Function to get 5-sided polygon (pentagon) or star (pentagram) co-ords.
<?php
function _makeFiveSidedStar( $x, $y, $radius, $shape='polygon', $spiky=NULL ) {
$point = array() ; // new array
$angle = 360 / 5 ;
$point[0]['x'] = $x ;
$point[0]['y'] = $y - $radius ;
$point[2]['x'] = $x + ( $radius * cos( deg2rad( 90 - $angle ) ) ) ;
$point[2]['y'] = $y - ( $radius * sin( deg2rad( 90 - $angle ) ) ) ;
$point[4]['x'] = $x + ( $radius * sin( deg2rad( 180 - ( $angle*2 ) ) ) ) ;
$point[4]['y'] = $y + ( $radius * cos( deg2rad( 180 - ( $angle*2 ) ) ) ) ;
$point[6]['x'] = $x - ( $radius * sin( deg2rad( 180 - ( $angle*2 ) ) ) ) ;
$point[6]['y'] = $y + ( $radius * cos( deg2rad( 180 - ( $angle*2 ) ) ) ) ;
$point[8]['x'] = $x - ( $radius * cos( deg2rad( 90 - $angle ) ) ) ;
$point[8]['y'] = $y - ( $radius * sin( deg2rad( 90 - $angle ) ) ) ;
if( $shape == 'star' ) {
if( $spiky == NULL ) $spiky = 0.5 ; // degree of spikiness, default to 0.5
$indent = $radius * $spiky ;
$point[1]['x'] = $x + ( $indent * cos( deg2rad( 90 - $angle/2 ) ) ) ;
$point[1]['y'] = $y - ( $indent * sin( deg2rad( 90 - $angle/2 ) ) ) ;
$point[3]['x'] = $x + ( $indent * sin( deg2rad( 180 - $angle ) ) ) ;
$point[3]['y'] = $y - ( $indent * cos( deg2rad( 180 - $angle ) ) ) ;
$point[5]['x'] = $x ;
$point[5]['y'] = $y + ( $indent * sin( deg2rad( 180 - $angle ) ) ) ;
$point[7]['x'] = $x - ( $indent * sin( deg2rad( 180 - $angle ) ) ) ;
$point[7]['y'] = $y - ( $indent * cos( deg2rad( 180 - $angle ) ) ) ;
$point[9]['x'] = $x - ( $indent * cos( deg2rad( 90 - $angle/2 ) ) ) ;
$point[9]['y'] = $y - ( $indent * sin( deg2rad( 90 - $angle/2 ) ) ) ;
}
ksort( $point ) ;
$coords = array() ; // new array
foreach( $point as $pKey=>$pVal ) {
if( is_array( $pVal ) ) {
foreach( $pVal as $pSubKey=>$pSubVal ) {
if( !empty( $pSubVal ) ) array_push( $coords, $pSubVal ) ;
}
}
}
return $coords ;
}
$values = _makeFiveSidedStar( 100, 100, 50, 'star' ) ;
?>