bresenham.h

#ifndef BRESENHAM_H_INCLUDED
#define BRESENHAM_H_INCLUDED

bool line(int y1, int x1, int y2, int x2, int z)
{
    bool fail = 0;
    int d, dx, dy, ai, bi, xi, yi;
    int x = x1, y = y1;
    if (x1 < x2)
    {
        xi = 1;
        dx = x2 - x1;
    }
    else
    {
        xi = -1;
        dx = x1 - x2;
    }
    if (y1 < y2)
    {
        yi = 1;
        dy = y2 - y1;
    }
    else
    {
        yi = -1;
        dy = y1 - y2;
    }
    if (dx > dy)
    {
        ai = (dy - dx) * 2;
        bi = dy * 2;
        d = bi - dx;
        while (x != x2)
        {
            if (d >= 0)
            {
                x += xi;
                y += yi;
                d += ai;
            }
            else
            {
                d += bi;
                x += xi;
            }
            if(map_g[y][x][z] == 2)
            {
                fail = 1;
            }
        }
    }
    else
    {
        ai = ( dx - dy ) * 2;
        bi = dx * 2;
        d = bi - dy;
        while (y != y2)
        {
            if (d >= 0)
            {
                x += xi;
                y += yi;
                d += ai;
            }
            else
            {
                d += bi;
                y += yi;
            }
            if(map_g[y][x][z] == 2)
            {
                fail = 1;
            }
        }
    }
    if(fail == 1)
    {
        return false;
    }
    else
    {
        return true;
    }
}


#endif // BRESENHAM_H_INCLUDED