Below is an example of how to use metrics to draw on the screen in C language

void write(const char * WORDS, int X, int Y)
{
    int i,t=strlen(WORDS);
    unsigned char l;
    position.x=X; //screen x
    position.y=Y; //screen y

    for (i=0; i<t; i++){
        l=WORDS[i];
        width.x=(l%16)*sizeChar.w; width.w=width[l];
        width.y=(l/16)*sizeChar.h; width.h=sizeChar.h;
        gsScreen->blitSurface(image,&width,&position);
        position.y=Y;
        position.x=position.x+width[l];
    }
}