forked from KolibriOS/kolibrios
581 lines
11 KiB
C
Executable File
581 lines
11 KiB
C
Executable File
// Emacs style mode select -*- C++ -*-
|
|
//-----------------------------------------------------------------------------
|
|
//
|
|
// $Id:$
|
|
//
|
|
// Copyright (C) 1993-1996 by id Software, Inc.
|
|
//
|
|
// This source is available for distribution and/or modification
|
|
// only under the terms of the DOOM Source Code License as
|
|
// published by id Software. All rights reserved.
|
|
//
|
|
// The source is distributed in the hope that it will be useful,
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
// FITNESS FOR A PARTICULAR PURPOSE. See the DOOM Source Code License
|
|
// for more details.
|
|
//
|
|
// $Log:$
|
|
//
|
|
// DESCRIPTION:
|
|
// BSP traversal, handling of LineSegs for rendering.
|
|
//
|
|
//-----------------------------------------------------------------------------
|
|
|
|
|
|
static const char
|
|
rcsid[] = "$Id: r_bsp.c,v 1.4 1997/02/03 22:45:12 b1 Exp $";
|
|
|
|
|
|
#include "doomdef.h"
|
|
|
|
#include "m_bbox.h"
|
|
|
|
#include "i_system.h"
|
|
|
|
#include "r_main.h"
|
|
#include "r_plane.h"
|
|
#include "r_things.h"
|
|
|
|
// State.
|
|
#include "doomstat.h"
|
|
#include "r_state.h"
|
|
|
|
//#include "r_local.h"
|
|
|
|
|
|
|
|
seg_t* curline;
|
|
side_t* sidedef;
|
|
line_t* linedef;
|
|
sector_t* frontsector;
|
|
sector_t* backsector;
|
|
|
|
drawseg_t drawsegs[MAXDRAWSEGS];
|
|
drawseg_t* ds_p;
|
|
|
|
|
|
void
|
|
R_StoreWallRange
|
|
( int start,
|
|
int stop );
|
|
|
|
|
|
|
|
|
|
//
|
|
// R_ClearDrawSegs
|
|
//
|
|
void R_ClearDrawSegs (void)
|
|
{
|
|
ds_p = drawsegs;
|
|
}
|
|
|
|
|
|
|
|
//
|
|
// ClipWallSegment
|
|
// Clips the given range of columns
|
|
// and includes it in the new clip list.
|
|
//
|
|
typedef struct
|
|
{
|
|
int first;
|
|
int last;
|
|
|
|
} cliprange_t;
|
|
|
|
|
|
#define MAXSEGS 32
|
|
|
|
// newend is one past the last valid seg
|
|
cliprange_t* newend;
|
|
cliprange_t solidsegs[MAXSEGS];
|
|
|
|
|
|
|
|
|
|
//
|
|
// R_ClipSolidWallSegment
|
|
// Does handle solid walls,
|
|
// e.g. single sided LineDefs (middle texture)
|
|
// that entirely block the view.
|
|
//
|
|
void
|
|
R_ClipSolidWallSegment
|
|
( int first,
|
|
int last )
|
|
{
|
|
cliprange_t* next;
|
|
cliprange_t* start;
|
|
|
|
// Find the first range that touches the range
|
|
// (adjacent pixels are touching).
|
|
start = solidsegs;
|
|
while (start->last < first-1)
|
|
start++;
|
|
|
|
if (first < start->first)
|
|
{
|
|
if (last < start->first-1)
|
|
{
|
|
// Post is entirely visible (above start),
|
|
// so insert a new clippost.
|
|
R_StoreWallRange (first, last);
|
|
next = newend;
|
|
newend++;
|
|
|
|
while (next != start)
|
|
{
|
|
*next = *(next-1);
|
|
next--;
|
|
}
|
|
next->first = first;
|
|
next->last = last;
|
|
return;
|
|
}
|
|
|
|
// There is a fragment above *start.
|
|
R_StoreWallRange (first, start->first - 1);
|
|
// Now adjust the clip size.
