void R_AddLine (seg_t *line)
{
int x1, x2;
angle_t angle1, angle2, span, tspan;
#ifdef __NeXT__
RD_DrawLineCheck (line);
#endif
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;
if (span >= ANG180)
return; // back side
rw_angle1 = angle1; // global angle needed by segcalc
angle1 -= viewangle;
angle2 -= viewangle;
tspan = angle1 + clipangle;
if (tspan > 2*clipangle)
{
tspan -= 2*clipangle;
if (tspan >= span)
return; // totally off the left edge
angle1 = clipangle;
}
tspan = clipangle - angle2;
if (tspan > 2*clipangle)
{
tspan -= 2*clipangle;
if (tspan >= span)
return; // totally off the left edge
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];
if (x1 == x2)
return; // does not cross a pixel
backsector = line->backsector;
if (!backsector)
goto clipsolid; // single sided line
if (backsector->ceilingheight <= frontsector->floorheight
|| backsector->floorheight >= frontsector->ceilingheight)
goto clipsolid; // closed door
if (backsector->ceilingheight != frontsector->ceilingheight
|| backsector->floorheight != frontsector->floorheight)
goto clippass; // window
// reject empty lines used for triggers and special events
if (backsector->ceilingpic == frontsector->ceilingpic
&& backsector->floorpic == frontsector->floorpic
&& backsector->lightlevel == frontsector->lightlevel
&& backsector->special == frontsector->special
&& curline->sidedef->midtexture == 0)
return;
clippass:
R_ClipPassWallSegment (x1, x2-1);
return;
clipsolid:
R_ClipSolidWallSegment (x1, x2-1);
}
//
// R_AddLine
// Clips the given segment and adds any visible pieces to the line list.
//
static void R_AddLine(seg_t *line)
{
INT32 x1, x2;
angle_t angle1, angle2, span, tspan;
static sector_t tempsec; // ceiling/water hack
if (line->polyseg && !(line->polyseg->flags & POF_RENDERSIDES))
return;
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.
span = angle1 - angle2;
// Back side? i.e. backface culling?
if (span >= ANGLE_180)
return;
// Global angle needed by segcalc.
rw_angle1 = angle1;
angle1 -= viewangle;
angle2 -= viewangle;
tspan = angle1 + clipangle;
if (tspan > doubleclipangle)
{
tspan -= doubleclipangle;
// Totally off the left edge?
if (tspan >= span)
return;
angle1 = clipangle;
}
tspan = clipangle - angle2;
if (tspan > doubleclipangle)
{
tspan -= doubleclipangle;
// Totally off the left edge?
if (tspan >= span)
return;
angle2 = -(signed)clipangle;
}
// The seg is in the view range, but not necessarily visible.
angle1 = (angle1+ANGLE_90)>>ANGLETOFINESHIFT;
angle2 = (angle2+ANGLE_90)>>ANGLETOFINESHIFT;
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;
// Portal line
if (line->linedef->special == 40 && P_PointOnLineSide(viewx, viewy, line->linedef) == 0)
{
if (portalrender < cv_maxportals.value)
{
// Find the other side!
INT32 line2 = P_FindSpecialLineFromTag(40, line->linedef->tag, -1);
if (line->linedef == &lines[line2])
line2 = P_FindSpecialLineFromTag(40, line->linedef->tag, line2);
if (line2 >= 0) // found it!
{
R_AddPortal(line->linedef-lines, line2, x1, x2); // Remember the lines for later rendering
//return; // Don't fill in that space now!
goto clipsolid;
}
}
// Recursed TOO FAR (viewing a portal within a portal)
// So uhhh, render it as a normal wall instead or something ???
}
// Single sided line?
if (!backsector)
goto clipsolid;
backsector = R_FakeFlat(backsector, &tempsec, NULL, NULL, true);
doorclosed = 0;
// Closed door.
