summaryrefslogtreecommitdiff
path: root/src/doom/r_segs.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/doom/r_segs.c')
-rw-r--r--src/doom/r_segs.c751
1 files changed, 751 insertions, 0 deletions
diff --git a/src/doom/r_segs.c b/src/doom/r_segs.c
new file mode 100644
index 00000000..5150b694
--- /dev/null
+++ b/src/doom/r_segs.c
@@ -0,0 +1,751 @@
+// Emacs style mode select -*- C++ -*-
+//-----------------------------------------------------------------------------
+//
+// Copyright(C) 1993-1996 Id Software, Inc.
+// Copyright(C) 2005 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.
+//
+// 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:
+// All the clipping: columns, horizontal spans, sky columns.
+//
+//-----------------------------------------------------------------------------
+
+
+
+
+
+
+
+#include <stdlib.h>
+
+#include "i_system.h"
+
+#include "doomdef.h"
+#include "doomstat.h"
+
+#include "r_local.h"
+#include "r_sky.h"
+
+
+// OPTIMIZE: closed two sided lines as single sided
+
+// True if any of the segs textures might be visible.
+boolean segtextured;
+
+// False if the back side is the same plane.
+boolean markfloor;
+boolean markceiling;
+
+boolean maskedtexture;
+int toptexture;
+int bottomtexture;
+int midtexture;
+
+
+angle_t rw_normalangle;
+// angle to line origin
+int rw_angle1;
+
+//
+// regular wall
+//
+int rw_x;
+int rw_stopx;
+angle_t rw_centerangle;
+fixed_t rw_offset;
+fixed_t rw_distance;
+fixed_t rw_scale;
+fixed_t rw_scalestep;
+fixed_t rw_midtexturemid;
+fixed_t rw_toptexturemid;
+fixed_t rw_bottomtexturemid;
+
+int worldtop;
+int worldbottom;
+int worldhigh;
+int worldlow;
+
+fixed_t pixhigh;
+fixed_t pixlow;
+fixed_t pixhighstep;
+fixed_t pixlowstep;
+
+fixed_t topfrac;
+fixed_t topstep;
+
+fixed_t bottomfrac;
+fixed_t bottomstep;
+
+
+lighttable_t** walllights;
+
+short* maskedtexturecol;
+
+
+
+//
+// R_RenderMaskedSegRange
+//
+void
+R_RenderMaskedSegRange
+( drawseg_t* ds,
+ int x1,
+ int x2 )
+{
+ unsigned index;
+ column_t* col;
+ int lightnum;
+ int texnum;
+
+ // Calculate light table.
+ // Use different light tables
+ // for horizontal / vertical / diagonal. Diagonal?
+ // OPTIMIZE: get rid of LIGHTSEGSHIFT globally
+ curline = ds->curline;
+ frontsector = curline->frontsector;
+ backsector = curline->backsector;
+ texnum = texturetranslation[curline->sidedef->midtexture];
+
+ lightnum = (frontsector->lightlevel >> LIGHTSEGSHIFT)+extralight;
+
+ if (curline->v1->y == curline->v2->y)
+ lightnum--;
