imagepstext
(PHP 4, PHP 5)
imagepstext — Draws a text over an image using PostScript Type1 fonts
Описание
Draws a text on an image using PostScript Type1 fonts.
Refer to PostScript documentation about fonts and their measuring system if you have trouble understanding how this works.
Список параметров
- image
-
An image resource, returned by one of the image creation functions, such as imagecreatetruecolor().
- text
-
The text to be written.
- font
-
Can be 1, 2, 3, 4, 5 for built-in fonts in latin2 encoding (where higher numbers corresponding to larger fonts) or any of your own font identifiers registered with imageloadfont().
- size
-
size is expressed in pixels.
- foreground
-
The color in which the text will be painted.
- background
-
The color to which the text will try to fade in with antialiasing. No pixels with the color background are actually painted, so the background image does not need to be of solid color.
- x
-
x-coordinate for the lower-left corner of the first character
- y
-
y-coordinate for the lower-left corner of the first character
- space
-
Allows you to change the default value of a space in a font. This amount is added to the normal value and can also be negative. Expressed in character space units, where 1 unit is 1/1000th of an em-square.
- tightness
-
tightness allows you to control the amount of white space between characters. This amount is added to the normal character width and can also be negative. Expressed in character space units, where 1 unit is 1/1000th of an em-square.
- angle
-
angle is in degrees.
- antialias_steps
-
Allows you to control the number of colours used for antialiasing text. Allowed values are 4 and 16. The higher value is recommended for text sizes lower than 20, where the effect in text quality is quite visible. With bigger sizes, use 4. It's less computationally intensive.
Возвращаемые значения
This function returns an array containing the following elements:
| 0 | lower left x-coordinate |
| 1 | lower left y-coordinate |
| 2 | upper right x-coordinate |
| 3 | upper right y-coordinate |
Примечания
Замечание: Эта функция доступна только в том случае, если PHP был скомпилирован с опцией --enable-t1lib.
- PHP Руководство
- Функции по категориям
- Индекс функций
- Справочник функций
- Обработка и генерация изображений
- Обработка изображений и GD
- gd_info
- getimagesize
- getimagesizefromstring
- image_type_to_extension
- image_type_to_mime_type
- image2wbmp
- imageaffine
- imageaffinematrixconcat
- imageaffinematrixget
- imagealphablending
- imageantialias
- imagearc
- imagechar
- imagecharup
- imagecolorallocate
- imagecolorallocatealpha
- imagecolorat
- imagecolorclosest
- imagecolorclosestalpha
- imagecolorclosesthwb
- imagecolordeallocate
- imagecolorexact
- imagecolorexactalpha
- imagecolormatch
- imagecolorresolve
- imagecolorresolvealpha
- imagecolorset
- imagecolorsforindex
- imagecolorstotal
- imagecolortransparent
- imageconvolution
- imagecopy
- imagecopymerge
- imagecopymergegray
- imagecopyresampled
- imagecopyresized
- imagecreate
- imagecreatefromgd2
- imagecreatefromgd2part
- imagecreatefromgd
- imagecreatefromgif
- imagecreatefromjpeg
- imagecreatefrompng
- imagecreatefromstring
- imagecreatefromwbmp
- imagecreatefromwebp
- imagecreatefromxbm
- imagecreatefromxpm
- imagecreatetruecolor
- imagecrop
- imagecropauto
- imagedashedline
- imagedestroy
- imageellipse
- imagefill
- imagefilledarc
- imagefilledellipse
- imagefilledpolygon
- imagefilledrectangle
- imagefilltoborder
- imagefilter
- imageflip
- imagefontheight
- imagefontwidth
- imageftbbox
- imagefttext
- imagegammacorrect
- imagegd2
- imagegd
- imagegif
- imagegrabscreen
- imagegrabwindow
- imageinterlace
- imageistruecolor
- imagejpeg
- imagelayereffect
- imageline
- imageloadfont
- imagepalettecopy
- imagepalettetotruecolor
- imagepng
- imagepolygon
- imagepsbbox
- imagepsencodefont
- imagepsextendfont
- imagepsfreefont
- imagepsloadfont
- imagepsslantfont
- imagepstext
- imagerectangle
- imagerotate
- imagesavealpha
- imagescale
- imagesetbrush
- imagesetinterpolation
- imagesetpixel
- imagesetstyle
- imagesetthickness
- imagesettile
- imagestring
- imagestringup
- imagesx
- imagesy
- imagetruecolortopalette
- imagettfbbox
- imagettftext
- imagetypes
- imagewbmp
- imagewebp
- imagexbm
- iptcembed
- iptcparse
- jpeg2wbmp
- png2wbmp
Коментарии
with a font included in t1lib:
<?PHP
Header ("Content-type: image/jpeg");
$im = ImageCreate (350, 45);
$black = ImageColorAllocate ($im, 0, 0, 0);
$white = ImageColorAllocate ($im, 255, 255, 255);
$font=ImagePsLoadFont("bchbi.pfb");
ImagePsText($im, "Testing... It worked!",
$font, 32, $white, $black, 32, 32);
ImagePsFreeFont($font);
ImageJpeg($im, "", 100);//for best quality... your mileage may vary
ImageDestroy ($im);
?>
Better than using freetype, but with freetype2, the difference is marginal. To flip backround and foreground colors, alternate the order of ImageColorAllocate statements.
