imageantialias
I didn't have much luck with the other two functions, one of them makes circles that look like they've been printed on a dot-matrix printer. This simple function builds a border out of circles, seems to work nicely.
<?php
function imagearcunfilled($image,$x,$y,$width,$height,$border_thickness, $color) {
imagesetthickness($image, 1);
$x_radius = $width / 2;
$y_radius = $height / 2;
for ($i = 0; $i < 360; $i++) {
if (TRUE) {
$x2 = $x + cos($i) * $x_radius;
$y2 = $y + sin($i) * $y_radius;
imagefilledarc($image,$x2,$y2,$border_thickness,$border_thickness,0,360,$color,IMG_ARC_PIE);
}
}
}
?>
imagearc
(PHP 4, PHP 5)
imagearc — Desenha um elipse parcial
Descrição
int imagearc
( resource
$image
, int $cx
, int $cy
, int $w
, int $h
, int $s
, int $e
, int $color
)
imagearc() desenha um elipse parcial centrado em
cx, cy (o canto superior esquerdo é
0, 0) na imagem representada por image.
W
e h representa respectivamente a largura e altura
enquanto os pontos de inÃcio e final são representados em graus
pelos parâmetros s e
e. 0° esta localizado na posição de três horas,
e o arco é desenhado no sentido horário.
Exemplo #1 Desenhando um cÃrculo com imagearc()
<?php
// cria uma imagem de 200 * 200
$img = imagecreate(200, 200);
// aloca algumas cores
$white = imagecolorallocate($img, 255, 255, 255);
$black = imagecolorallocate($img, 0, 0, 0);
// desenha um cÃrculo preto
imagearc($img, 100, 100, 150, 150, 0, 360, $black);
// envia a imagem para o browser
header("Content-type: image/png");
imagepng($img);
// libera a mémoria
imagedestroy($img);
?>
Veja também imageellipse(), imagefilledellipse(), e imagefilledarc().
add a note
User Contributed Notes
imagearc - [22 notes]
joe dot tym at gmail dot com ¶
8 months ago
chandlerklebs at gmail dot com ¶
1 year ago
This is an example script I wrote for myself to help me learn how to used the imagearc functions. Maybe if will also help others.
<?php
//example PHP script of imagearc functions
$image_width=360;$image_height=360;
$img = imagecreatetruecolor($image_width,$image_height); //make image variable
//create a background color by making a filled rectangle
$color = imagecolorallocate($img,255,255,255);
imagefilledrectangle($img,0,0,$image_width,$image_height,$color);
$r=$image_width/2 - $image_width/32 ; //radius
$cx=$image_width/2;
$cy=$image_height/2;
$color = imagecolorallocate($img,0,0,0);
imagearc($img, $cx, $cy, $r*2, $r*2, 0, 360, $color); //regular outlines arc
imagefilledarc($img, $cx, $cy, $r*1, $r*1, 0, 90, $color,IMG_ARC_CHORD); //filled triangle with chord of circle
imagefilledarc($img, $cx, $cy, $r*1, $r*1, 180, 270, $color,IMG_ARC_PIE); //pie slice
$font_number=5; //can use built in fonts numbered 1 to 5
$string="Hello world!";
imagestring($img, $font_number, $cx-(imagefontwidth($font_number)*strlen($string))/2, $cy-120, $string, $color);
header("Content-type: image/png");
imagepng($img);// output image in the browser
$filename="imagearc";
imagepng($img,"./frames/$filename.png",9); //make highly compressed png
imagedestroy($img);
?>
Michael ¶
2 years ago
Hi, this is a function that replaces "imagearc" to solve the thickness-problem. it does not use the global value set by imagesetthickness, so you have to pass it along.
"connecting" the arc to lines is still a problem, it sometimes shifts by 1px, but so does the original function.
Theres still alot to improve ...