+ else if (curline->v1->x == curline->v2->x)
+ lightnum++;
+
+ if (lightnum < 0)
+ walllights = scalelight[0];
+ else if (lightnum >= LIGHTLEVELS)
+ walllights = scalelight[LIGHTLEVELS-1];
+ else
+ walllights = scalelight[lightnum];
+
+ maskedtexturecol = ds->maskedtexturecol;
+
+ rw_scalestep = ds->scalestep;
+ spryscale = ds->scale1 + (x1 - ds->x1)*rw_scalestep;
+ mfloorclip = ds->sprbottomclip;
+ mceilingclip = ds->sprtopclip;
+
+ // find positioning
+ if (curline->linedef->flags & ML_DONTPEGBOTTOM)
+ {
+ dc_texturemid = frontsector->floorheight > backsector->floorheight
+ ? frontsector->floorheight : backsector->floorheight;
+ dc_texturemid = dc_texturemid + textureheight[texnum] - viewz;
+ }
+ else
+ {
+ dc_texturemid =frontsector->ceilingheight<backsector->ceilingheight
+ ? frontsector->ceilingheight : backsector->ceilingheight;
+ dc_texturemid = dc_texturemid - viewz;
+ }
+ dc_texturemid += curline->sidedef->rowoffset;
+
+ if (fixedcolormap)
+ dc_colormap = fixedcolormap;
+
+ // draw the columns
+ for (dc_x = x1 ; dc_x <= x2 ; dc_x++)
+ {
+ // calculate lighting
+ if (maskedtexturecol[dc_x] != SHRT_MAX)
+ {
+ if (!fixedcolormap)
+ {
+ index = spryscale>>LIGHTSCALESHIFT;
+
+ if (index >= MAXLIGHTSCALE )
+ index = MAXLIGHTSCALE-1;
+
+ dc_colormap = walllights[index];
+ }
+
+ sprtopscreen = centeryfrac - FixedMul(dc_texturemid, spryscale);
+ dc_iscale = 0xffffffffu / (unsigned)spryscale;
+
+ // draw the texture
+ col = (column_t *)(
+ (byte *)R_GetColumn(texnum,maskedtexturecol[dc_x]) -3);
+
+ R_DrawMaskedColumn (col);
+ maskedtexturecol[dc_x] = SHRT_MAX;
+ }
+ spryscale += rw_scalestep;
+ }
+
+}
+
+
+
+
+//
+// R_RenderSegLoop
+// Draws zero, one, or two textures (and possibly a masked
+// texture) for walls.
+// Can draw or mark the starting pixel of floor and ceiling
+// textures.
+// CALLED: CORE LOOPING ROUTINE.
+//
+#define HEIGHTBITS 12
+#define HEIGHTUNIT (1<<HEIGHTBITS)
+
+void R_RenderSegLoop (void)
+{
+ angle_t angle;
+ unsigned index;
+ int yl;
+ int yh;
+ int mid;
+ fixed_t texturecolumn;
+ int top;
+ int bottom;
+
+ for ( ; rw_x < rw_stopx ; rw_x++)
+ {
+ // mark floor / ceiling areas
+ yl = (topfrac+HEIGHTUNIT-1)>>HEIGHTBITS;
+
+ // no space above wall?
+ if (yl < ceilingclip[rw_x]+1)
+ yl = ceilingclip[rw_x]+1;
+
+ if (markceiling)
+ {
+ top = ceilingclip[rw_x]+1;
+ bottom = yl-1;
+
+ if (bottom >= floorclip[rw_x])
+ bottom = floorclip[rw_x]-1;
+
+ if (top <= bottom)
+ {
+ ceilingplane->top[rw_x] = top;
+ ceilingplane->bottom[rw_x] = bottom;
+ }
