how do I create a line of arbitrary thickness using Bresenham?

Question

I am currently using Bresenham\'s algorithm to draw lines but they are (of course) one pixel in thickness. My question is what is the most efficient way to draw lines of arb

Answer 1

For those who want a Python version here goes the code (based on the answer of @Fabel):

def drawline(x1,y1,x2,y2,**kwargs):  
    if kwargs.get('thickness')==None:
        thickness=1
    else:
        thickness=kwargs['thickness']
    if kwargs.get('roundcap')==None:
        roundcap=False
    else:
        roundcap=True
    angle = np.arctan2(y2-y1,x2-x1)
    xx = np.zeros(4)
    yy = np.zeros(4)
    xx[0] = np.round(x1 + thickness*np.cos(angle+np.pi/2))
    yy[0] = np.round(y1 + thickness*np.sin(angle+np.pi/2))
    xx[1] = np.round(x1 + thickness*np.cos(angle-np.pi/2))
    yy[1] = np.round(y1 + thickness*np.sin(angle-np.pi/2))
    xx[2] = np.round(x2 + thickness*np.cos(angle-np.pi/2))
    yy[2] = np.round(y2 + thickness*np.sin(angle-np.pi/2))
    xx[3] = np.round(x2 + thickness*np.cos(angle+np.pi/2))
    yy[3] = np.round(y2 + thickness*np.sin(angle+np.pi/2))
    u,v=polygon(xx,yy)    
    if roundcap:
        temp1x, temp1y = circle(x1,y1,thickness)
        temp2x, temp2y = circle(x1,y1,thickness)
        u = np.append(u,temp1x,temp2x)
        v = np.append(v,temp1y,temp2y)
    return u,v

When calling the function you can optionally specify thickness and roundcap. For example:

drawline(10,10,50,50,thickness=3,roundcap=False)