 = R_PointToAngle (line->v1->x, line->v1->y);
angle2 = R_PointToAngle (line->v2->x, line->v2->y);
// Clip to view edges.
span = angle1 - angle2;
// Back side, i.e. backface culling
if (span >= ANG180)
return;
// Global angle needed by segcalc.
rw_angle1 = angle1;
angle1 -= viewangle;
angle2 -= viewangle;
tspan = angle1 + clipangle;
if (tspan > 2*clipangle)
{
tspan -= 2*clipangle;
// Totally off the left edge?
if (tspan >= span)
return;
angle1 = clipangle;
}
tspan = clipangle - angle2;
if (tspan > 2*clipangle)
{
tspan -= 2*clipangle;
// Totally off the left edge?
if (tspan >= span)
return;
angle2 = 0-clipangle;
}
// The seg is in the view range,
// but not necessarily visible.
angle1 = (angle1+ANG90)>>ANGLETOFINESHIFT;
angle2 = (angle2+ANG90)>>ANGLETOFINESHIFT;
// killough 1/31/98: Here is where "slime trails" can SOMETIMES occur:
x1 = viewangletox[angle1];
x2 = viewangletox[angle2];
// Does not cross a pixel?
if (x1 >= x2) // killough 1/31/98 -- change == to >= for robustness
return;
backsector = line->backsector;
// Single sided line?
if (backsector)
// killough 3/8/98, 4/4/98: hack for invisible ceilings / deep water
backsector = R_FakeFlat(backsector, &tempsec, NULL, NULL, true);
/* cph - roll up linedef properties in flags */
if ((linedef = curline->linedef)->r_validcount != gametic)
R_RecalcLineFlags();
if (linedef->r_flags & RF_IGNORE)
{
return;
}
else
R_ClipWallSegment (x1, x2, linedef->r_flags & RF_CLOSED);
}
//
// R_CheckBBox
// Checks BSP node/subtree bounding box.
// Returns true
// if some part of the bbox might be visible.
//
static const int checkcoord[12][4] = // killough -- static const
{
{
3,0,2,1},
{3,0,2,0},
{3,1,2,0},
{0},
{2,0,2,1},
{0,0,0,0},
{3,1,3,0},
{0},
{2,0,3,1},
{2,1,3,1},
{2,1,3,0}
};
// killough 1/28/98: static // CPhipps - const parameter, reformatted
static boolean R_CheckBBox(const fixed_t *bspcoord)
{
angle_t angle1, angle2;
{
int boxpos;
const int* check;
// Find the corners of the box
// that define the edges from current viewpoint.
boxpos = (viewx <= bspcoord[BOXLEFT] ? 0 : viewx < bspcoord[BOXRIGHT ] ? 1 : 2) +
(viewy >= bspcoord[BOXTOP ] ? 0 : viewy > bspcoord[BOXBOTTOM] ? 4 : 8);
if (boxpos == 5)
return true;
check = checkcoord[boxpos];
angle1 = R_PointToAngle (bspcoord[check[0]], bspcoord[check[1]]) - viewangle;
angle2 = R_PointToAngle (bspcoord[check[2]], bspcoord[check[3]]) - viewangle;
}
// cph - replaced old code, which was unclear and badly commented
// Much more efficient code now
if ((signed)angle1 < (signed)angle2)
{ /* it's "behind" us */
/* Either angle1 or angle2 is behind us, so it doesn't matter if we
* change it to the corect sign
*/
if ((angle1 >= ANG180) && (angle1 < ANG270))
angle1 = INT_MAX; /* which is ANG180-1 */
else
angle2 = INT_MIN;
}
if ((signed)angle2 >= (signed)clipangle)
return false; // Both off left edge
if ((signed)angle1 <= -(signed)clipangle)
return false; // Both off right edge
if ((signed)angle1 >= (signed)clipangle)
angle1 = clipangle; // Clip at left edge
if ((signed)angle2 <= -(signed)clipangle)
angle2 = 0-clipangle; // Clip at right edge
// Find the first clippost
// that touches the source post
// (adjacent pixels are touching).
angle1 = (angle1+ANG90)>>ANGLETOFINESHIFT;
angle2 = (angle2+ANG90)>>ANGLETOFINESHIFT;
{
int sx1 = viewangletox[angle1];
int sx2 = viewangletox[angle2];
// const cliprange_t *start;
// Does not cross a pixel.
if (sx1 == sx2)
return false;
if (!memchr(solidcol+sx1, 0, sx2-sx1))
return false;
// All columns it covers are already solidly covered
}
return true;
}
//
// R_Subsector
// Determine floor/ceiling planes.