+ }
+
+ yh = bottomfrac>>HEIGHTBITS;
+
+ if (yh >= floorclip[rw_x])
+ yh = floorclip[rw_x]-1;
+
+ if (markfloor)
+ {
+ top = yh+1;
+ bottom = floorclip[rw_x]-1;
+ if (top <= ceilingclip[rw_x])
+ top = ceilingclip[rw_x]+1;
+ if (top <= bottom)
+ {
+ floorplane->top[rw_x] = top;
+ floorplane->bottom[rw_x] = bottom;
+ }
+ }
+
+ // texturecolumn and lighting are independent of wall tiers
+ if (segtextured)
+ {
+ // calculate texture offset
+ angle = (rw_centerangle + xtoviewangle[rw_x])>>ANGLETOFINESHIFT;
+ texturecolumn = rw_offset-FixedMul(finetangent[angle],rw_distance);
+ texturecolumn >>= FRACBITS;
+ // calculate lighting
+ index = rw_scale>>LIGHTSCALESHIFT;
+
+ if (index >= MAXLIGHTSCALE )
+ index = MAXLIGHTSCALE-1;
+
+ dc_colormap = walllights[index];
+ dc_x = rw_x;
+ dc_iscale = 0xffffffffu / (unsigned)rw_scale;
+ }
+ else
+ {
+ // purely to shut up the compiler
+
+ texturecolumn = 0;
+ }
+
+ // draw the wall tiers
+ if (midtexture)
+ {
+ // single sided line
+ dc_yl = yl;
+ dc_yh = yh;
+ dc_texturemid = rw_midtexturemid;
+ dc_source = R_GetColumn(midtexture,texturecolumn);
+ colfunc ();
+ ceilingclip[rw_x] = viewheight;
+ floorclip[rw_x] = -1;
+ }
+ else
+ {
+ // two sided line
+ if (toptexture)
+ {
+ // top wall
+ mid = pixhigh>>HEIGHTBITS;
+ pixhigh += pixhighstep;
+
+ if (mid >= floorclip[rw_x])
+ mid = floorclip[rw_x]-1;
+
+ if (mid >= yl)
+ {
+ dc_yl = yl;
+ dc_yh = mid;
+ dc_texturemid = rw_toptexturemid;
+ dc_source = R_GetColumn(toptexture,texturecolumn);
+ colfunc ();
+ ceilingclip[rw_x] = mid;
+ }
+ else
+ ceilingclip[rw_x] = yl-1;
+ }
+ else
+ {
+ // no top wall
+ if (markceiling)
+ ceilingclip[rw_x] = yl-1;
+ }
+
+ if (bottomtexture)
+ {
+ // bottom wall
+ mid = (pixlow+HEIGHTUNIT-1)>>HEIGHTBITS;
+ pixlow += pixlowstep;
+
+ // no space above wall?
+ if (mid <= ceilingclip[rw_x])
+ mid = ceilingclip[rw_x]+1;
+
+ if (mid <= yh)
+ {
+ dc_yl = mid;
+ dc_yh = yh;
+ dc_texturemid = rw_bottomtexturemid;
+ dc_source = R_GetColumn(bottomtexture,
+ texturecolumn);
+ colfunc ();
+ floorclip[rw_x] = mid;
+ }
+ else
+ floorclip[rw_x] = yh+1;
+ }
+ else
+ {
+ // no bottom wall
+ if (markfloor)
+ floorclip[rw_x] = yh+1;
+ }
+
+ if (maskedtexture)
+ {
+ // save texturecol
+ // for backdrawing of masked mid texture
+ maskedtexturecol[rw_x] = texturecolumn;
+ }
+ }
+
+ rw_scale += rw_scalestep;
+ topfrac += topstep;
+ bottomfrac += bottomstep;
+ }
+}
+
+
+
+
+//
+// R_StoreWallRange
+// A wall segment will be drawn
+// between start and stop pixels (inclusive).
