ref: 0d4b3504cc557b5ded1180e2fd00cd210c1024d7
dir: /u/gl_mesh.c/
/*
Copyright (C) 1996-1997 Id Software, Inc.
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.
*/
// gl_mesh.c: triangle model functions
#include "quakedef.h"
/*
=================================================================
ALIAS MODEL DISPLAY LIST GENERATION
=================================================================
*/
model_t *aliasmodel;
aliashdr_t *paliashdr;
qboolean used[8192];
// the command list holds counts and s/t values that are valid for
// every frame
int commands[8192];
int numcommands;
// all frames will have their vertexes rearranged and expanded
// so they are in the order expected by the command list
int vertexorder[8192];
int numorder;
int allverts, alltris;
int stripverts[128];
int striptris[128];
int stripcount;
/*
================
StripLength
================
*/
int StripLength (int starttri, int startv)
{
int m1, m2;
int j;
mtriangle_t *last, *check;
int k;
used[starttri] = 2;
last = &triangles[starttri];
stripverts[0] = last->vertindex[(startv)%3];
stripverts[1] = last->vertindex[(startv+1)%3];
stripverts[2] = last->vertindex[(startv+2)%3];
striptris[0] = starttri;
stripcount = 1;
m1 = last->vertindex[(startv+2)%3];
m2 = last->vertindex[(startv+1)%3];
// look for a matching triangle
nexttri:
for (j=starttri+1, check=&triangles[starttri+1] ; j<pheader->numtris ; j++, check++)
{
if (check->facesfront != last->facesfront)
continue;
for (k=0 ; k<3 ; k++)
{
if (check->vertindex[k] != m1)
continue;
if (check->vertindex[ (k+1)%3 ] != m2)
continue;
// this is the next part of the fan
// if we can't use this triangle, this tristrip is done
if (used[j])
goto done;
// the new edge
if (stripcount & 1)
m2 = check->vertindex[ (k+2)%3 ];
else
m1 = check->vertindex[ (k+2)%3 ];
stripverts[stripcount+2] = check->vertindex[ (k+2)%3 ];
striptris[stripcount] = j;
stripcount++;
used[j] = 2;
goto nexttri;
}
}
done:
// clear the temp used flags
for (j=starttri+1 ; j<pheader->numtris ; j++)
if (used[j] == 2)
used[j] = 0;
return stripcount;
}
/*
===========
FanLength
===========
*/
int FanLength (int starttri, int startv)
{
int m1, m2;
int j;
mtriangle_t *last, *check;
int k;
used[starttri] = 2;
last = &triangles[starttri];
stripverts[0] = last->vertindex[(startv)%3];
stripverts[1] = last->vertindex[(startv+1)%3];
stripverts[2] = last->vertindex[(startv+2)%3];
striptris[0] = starttri;
stripcount = 1;
m1 = last->vertindex[(startv+0)%3];
m2 = last->vertindex[(startv+2)%3];
// look for a matching triangle
nexttri:
for (j=starttri+1, check=&triangles[starttri+1] ; j<pheader->numtris ; j++, check++)
{
if (check->facesfront != last->facesfront)
continue;
for (k=0 ; k<3 ; k++)
{
if (check->vertindex[k] != m1)
continue;
if (check->vertindex[ (k+1)%3 ] != m2)
continue;
// this is the next part of the fan
// if we can't use this triangle, this tristrip is done
if (used[j])
goto done;
// the new edge
m2 = check->vertindex[ (k+2)%3 ];
stripverts[stripcount+2] = m2;
striptris[stripcount] = j;
stripcount++;
used[j] = 2;
goto nexttri;
}
}
done:
// clear the temp used flags
for (j=starttri+1 ; j<pheader->numtris ; j++)
if (used[j] == 2)
used[j] = 0;
return stripcount;
}
/*
================
BuildTris
Generate a list of trifans or strips
for the model, which holds for all frames