|
|
start->first = first;
|
|
}
|
|
|
|
// Bottom contained in start?
|
|
if (last <= start->last)
|
|
return;
|
|
|
|
next = start;
|
|
while (last >= (next+1)->first-1)
|
|
{
|
|
// There is a fragment between two posts.
|
|
R_StoreWallRange (next->last + 1, (next+1)->first - 1);
|
|
next++;
|
|
|
|
if (last <= next->last)
|
|
{
|
|
// Bottom is contained in next.
|
|
// Adjust the clip size.
|
|
start->last = next->last;
|
|
goto crunch;
|
|
}
|
|
}
|
|
|
|
// There is a fragment after *next.
|
|
R_StoreWallRange (next->last + 1, last);
|
|
// Adjust the clip size.
|
|
start->last = last;
|
|
|
|
// Remove start+1 to next from the clip list,
|
|
// because start now covers their area.
|
|
crunch:
|
|
if (next == start)
|
|
{
|
|
// Post just extended past the bottom of one post.
|
|
return;
|
|
}
|
|
|
|
|
|
while (next++ != newend)
|
|
{
|
|
// Remove a post.
|
|
*++start = *next;
|
|
}
|
|
|
|
newend = start+1;
|
|
}
|
|
|
|
|
|
|
|
//
|
|
// R_ClipPassWallSegment
|
|
// Clips the given range of columns,
|
|
// but does not includes it in the clip list.
|
|
// Does handle windows,
|
|
// e.g. LineDefs with upper and lower texture.
|
|
//
|
|
void
|
|
R_ClipPassWallSegment
|
|
( int first,
|
|
int last )
|
|
{
|
|
cliprange_t* start;
|
|
|
|
// Find the first range that touches the range
|
|
// (adjacent pixels are touching).
|
|
start = solidsegs;
|
|
while (start->last < first-1)
|
|
start++;
|
|
|
|
if (first < start->first)
|
|
{
|
|
if (last < start->first-1)
|
|
{
|
|
// Post is entirely visible (above start).
|
|
R_StoreWallRange (first, last);
|
|
return;
|
|
}
|
|
|
|
// There is a fragment above *start.
|
|
R_StoreWallRange (first, start->first - 1);
|
|
}
|
|
|
|
// Bottom contained in start?
|
|
if (last <= start->last)
|
|
return;
|
|
|
|
while (last >= (start+1)->first-1)
|
|
{
|
|
// There is a fragment between two posts.
|
|
R_StoreWallRange (start->last + 1, (start+1)->first - 1);
|
|
start++;
|
|
|
|
if (last <= start->last)
|
|
return;
|
|
}
|
|
|
|
// There is a fragment after *next.
|
|
R_StoreWallRange (start->last + 1, last);
|
|
}
|
|
|
|
|
|
|
|
//
|
|
// R_ClearClipSegs
|
|
//
|
|
void R_ClearClipSegs (void)
|
|
{
|
|
solidsegs[0].first = -0x7fffffff;
|
|
solidsegs[0].last = -1;
|
|
solidsegs[1].first = viewwidth;
|
|
solidsegs[1].last = 0x7fffffff;
|
|
newend = solidsegs+2;
|
|
}
|
|
|
|
//
|
|
// R_AddLine
|
|
// Clips the given segment
|
|
// and adds any visible pieces to the line list.
|
|
//
|
|
void R_AddLine (seg_t* line)
|
|
{
|
|
int x1;
|
|
int x2;
|
|
angle_t angle1;
|
|
angle_t angle2;
|
|
angle_t span;
|
|
angle_t tspan;
|
|
|
|
curline = line;
|
|
|
|
// OPTIMIZE: quickly reject orthogonal back sides.
|
|
angle1 = R_PointToAngle (line->v1->x, line->v1->y);
|
|
angle2 = R_PointToAngle (line->v2->x, line->v2->y);
|
|
|
|
// Clip to view edges.