<?php
function myimagearc($im,$mid_x,$mid_y,$rad,$w1,$w2,$col,$thickness){
global $cols;
$rad+=$thickness/2; // to calculate outer edge
$th_fact = 1-((($thickness-1)/$rad));
$pts = 36*$rad; // adjust density
$fact = $pts/360;
$w1 = $w1*$fact;
$w2 = $w2*$fact;
if($thickness > 2) // to make sure we have neither gaps nor ugly looking artefacts
imagesetthickness($handle,2);
else
imagesetthickness($handle,1);
$winkel = (2*pi())/$pts;
for($i=$w1+1;$i< $w2;$i++){
$x = (cos($i*$winkel)*($rad));
$y = (sin($i*$winkel)*($rad));
$x1 = $x+$mid_x;
$y1 = $y+$mid_y;
$x2 = $th_fact*$x+$mid_x;
$y2 = $th_fact*$y+$mid_y;
imageline($im, $x1,$y1,$x2,$y2,$col);
}
imagesetthickness($handle,1); // just to reset
}
?>
ajim1417 at gmail dot com ¶
3 years ago
I wrote a simple function that can draws an arc counter-clockwisekly. Here it is :
<?php
function imagearcCC(&$im, $cx, $cy, $w, $h, $s, $e, $c) {
$start = 360 - $e;
$end = 360 - $s;
return imagearc($im, $cx, $cy, $w, $h, $start, $end, $c);
}
?>
The params of this function is exactly the same as the usual imagearc function.
anton dot vandeghinste at telenet dot be ¶
3 years ago
I needed an arc with a thick border and i didn't like to use 359.9 as end angle so i made a function that works pretty well:
<?php
function imagearcthick($image, $x, $y, $w, $h, $s, $e, $color, $thick = 1)
{
if($thick == 1)
{
return imagearc($image, $x, $y, $w, $h, $s, $e, $color);
}
for($i = 1;$i<($thick+1);$i++)
{
imagearc($image, $x, $y, $w-($i/5), $h-($i/5),$s,$e,$color);
imagearc($image, $x, $y, $w+($i/5), $h+($i/5), $s, $e, $color);
}
}
?>
mojiro at awmn dot net ¶
7 years ago
A previous for the Rotated (Filled)Ellipse note from(nojer2 at yahoo dot com, 02-Apr-2001 12:06) has a mistake, at the second arc. Replace them with the following listing.
if ($filled) {
triangle($im, $cx, $cy, $cx+$px, $cy+$py, $cx+$x, $cy+$y, $colour);
triangle($im, $cx, $cy, $cx-$px, $cy-$py, $cx-$x, $cy-$y, $colour);
} else {
imageline($im, $cx+$px, $cy+$py, $cx+$x, $cy+$y, $colour);
imageline($im, $cx-$px, $cy-$py, $cx-$x, $cy-$y, $colour);
}
ruturaj_v at yahoo dot com ¶
9 years ago
this is another piechart eg. very simple ...
<?php
global $deg;
function get_polar($xrel, $yrel, $ang, $radius) {
$i = $ang;
$ang = ($ang * pi())/ 180;
$ix = abs($radius*cos($ang));
$iy = abs($radius*sin($ang));
if ($i>=0 && $i<=90) {
$ix = $xrel + $ix;
$iy = $yrel - $iy;
}
if ($i>90 && $i<=180) {
$ix = $xrel - $ix;
$iy = $yrel - $iy;
}
if ($i>180 && $i<=270) {
$ix = $xrel - $ix;
$iy = $yrel + $iy;
}
if ($i>270 && $i<=360) {
$ix = $xrel + $ix;
$iy = $yrel + $iy;
}
$ix = floor($ix);
$iy = floor($iy);
//echo ($ix . " $iy<br>");
$returnvals = array (
'x1' => $xrel,
'y1' => $yrel,
'x2' => $ix,
'y2' => $iy
);
return $returnvals;
}
function get_degtotal($degindex)
{
global $deg;
if ($degindex == 0 ) {
return ( $deg[$degindex] );
}
else {
return ( $deg[$degindex] + get_degtotal($degindex-1) );
}
}
$im = imagecreate (400, 400);
$w = imagecolorallocate ($im, 255, 255, 255);
$black = imagecolorallocate ($im, 0, 0, 0);
$red = imagecolorallocate ($im, 255, 0, 0);
$green = imagecolorallocate ($im, 0, 180, 0);
$randcolor[0] = imagecolorallocate($im, 243, 54, 163);
