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 ;)
imagerectangle
(PHP 4, PHP 5)
imagerectangle — 矩形を描画する
説明
bool imagerectangle ( resource $image, int $x1, int $y1, int $x2, int $y2, int $color )imagerectangle() は、指定した座標から始まる矩形を作成します。
パラメータ
- image
imagecreatetruecolor() のような画像作成関数が返す画像リソース。
- x1
左上の x 座標。
- y1
左上の y 座標。 0, 0 が画像の左上隅を表します。
- x2
右下の x 座標。
- y2
右下の y 座標。
- color
imagecolorallocate() で作成した色 ID。
返り値
成功した場合に TRUE を、失敗した場合に FALSE を返します。
imagerectangle
rogier
27-Jun-2007 09:27
27-Jun-2007 09:27
Corey
14-Feb-2007 08:09
14-Feb-2007 08:09
Matt,
I agree that drawing 100 boxes for a 10x10 square is ludicrous. However, if we're going to talk about the best way to draw it in GD, you're still off.
Since a rectangle will draw two vertical lines in one draw, we should use it to our advantage. You can draw 5 rectangles that have the tops and bottoms outside of the image, and there you have your ten rows. Draw 5 more who's sides are out of the image and you have your columns. We just drew a 10x10 (you could do 11x11) grid in 10 draw operations.
:)
administrador(ensaimada)sphoera(punt)com
04-May-2006 11:28
04-May-2006 11:28
<?php
// With this function you will draw rounded corners rectangles with transparent colors.
// Empty (not filled) figures are allowed too!!
function draw_roundrectangle($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
20-Feb-2006 08:02
20-Feb-2006 08:02
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($im);
?>
matt at bargolf dot net
31-Jan-2006 07:25
31-Jan-2006 07:25
Lets not do it Mr Benson's way OK!
I'm sure if I had to draw a 10x10 grid on paper I wouldn't do it by drawing 100 individual squares, redrawing nearly half of the lines twice.
I'd probably do it by drawing 11 vertical lines and 11 horizontal lines.
function ImageGrid2(&$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, $color );
}
}
eustaquiorangel at yahoo dot com
18-Dec-2002 02:21
18-Dec-2002 02:21
If you want an empty rectangle, I mean, just the borders, fill it first with the ImageFilledRectangle function with the background color and then draw it with this function.
jbenson at technologist dot com
28-Nov-2000 03:41
28-Nov-2000 03:41
For those wanting a function to draw a grid I've created one. I hope this is the right place to post it.
function ImageGrid(&$im,$startx,$starty,$width,$height,$xcols,$yrows,&$color) {
for ( $x=0; $x < $xcols; $x++ ) {
for ( $y=0; $y < $yrows; $y++ ) {
$x1 = $startx + ($width * $x);
$x2 = $startx + ($width * ($x+1));
$y1 = $starty + ($height * $y);
$y2 = $starty + ($height * ($y+1));
ImageRectangle($im, $x1, $y1, $x2, $y2, $color);
}
}
} // end function ImageGrid