ref: 290c921d1d01119b7d4550770da06c491508508f
dir: /sys/src/games/doom/r_plane.c/
// 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: // Here is a core component: drawing the floors and ceilings, // while maintaining a per column clipping list only. // Moreover, the sky areas have to be determined. // //----------------------------------------------------------------------------- static const char rcsid[] = "$Id: r_plane.c,v 1.4 1997/02/03 16:47:55 b1 Exp $"; #include "i_system.h" #include "z_zone.h" #include "w_wad.h" #include "doomdef.h" #include "doomstat.h" #include "r_local.h" #include "r_sky.h" planefunction_t floorfunc; planefunction_t ceilingfunc; // // opening // // Here comes the obnoxious "visplane". #define MAXVISPLANES 128 visplane_t visplanes[MAXVISPLANES]; visplane_t* lastvisplane; visplane_t* floorplane; visplane_t* ceilingplane; // ? #define MAXOPENINGS SCREENWIDTH*64 short openings[MAXOPENINGS]; short* lastopening; // // Clip values are the solid pixel bounding the range. // floorclip starts out SCREENHEIGHT // ceilingclip starts out -1 // short floorclip[SCREENWIDTH]; short ceilingclip[SCREENWIDTH]; // // spanstart holds the start of a plane span // initialized to 0 at start // 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; fixed_t baseyscale; fixed_t cachedheight[SCREENHEIGHT]; fixed_t cacheddistance[SCREENHEIGHT]; fixed_t cachedxstep[SCREENHEIGHT]; fixed_t cachedystep[SCREENHEIGHT]; // // R_InitPlanes // Only at game startup. // void R_InitPlanes (void) { // Doh! } // // R_MapPlane // // Uses global vars: // planeheight // ds_source // basexscale // baseyscale // viewx // viewy // // BASIC PRIMITIVE // void R_MapPlane ( int y, int x1, int x2 ) { angle_t angle; fixed_t distance; fixed_t 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; // high or low detail spanfunc (); } // // R_ClearPlanes // At begining of 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)); // left to right mapping angle = (viewangle-ANG90)>>ANGLETOFINESHIFT; // 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 ) { visplane_t* check; if (picnum == skyflatnum) { height = 0; // all skys map together lightlevel = 0; } for (check=visplanes; check<lastvisplane; check++) { if (height == check->height && picnum == check->picnum && lightlevel == check->lightlevel) { 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->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; int intrh; int unionl; int 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; // use the same one return pl; } // make a new visplane lastvisplane->height = pl->height; lastvisplane->picnum = pl->picnum; lastvisplane->lightlevel = pl->lightlevel; 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 // At the end of each frame. // void R_DrawPlanes (void) { visplane_t* pl; int light; int x; int stop; int angle; #ifdef RANGECHECK if (ds_p - drawsegs > MAXDRAWSEGS) I_Error ("R_DrawPlanes: drawsegs overflow (%i)", ds_p - drawsegs); if (lastvisplane - visplanes > MAXVISPLANES) I_Error ("R_DrawPlanes: visplane overflow (%i)", lastvisplane - visplanes); if (lastopening - openings > MAXOPENINGS) I_Error ("R_DrawPlanes: opening overflow (%i)", lastopening - openings); #endif for (pl = visplanes ; pl < lastvisplane ; pl++) { if (pl->minx > pl->maxx) continue; // sky flat if (pl->picnum == skyflatnum) { dc_iscale = pspriteiscale>>detailshift; // Sky is allways drawn full bright, // i.e. colormaps[0] is used. // Because of this hack, sky is not affected // by INVUL inverse mapping. dc_colormap = colormaps; dc_texturemid = skytexturemid; for (x=pl->minx ; x <= pl->maxx ; x++) { dc_yl = pl->top[x]; dc_yh = pl->bottom[x]; if (dc_yl <= dc_yh) { angle = (viewangle + xtoviewangle[x])>>ANGLETOSKYSHIFT; dc_x = x; dc_source = R_GetColumn(skytexture, angle); colfunc (); } } continue; } // regular flat ds_source = W_CacheLumpNum(firstflat + flattranslation[pl->picnum], PU_STATIC); 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]); } Z_ChangeTag (ds_source, PU_CACHE); } }