GLubyte* 
glmReadPPM2(char* filename, int* width, int* height)
{
    FILE* fp;
    int i, w, h, d;
    unsigned char* image;
    char head[70];          /* max line <= 70 in PPM (per spec). */
    
    fp = fopen(filename, "rb");
    if (!fp) {
        perror(filename);
        return NULL;
    }
    
    /* grab first two chars of the file and make sure that it has the
       correct magic cookie for a raw PPM file. */
    fgets(head, 70, fp);
    if (strncmp(head, "P6", 2)) {
        fprintf(stderr, "%s: Not a raw PPM file\n", filename);
        return NULL;
    }
    
    /* grab the three elements in the header (width, height, maxval). */
    i = 0;
    while(i < 3) {
        fgets(head, 70, fp);
        if (head[0] == '#')     /* skip comments. */
            continue;
        if (i == 0)
            i += sscanf(head, "%d %d %d", &w, &h, &d);
        else if (i == 1)
            i += sscanf(head, "%d %d", &h, &d);
        else if (i == 2)
            i += sscanf(head, "%d", &d);
    }
    
    /* grab all the image data in one fell swoop. */
    image = (unsigned char*)malloc(sizeof(unsigned char)*w*h*3);
    fread(image, sizeof(unsigned char), w*h*3, fp);
    fclose(fp);
    
    *width = w;
    *height = h;
    return image;
}
void initTexture()
{
	glPixelStorei(GL_UNPACK_ALIGNMENT,1);
	glGenTextures(1,&texName_2d);
	glBindTexture(GL_TEXTURE_2D, texName_2d);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
	glTexImage2D(GL_TEXTURE_2D,0,GL_RGB8,imgwidth,imgheight,
		0,GL_RGB,GL_UNSIGNED_BYTE,&image[0]);
}