$randcolor[1] = imagecolorallocate($im, 179, 51, 247);
$randcolor[2] = imagecolorallocate($im, 103, 48, 250);
$randcolor[3] = imagecolorallocate($im, 53, 145, 244);
$randcolor[4] = imagecolorallocate($im, 54, 243, 243);
$randcolor[5] = imagecolorallocate($im, 107, 245, 180);
$randcolor[6] = imagecolorallocate($im, 203, 242, 111);
$randcolor[7] = imagecolorallocate($im, 248, 201, 105);
$data[0] = 30;
$data[1] = 20;
$data[2] = 15;
$data[3] = 10;
$data[4] = 8;
$data[5] = 7;
$data[6] = 5;
$data[7] = 5;
$datasum = array_sum($data);
$deg[0] = number_format((30 / $datasum * 360), 2, ".", "");
$deg[1] = number_format((20 / $datasum * 360), 2, ".", "");
$deg[2] = number_format((15 / $datasum * 360), 2, ".", "");
$deg[3] = number_format((10 / $datasum * 360), 2, ".", "");
$deg[4] = number_format((8 / $datasum * 360), 2, ".", "");
$deg[5] = number_format((7 / $datasum * 360), 2, ".", "");
$deg[6] = number_format((5 / $datasum * 360), 2, ".", "");
$deg[7] = number_format((5 / $datasum * 360), 2, ".", "");
echo ('<pre>');
//print_r($deg);
$datadeg = array();
$datapol = array();
$degbetween = array();
$databetweenpol = array();
for ($i=0; $i < count($deg) ; $i++) {
$datadeg[$i] = get_degtotal($i);
$datapol[$i] = get_polar(200, 200, $datadeg[$i], 100);
}
for ($i=0; $i < count($datadeg) ; $i++) {
/*this is a trick where you take 2deg angle before
and get the smaller radius so that you can have a pt to
`imagefill` the chartboundary
*/
$degbetween[$i] = ($datadeg[$i]-2);
$databetweenpol[$i] = get_polar(200, 200, $degbetween[$i], 50);
}
print_r($datadeg);
print_r($degbetween);
print_r($databetweenpol);
//exit;
for ($i=0; $i<count($deg); $i++) {
imageline ($im, 200, 200, $datapol[$i]['x2'], $datapol[$i]['y2'], $black);
}
imagearc($im, 200, 200, 200, 200, 0, 360, $black);
for ($i=0; $i<count($deg); $i++) {
imagefill ($im, $databetweenpol[$i]['x2'], $databetweenpol[$i]['y2'], $randcolor[$i]);
}
//header ("Content-type: image/png");
imagepng($im, 'piechart.png');
?>
<img src='piechart.png'>
jerryscript at aol dot com ¶
9 years ago
[note-Apache/1.3.29 (Win32) PHP/4.3.4]
The imagearc (and imageellipse) functions do not accept line thicknesses when drawn from 0 to 360 degrees.
Drawing from 0 to 359 and again from 359 to 360 does create an ellipse with the current line thickness.
Jerry
eamon at hostelworld dot com ¶
9 years ago
Right...
possibly the easiest way of drawing a filled circle:
Loop through the imagearc function incrementing the diameter by one pixel:
<?
// --- code fragment --- //
for($i=1; $i<$Diameter; $i++){
imagearc($Image, $CenterX, $CenterY, $i, $i, $Start, $End, $Color);
}
// --------------------- //
?>
This works great for circles with diameters up to about 60 or 70 pixels wide. After that, you start to get pixle gaps.
logang at deltatee dot com ¶
9 years ago
Heres a function to make a curve between two points... This will be a downward curve but it wouldn't be hard to make a similar function to make an upward curve. The first point has to be to the left of the second point ($x1 < $x2), and height is actually backwards. The larger height is the less of a crest the curve has. I imagine with a few modifications this functions could make upward curves as well.
