# NAME

Algorithm::Line::Bresenham - simple pixellated line-drawing algorithm

# SYNOPSIS

`````` use Algorithm::Line::Bresenham qw/line/;
my @points = line(3,3 => 5,0);
# returns the list: [3,3], [4,2], [4,1], [5,0]
line(3,3 => 5,0,  \&draw_line);
# calls draw_line on each point in turn``````

# DESCRIPTION

Bresenham is one of the canonical line drawing algorithms for pixellated grids. Given a start and an end-point, Bresenham calculates which points on the grid need to be filled to generate the line between them.

Googling for 'Bresenham', and 'line drawing algorithms' gives some good overview. The code here takes its starting point from Mark Feldman's Pascal code in his article Bresenham's Line and Circle Algorithms at http://www.gamedev.net/reference/articles/article767.asp.

# FUNCTIONS

## `line`

`` line (\$from_y, \$from_x => \$to_y, \$to_x);``

Generates a list of all the intermediate points. This is returned as a list of array references.

`` line (\$from_y, \$from_x => \$to_y, \$to_x,  \&callback);``

Calls the referenced function on each point in turn. The callback could be used to actually draw the point. Returns the collated return values from the callback.

## `circle`

``    my @points = circle (\$y, \$x, \$radius)``

Returns the points to draw a circle with

None currently.

# THANKS

Patches for the circle algorithm and a float value bug contributed by Richard Clamp, thanks!