#ifdef ESLOPE
// Just don't bother checking this if one side is sloped. This is probably inefficient, but it's better than
// random renderer stopping around slopes...
if (!(frontsector->f_slope || frontsector->c_slope || backsector->f_slope || backsector->c_slope))
#endif
if (backsector->ceilingheight <= frontsector->floorheight
|| backsector->floorheight >= frontsector->ceilingheight)
{
goto clipsolid;
}
// Check for automap fix. Store in doorclosed for r_segs.c
doorclosed = R_DoorClosed();
if (doorclosed)
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 (
#ifdef POLYOBJECTS
!line->polyseg &&
#endif
backsector->ceilingpic == frontsector->ceilingpic
&& backsector->floorpic == frontsector->floorpic
#ifdef ESLOPE
&& backsector->f_slope == frontsector->f_slope
&& backsector->c_slope == frontsector->c_slope
#endif
&& backsector->lightlevel == frontsector->lightlevel
&& !curline->sidedef->midtexture
// Check offsets too!
&& backsector->floor_xoffs == frontsector->floor_xoffs
&& backsector->floor_yoffs == frontsector->floor_yoffs
&& backsector->floorpic_angle == frontsector->floorpic_angle
&& backsector->ceiling_xoffs == frontsector->ceiling_xoffs
&& backsector->ceiling_yoffs == frontsector->ceiling_yoffs
&& backsector->ceilingpic_angle == frontsector->ceilingpic_angle
// Consider altered lighting.
&& backsector->floorlightsec == frontsector->floorlightsec
&& backsector->ceilinglightsec == frontsector->ceilinglightsec
// Consider colormaps
&& backsector->extra_colormap == frontsector->extra_colormap
&& ((!frontsector->ffloors && !backsector->ffloors)
|| frontsector->tag == backsector->tag))
{
return;
}
clippass:
R_ClipPassWallSegment(x1, x2 - 1);
return;
clipsolid:
R_ClipSolidWallSegment(x1, x2 - 1);
}
//
// 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.
// [crispy] remove slime trails
angle1 = R_PointToAngle (line->v1->px, line->v1->py);
angle2 = R_PointToAngle (line->v2->px, line->v2->py);
// 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;
// [AM] Interpolate sector movement before
// running clipping tests. Frontsector
// should already be interpolated.
R_MaybeInterpolateSector(backsector);
// Closed door.
if (backsector->interpceilingheight <= frontsector->interpfloorheight
|| backsector->interpfloorheight >= frontsector->interpceilingheight)
goto clipsolid;
// Window.
if (backsector->interpceilingheight != frontsector->interpceilingheight
|| backsector->interpfloorheight != frontsector->interpfloorheight)
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_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;
static sector_t tempsec; // killough 3/8/98: ceiling/water hack
curline = line;
// [RH] Color if not texturing line
dc_color = ((line - segs) & 31) * 4;
// 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)
{
// Totally off the left edge?
if (tspan - 2*clipangle >= span)
return;
angle1 = clipangle;
}
tspan = clipangle - angle2;
if (tspan > 2*clipangle)
{
// Totally off the left edge?
if (tspan - 2*clipangle >= span)
return;
angle2 = (unsigned) (-(int)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)
goto clipsolid;
// killough 3/8/98, 4/4/98: hack for invisible ceilings / deep water
backsector = R_FakeFlat (backsector, &tempsec, NULL, NULL, true);
doorclosed = 0; // killough 4/16/98
// Closed door.
if (backsector->ceilingheight <= frontsector->floorheight
|| backsector->floorheight >= frontsector->ceilingheight)
goto clipsolid;
// This fixes the automap floor height bug -- killough 1/18/98:
// killough 4/7/98: optimize: save result in doorclosed for use in r_segs.c
if ((doorclosed = R_DoorClosed()))
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->lightlevel == frontsector->lightlevel
&& backsector->floorpic == frontsector->floorpic
&& backsector->ceilingpic == frontsector->ceilingpic
&& curline->sidedef->midtexture == 0
// killough 3/7/98: Take flats offsets into account:
&& backsector->floor_xoffs == frontsector->floor_xoffs
&& (backsector->floor_yoffs + backsector->base_floor_yoffs) == (frontsector->floor_yoffs + backsector->base_floor_yoffs)
&& backsector->ceiling_xoffs == frontsector->ceiling_xoffs
&& (backsector->ceiling_yoffs + backsector->base_ceiling_yoffs) == (frontsector->ceiling_yoffs + frontsector->base_ceiling_yoffs)
// killough 4/16/98: consider altered lighting
&& backsector->floorlightsec == frontsector->floorlightsec
&& backsector->ceilinglightsec == frontsector->ceilinglightsec
// [RH] Also consider colormaps
&& backsector->floorcolormap == frontsector->floorcolormap
&& backsector->ceilingcolormap == frontsector->ceilingcolormap
// [RH] and scaling
&& backsector->floor_xscale == frontsector->floor_xscale
&& backsector->floor_yscale == frontsector->floor_yscale
&& backsector->ceiling_xscale == frontsector->ceiling_xscale
&& backsector->ceiling_yscale == frontsector->ceiling_yscale
// [RH] and rotation
&& (backsector->floor_angle + backsector->base_floor_angle) == (frontsector->floor_angle + frontsector->base_floor_angle)
&& (backsector->ceiling_angle + backsector->base_ceiling_angle) == (frontsector->ceiling_angle + frontsector->base_ceiling_angle)
)
{
return;
}
clippass:
R_ClipPassWallSegment (x1, x2-1);
return;
clipsolid:
R_ClipSolidWallSegment (x1, x2-1);
}
//
// 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
curline = line;
angle1 = R_PointToAngleEx(line->v1->x, line->v1->y);
angle2 = R_PointToAngleEx(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.
