php代码
$r*cos(($theta+$i*72)*$PI/180)+$position_X,'y'=>-$r*sin(($theta+$i*72)*$PI/180)+$position_Y);
}
for($i=0;$i<5;$i++){//五条线坐标
$j=$i>2?$i-3:$i+2;
$lines[$i] = array('x1' => $points[$i]['x'], 'y1' => $points[$i]['y'], 'x2' => $points[$j]['x'], 'y2' => $points[$j]['y']);
}
for($i=0;$i<5;$i++){//五交点坐标
$j = $i>3?0:$i+1;
$x12 = $lines[$i]['x1'] - $lines[$i]['x2'];
$x34 = $lines[$j]['x1'] - $lines[$j]['x2'];
$y12 = $lines[$i]['y1'] - $lines[$i]['y2'];
$y34 = $lines[$j]['y1'] - $lines[$j]['y2'];
$c = $x12 * $y34 - $y12 * $x34;
$a = $lines[$i]['x1'] * $lines[$i]['y2'] - $lines[$i]['y1'] * $lines[$i]['x2'];
$b = $lines[$j]['x1'] * $lines[$j]['y2'] - $lines[$j]['y1'] * $lines[$j]['x2'];
$x = ($a * $x34 - $b * $x12) / $c;
$y = ($a * $y34 - $b * $y12) / $c;
$intersection[$i]= array('x'=>$x,'y'=>$y);
}
for($i=0;$i<3;$i++){//三个三角形
$Polygon[$i] = array($points[$i]['x'],$points[$i]['y'],$points[$i+2]['x'],$points[$i+2]['y'],$intersection[$i+2]['x'],$intersection[$i+2]['y']);
imagefilledpolygon($mFlag, $Polygon[$i], 3, $yellow);
}
}
?> 