function ImageCurveDown ($image, $x1, $y1, $x2, $y2, $height, $color) {
$presicion = 1;
for ($left = ($x1-$x2); $left < 0; $left++){
if ($y1 < $y2) {
$cy = $y2 + $height;
$cx = $x1 - $left;
} else {
$cy = $y1 + $height;
$cx = $x2 + $left;
}
$nx1 = abs($x1 - $cx);
$ny1 = abs($y1 - $cy);
$nx2 = abs($x2 - $cx);
$ny2 = abs($y2 - $cy);
if ($y1 < $y2) {
if ($nx2 == 0 || $ny1 == 0) continue;
$angle1 = atan($height/$nx2);
$A1 = $nx2/cos ($angle1);
$B1 = $ny2/sin ($angle1);
$angle2 = pi()/2 +atan($left/$ny1);
$A2 = $nx1/cos ($angle2);
$B2 = $ny1/sin ($angle2);
} else {
if ($ny2 == 0 || $nx1 == 0) continue;
$angle1 = atan($ny2/$nx2);
$A1 = abs($nx2/cos ($angle1));
$B1 = abs($ny2/sin ($angle1));
$angle2 = atan($height/$nx1);
$A2 = abs ($nx1/cos ($angle2));
$B2 = abs($ny1/sin ($angle2));
}
if (abs($A1 - $A2) < $presicion && abs ($B1 - $B2) < $presicion) {
ImageArc($image, $cx, $cy, $A1*2, $B1*2, 180+rad2deg($angle2), 360-rad2deg($angle1), $color);
}
}
}
Anonymous ¶
10 years ago
Please note that in order to draw a complete circle or ellipse (without using the imageellipse) you mustn't use 0° for both s and e. If you do this you will get, umm, nothing. Instead set s to 0° and e to 360° to get a complete circle or ellipse.
jinny at 263 dot net ¶
11 years ago
imagesetstyle() sets the style to be used by all line drawing functions when drawing with the special color .
Here goes a example of drawing a dashed-line circle.enjoy!
<?php
header("Content-type: image/jpeg");
$im = imagecreate(100,100);
$b = imagecolorallocate ($im, 0, 0, 0);
$w = imagecolorallocate ($im, 255, 255, 255);
$style = array ($b,$b,$b,$b,$b,$w,$w,$w,$w,$w);
imagesetstyle ($im, $style);
imagearc($im,50,50,100,100,0,360,IMG_COLOR_STYLED);
imagejpeg($im);
imagedestroy($im);
?>
arve at skogvold dot as ¶
11 years ago
I found a better way for drawing a pie chart:
header ("Content-type: image/png");
$diameter = 100;
$radius = $diameter / 2;
$centerX = $radius;
$centerY = $radius;
$im = @ImageCreate ($diameter, $diameter)
or die ("Cannot Initialize new GD image stream");
$background = ImageColorAllocate ($im, 0, 0, 0);
$red = ImageColorAllocate ($im, 176, 0, 0);
function fill_arc($start, $end, $color) {
global $diameter, $centerX, $centerY, $im, $radius;
imagearc($im, $centerX, $centerY, $diameter, $diameter, $start, $end, $color);
imageline($im, $centerX, $centerY, $centerX + cos(deg2rad($start)) * $radius, $centerY + sin(deg2rad($start)) * $radius, $color);
imageline($im, $centerX, $centerY, $centerX + cos(deg2rad($end)) * $radius, $centerY + sin(deg2rad($end)) * $radius, $color);
imagefill ($im,$centerX + $radius * 0.5 *cos(deg2rad($start+($end-$start)/2)), $centerY + $radius * 0.5 * sin(deg2rad($start+($end-$start)/2)), $color);
}
fill_arc(0,30,$red);
// Will make a red filled arc, starting at 0 degrees, ending at 30 degrees
ImagePng ($im);
marc at resiteit dot com ¶
11 years ago
Round cornered anti-aliased dynamically sized button.
$w=40;
$h=20;
$im = ImageCreate($w,$h);
$white=ImageColorAllocate($im,255,255,255);
ImageFilledRectangle($im,0,0,$w,$h,$white);
imagecolortransparent ($im, $white);
ImageTTFText ($im, $h+ceil($h/3)+1, 0, -1, $h-1, $col1, "arialbd.ttf", "O");
ImageTTFText ($im, $h+ceil($h/3)+1, 0, $w-$h, $h-1, $col1, "arialbd.ttf", "O");
ImageTTFText ($im, $h+ceil($h/3)+1, 0, 1, $h-1, $col1, "arialbd.ttf", "O");
ImageTTFText ($im, $h+ceil($h/3)+1, 0, $w-$h-2, $h-1, $col1, "arialbd.ttf", "O");
$points=array(
1,round($h/2),
round($h/4),$h-round($h/4),
round($h/2),$h,
$w-(round($h/2)),$h,
$w-(round($h/4)),$h-round($h/4),
$w-2,round($h/2),
$w-round($h/4),round($h/4),
$w-round($h/2),0,
round($h/2),0,
round($h/4),round($h/4)
);
imagefilledpolygon ($im, $points, 10, $col1);
header("content-type: image/gif");
header("Content-Disposition: filename=name.gif");
ImageGif($im);
ImageDestroy($im);
foripepe at yahoo dot com ¶
11 years ago
To fill an arc (DiameterX != DiameterY):
<?
