PHP uses GD library to draw a five-pointed star_PHP tutorial

01 $width = 500;

02 $height = 500;

03

04 $im = imagecreatetruecolor($width, $height);

05

06 $red = imagecolorallocate($im, 230, 0, 0);

07 imagefill($im, 0, 0, $red);

08

09 $yellow = imagecolorallocate($im, 255, 255, 0);

10 

11 //Set the side length of the regular pentagon formed by drawing the five vertices of the five-pointed star

12 $b=100;

13 $pi=3.14/180;

14

15 $p1x = 150;

16 $p1y = 250;

17

18 $p2x = 150+(cos(36*$pi)*$b);

19 $p2y = 250-(sin(36*$pi)*$b);

20

21 $p3x = 150+(2*cos(36*$pi)*$b);

22 $p3y = 250;

23

24 $p4x = $p3x-sin(18*$pi)*$b;

25 $p4y = 250+cos(18*$pi)*$b;

26

27 $p5x = 150+sin(18*$pi)*$b;

28 $p5y = 250+cos(18*$pi)*$b;

29 

30 //Connect the corresponding points and draw lines

31 imageline($im, $p1x, $p1y, $p3x, $p3y, $yellow);

32 imageline($im, $p1x, $p1y, $p4x, $p4y, $yellow);

33

34 imageline($im, $p2x, $p2y, $p4x, $p4y, $yellow);

35 imageline($im, $p2x, $p2y, $p5x, $p5y, $yellow);

36

37 imageline($im, $p3x, $p3y, $p5x, $p5y, $yellow);

38

39 header('Content-Type:image/png');

40

41 imagepng($im);

42

43 imagedestroy($im);

44

45 ?>