+//
+void
+R_StoreWallRange
+( int start,
+ int stop )
+{
+ fixed_t hyp;
+ fixed_t sineval;
+ angle_t distangle, offsetangle;
+ fixed_t vtop;
+ int lightnum;
+
+ // don't overflow and crash
+ if (ds_p == &drawsegs[MAXDRAWSEGS])
+ return;
+
+#ifdef RANGECHECK
+ if (start >=viewwidth || start > stop)
+ I_Error ("Bad R_RenderWallRange: %i to %i", start , stop);
+#endif
+
+ sidedef = curline->sidedef;
+ linedef = curline->linedef;
+
+ // mark the segment as visible for auto map
+ linedef->flags |= ML_MAPPED;
+
+ // calculate rw_distance for scale calculation
+ rw_normalangle = curline->angle + ANG90;
+ offsetangle = abs(rw_normalangle-rw_angle1);
+
+ if (offsetangle > ANG90)
+ offsetangle = ANG90;
+
+ distangle = ANG90 - offsetangle;
+ hyp = R_PointToDist (curline->v1->x, curline->v1->y);
+ sineval = finesine[distangle>>ANGLETOFINESHIFT];
+ rw_distance = FixedMul (hyp, sineval);
+
+
+ ds_p->x1 = rw_x = start;
+ ds_p->x2 = stop;
+ ds_p->curline = curline;
+ rw_stopx = stop+1;
+
+ // calculate scale at both ends and step
+ ds_p->scale1 = rw_scale =
+ R_ScaleFromGlobalAngle (viewangle + xtoviewangle[start]);
+
+ if (stop > start )
+ {
+ ds_p->scale2 = R_ScaleFromGlobalAngle (viewangle + xtoviewangle[stop]);
+ ds_p->scalestep = rw_scalestep =
+ (ds_p->scale2 - rw_scale) / (stop-start);
+ }
+ else
+ {
+ // UNUSED: try to fix the stretched line bug
+#if 0
+ if (rw_distance < FRACUNIT/2)
+ {
+ fixed_t trx,try;
+ fixed_t gxt,gyt;
+
+ trx = curline->v1->x - viewx;
+ try = curline->v1->y - viewy;
+
+ gxt = FixedMul(trx,viewcos);
+ gyt = -FixedMul(try,viewsin);
+ ds_p->scale1 = FixedDiv(projection, gxt-gyt)<<detailshift;
+ }
+#endif
+ ds_p->scale2 = ds_p->scale1;
+ }
+
+ // calculate texture boundaries
+ // and decide if floor / ceiling marks are needed
+ worldtop = frontsector->ceilingheight - viewz;
+ worldbottom = frontsector->floorheight - viewz;
+
+ midtexture = toptexture = bottomtexture = maskedtexture = 0;
+ ds_p->maskedtexturecol = NULL;
+
+ if (!backsector)
+ {
+ // single sided line
+ midtexture = texturetranslation[sidedef->midtexture];
+ // a single sided line is terminal, so it must mark ends
+ markfloor = markceiling = true;
+ if (linedef->flags & ML_DONTPEGBOTTOM)
+ {
+ vtop = frontsector->floorheight +
+ textureheight[sidedef->midtexture];
+ // bottom of texture at bottom
+ rw_midtexturemid = vtop - viewz;
+ }
+ else
+ {
+ // top of texture at top
+ rw_midtexturemid = worldtop;
+ }
+ rw_midtexturemid += sidedef->rowoffset;
+
+ ds_p->silhouette = SIL_BOTH;
+ ds_p->sprtopclip = screenheightarray;
+ ds_p->sprbottomclip = negonearray;
+ ds_p->bsilheight = INT_MAX;
+ ds_p->tsilheight = INT_MIN;
+ }
+ else
+ {
+ // two sided line
+ ds_p->sprtopclip = ds_p->sprbottomclip = NULL;
+ ds_p->silhouette = 0;
+
+ if (frontsector->floorheight > backsector->floorheight)
+ {
+ ds_p->silhouette = SIL_BOTTOM;
+ ds_p->bsilheight = frontsector->floorheight;
+ }
+ else if (backsector->floorheight > viewz)
+ {
+ ds_p->silhouette = SIL_BOTTOM;
+ ds_p->bsilheight = INT_MAX;
+ // ds_p->sprbottomclip = negonearray;
+ }
+
+ if (frontsector->ceilingheight < backsector->ceilingheight)
+ {
+ ds_p->silhouette |= SIL_TOP;
+ ds_p->tsilheight = frontsector->ceilingheight;
+ }
+ else if (backsector->ceilingheight < viewz)
+ {
+ ds_p->silhouette |= SIL_TOP;
+ ds_p->tsilheight = INT_MIN;
+ // ds_p->sprtopclip = screenheightarray;
+ }
+
+ if (backsector->ceilingheight <= frontsector->floorheight)
+ {
+ ds_p->sprbottomclip = negonearray;
