1Text(3) User Contributed Perl Documentation Text(3)
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6 GD::Text - Text utilities for use with GD
7
9 use GD;
10 use GD::Text;
11 my $gd_text = GD::Text->new() or die GD::Text::error();
13 $gd_text->set_font('funny.ttf', 12) or die $gd_text->error;
14 $gd_text->set_font(gdTinyFont);
15 $gd_text->set_font(GD::Font::Tiny);
16 ...
17 $gd_text->set_text($string);
18 my ($w, $h) = $gd_text->get('width', 'height');
19 if ($gd_text->is_ttf)
21 {
22 ...
23 }
24 Or alternatively
26 my $gd_text = GD::Text->new(
28 text => 'Some text',
29 font => 'funny.ttf',
30 ptsize => 14,
31 );
32
34 This module provides a font-independent way of dealing with text in GD,
35 for use with the GD::Text::* modules and GD::Graph.
36
38 As with all Modules for Perl: Please stick to using the interface. If
39 you try to fiddle too much with knowledge of the internals of this
40 module, you could get burned. I may change them at any time.
41 You can only use TrueType fonts with version of GD > 1.20, and then
43 only if compiled with support for this. If you attempt to do it anyway,
44 you will get errors.
45 If you want to refer to builtin GD fonts by their short name
47 ("gdTinyFont", "gdGiantFont"), you will need to "use" the GD module as
48 well as one the GD::Text modules, because it is GD that exports those
49 names into your name space. If you don't like that, use the longer
50 alternatives ("GD::Font-"Giant>) instead.
51
53 GD::Text->new( attrib => value, ... )
54 Create a new object. See the "set()" method for attributes.
55 GD::Text::error() or $gd_text->error();
57 Return the last error that occured in the class. This may be imperfect.
58 $gd_text->set_font( font, size )
60 Set the font to use for this string. The arguments are either a GD
61 builtin font (like gdSmallFont or GD::Font->Small) or the name of a
62 TrueType font file and the size of the font to use. See also
63 "font_path".
64 If you are not using an absolute path to the font file, you can leave
66 of the .ttf file extension, but you have to append it for absolute
67 paths:
68 $gd_text->set_font('arial', 12);
70 # but
71 $gd_text->set_font('/usr/fonts/arial.ttf', 12);
72 The first argument can be a reference to an array of fonts. The first
74 font from the array that can be found will be used. This allows you to
75 do something like
76 $gd_text->font_path( '/usr/share/fonts:/usr/fonts');
78 $gd_text->set_font(
79 ['verdana', 'arial', gdMediumBoldFont], 14);
80 if you'd prefer verdana to be used, would be satisfied with arial, but
82 if none of that is available just want to make sure you can fall back
83 on something that will be available.
84 Returns true on success, false on error.
86 $gd_text->set_text('some text')
88 Set the text to operate on. Returns true on success and false on
89 error.
90 $gd_text->set( attrib => value, ... )
92 The set method provides a convenience replacement for the various other
93 "set_xxx()" methods. Valid attributes are:
94 text
96 The text to operate on, see also "set_text()".
97 font, ptsize
99 The font to use and the point size. The point size is only used for
100 TrueType fonts. Also see "set_font()".
101 Returns true on success, false on any error, even if it was partially
103 successful. When an error is returned, no guarantees are given about
104 the correctness of the attributes.
105 $gd_text->get( attrib, ... )
107 Get the value of an attribute. Return a list of the attribute values
108 in list context, and the value of the first attribute in scalar
109 context.
110 The attributes that can be retrieved are all the ones that can be set,
112 and:
113 width, height
115 The width (height) of the string in pixels
116 space
118 The width of a space in pixels
119 char_up, char_down
121 The number of pixels that a character can stick out above and below
122 the baseline. Note that this is only useful for TrueType fonts. For
123 builtins char_up is equal to height, and char_down is always 0.
124 Note that some of these parameters (char_up, char_down and space) are
126 generic font properties, and not necessarily a property of the text
127 that is set.
128 $gd_text->width('string')
130 Return the length of a string in pixels, without changing the current
131 value of the text. Returns the width of 'string' rendered in the
132 current font and size. On failure, returns undef.
133 The use of this method is vaguely deprecated.
135 $gd_text->is_builtin
137 Returns true if the current object is based on a builtin GD font.
138 $gd_text->is_ttf
140 Returns true if the current object is based on a TrueType font.
141 $gd_text->can_do_ttf() or GD::Text->can_do_ttf()
143 Return true if this object can handle TTF fonts.
144 This depends on whether your version of GD is newer than 1.19 and has
146 TTF support compiled into it.
147 $gd_text->font_path(path_spec), GD::Text->font_path(path_spec)
149 This sets the font path for the class (i.e. not just for the object).
150 The "set_font" method will search this path to find the font specified
151 if it is a TrueType font. It should contain a list of paths. The
152 current directory is always searched first, unless '.' is present in
153 FONT_PATH. Examples:
154 GD::Text->font_path('/usr/ttfonts'); # Unix
156 GD::Text->font_path('c:/fonts'); # MS-OS
157 Any font name that is not an absolute path will first be looked for in
159 the current directory, and then in /usr/ttfonts (c:\fonts).
160 GD::Text->font_path('/usr/ttfonts:.:lib/fonts'); # Unix
162 GD::Text->font_path('c:/fonts;.;f:/fonts'); # MS-OS
163 Any font name that is not an absolute path will first be looked for in
165 /usr/ttfonts (c:\fonts), then in the current directory. and then in
166 lib/fonts (f:\fonts), relative to the current directory.
167 GD::Text->font_path(undef);
169 Font files are only looked for in the current directory.
171 FONT_PATH is initialised at module load time from the environment
173 variables FONT_PATH or, if that's not present, TTF_FONT_PATH, or
174 TT_FONT_PATH.
175 Returns the value the font path is set to. If called without arguments
177 "font_path" returns the current font path.
178 Note: This currently only works for unices, and (hopefully) for
180 Microsoft based OS's. If anyone feels the urge to have a look at the
181 code, and send me patches for their OS, I'd be most grateful)
182
184 This module has only been tested with anglo-centric 'normal' fonts and
185 encodings. Fonts that have other characteristics may not work well.
186 If that happens, please let me know how to make this work better.
187 The font height gets estimated by building a string with all printable
189 characters (with an ordinal value between 0 and 255) that pass the
190 POSIX::isprint() test (and not the isspace() test). If your system
191 doesn't have POSIX, I make an approximation that may be false. Under
192 Perl 5.8.0 the [[:print:]] character class is used, since the POSIX
193 is*() functions don't seem to work correctly.
194 The whole font path thing works well on Unix, but probably not very
196 well on other OS's. This is only a problem if you try to use a font
197 path. If you don't use a font path, there should never be a problem. I
198 will try to expand this in the future, but only if there's a demand for
199 it. Suggestions welcome.
200
202 copyright 1999 Martien Verbruggen (mgjv@comdyn.com.au)
203
205 GD(3), GD::Text::Wrap(3), GD::Text::Align(3)
206
208 Hey! The above document had some coding errors, which are explained
209 below:
210 Around line 197:
212 =pod directives shouldn't be over one line long! Ignoring all 20
213 lines of content
214perl v5.30.1 2020-01-30 Text(3)