[PHP 4, PHP 5, PHP 7, PHP 8]
imageline — Draw a line
Description
imageline[
GdImage $image,
int $x1,
int
$y1,
int $x2,
int $y2,
int $color
]: bool
Parameters
imageA GdImage object, returned by one of the image creation functions, such as imagecreatetruecolor[].
x1x-coordinate for first point.
y1y-coordinate for first point.
x2x-coordinate for second point.
y2y-coordinate for second point.
colorThe line color. A color identifier created with imagecolorallocate[].
Return Values
Returns true on success or false on failure.
Changelog
| 8.0.0 | image expects a GdImage instance now; previously, a resource was expected.
|
Examples
Example #1 Drawing a thick line
See Also
- imagecreatetruecolor[] - Create a new true color image
- imagecolorallocate[] - Allocate a color for an image
pb_2001 at haefft dot de ¶
16 years ago
This is a function to make a dotted line. It accepts [it actually requires] 7 parameters and returns 1 if everything went OK and 0 if there was a problem.
int imagelinedotted [ resource im, int x1, int y1, int x2, int y2, int dist, int col ]
imagelinedotted[] draws a line from x1, y1 to x2, y2 [top left is 0, 0] in image im of colour col where dist defines the distance [measured in pixels] between one dot and another.
Jonathan W. ¶
15 years ago
I've modified the previous entry for drawing on a polar coordinate system to better represent angles based on a 360º whole circle bearing.
d [AT] sprid [DOT] de ¶
17 years ago
Here my function do clear all problems. With this, you can draw firstly smooth lines [basic code adapted from code_couturier at graffiti dot net, with some performance changes]. The special is, you can define the alpha-value of the line [0 = normal smooth line, 127 = fully transparent]. Change whatever you want to make it better, but post your results ;]
kramesch_NOSPAM_ at _nospam_idsolutions dot at ¶
20 years ago
Here is a simple code to draw a line with an arbitrary stroke. The parameter aStroke is treated as a cyclic boolean array where true equals "set a point"
e.g. $aDotStroke = array[true,false];
function ImageStrokeLine[$im,$x1,$y1,$x2,$y2,$farbe, $aStroke]
{
$deltax = abs[$x2 - $x1];
$deltay = abs[$y2 - $y1];
$x = $x1;
$y = $y1;
if [$x2 >= $x1]
{
$xinc1 = 1;
$xinc2 = 1;
}
else
{
$xinc1 = -1;
$xinc2 = -1;
}
if [$y2 >= $y1]
{
$yinc1 = 1;
$yinc2 = 1;
}
else
{
$yinc1 = -1;
$yinc2 = -1;
}
if [$deltax >= $deltay]
{
$xinc1 = 0;
$yinc2 = 0;
$den = $deltax;
$num = $deltax / 2;
$numadd = $deltay;
$numpixels = $deltax;
}
else
{
$xinc2 = 0;
$yinc1 = 0;
$den = $deltay;
$num = $deltay / 2;
$numadd = $deltax;
$numpixels = $deltay;
}
for [$curpixel = 0; $curpixel = count[$aStroke]]
{
$iStrokeCount = 0;
}
if [$aStroke[$iStrokeCount++]]
{
ImageSetPixel[$im,$x, $y,$farbe];
}
$num += $numadd;
if [$num >= $den]
{
$num -= $den;
$x += $xinc1;
$y += $yinc1;
}
$x += $xinc2;
$y += $yinc2;
}
}
Nils ¶
10 years ago
A quick function using imageline that I wrote so i could specify a starting point, angle and length of vector.
Thought other people might find this useful.