+ ds_p->bsilheight = INT_MAX;
+ ds_p->silhouette |= SIL_BOTTOM;
+ }
+
+ if (backsector->floorheight >= frontsector->ceilingheight)
+ {
+ ds_p->sprtopclip = screenheightarray;
+ ds_p->tsilheight = INT_MIN;
+ ds_p->silhouette |= SIL_TOP;
+ }
+
+ worldhigh = backsector->ceilingheight - viewz;
+ worldlow = backsector->floorheight - viewz;
+
+ // hack to allow height changes in outdoor areas
+ if (frontsector->ceilingpic == skyflatnum
+ && backsector->ceilingpic == skyflatnum)
+ {
+ worldtop = worldhigh;
+ }
+
+
+ if (worldlow != worldbottom
+ || backsector->floorpic != frontsector->floorpic
+ || backsector->lightlevel != frontsector->lightlevel)
+ {
+ markfloor = true;
+ }
+ else
+ {
+ // same plane on both sides
+ markfloor = false;
+ }
+
+
+ if (worldhigh != worldtop
+ || backsector->ceilingpic != frontsector->ceilingpic
+ || backsector->lightlevel != frontsector->lightlevel)
+ {
+ markceiling = true;
+ }
+ else
+ {
+ // same plane on both sides
+ markceiling = false;
+ }
+
+ if (backsector->ceilingheight <= frontsector->floorheight
+ || backsector->floorheight >= frontsector->ceilingheight)
+ {
+ // closed door
+ markceiling = markfloor = true;
+ }
+
+
+ if (worldhigh < worldtop)
+ {
+ // top texture
+ toptexture = texturetranslation[sidedef->toptexture];
+ if (linedef->flags & ML_DONTPEGTOP)
+ {
+ // top of texture at top
+ rw_toptexturemid = worldtop;
+ }
+ else
+ {
+ vtop =
+ backsector->ceilingheight
+ + textureheight[sidedef->toptexture];
+
+ // bottom of texture
+ rw_toptexturemid = vtop - viewz;
+ }
+ }
+ if (worldlow > worldbottom)
+ {
+ // bottom texture
+ bottomtexture = texturetranslation[sidedef->bottomtexture];
+
+ if (linedef->flags & ML_DONTPEGBOTTOM )
+ {
+ // bottom of texture at bottom
+ // top of texture at top
+ rw_bottomtexturemid = worldtop;
+ }
+ else // top of texture at top
+ rw_bottomtexturemid = worldlow;
+ }
+ rw_toptexturemid += sidedef->rowoffset;
+ rw_bottomtexturemid += sidedef->rowoffset;
+
+ // allocate space for masked texture tables
+ if (sidedef->midtexture)
+ {
+ // masked midtexture
+ maskedtexture = true;
+ ds_p->maskedtexturecol = maskedtexturecol = lastopening - rw_x;
+ lastopening += rw_stopx - rw_x;
+ }
+ }
+
+ // calculate rw_offset (only needed for textured lines)
+ segtextured = midtexture | toptexture | bottomtexture | maskedtexture;
+
+ if (segtextured)
+ {
+ offsetangle = rw_normalangle-rw_angle1;
+
+ if (offsetangle > ANG180)
+ offsetangle = -offsetangle;
+
+ if (offsetangle > ANG90)
+ offsetangle = ANG90;
+
+ sineval = finesine[offsetangle >>ANGLETOFINESHIFT];
+ rw_offset = FixedMul (hyp, sineval);
+
+ if (rw_normalangle-rw_angle1 < ANG180)
+ rw_offset = -rw_offset;
+
+ rw_offset += sidedef->textureoffset + curline->offset;
+ rw_centerangle = ANG90 + viewangle - rw_normalangle;
+
+ // calculate light table
+ // use different light tables
+ // for horizontal / vertical / diagonal
+ // OPTIMIZE: get rid of LIGHTSEGSHIFT globally
+ if (!fixedcolormap)
+ {
+ lightnum = (frontsector->lightlevel >> LIGHTSEGSHIFT)+extralight;
+
+ if (curline->v1->y == curline->v2->y)
+ lightnum--;
+ else if (curline->v1->x == curline->v2->x)
+ lightnum++;
+
+ if (lightnum < 0)
+ walllights = scalelight[0];
+ else if (lightnum >= LIGHTLEVELS)
+ walllights = scalelight[LIGHTLEVELS-1];
+ else
+ walllights = scalelight[lightnum];
+ }
+ }
+
+ // if a floor / ceiling plane is on the wrong side
+ // of the view plane, it is definitely invisible
+ // and doesn't need to be marked.
