util.c

#include <stdlib.h>
#include <string.h>
#include <math.h>

#include "util.h"

int file_size(FILE *fp)
{
    int prev = ftell(fp);
    fseek(fp, 0L, SEEK_END);
    int size = ftell(fp);
    fseek(fp, prev, SEEK_SET); /* go back to where we were */

    return size;
}

char *file_contents(const char *name)
{
    int c;
    FILE *fp = fopen(name, "r");

    if (!fp)
    {
        fputs("Error opening file for reading!\n", stderr);
        return NULL;
    }

    char *ret = malloc(file_size(fp) + 1);

    if (!ret)
    {
        fputs("Error allocating memory for ret!\n", stderr);
        return NULL;
    }

    size_t i = 0;
    while ((c = fgetc(fp)) != EOF)
    {
        ret[i] = c;
        ++i;
    }

    ret[i] = '\0';

    fclose(fp);

    return ret;
}

void perspective(GLdouble fovY, GLdouble aspect, GLdouble zNear, GLdouble zFar)
{
    const GLdouble pi = 3.1415926535897932384626433832795;
    GLdouble fW, fH;

    //fH = tan( (fovY / 2) / 180 * pi ) * zNear;
    fH = tan(fovY / 360 * pi) * zNear;
    fW = fH * aspect;

    glFrustum(-fW, fW, -fH, fH, zNear, zFar);
}