For this script angles work in a anti-clockwise direction [modify + and - in function to change start of 0 degrees and also direction of angle calculated]
sbm007 at gmail dot com ¶
12 years ago
Here is a analog clock representation of the system time along with digits for hours and little dots for minutes/seconds:
nanobot at chipx86 dot com ¶
19 years ago
Here is a function for making antialiased lines:
function imagesmoothline [ $image , $x1 , $y1 , $x2 , $y2 , $color ]
{
$colors = imagecolorsforindex [ $image , $color ];
if [ $x1 == $x2 ]
{
imageline [ $image , $x1 , $y1 , $x2 , $y2 , $color ]; // Vertical line
}
else
{
$m = [ $y2 - $y1 ] / [ $x2 - $x1 ];
$b = $y1 - $m * $x1;
if [ abs [ $m ]
Tyron ¶
17 years ago
// Here's a function for drawing a rotated gradient Rectangle [based on a previous note]
// Create An Image 255x255
$img = ImageCreateTrueColor[255, 255];
GradientRect[$img,50,50,80,80,30];
ImagePng[$img,"test.png"];
ImageDestroy[$img];
echo "
";
function GradientRect[$img, $x1, $y1, $x2, $y2, $wdt] {
$alpha = atan2[$y2-$y1,$x2-$x1];
$real_wdt = $wdt*sin[$alpha];
$real_hgt = $wdt*cos[$alpha];
echo "real wdt:".$real_wdt;
echo "
real hgt:".$real_hgt;
echo "
angle: ".[$angle*180/pi[]];
$plotD = 0;
$i=0;
$dy = $real_hgt/$wdt;
$dx = $real_wdt/$wdt;
$drgb= 256/$wdt;
while[$i++ < $wdt] {
// Draw a line and move it down and make it lighter to get the gradient effect
ImageLine[$img, $x1-$i*$dx, $y1+$i*$dy, $x2-$i*$dx, $y2+$i*$dy, ImageColorAllocate[$img, $i*$drgb, 0, 0]];
ImageLine[$img, $x1-$i*$dx+1, $y1+$i*$dy, $x2-$i*$dx+1, $y2+$i*$dy, ImageColorAllocate[$img, $i*$drgb, 0, 0]];
}
}
yl at sota dot ch ¶
18 years ago
Simple function to create border for jpg-images:
function createImageBorder[$imgName]{
$img = substr[$imgName, 0, -4]; // remove fileExtension
$ext = ".jpg";
$quality = 95;
$borderColor = 255; // 255 = white
/*
a b
+-------------------------+
|
| IMAGE
|
+-------------------------+
c d
*/
$scr_img = imagecreatefromjpeg[$img.$ext];
$width = imagesx[$scr_img];
$height = imagesy[$scr_img];
// line a - b
$abX = 0;
$abY = 0;
$abX1 = $width;
$abY1 = 0;
// line a - c
$acX = 0;
$acY = 0;
$acX1 = 0;
$acY1 = $height;
// line b - d
$bdX = $width-1;
$bdY = 0;
$bdX1 = $width-1;
$bdY1 = $height;
// line c - d
$cdX = 0;
$cdY = $height-1;
$cdX1 = $width;
$cdY1 = $height-1;
// DRAW LINES
imageline[$scr_img,$abX,$abY,$abX1,$abY1,$borderColor];
imageline[$scr_img,$acX,$acY,$acX1,$acY1,$borderColor];
imageline[$scr_img,$bdX,$bdY,$bdX1,$bdY1,$borderColor];
imageline[$scr_img,$cdX,$cdY,$cdX1,$cdY1,$borderColor];
// create copy from image
imagejpeg[$scr_img, $img."_border.jpg", $quality];
imagedestroy[$scr_img];
}
createImageBorder["myfile.jpg"];
mueller at inf dot ufsc dot br ¶
18 years ago
an algorithm to draw a bezier spline
v dot krypton at yandex dot ru ¶
6 years ago
This function draw border to image.
function imageborder[$img,$color] {
$width = imagesx[$img];
$height = imagesy[$img];
ImageLine[$img, 0, 0, $width, 0, $color];
ImageLine[$img, 0, 0, 0, $height, $color];
ImageLine[$img, $width-1, 0, $height-1, $height, $color];
ImageLine[$img, 0, $height-1, $width, $height-1, $color];
}
teixeira dot cmo at gmail.com ¶
5 years ago
If you draw on a canvas, using js ctx.lineJoin = "round"; and then try to do the same on a GD $img the result will not be the same.
Here is a simple code to draw a line similar to one made using lineJoin round.
$w=5; //set your line thickness;
imagesetthickness[$img, $w];
imageline[$img, $x1, $y1, $x2, $y2, $color];
imagesetthickness[$img, 1];
imagefilledellipse [ $img , $x2 , $y2 , $w ,$w, $color];
Anonymous ¶
11 years ago
The most bold-line-functions i found have problems with lines in a certian direction [they draw smaller lines with some angles]. To do a real bold line just use this function:
Anonymous ¶
13 years ago
Here's another way of modifying likavcan's code to display filled arrows. This makes use of imagefilledpolygon[...] instead of recursive function calls.
huirong dot jin at gmail dot com ¶
14 years ago
An example to draw Amplitude Modulation curve: y = c * sin [x/a] * sin [x/b] . You can easily modify the codes to create your own oscilloscope application!