GD Library Circle Corners

Ok, I have been working on a number of projects over the last 3 months or so which use the GD Library. While I do not confess to being an expert by any means, I’m starting to get into the swing of things!

Last night I was faced with a challenge. Within a table I held the pixel co-ordinates for the X&Y Axis, and the radius of the circle (Green & Red respectively). Now all I needed to do was to find the X&Y co-ordinates for each corner of the circle, so that I can place text correctly

$top_left = array();
$top_left['x'] = $left-(($radius/sin(deg2rad(90)))*sin(deg2rad(45)));
$top_left['y'] = $top-(($radius/sin(deg2rad(90)))*sin(deg2rad(45)));

$top_right = array();
$top_right['x'] = $left+(($radius/sin(deg2rad(90)))*sin(deg2rad(45)));
$top_right['y'] = $top-(($radius/sin(deg2rad(90)))*sin(deg2rad(45)));

$bottom_left = array();
$bottom_left['x'] = $left-(($radius/sin(deg2rad(90)))*sin(deg2rad(45)));
$bottom_left['y'] = $top+(($radius/sin(deg2rad(90)))*sin(deg2rad(45)));

$bottom_right = array();
$bottom_right['x'] = $left+(($radius/sin(deg2rad(90)))*sin(deg2rad(45)));
$bottom_right['y'] = $top+(($radius/sin(deg2rad(90)))*sin(deg2rad(45)));

Stay tuned for more snippets about the GD Library within PHP!