|
|
// OPTIMIZE: make constant out of 2*clipangle (FIELDOFVIEW).
|
|
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 = -clipangle;
|
|
}
|
|
|
|
// The seg is in the view range,
|
|
// but not necessarily visible.
|
|
angle1 = (angle1+ANG90)>>ANGLETOFINESHIFT;
|
|
angle2 = (angle2+ANG90)>>ANGLETOFINESHIFT;
|
|
x1 = viewangletox[angle1];
|
|
x2 = viewangletox[angle2];
|
|
|
|
// Does not cross a pixel?
|
|
if (x1 == x2)
|
|
return;
|
|
|
|
backsector = line->backsector;
|
|
|
|
// Single sided line?
|
|
if (!backsector)
|
|
goto clipsolid;
|
|
|
|
// Closed door.
|
|
if (backsector->ceilingheight <= frontsector->floorheight
|
|
|| backsector->floorheight >= frontsector->ceilingheight)
|
|
goto clipsolid;
|
|
|
|
// Window.
|
|
if (backsector->ceilingheight != frontsector->ceilingheight
|
|
|| backsector->floorheight != frontsector->floorheight)
|
|
goto clippass;
|
|
|
|
// 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.
|
|
if (backsector->ceilingpic == frontsector->ceilingpic
|
|
&& backsector->floorpic == frontsector->floorpic
|
|
&& backsector->lightlevel == frontsector->lightlevel
|
|
&& curline->sidedef->midtexture == 0)
|
|
{
|
|
return;
|
|
}
|
|
|
|
|
|
clippass:
|
|
R_ClipPassWallSegment (x1, x2-1);
|
|
return;
|
|
|
|
clipsolid:
|
|
R_ClipSolidWallSegment (x1, x2-1);
|
|
}
|
|
|
|
|
|
//
|
|
// R_CheckBBox
|
|
// Checks BSP node/subtree bounding box.
|
|
// Returns true
|
|
// if some part of the bbox might be visible.
|
|
//
|
|
int checkcoord[12][4] =
|
|
{
|
|
{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}
|
|
};
|
|
|
|
|
|
boolean R_CheckBBox (fixed_t* bspcoord)
|
|
{
|
|
int boxx;
|
|
int boxy;
|
|
int boxpos;
|
|
|
|
fixed_t x1;
|
|
fixed_t y1;
|
|
fixed_t x2;
|
|
fixed_t y2;
|
|
|
|
angle_t angle1;
|
|
angle_t angle2;
|
|
angle_t span;
|
|
angle_t tspan;
|
|
|
|
cliprange_t* start;
|
|
|
|
int sx1;
|
|
int sx2;
|
|
|
|
// Find the corners of the box
|
|
// that define the edges from current viewpoint.
|
|
if (viewx <= bspcoord[BOXLEFT])
|
|
boxx = 0;
|
|
else if (viewx < bspcoord[BOXRIGHT])
|
|
boxx = 1;
|
|
else
|
|
boxx = 2;
|
|
|
|
if (viewy >= bspcoord[BOXTOP])
|
|
boxy = 0;
|
|
else if (viewy > bspcoord[BOXBOTTOM])
|
|
boxy = 1;
|
|
else
|
|
boxy = 2;
|
|
|
|
boxpos = (boxy<<2)+boxx;
|
|
if (boxpos == 5)
|
|
return true;
|
|
|
|
x1 = bspcoord[checkcoord[boxpos][0]];
|
|
y1 = bspcoord[checkcoord[boxpos][1]];
|
|
x2 = bspcoord[checkcoord[boxpos][2]];
|
|
y2 = bspcoord[checkcoord[boxpos][3]];
|
|
|
|
// check clip list for an open space
|
|
angle1 = R_PointToAngle (x1, y1) - viewangle;
|
|
angle2 = R_PointToAngle (x2, y2) - viewangle;
|
|
|
|
span = angle1 - angle2;
|
|
|
|
// Sitting on a line?