+
+
+ if (frontsector->floorheight >= viewz)
+ {
+ // above view plane
+ markfloor = false;
+ }
+
+ if (frontsector->ceilingheight <= viewz
+ && frontsector->ceilingpic != skyflatnum)
+ {
+ // below view plane
+ markceiling = false;
+ }
+
+
+ // calculate incremental stepping values for texture edges
+ worldtop >>= 4;
+ worldbottom >>= 4;
+
+ topstep = -FixedMul (rw_scalestep, worldtop);
+ topfrac = (centeryfrac>>4) - FixedMul (worldtop, rw_scale);
+
+ bottomstep = -FixedMul (rw_scalestep,worldbottom);
+ bottomfrac = (centeryfrac>>4) - FixedMul (worldbottom, rw_scale);
+
+ if (backsector)
+ {
+ worldhigh >>= 4;
+ worldlow >>= 4;
+
+ if (worldhigh < worldtop)
+ {
+ pixhigh = (centeryfrac>>4) - FixedMul (worldhigh, rw_scale);
+ pixhighstep = -FixedMul (rw_scalestep,worldhigh);
+ }
+
+ if (worldlow > worldbottom)
+ {
+ pixlow = (centeryfrac>>4) - FixedMul (worldlow, rw_scale);
+ pixlowstep = -FixedMul (rw_scalestep,worldlow);
+ }
+ }
+
+ // render it
+ if (markceiling)
+ ceilingplane = R_CheckPlane (ceilingplane, rw_x, rw_stopx-1);
+
+ if (markfloor)
+ floorplane = R_CheckPlane (floorplane, rw_x, rw_stopx-1);
+
+ R_RenderSegLoop ();
+
+
+ // save sprite clipping info
+ if ( ((ds_p->silhouette & SIL_TOP) || maskedtexture)
+ && !ds_p->sprtopclip)
+ {
+ memcpy (lastopening, ceilingclip+start, 2*(rw_stopx-start));
+ ds_p->sprtopclip = lastopening - start;
+ lastopening += rw_stopx - start;
+ }
+
+ if ( ((ds_p->silhouette & SIL_BOTTOM) || maskedtexture)
+ && !ds_p->sprbottomclip)
+ {
+ memcpy (lastopening, floorclip+start, 2*(rw_stopx-start));
+ ds_p->sprbottomclip = lastopening - start;
+ lastopening += rw_stopx - start;
+ }
+
+ if (maskedtexture && !(ds_p->silhouette&SIL_TOP))
+ {
+ ds_p->silhouette |= SIL_TOP;
+ ds_p->tsilheight = INT_MIN;
+ }
+ if (maskedtexture && !(ds_p->silhouette&SIL_BOTTOM))
+ {
+ ds_p->silhouette |= SIL_BOTTOM;
+ ds_p->bsilheight = INT_MAX;
+ }
+ ds_p++;
+}
+