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 Last updated: Sat, 07 Jan 2012

# imagepolygon

(PHP 4, PHP 5)

imagepolygonDraws a polygon

### 설명

bool imagepolygon ( resource \$image , array \$points , int \$num_points , int \$color )

imagepolygon() creates a polygon in the given image.

### 인수

image

imagecreatetruecolor() 등의 이미지 생성 함수에서 반환한 이미지 자원.

points

An array containing the polygon's vertices, e.g.:

 points[0] = x0 points[1] = y0 points[2] = x1 points[3] = y1

num_points

Total number of points (vertices).

color

A color identifier created with imagecolorallocate().

### 반환값

성공할 경우 TRUE를, 실패할 경우 FALSE를 반환합니다.

### 예제

Example #1 imagepolygon() example

``` <?php// Create a blank image\$image = imagecreatetruecolor(400, 300);// Allocate a color for the polygon\$col_poly = imagecolorallocate(\$image, 255, 255, 255);// Draw the polygonimagepolygon(\$image, array(        0,   0,        100, 200,        300, 200    ),    3,    \$col_poly);// Output the picture to the browserheader('Content-type: image/png');imagepng(\$image);imagedestroy(\$image);?> ```

위 예제의 출력 예시:

### 참고

 Last updated: Sat, 07 Jan 2012

User Contributed Notes imagepolygon - [5 notes]
licson0729 at gmail dot com
1 year ago
``` Function to draw a n-sided regular polygon <?php \$img = imagecreatetruecolor(1360,768); function regularPolygon(\$img,\$x,\$y,\$radius,\$sides,\$color) {     \$points = array();     for(\$a = 0;\$a <= 360; \$a += 360/\$sides)     {         \$points[] = \$x + \$radius * cos(deg2rad(\$a));         \$points[] = \$y + \$radius * sin(deg2rad(\$a));     }     return imagepolygon(\$img,\$points,\$sides,\$color); } regularPolygon(\$img,1360/2,768/2,300,8,0xffffff);//Test draw header('Content-type: image/png'); imagepng(\$img); imagedestroy(\$img); ?> ```
licson0729 at gmail dot com
1 year ago
``` Here's a function to draw a n-sided star: <?php function drawStar(\$img,\$x,\$y,\$radius,\$sides,\$color,\$spikness=0.5) {     \$point =array();     \$t = 0;     for(\$a = 0;\$a <= 360;\$a += 360/(\$sides*2))     {         \$t++;         if(\$t % 2 == 0)         {             \$point[] = \$x + (\$radius * \$spikness) * cos(deg2rad(\$a));             \$point[] = \$y + (\$radius * \$spikness) * sin(deg2rad(\$a));         }else{             \$point[] = \$x + \$radius * cos(deg2rad(\$a));             \$point[] = \$y + \$radius * sin(deg2rad(\$a));         }     }     return imagepolygon(\$img,\$point,\$sides*2,\$color); } ?> ```
tatlar at yahoo dot com
6 years ago
``` 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' ) ; ?> ```
glowell at flash dot net
7 years ago
``` Something to be aware of, ImagePolygon appears to convert the array of points passed to it from whatever format they may have been in originally into integers. This means if you pass it an array of floats (after running a rotation routine for example) the floats will be changed to integers INSIDE THE ORIGINAL ARRAY. An extreme example: if for some reason you had an unit-sized polygon pt-array ( -1<x|y<1 for easy scaling purpose for instance) and for some reason your code calls imagepolygon on it (why? it'd only be a dot anyway) the array would be unusable after that (all either 1s, 0s or -1s). Scaling a unit-sized array, drawing it and then scaling it again will also may have a different result than expected. Obviously, if the array in its original state is important to your code, it should use a copy of the original array for this call. If your code draws the same polygon multiple times but resizes it for different cases, you should have each size be created off an original template rather than adjusting a single polygon array. ```
jsnell at networkninja dot com
12 years ago
``` Here are some handy routines for rotation and translation of polygons.  Scaling could be added easily as well. <?php function translate_point(&\$x,&\$y,\$angle,\$about_x,\$about_y,\$shift_x,\$shift_y) {     \$x -= \$about_x;     \$y -= \$about_y;     \$angle = (\$angle / 180) * M_PI; /* math: [x2,y2] = [x,  *  [[cos(a),-sin(a)],            y]      [sin(a),cos(a)]] ==> x = x * cos(a) + y*sin(a) y = x*-sin(a) + y*cos(a) */     \$new_x = \$x * cos(\$angle) - \$y * sin(\$angle);     \$new_y = \$x * sin(\$angle) + \$y * cos(\$angle);     \$x = \$new_x+ \$about_x + \$shift_x ;     \$y = \$new_y + \$about_y + \$shift_y; } function translate_poly(\$point_array, \$angle, \$about_x, \$about_y,\$shift_x,\$shift_y) {     \$translated_poly = Array();     while(count(\$point_array) > 1)     {         \$temp_x = array_shift(\$point_array);         \$temp_y = array_shift(\$point_array);         translate_point(\$temp_x, \$temp_y, \$angle, \$about_x, \$about_y,\$shift_x, \$shift_y);         array_push(\$translated_poly, \$temp_x);         array_push(\$translated_poly, \$temp_y);     }     return \$translated_poly; } ?> ```