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)
return;
backsector = line->backsector;
// Single sided line?
if (!backsector)
goto clipsolid;
// [AM] Interpolate sector movement before
// running clipping tests. Frontsector
// should already be interpolated.
R_MaybeInterpolateSector(backsector);
// killough 3/8/98, 4/4/98: hack for invisible ceilings / deep water
backsector = R_FakeFlat(backsector, &tempsec, NULL, NULL, true);
doorclosed = false; // killough 4/16/98
// Closed door.
if (backsector->interpceilingheight <= frontsector->interpfloorheight
|| backsector->interpfloorheight >= frontsector->interpceilingheight)
goto clipsolid;
// This fixes the automap floor height bug -- killough 1/18/98:
// killough 4/7/98: optimize: save result in doorclosed for use in r_segs.c
if ((doorclosed = R_DoorClosed()))
goto clipsolid;
// Window.
if (backsector->interpceilingheight != frontsector->interpceilingheight
|| backsector->interpfloorheight != frontsector->interpfloorheight)
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
// killough 3/7/98: Take flats offsets into account:
&& backsector->floor_xoffs == frontsector->floor_xoffs
&& backsector->floor_yoffs == frontsector->floor_yoffs
&& backsector->ceiling_xoffs == frontsector->ceiling_xoffs
&& backsector->ceiling_yoffs == frontsector->ceiling_yoffs
// killough 4/16/98: consider altered lighting
&& backsector->floorlightsec == frontsector->floorlightsec
&& backsector->ceilinglightsec == frontsector->ceilinglightsec)
return;
clippass:
R_ClipPassWallSegment(x1, x2 - 1);
return;
clipsolid:
R_ClipSolidWallSegment(x1, x2 - 1);
}
//
// 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;
static sector_t tempsec; // killough 3/8/98: ceiling/water hack
curline = line;
// [RH] Color if not texturing line
dc_color = ((line - segs) & 31) * 4;
// 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)
{
// Totally off the left edge?
if (tspan - 2*clipangle >= span)
return;
angle1 = clipangle;
}
tspan = clipangle - angle2;
if (tspan > 2*clipangle)
{
// Totally off the left edge?
if (tspan - 2*clipangle >= span)
return;
angle2 = (unsigned) (-(int)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;
rw_start = x1;
rw_stop = x2 - 1;
rw_frontcz1 = P_CeilingHeight(line->v1->x, line->v1->y, frontsector);
rw_frontfz1 = P_FloorHeight(line->v1->x, line->v1->y, frontsector);
rw_frontcz2 = P_CeilingHeight(line->v2->x, line->v2->y, frontsector);
rw_frontfz2 = P_FloorHeight(line->v2->x, line->v2->y, frontsector);
backsector = line->backsector;
// Single sided line?
if (!backsector)
goto clipsolid;
// killough 3/8/98, 4/4/98: hack for invisible ceilings / deep water
backsector = R_FakeFlat (backsector, &tempsec, NULL, NULL, true);
rw_backcz1 = P_CeilingHeight(line->v1->x, line->v1->y, backsector);
rw_backfz1 = P_FloorHeight(line->v1->x, line->v1->y, backsector);
rw_backcz2 = P_CeilingHeight(line->v2->x, line->v2->y, backsector);
rw_backfz2 = P_FloorHeight(line->v2->x, line->v2->y, backsector);
// [SL] Check for closed doors or other scenarios that would make this
// line seg solid.