================
*/
void BuildTris (void)
{
int i, j, k;
int startv;
mtriangle_t *last, *check;
int m1, m2;
int striplength;
trivertx_t *v;
mtriangle_t *tv;
float s, t;
int index;
int len, bestlen, besttype;
int bestverts[1024];
int besttris[1024];
int type;
//
// build tristrips
//
numorder = 0;
numcommands = 0;
memset (used, 0, sizeof(used));
for (i=0 ; i<pheader->numtris ; i++)
{
// pick an unused triangle and start the trifan
if (used[i])
continue;
bestlen = 0;
for (type = 0 ; type < 2 ; type++)
// type = 1;
{
for (startv =0 ; startv < 3 ; startv++)
{
if (type == 1)
len = StripLength (i, startv);
else
len = FanLength (i, startv);
if (len > bestlen)
{
besttype = type;
bestlen = len;
for (j=0 ; j<bestlen+2 ; j++)
bestverts[j] = stripverts[j];
for (j=0 ; j<bestlen ; j++)
besttris[j] = striptris[j];
}
}
}
// mark the tris on the best strip as used
for (j=0 ; j<bestlen ; j++)
used[besttris[j]] = 1;
if (besttype == 1)
commands[numcommands++] = (bestlen+2);
else
commands[numcommands++] = -(bestlen+2);
for (j=0 ; j<bestlen+2 ; j++)
{
// emit a vertex into the reorder buffer
k = bestverts[j];
vertexorder[numorder++] = k;
// emit s/t coords into the commands stream
s = stverts[k].s;
t = stverts[k].t;
if (!triangles[besttris[0]].facesfront && stverts[k].onseam)
s += pheader->skinwidth / 2; // on back side
s = (s + 0.5) / pheader->skinwidth;
t = (t + 0.5) / pheader->skinheight;
*(float *)&commands[numcommands++] = s;
*(float *)&commands[numcommands++] = t;
}
}
commands[numcommands++] = 0; // end of list marker
Con_DPrintf ("%3i tri %3i vert %3i cmd\n", pheader->numtris, numorder, numcommands);
allverts += numorder;
alltris += pheader->numtris;
}
/*
================
GL_MakeAliasModelDisplayLists
================
*/
void GL_MakeAliasModelDisplayLists (model_t *m, aliashdr_t *hdr)
{
int i, j;
maliasgroup_t *paliasgroup;
int *cmds;
trivertx_t *verts;
char cache[MAX_QPATH], fullpath[MAX_OSPATH], *c;
FILE *f;
int len;
byte *data;
aliasmodel = m;
paliashdr = hdr; // (aliashdr_t *)Mod_Extradata (m);
//
// look for a cached version
//
strcpy (cache, "glquake/");
COM_StripExtension (m->name+strlen("progs/"), cache+strlen("glquake/"));
strcat (cache, ".ms2");
COM_FOpenFile (cache, &f);
if (f)
{
fread (&numcommands, 4, 1, f);
fread (&numorder, 4, 1, f);
fread (&commands, numcommands * sizeof(commands[0]), 1, f);
fread (&vertexorder, numorder * sizeof(vertexorder[0]), 1, f);
fclose (f);
}
else
{
//
// build it from scratch
//
Con_Printf ("meshing %s...\n",m->name);
BuildTris (); // trifans or lists
//
// save out the cached version
//
sprintf (fullpath, "%s/%s", com_gamedir, cache);
f = fopen (fullpath, "wb");
if (f)
{
fwrite (&numcommands, 4, 1, f);
fwrite (&numorder, 4, 1, f);
fwrite (&commands, numcommands * sizeof(commands[0]), 1, f);
fwrite (&vertexorder, numorder * sizeof(vertexorder[0]), 1, f);
fclose (f);
}
}
// save the data out
paliashdr->poseverts = numorder;
cmds = Hunk_Alloc (numcommands * 4);
paliashdr->commands = (byte *)cmds - (byte *)paliashdr;
memcpy (cmds, commands, numcommands * 4);
verts = Hunk_Alloc (paliashdr->numposes * paliashdr->poseverts
* sizeof(trivertx_t) );
paliashdr->posedata = (byte *)verts - (byte *)paliashdr;
for (i=0 ; i<paliashdr->numposes ; i++)
for (j=0 ; j<numorder ; j++)
*verts++ = poseverts[i][vertexorder[j]];
}