function imagefilledarc($Image, $CenterX, $CenterY, $DiameterX, $DiameterY, $Start, $End, $Color) {
// To draw the arc
imagearc($Image, $CenterX, $CenterY, $DiameterX, $DiameterY, $Start, $End, $Color);
// To close the arc with 2 lines between the center and the 2 limits of the arc
$x = $CenterX + (cos(deg2rad($Start))*($DiameterX/2));
$y = $CenterY + (sin(deg2rad($Start))*($DiameterY/2));
imageline($Image, $x, $y, $CenterX, $CenterY, $Color);
$x = $CenterX + (cos(deg2rad($End))*($DiameterX/2));
$y = $CenterY + (sin(deg2rad($End))*($DiameterY/2));
imageline($Image, $x, $y, $CenterX, $CenterY, $Color);
// To fill the arc, the starting point is a point in the middle of the closed space
$x = $CenterX + (cos(deg2rad(($Start+$End)/2))*($DiameterX/4));
$y = $CenterY + (sin(deg2rad(($Start+$End)/2))*($DiameterY/4));
imagefilltoborder($Image, $x, $y, $Color, $Color);
}
?>
To close the arc with 2 lines (DiameterX != DiameterY):
<?
function imagenofilledarc($Image, $CenterX, $CenterY, $DiameterX, $DiameterY, $Start, $End, $Color) {
// To draw the arc
imagearc($Image, $CenterX, $CenterY, $DiameterX, $DiameterY, $Start, $End, $Color);
// To close the arc with 2 lines between the center and the 2 limits of the arc
$x = $CenterX + (cos(deg2rad($Start))*($DiameterX/2));
$y = $CenterY + (sin(deg2rad($Start))*($DiameterY/2));
imageline($Image, $x, $y, $CenterX, $CenterY, $Color);
$x = $CenterX + (cos(deg2rad($End))*($DiameterX/2));
$y = $CenterY + (sin(deg2rad($End))*($DiameterY/2));
imageline($Image, $x, $y, $CenterX, $CenterY, $Color);
}
?>
An example:
<?
$destImage = imagecreate( 216, 152 );
$c0 = imagecolorallocate( $destImage, 0, 255, 255 );
$c1 = imagecolorallocate( $destImage, 0, 0, 0 );
$c2 = imagecolorallocate( $destImage, 255, 0, 0 );
ImageFilledRectangle ( $destImage, 0, 0, 216, 152, $c0 );
imagefilledarc( $destImage, 108, 76, 180, 80, 0, 130, $c1 );
imagenofilledarc( $destImage, 108, 76, 180, 80, 0, 130, $c2 );
header("content-type: image/PNG");
ImagePNG( $destImage );
ImageDestroy( $destImage );
?>
Anonymous ¶
12 years ago
The following site contains heaps of different functions to draw graphs with easy to follow code for newbies and heaps of examples with OVER 60 different predefined graphs
http://www.aditus.nu/jpgraph/index.php
nojer2 at yahoo dot com ¶
12 years ago
Here's a dashed circle function:
<?php
function dashedcircle($im, $cx, $cy, $radius, $colour, $dashsize=5) {
$dash=false;
for ($angle=0; $angle<=(180+$dashsize); $angle+=$dashsize) {
$x = ($radius * cos(deg2rad($angle)));
$y = ($radius * sin(deg2rad($angle)));
if ($dash) {
imageline($im, $cx+$px, $cy+$py, $cx+$x, $cy+$y, $colour);
imageline($im, $cx-$px, $cx-$py, $cx-$x, $cy-$y, $colour);
}
$dash=!$dash;
$px=$x;
$py=$y;
}
}
?>
nojer2 at yahoo dot com ¶
12 years ago
Here's the function to draw rotated ellipses again. This time I've optimised it a bit, fixed the no-fill bug, and used a 'squishratio' rather than a 'radiusmodifier', to make the curves perfect, so ignore my previous version.
