imagerectangle

(PHP 4, PHP 5, PHP 7)

imagerectangle — 画一个矩形

说明

bool imagerectangle ( resource $image , int $x1 , int $y1 , int $x2 , int $y2 , int $col )

imagerectangle() 用 col 颜色在 image 图像中画一个矩形，其左上角坐标为 x1, y1，右下角坐标为 x2, y2。图像的左上角坐标为 0, 0。

用户评论:

[#1] stanislav dot eckert at vizson dot de [2015-06-10 09:15:24]

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.

[#2] rogier [2007-06-27 05:27:43]

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

<?php function 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 ;)

[#3] Corey [2007-02-13 15:09:40]

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.

:)

[#4] administrador(ensaimada)sphoera(punt)com [2006-05-04 07:28:19]

<?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

[#5] carl at pappenheim dot net [2006-02-20 03:02:44]

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

<?php $rows = 5; $cols = 11; $eachx = 12; $eachy = 18; $max = array($cols*$eachx, $rows*$eachy); $im = imagecreatetruecolor($max[0]+1,$max[1]+1); $white = imagecolorallocate($im,255,255,255); imagefill($im,0,0,$white); $black = imagecolorallocate($im,50,50,50); for($x=$max[0]/2;$x>=0;$x-=$eachx) { imagerectangle($im, ($max[0]/2)+$x,0, ($max[0]/2)-$x,$max[1], $black); } for($y=$max[1]/2;$y>=0;$y-=$eachy) { imagerectangle($im, 0,($max[1]/2)+$y, $max[0],($max[1]/2)-$y, $black); } header("Content-type: image/jpeg"); imagejpeg($im,'',80); imagedestroy($im); ?>

[#6] matt at bargolf dot net [2006-01-30 14:25:27]

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 );
    }
}

[#7] eustaquiorangel at yahoo dot com [2002-12-17 09:21:54]

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.