Quake-III-Arena

l3dslib.c (6068B)

---

 /*
 ===========================================================================
 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);
 }