Php draw rectangle on image

(PHP 4, PHP 5, PHP 7, PHP 8)

imagerectangle — Draw a rectangle

Description

imagerectangle(
    GdImage $image,
    int $x1,
    int $y1,
    int $x2,
    int $y2,
    int $color
): bool

Parameters

A GdImage object, returned by one of the image creation functions, such as imagecreatetruecolor().

Upper left x coordinate.

Upper left y coordinate 0, 0 is the top left corner of the image.

Bottom right x coordinate.

Bottom right y coordinate.

A color identifier created with imagecolorallocate().

Return Values

Returns true on success or false on failure.

Changelog

Examples

Example #1 Simple imagerectangle() example

<?php
// Create a 200 x 200 image
$canvas = imagecreatetruecolor(200, 200);// Allocate colors
$pink = imagecolorallocate($canvas, 255, 105, 180);
$white = imagecolorallocate($canvas, 255, 255, 255);
$green = imagecolorallocate($canvas, 132, 135, 28);// Draw three rectangles each with its own color
imagerectangle($canvas, 50, 50, 150, 150, $pink);
imagerectangle($canvas, 45, 60, 120, 100, $white);
imagerectangle($canvas, 100, 120, 75, 160, $green);// Output and free from memory
header('Content-Type: image/jpeg');imagejpeg($canvas);
imagedestroy($canvas);
?>

The above example will output something similar to:

stanislav dot eckert at vizson dot de ¶

7 years ago

Please pay attention if you want to draw pixel perfect rectangles: Since this function uses absolute values for the second coordinate points (instead of width and height), you might face a logical problem. PHP counts from 0. But a pixel at position 0,0 occupies already a 1x1 space. In the example above you have the following line:

imagerectangle($canvas, 50, 50, 150, 150, $pink);

If you don't pay attention, you might thing that the difference between the two coordinates is exactly 100 and assume that the drawn rectangle would have the dimension of 100 x 100 pixels too. But it would be 101 x 101, because PHP counts from 0 and imagerectangle() uses absolute coordinates for the second point too. A smaller example: A rectangle with coordinates 0,0 and 5,5 means 0,1,2,3,4,5 which are 6 pixels, not 5.

eustaquiorangel at yahoo dot com ¶

19 years ago

If you want an empty rectangle, I mean, just the borders, fill it first with the ImageFilledRectangle function with the background color and then draw it with this function.

rogier ¶

15 years ago

In addition to Corey's note, this is the kind of code he means. Note that I always draw an outer grid border, so drawing lines will always take
1 + ceil((rows+cols)/2) actions. For a 20X20 grid, this means 21 actions, a 10X25 grid takes 19 Actions

<?phpfunction draw_grid(&$img, $x0, $y0, $width, $height, $cols, $rows, $color) {
    //draw outer border
    imagerectangle($img, $x0, $y0, $x0+$width*$cols, $y0+$height*$rows, $color);
    //first draw horizontal
    $x1 = $x0;
    $x2 = $x0 + $cols*$width;
    for ($n=0; $n<ceil($rows/2); $n++) {
        $y1 = $y0 + 2*$n*$height;
        $y2 = $y0 + (2*$n+1)*$height;
        imagerectangle($img, $x1,$y1,$x2,$y2, $color);
    }
    //then draw vertical
    $y1 = $y0;
    $y2 = $y0 + $rows*$height;
    for ($n=0; $n<ceil($cols/2); $n++) {
        $x1 = $x0 + 2*$n*$width;
        $x2 = $x0 + (2*$n+1)*$width;
        imagerectangle($img, $x1,$y1,$x2,$y2, $color);
    }
}//example
$img = imagecreatetruecolor(300, 200);
$red   = imagecolorallocate($img, 255,   0,   0);
draw_grid($img, 0,0,15,20,20,10,$red);
header("Content-type: image/png");
imagepng($img);
imagedestroy($img);
?>
have fun ;)

administrador(ensaimada)sphoera(punt)com ¶

16 years ago

<?php
// With this function you will draw rounded corners rectangles with transparent colors.
// Empty (not filled) figures are allowed too!!function draw_roundrectangle($img, $x1, $y1, $x2, $y2, $radius, $color,$filled=1) {
    if ($filled==1){
        imagefilledrectangle($img, $x1+$radius, $y1, $x2-$radius, $y2, $color);
        imagefilledrectangle($img, $x1, $y1+$radius, $x1+$radius-1, $y2-$radius, $color);
        imagefilledrectangle($img, $x2-$radius+1, $y1+$radius, $x2, $y2-$radius, $color);imagefilledarc($img,$x1+$radius, $y1+$radius, $radius*2, $radius*2, 180 , 270, $color, IMG_ARC_PIE);
        imagefilledarc($img,$x2-$radius, $y1+$radius, $radius*2, $radius*2, 270 , 360, $color, IMG_ARC_PIE);
        imagefilledarc($img,$x1+$radius, $y2-$radius, $radius*2, $radius*2, 90 , 180, $color, IMG_ARC_PIE);
        imagefilledarc($img,$x2-$radius, $y2-$radius, $radius*2, $radius*2, 360 , 90, $color, IMG_ARC_PIE);
    }else{
        imageline($img, $x1+$radius, $y1, $x2-$radius, $y1, $color);
        imageline($img, $x1+$radius, $y2, $x2-$radius, $y2, $color);
        imageline($img, $x1, $y1+$radius, $x1, $y2-$radius, $color);
        imageline($img, $x2, $y1+$radius, $x2, $y2-$radius, $color);imagearc($img,$x1+$radius, $y1+$radius, $radius*2, $radius*2, 180 , 270, $color);
        imagearc($img,$x2-$radius, $y1+$radius, $radius*2, $radius*2, 270 , 360, $color);
        imagearc($img,$x1+$radius, $y2-$radius, $radius*2, $radius*2, 90 , 180, $color);
        imagearc($img,$x2-$radius, $y2-$radius, $radius*2, $radius*2, 360 , 90, $color);
    }               
}?>
More functions at http://www.sphoera.com

carl at pappenheim dot net ¶

16 years ago

Oh I don't know.  He was on the right track..

<?php

$rows

matt at bargolf dot net ¶

16 years ago

Lets not do it Mr Benson's way OK!

I'm sure if I had to draw a 10x10 grid on paper I wouldn't do it by drawing 100 individual squares, redrawing nearly half of the lines twice.

I'd probably do it by drawing 11 vertical lines and 11 horizontal lines.

function ImageGrid2(&$im,$startx,$starty,$width,$height,$xcols,$yrows,&$color) {
    $endy = $starty + $height * $yrows;
    for ( $x=0; $x <= $xcols; $x++ ) {
        $x1 = $startx + $width * $x;
        imageline ( $im, $x1, $starty, $x1, $endy, $color );
    }

    $endx = $startx + $width * $xcols;
    for ( $y=0; $y <= $yrows; $y++ ) {
     $y1 = $starty + $height * $y;
     imageline ( $im, $startx, $y1, $endx, $y1, $color );
    }
}

Corey ¶

15 years ago

Matt,

I agree that drawing 100 boxes for a 10x10 square is ludicrous. However, if we're going to talk about the best way to draw it in GD, you're still off.

Since a rectangle will draw two vertical lines in one draw, we should use it to our advantage. You can draw 5 rectangles that have the tops and bottoms outside of the image, and there you have your ten rows. Draw 5 more who's sides are out of the image and you have your columns. We just drew a 10x10 (you could do 11x11) grid in 10 draw operations.

:)