GameStar 2004 April/Gamestar_61_2004-04_dvdb.iso/DVDStar/Editace/hltp.exe/{app}/Source Code/Textures SDK/common/trilib.c

C/C++ Source or Header | 1998-12-02 | 4KB | 181 lines

/***
*
*    Copyright (c) 1998, Valve LLC. All rights reserved.
*
*    This product contains software technology licensed from Id
*    Software, Inc. ("Id Technology").  Id Technology (c) 1996 Id Software, Inc.
*    All Rights Reserved.
*
****/

//
// trilib.c: library for loading triangles from an Alias triangle file
//

#include <stdio.h>
#include "cmdlib.h"
#include "mathlib.h"
#include "trilib.h"

// on disk representation of a face


#define    FLOAT_START    99999.0
#define    FLOAT_END    -FLOAT_START
#define MAGIC       123322

//#define NOISY 1

typedef struct {
    float v[3];
} vector;

typedef struct
{
    vector n;    /* normal */
    vector p;    /* point */
    vector c;    /* color */
    float  u;    /* u */
    float  v;    /* v */
} aliaspoint_t;

typedef struct {
    aliaspoint_t    pt[3];
} tf_triangle;


void ByteSwapTri (tf_triangle *tri)
{
    int        i;

    for (i=0 ; i<sizeof(tf_triangle)/4 ; i++)
    {
        ((int *)tri)[i] = BigLong (((int *)tri)[i]);
    }
}

void LoadTriangleList (char *filename, triangle_t **pptri, int *numtriangles)
{
    FILE        *input;
    float       start;
    char        name[256], tex[256];
    int         i, count, magic;
    tf_triangle    tri;
    triangle_t    *ptri;
    int            iLevel;
    int            exitpattern;
    float        t;


    t = -FLOAT_START;
    *((unsigned char *)&exitpattern + 0) = *((unsigned char *)&t + 3);
    *((unsigned char *)&exitpattern + 1) = *((unsigned char *)&t + 2);
    *((unsigned char *)&exitpattern + 2) = *((unsigned char *)&t + 1);
    *((unsigned char *)&exitpattern + 3) = *((unsigned char *)&t + 0);

    if ((input = fopen(filename, "rb")) == 0) {
        fprintf(stderr,"reader: could not open file '%s'\n", filename);
        exit(0);
    }

    iLevel = 0;

    fread(&magic, sizeof(int), 1, input);
    if (BigLong(magic) != MAGIC) {
        fprintf(stderr,"File is not a Alias object separated triangle file, magic number is wrong.\n");
        exit(0);
    }

    ptri = malloc (MAXTRIANGLES * sizeof(triangle_t));

    *pptri = ptri;

    while (feof(input) == 0) {
        fread(&start,  sizeof(float), 1, input);
        *(int *)&start = BigLong(*(int *)&start);
        if (*(int *)&start != exitpattern)
        {
            if (start == FLOAT_START) {
                /* Start of an object or group of objects. */
                i = -1;
                do {
                    /* There are probably better ways to read a string from */
                    /* a file, but this does allow you to do error checking */
                    /* (which I'm not doing) on a per character basis.      */
                    ++i;
                    fread( &(name[i]), sizeof( char ), 1, input);
                } while( name[i] != '\0' );

    //            indent();
    //            fprintf(stdout,"OBJECT START: %s\n",name);
                fread( &count, sizeof(int), 1, input);
                count = BigLong(count);
                ++iLevel;
                if (count != 0) {
    //                indent();

    //                fprintf(stdout,"NUMBER OF TRIANGLES: %d\n",count);

                    i = -1;
                    do {
                        ++i;
                        fread( &(tex[i]), sizeof( char ), 1, input);
                    } while( tex[i] != '\0' );

    //                indent();
    //                fprintf(stdout,"  Object texture name: '%s'\n",tex);
                }

                /* Else (count == 0) this is the start of a group, and */
                /* no texture name is present. */
            }
            else if (start == FLOAT_END) {
                /* End of an object or group. Yes, the name should be */
                /* obvious from context, but it is in here just to be */
                /* safe and to provide a little extra information for */
                /* those who do not wish to write a recursive reader. */
                /* Mia culpa. */
                --iLevel;
                i = -1;
                do {
                    ++i;
                    fread( &(name[i]), sizeof( char ), 1, input);
                } while( name[i] != '\0' );

    //            indent();
    //            fprintf(stdout,"OBJECT END: %s\n",name);
                continue;
            }
        }

//
// read the triangles
//
        for (i = 0; i < count; ++i) {
            int        j;

            fread( &tri, sizeof(tf_triangle), 1, input );
            ByteSwapTri (&tri);
            for (j=0 ; j<3 ; j++)
            {
                int        k;

                for (k=0 ; k<3 ; k++)
                {
                    ptri->verts[j][k] = tri.pt[j].p.v[k];
                }
            }

            ptri++;

            if ((ptri - *pptri) >= MAXTRIANGLES)
                Error ("Error: too many triangles; increase MAXTRIANGLES\n");
        }
    }

    *numtriangles = ptri - *pptri;

    fclose (input);
}