//
// This fixes the automap floor height bug -- killough 1/18/98:
// killough 4/7/98: optimize: save result in doorclosed for use in r_segs.c
if (!(line->linedef->flags & ML_TWOSIDED) ||
(rw_backcz1 <= rw_frontfz1 && rw_backcz2 <= rw_frontfz2) ||
(rw_backfz1 >= rw_frontcz1 && rw_backfz2 >= rw_frontcz2) ||
// handle a case where the backsector slopes one direction
// and the frontsector slopes the opposite:
(rw_backcz1 <= rw_frontfz1 && rw_backfz1 >= rw_frontcz1) ||
(rw_backcz2 <= rw_frontfz2 && rw_backfz2 >= rw_frontcz2) ||
// if door is closed because back is shut:
((rw_backcz1 <= rw_backfz1 && rw_backcz2 <= rw_backfz2) &&
// preserve a kind of transparent door/lift special effect:
((rw_backcz1 >= rw_frontcz1 && rw_backcz2 >= rw_frontcz2) ||
line->sidedef->toptexture) &&
((rw_backfz1 <= rw_frontfz1 && rw_backfz2 <= rw_frontfz2) ||
line->sidedef->bottomtexture) &&
// properly render skies (consider door "open" if both ceilings are sky):
(backsector->ceilingpic !=skyflatnum ||
frontsector->ceilingpic!=skyflatnum)))
{
doorclosed = true;
goto clipsolid;
}
else
{
doorclosed = false;
}
// Window.
if (!P_IdenticalPlanes(&frontsector->ceilingplane, &backsector->ceilingplane) ||
!P_IdenticalPlanes(&frontsector->floorplane, &backsector->floorplane))
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->lightlevel == frontsector->lightlevel
&& backsector->floorpic == frontsector->floorpic
&& backsector->ceilingpic == frontsector->ceilingpic
&& curline->sidedef->midtexture == 0
// killough 3/7/98: Take flats offsets into account:
&& backsector->floor_xoffs == frontsector->floor_xoffs
&& (backsector->floor_yoffs + backsector->base_floor_yoffs) == (frontsector->floor_yoffs + backsector->base_floor_yoffs)
&& backsector->ceiling_xoffs == frontsector->ceiling_xoffs
&& (backsector->ceiling_yoffs + backsector->base_ceiling_yoffs) == (frontsector->ceiling_yoffs + frontsector->base_ceiling_yoffs)
// killough 4/16/98: consider altered lighting
&& backsector->floorlightsec == frontsector->floorlightsec
&& backsector->ceilinglightsec == frontsector->ceilinglightsec
// [RH] Also consider colormaps
&& backsector->floorcolormap == frontsector->floorcolormap
&& backsector->ceilingcolormap == frontsector->ceilingcolormap
// [RH] and scaling
&& backsector->floor_xscale == frontsector->floor_xscale
&& backsector->floor_yscale == frontsector->floor_yscale
&& backsector->ceiling_xscale == frontsector->ceiling_xscale
&& backsector->ceiling_yscale == frontsector->ceiling_yscale
// [RH] and rotation
&& (backsector->floor_angle + backsector->base_floor_angle) == (frontsector->floor_angle + frontsector->base_floor_angle)
&& (backsector->ceiling_angle + backsector->base_ceiling_angle) == (frontsector->ceiling_angle + frontsector->base_ceiling_angle)
)
{
return;
}
clippass:
R_ClipPassWallSegment (x1, x2-1);
return;
clipsolid:
R_ClipSolidWallSegment (x1, x2-1);
}
//
// R_AddLine
// Clips the given segment
// and adds any visible pieces to the line list.
//
void R_AddLine(seg_t* line, vector<SegInfo>& segInfo, int parentIdx)
{
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 = -static_cast<int>(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:
AddSegInfo(line, segInfo, parentIdx);
R_ClipPassWallSegment(x1, x2 - 1);
return;
clipsolid:
AddSegInfo(line, segInfo, parentIdx);
R_ClipSolidWallSegment(x1, x2 - 1);
}