|
|
if (span >= ANG180)
|
|
return true;
|
|
|
|
tspan = angle1 + clipangle;
|
|
|
|
if (tspan > 2*clipangle)
|
|
{
|
|
tspan -= 2*clipangle;
|
|
|
|
// Totally off the left edge?
|
|
if (tspan >= span)
|
|
return false;
|
|
|
|
angle1 = clipangle;
|
|
}
|
|
tspan = clipangle - angle2;
|
|
if (tspan > 2*clipangle)
|
|
{
|
|
tspan -= 2*clipangle;
|
|
|
|
// Totally off the left edge?
|
|
if (tspan >= span)
|
|
return false;
|
|
|
|
angle2 = -clipangle;
|
|
}
|
|
|
|
|
|
// Find the first clippost
|
|
// that touches the source post
|
|
// (adjacent pixels are touching).
|
|
angle1 = (angle1+ANG90)>>ANGLETOFINESHIFT;
|
|
angle2 = (angle2+ANG90)>>ANGLETOFINESHIFT;
|
|
sx1 = viewangletox[angle1];
|
|
sx2 = viewangletox[angle2];
|
|
|
|
// Does not cross a pixel.
|
|
if (sx1 == sx2)
|
|
return false;
|
|
sx2--;
|
|
|
|
start = solidsegs;
|
|
while (start->last < sx2)
|
|
start++;
|
|
|
|
if (sx1 >= start->first
|
|
&& sx2 <= start->last)
|
|
{
|
|
// The clippost contains the new span.
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
|
|
|
|
//
|
|
// R_Subsector
|
|
// Determine floor/ceiling planes.
|
|
// Add sprites of things in sector.
|
|
// Draw one or more line segments.
|
|
//
|
|
void R_Subsector (int num)
|
|
{
|
|
int count;
|
|
seg_t* line;
|
|
subsector_t* sub;
|
|
|
|
#ifdef RANGECHECK
|
|
if (num>=numsubsectors)
|
|
I_Error ("R_Subsector: ss %i with numss = %i",
|
|
num,
|
|
numsubsectors);
|
|
#endif
|
|
|
|
sscount++;
|
|
sub = &subsectors[num];
|
|
frontsector = sub->sector;
|
|
count = sub->numlines;
|
|
line = &segs[sub->firstline];
|
|
|
|
if (frontsector->floorheight < viewz)
|
|
{
|
|
floorplane = R_FindPlane (frontsector->floorheight,
|
|
frontsector->floorpic,
|
|
frontsector->lightlevel);
|
|
}
|
|
else
|
|
floorplane = NULL;
|
|
|
|
if (frontsector->ceilingheight > viewz
|
|
|| frontsector->ceilingpic == skyflatnum)
|
|
{
|
|
ceilingplane = R_FindPlane (frontsector->ceilingheight,
|
|
frontsector->ceilingpic,
|
|
frontsector->lightlevel);
|
|
}
|
|
else
|
|
ceilingplane = NULL;
|
|
|
|
R_AddSprites (frontsector);
|
|
|
|
while (count--)
|
|
{
|
|
R_AddLine (line);
|
|
line++;
|
|
}
|
|
}
|
|
|
|
|
|
|
|
|
|
//
|
|
// RenderBSPNode
|
|
// Renders all subsectors below a given node,
|
|
// traversing subtree recursively.
|
|
// Just call with BSP root.
|
|
void R_RenderBSPNode (int bspnum)
|
|
{
|
|
node_t* bsp;
|
|
int side;
|
|
|
|
// Found a subsector?
|
|
if (bspnum & NF_SUBSECTOR)
|
|
{
|
|
if (bspnum == -1)
|
|
R_Subsector (0);
|
|
else
|
|
R_Subsector (bspnum&(~NF_SUBSECTOR));
|
|
return;
|
|
}
|
|
|
|
bsp = &nodes[bspnum];
|
|
|
|
// Decide which side the view point is on.
|
|
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]))
|
|
R_RenderBSPNode (bsp->children[side^1]);
|
|
}
|
|
|
|
|