// Add sprites of things in sector.
// Draw one or more line segments.
//
// killough 1/31/98 -- made static, polished
// Had to move this out of the function - causes stack overflows in RockBox
sector_t tempsec IBSS_ATTR; // killough 3/7/98: deep water hack
static void R_Subsector(int num)
{
int count;
seg_t *line;
subsector_t *sub;
int floorlightlevel; // killough 3/16/98: set floor lightlevel
int ceilinglightlevel; // killough 4/11/98
#ifdef RANGECHECK
if (num>=numsubsectors)
I_Error ("R_Subsector: ss %i with numss = %i", num, numsubsectors);
#endif
sub = &subsectors[num];
frontsector = sub->sector;
count = sub->numlines;
line = &segs[sub->firstline];
// sscount++;
// killough 3/8/98, 4/4/98: Deep water / fake ceiling effect
frontsector = R_FakeFlat(frontsector, &tempsec, &floorlightlevel,
&ceilinglightlevel, false); // killough 4/11/98
// killough 3/7/98: Add (x,y) offsets to flats, add deep water check
// killough 3/16/98: add floorlightlevel
// killough 10/98: add support for skies transferred from sidedefs
floorplane = frontsector->floorheight < viewz || // killough 3/7/98
(frontsector->heightsec != -1 &&
sectors[frontsector->heightsec].ceilingpic == skyflatnum) ?
R_FindPlane(frontsector->floorheight,
frontsector->floorpic == skyflatnum && // kilough 10/98
frontsector->sky & PL_SKYFLAT ? frontsector->sky :
frontsector->floorpic,
floorlightlevel, // killough 3/16/98
frontsector->floor_xoffs, // killough 3/7/98
frontsector->floor_yoffs
) : NULL;
ceilingplane = frontsector->ceilingheight > viewz ||
frontsector->ceilingpic == skyflatnum ||
(frontsector->heightsec != -1 &&
sectors[frontsector->heightsec].floorpic == skyflatnum) ?
R_FindPlane(frontsector->ceilingheight, // killough 3/8/98
frontsector->ceilingpic == skyflatnum && // kilough 10/98
frontsector->sky & PL_SKYFLAT ? frontsector->sky :
frontsector->ceilingpic,
ceilinglightlevel, // killough 4/11/98
frontsector->ceiling_xoffs, // killough 3/7/98
frontsector->ceiling_yoffs
) : NULL;
// killough 9/18/98: Fix underwater slowdown, by passing real sector
// instead of fake one. Improve sprite lighting by basing sprite
// lightlevels on floor & ceiling lightlevels in the surrounding area.
//
// 10/98 killough:
//
// NOTE: TeamTNT fixed this bug incorrectly, messing up sprite lighting!!!
// That is part of the 242 effect!!! If you simply pass sub->sector to
// the old code you will not get correct lighting for underwater sprites!!!
// Either you must pass the fake sector and handle validcount here, on the
// real sector, or you must account for the lighting in some other way,
// like passing it as an argument.
R_AddSprites(sub, (floorlightlevel+ceilinglightlevel)/2);
while (count--)
{
if (line->miniseg == false)
R_AddLine (line);
line++;
}
}
//
// RenderBSPNode
// Renders all subsectors below a given node,
// traversing subtree recursively.
// Just call with BSP root.
//
// killough 5/2/98: reformatted, removed tail recursion
void R_RenderBSPNode(int bspnum)
{
while (!(bspnum & NF_SUBSECTOR)) // Found a subsector?
{
const node_t *bsp = &nodes[bspnum];
// Decide which side the view point is on.
int side = R_PointOnSide(viewx, viewy, bsp);
// Recursively divide front space.
R_RenderBSPNode(bsp->children[side]);
// Possibly divide back space.
if (!R_CheckBBox(bsp->bbox[side^1]))
return;
bspnum = bsp->children[side^1];
}
R_Subsector(bspnum == -1 ? 0 : bspnum & ~NF_SUBSECTOR);
}