If you get outlines (the antialiasing produces these) reverse the $black and $white color identifiers in the ImagePsText function.
Happy PostScripting!
thx,
Neil
One other thing... variables. It is important to convert variables to the proper type before they hit this function. In this respect, ImageTtfText is easier to work with. IE, if you pass a font size from one page to the next, via GPC, it becomes a string type. Sooo... use IntVal() to convert it to an integer type that ImagePsText can digest. In addition you must convert HTML special characters or use chr() to represent special characters. ImagePsFont will not decode to represent a space, use Chr(32) or a space:
<?php
$fontsize=IntVal($fontsize);
$font=ImagePsLoadFont("fonts/IntR.pfb");
ImagePsText($im, $textstring, $font, $fontsize, $textcolor, $background, 0, $fontsize,'','','',16); //note antialias is set
ImagePsFreeFont($font);
?>
thx,
Neil
If you have a programming error in your code, using ImagePsText, sometimes t1lib crashes with an unrecoverable error. Because of this, httpd needs to be restarted.
This problem only occurs if there is a programming error, but can drive you crazy when debugging, if you don't know about it. By killing the parent process(httpd) you "reset" t1lib. When debugging, if you get an error then make a code change, restart httpd before testing it again. This will save hours of frustration. Make it a habit to just restart httpd after every error, and you will be much happier.
Also, to see debugging messages, (if you are rendering x's) comment the jpeg header, and the ImageJpeg statement. You will get beautiful error messages. When you get a blank page, your ImagePsText code is working correctly. Uncomment the Header() and ImageJpeg() and see what you have. You might be passing parameters that render a white image with no text, but the code is working!
Numeric t1lib error messages can be decoded using the t1lib_doc.pdf file that comes with t1lib. PHP simply relays these errors from t1lib to the page. Please don't ask the PHP people about these errors... t1lib has beautiful documentation.... use it: )
thx,
Neil
a note on kernnig:
t1lib tries to load a corresponding afm file in the directory of the font file.
it does this by replacing the extension (.PFB .pfb) with ".afm". note that this has to be a lowercase afm! usually windows-ps-fonts have file names in all-uppercase, so try renaming the *.AFM file to *.afm.
i also noticed that sometimes this gives an error -2. it seems like t1lib chokes on windows-linebreaks in the afm file.
try 'recode dos..lat1 fontfile.afm' and check again.
if it all works, combinations like "Ta" or "Te" should show the second letter slightly moved to the capital T (on normal fonts like Times anyway).
If you use fonts with special chars, remeber to read in the encoded file *.enc with imagepsencodefont ... etc. for Danish, Swedish, German.....I made a function that makes it easy to align text to the right
of an image. Below you can find the code because for me it
works great. You can also use it to center text as well, if you
like to have that simply remove the -10 and split the result
of $imgwidth and $texwidth
function AlignRight($string, $font, $imgwidth, $fontsize) {
list($lx,$ly,$rx,$ry) = imagepsbbox($string,$font,$fontsize,0,0,0);
$textwidth = $rx - $lx;
$imw = ($imgwidth-10-$textwidth);
return $imw;
}
I found a way to let imagepstext understand 32-bit colors (RGBA) by replacing in gd.c:PHP_FUNCTION(imagepstext)
int _fg, _bg, x, y, size, space = 0, aa_steps = 4, width = 0;
with
unsigned int _fg, _bg, x, y, size, space = 0, aa_steps = 4, width = 0;
It is important so make shure that the "text" really is a string.
imagepstext ($im, $text, $font, $textsize, $black, $white, 10, 10);
won't work if $text is undefined, so PHP will quit with an error.
so always write it like this:
imagepstext ($im, "$text", $font, $textsize, $black, $white, 10, 10);
The coordinates given by x, y represent actually a starting point of the text baseline. They represent the lower left corner of the first character only in case that any part of the character doesn't lie below baseline (it works for "Hello" but for "Howdy" it does not - because of letter y). There may be some small differences according to the font and size chosen.imagepstext() appears to be quite memory intensive and we had a problem where about 50% of the time the script would error. You need to make sure PHP has enough memory assigned to it - we had to increase PHP's allocation from 8MB to 16MB for a simple "hello world" example to work smoothly.
If the png header was commented out it would sometimes error with a message like:
Warning: imagepstext() [function.imagepstext]: T1Lib Error 11 or 14
and if the png header was there it would sometimes say:
The image [...] cannot be displayed, because it contains errors.
The documentation above is bad. It says $font:
"Can be 1, 2, 3, 4, 5 for built-in fonts in latin2 encoding (where higher numbers corresponding to larger fonts) or any of your own font identifiers registered with imageloadfont()."
But it can't. When I put in 1,2,3,4,5 I get
"Warning: imagepstext() expects parameter 3 to be resource, integer given"
I get the same thing when using imageloadfont() because imageloadfont() also returns an integer. The documentation should instead say:
"resource returned from imagepsloadfont()."
As of PHP 5.2.13 with bundled GD (2.0.34) antialiasing_steps mustn't be "4 to 16", but "4 or 16". Values from 5 to 15 result in a warning.