php104.tmp,PHP imagettfbbox 用法 手册 | 示例代码

This script shows you side by side the difference between a font rendered at a certain size and the same font rendered at some multiple of that size and then scaled down by the same multiple. It seems to help small sizes and affects large ones less. This script lets you see if it is worth implementing for your situation. Included is the great "imagettfbboxextended" function by mike at mikeleigh dot com below.

$size = 30;

$factor = 16;

$smallSize = imagettfbboxextended($size, 0, "fonts/MPlantin.ttf", "The quick brown fox jumps over the lazy dog.");

$smallWidth = $smallSize['width'];

$smallHeight = $smallSize['height'];

$canvas = imagecreatetruecolor($smallWidth + 20, $smallHeight * 2 + 20);

imagefill($canvas, 0, 0, imagecolorallocate($canvas, 255, 255, 255));

imagettftext($canvas, $size, 0, 10 + $smallSize['x'], 10 + $smallSize['y'], imagecolorallocate($canvas, 0, 0, 0), "fonts/MPlantin.ttf", "The quick brown fox jumps over the lazy dog.");

$largeSize = imagettfbboxextended($size * $factor, 0, "fonts/MPlantin.ttf", "The quick brown fox jumps over the lazy dog.");

$largeWidth = $largeSize['width'];

$largeHeight = $largeSize['height'];

$temp = imagecreatetruecolor($largeWidth, $largeHeight);

imagefill($temp, 0, 0, imagecolorallocate($canvas, 255, 255, 255));

imagettftext($temp, $size * $factor, 0, $largeSize['x'], $largeSize['y'], imagecolorallocate($temp, 0, 0, 0), "fonts/MPlantin.ttf", "The quick brown fox jumps over the lazy dog.");

imagecopyresampled($canvas, $temp, 10 + $smallSize['x'], 10 + $smallSize['y'] + 10, 0, 0, $smallWidth, $smallHeight, $largeWidth, $largeHeight);

imagepng($temp, "temp.png");

imagepng($canvas, "test.png");

function imagettfbboxextended($size, $angle, $fontfile, $text) {

/*this function extends imagettfbbox and includes within the returned array

the actual text width and height as well as the x and y coordinates the

text should be drawn from to render correctly.  This currently only works

for an angle of zero and corrects the issue of hanging letters e.g. jpqg*/

$bbox = imagettfbbox($size, $angle, $fontfile, $text);

//calculate x baseline

if($bbox[0] >= -1) {

$bbox['x'] = abs($bbox[0] + 1) * -1;

} else {

//$bbox['x'] = 0;

$bbox['x'] = abs($bbox[0] + 2);

}

//calculate actual text width

$bbox['width'] = abs($bbox[2] - $bbox[0]);

if($bbox[0] < -1) {

$bbox['width'] = abs($bbox[2]) + abs($bbox[0]) - 1;

}

//calculate y baseline

$bbox['y'] = abs($bbox[5] + 1);

//calculate actual text height

$bbox['height'] = abs($bbox[7]) - abs($bbox[1]);

if($bbox[3] > 0) {

$bbox['height'] = abs($bbox[7] - $bbox[1]) - 1;

}

return $bbox;

}