ref: 13ca2581f9f18d441ce911e42c2bd93e387cee4d
dir: /common/l3dslib.c/
/*
===========================================================================
Copyright (C) 1999-2005 Id Software, Inc.
This file is part of Quake III Arena source code.
Quake III Arena source code 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.
Quake III Arena source code 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 Foobar; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
===========================================================================
*/
//
// l3dslib.c: library for loading triangles from an Alias triangle file
//
#include <stdio.h>
#include "cmdlib.h"
#include "mathlib.h"
#include "trilib.h"
#include "l3dslib.h"
#define MAIN3DS 0x4D4D
#define EDIT3DS 0x3D3D // this is the start of the editor config
#define EDIT_OBJECT 0x4000
#define OBJ_TRIMESH 0x4100
#define TRI_VERTEXL 0x4110
#define TRI_FACEL1 0x4120
#define MAXVERTS 2000
typedef struct {
int v[4];
} tri;
float fverts[MAXVERTS][3];
tri tris[MAXTRIANGLES];
int bytesread, level, numtris, totaltris;
int vertsfound, trisfound;
triangle_t *ptri;
// Alias stores triangles as 3 explicit vertices in .tri files, so even though we
// start out with a vertex pool and vertex indices for triangles, we have to convert
// to raw, explicit triangles
void StoreAliasTriangles (void)
{
int i, j, k;
if ((totaltris + numtris) > MAXTRIANGLES)
Error ("Error: Too many triangles");
for (i=0; i<numtris ; i++)
{
for (j=0 ; j<3 ; j++)
{
for (k=0 ; k<3 ; k++)
{
ptri[i+totaltris].verts[j][k] = fverts[tris[i].v[j]][k];
}
}
}
totaltris += numtris;
numtris = 0;
vertsfound = 0;
trisfound = 0;
}
int ParseVertexL (FILE *input)
{
int i, j, startbytesread, numverts;
unsigned short tshort;
if (vertsfound)
Error ("Error: Multiple vertex chunks");
vertsfound = 1;
startbytesread = bytesread;
if (feof(input))
Error ("Error: unexpected end of file");
fread(&tshort, sizeof(tshort), 1, input);
bytesread += sizeof(tshort);
numverts = (int)tshort;
if (numverts > MAXVERTS)
Error ("Error: Too many vertices");
for (i=0 ; i<numverts ; i++)
{
for (j=0 ; j<3 ; j++)
{
if (feof(input))
Error ("Error: unexpected end of file");
fread(&fverts[i][j], sizeof(float), 1, input);
bytesread += sizeof(float);
}
}
if (vertsfound && trisfound)
StoreAliasTriangles ();
return bytesread - startbytesread;
}
int ParseFaceL1 (FILE *input)
{
int i, j, startbytesread;
unsigned short tshort;
if (trisfound)
Error ("Error: Multiple face chunks");
trisfound = 1;
startbytesread = bytesread;
if (feof(input))
Error ("Error: unexpected end of file");
fread(&tshort, sizeof(tshort), 1, input);
bytesread += sizeof(tshort);
numtris = (int)tshort;
if (numtris > MAXTRIANGLES)
Error ("Error: Too many triangles");
for (i=0 ; i<numtris ; i++)
{
for (j=0 ; j<4 ; j++)
{
if (feof(input))
Error ("Error: unexpected end of file");
fread(&tshort, sizeof(tshort), 1, input);
bytesread += sizeof(tshort);
tris[i].v[j] = (int)tshort;
}
}
if (vertsfound && trisfound)
StoreAliasTriangles ();
return bytesread - startbytesread;
}
int ParseChunk (FILE *input)
{
#define BLOCK_SIZE 4096
char temp[BLOCK_SIZE];
unsigned short type;
int i, length, w, t, retval;
level++;
retval = 0;
// chunk type
if (feof(input))
Error ("Error: unexpected end of file");
fread(&type, sizeof(type), 1, input);
bytesread += sizeof(type);
// chunk length
if (feof(input))
Error ("Error: unexpected end of file");
fread (&length, sizeof(length), 1, input);
bytesread += sizeof(length);
w = length - 6;
// process chunk if we care about it, otherwise skip it
switch (type)
{
case TRI_VERTEXL:
w -= ParseVertexL (input);
goto ParseSubchunk;
case TRI_FACEL1:
w -= ParseFaceL1 (input);
goto ParseSubchunk;
case EDIT_OBJECT:
// read the name
i = 0;
do
{
if (feof(input))
Error ("Error: unexpected end of file");
fread (&temp[i], 1, 1, input);
i++;
w--;
bytesread++;
} while (temp[i-1]);
case MAIN3DS:
case OBJ_TRIMESH:
case EDIT3DS:
// parse through subchunks
ParseSubchunk:
while (w > 0)
{
w -= ParseChunk (input);
}
retval = length;
goto Done;
default:
// skip other chunks
while (w > 0)
{
t = w;
if (t > BLOCK_SIZE)
t = BLOCK_SIZE;
if (feof(input))
Error ("Error: unexpected end of file");
fread (&temp, t, 1, input);
bytesread += t;
w -= t;
}
retval = length;
goto Done;
}
Done:
level--;
return retval;
}
void Load3DSTriangleList (char *filename, triangle_t **pptri, int *numtriangles)
{
FILE *input;
short int tshort;
bytesread = 0;
level = 0;
numtris = 0;
totaltris = 0;
vertsfound = 0;
trisfound = 0;
if ((input = fopen(filename, "rb")) == 0) {
fprintf(stderr,"reader: could not open file '%s'\n", filename);
exit(0);
}
fread(&tshort, sizeof(tshort), 1, input);
// should only be MAIN3DS, but some files seem to start with EDIT3DS, with
// no MAIN3DS
if ((tshort != MAIN3DS) && (tshort != EDIT3DS)) {
fprintf(stderr,"File is not a 3DS file.\n");
exit(0);
}
// back to top of file so we can parse the first chunk descriptor
fseek(input, 0, SEEK_SET);
ptri = malloc (MAXTRIANGLES * sizeof(triangle_t));
*pptri = ptri;
// parse through looking for the relevant chunk tree (MAIN3DS | EDIT3DS | EDIT_OBJECT |
// OBJ_TRIMESH | {TRI_VERTEXL, TRI_FACEL1}) and skipping other chunks
ParseChunk (input);
if (vertsfound || trisfound)
Error ("Incomplete triangle set");
*numtriangles = totaltris;
fclose (input);
}