imagearc

add a note User Contributed Notes

mojiro at awmn dot net
14-Dec-2005 04:28


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);

}

hans at lintoo dot dk
18-Jul-2004 10:19


When doing a pie chart... you really should not use imagearc, use imagefilledarc instead... it is much much easier...(and I guess every hosting company should support it by now)



3D Piechart:

Se my modified code at: http://dk.php.net/manual/en/function.imagefilledarc.php



For a quick sample see the online demo at:

http://webstatistik.lintoo.dk/

ruturaj_v at yahoo dot com
17-May-2004 09:32


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
26-Dec-2003 06:05


[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
17-Dec-2003 11:24


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
05-Aug-2003 11:19


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);

        }

    }

}

24-Jan-2003 12:55


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
14-May-2002 01:27


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
01-Dec-2001 05:04


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
09-Nov-2001 05:04


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
03-Sep-2001 12:56


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 );


?>

09-Apr-2001 01:37


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
02-Apr-2001 05:18


Here's a dashed circle function:





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
02-Apr-2001 05:06


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.





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
29-Sep-2000 07:30


If circles overlap, a temporary border is needed when filling:


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
18-Sep-2000 10:03


There is another way to fill an arc :





// 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
17-Aug-2000 06:58


To do filled arcs, try something like this:





$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
23-Dec-1999 10:36


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

add a note

imagearc

说明