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 best accuracy, and also good performance for thicker lines especially, you can draw the line as a polygon. Some pseudo code:

draw_line(x1,y1,x2,y2,thickness)
  Point p[4];
  angle = atan2(y2-y1,x2-x1);
  p[0].x = x1 + thickness*cos(angle+PI/2);
  p[0].y = y1 + thickness*sin(angle+PI/2);
  p[1].x = x1 + thickness*cos(angle-PI/2);
  p[1].y = y1 + thickness*sin(angle-PI/2);
  p[2].x = x2 + thickness*cos(angle-PI/2);
  p[2].y = y2 + thickness*sin(angle-PI/2);
  p[3].x = x2 + thickness*cos(angle+PI/2);
  p[3].y = y2 + thickness*sin(angle+PI/2);
  draw_polygon(p,4)

And optionally a circle could be drawn at each end point.