<?php
function rotatedellipse($im, $cx, $cy, $width, $height, $rotateangle, $colour, $filled=true) {
$step=2;
$cosangle=cos(deg2rad($rotateangle));
$sinangle=sin(deg2rad($rotateangle));
$squishratio = $height/$width;
$nopreviouspoint = true;
for ($angle=0; $angle<=(180+$step); $angle+=$step) {
$ox = ($width * cos(deg2rad($angle)));
$oy = ($width * sin(deg2rad($angle))) * $squishratio;
$x = + (($ox * $cosangle) - ($oy * $sinangle));
$y = $centrey + (($ox * $sinangle) + ($oy * $cosangle));
if ($nopreviouspoint) {
$px=$x;
$py=$y;
$nopreviouspoint=false;
}
if ($filled) {
triangle($im, $cx, $cy, $cx+$px, $cy+$py, $cx+$x, $cy+$y, $colour);
triangle($im, $cx, $cy, $cx-$px, $cx-$py, $cx-$x, $cy-$y, $colour);
} else {
imageline($im, $cx+$px, $cy+$py, $cx+$x, $cy+$y, $colour);
imageline($im, $cx-$px, $cx-$py, $cx-$x, $cy-$y, $colour);
}
$px=$x;
$py=$y;
}
}
function triangle($im, $x1,$y1, $x2,$y2, $x3,$y3, $colour) {
$coords = array($x1,$y1, $x2,$y2, $x3,$y3);
imagefilledpolygon($im, $coords, 3, $colour);
}
?>
ericquil at yahoo dot com ¶
12 years ago
If circles overlap, a temporary border is needed when filling:
<?php
ImageArc ($im,$x,$y,$w,$h,0,360,$temp_color);
ImageFillToBorder($im,$x,$y,$temp_color,$fill_color);
ImageArc ($im,$x,$y,$w,$h,0,360,$fill_color);
?>
cbriou at orange-art dot fr ¶
12 years ago
There is another way to fill an arc :
<?php
// To draw the arc
$Color = imagecolorallocate($Image, $Red, $Green, $Blue);
imagearc($Image, $CenterX, $CenterY, $Diameter, $Diameter, $Start, $End, $Color);
// To close the arc with 2 lines between the center and the 2 limits of the arc
$x = $CenterX + (cos(deg2rad($Start))*($Diameter/2));
$y = $CenterY + (sin(deg2rad($Start))*($Diameter/2));
imageline($Image, $x, $y, $CenterX, $CenterY, $Color);
$x = $CenterX + (cos(deg2rad($End))*($Diameter/2));
$y = $CenterY + (sin(deg2rad($End))*($Diameter/2));
imageline($Image, $x, $y, $CenterX, $CenterY, $Color);
// To fill the arc, the starting point is a point in the middle of the closed space
$x = $CenterX + (cos(deg2rad(($Start+$End)/2))*($Diameter/4));
$y = $CenterY + (sin(deg2rad(($Start+$End)/2))*($Diameter/4));
imagefilltoborder($Image, $x, $y, $Color, $Color);
?>
timothyhouck at yahoo dot com ¶
12 years ago
To do filled arcs, try something like this:
<?php
$diameter = 50;
imagearc($image, 25, 25, $diameter, $diameter, $start, $end, $color);
while($diameter > 0) {
imagearc($image, 25, 25, $diameter, $diameter, $start, $start + 1, $color);
imagearc($image, 25, 25, $diameter, $diameter, $end - 1, $end, $color);
$diameter--;
}
?>
...well you get the point. It's a kludge, and *very* slow, but it's free.
travis at duluth dot com ¶
13 years ago
The wierd thing is that the first two integers tell where to place the "circle".
So for example I first create the "pallet" to place the circle on.
$image = imagecreate(500, 500);
(this makes a huge 500x500 gif :) )
$colorBody = imagecolorallocate($image, 0, 0, 0);
(make the default color of the "pallet" black
$circleColor = imagecolorallocate($image, 255, 0, 255);
(going to make the circle an ugly pink color)
imagearc($image, 250, 250, 300, 300, 0, 360, $circleColor);
Places the image in the center (250,250) and the circle is 300 pixels in diameter.
Hope this helps.
Travis Kent Beste