GD::Text::Align(3pm)

1Text::Align(3)        User Contributed Perl Documentation       Text::Align(3)
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NAME

6       GD::Text::Align - Draw aligned strings
7

SYNOPSIS

9         use GD;
10         use GD::Text::Align;
11
12         my $gd = GD::Image->new(800,600);
13         # allocate colours, do other things.
14
15         my $align = GD::Text::Align->new($gd
16           valign => 'top',
17           halign => 'right',
18         );
19         $align->set_font('arial', 12);
20         $align->set_text('some string');
21         @bb = $align->bounding_box(200, 400, PI/3);
22         # you can do things based on the bounding box here
23         $align->draw(200, 400, PI/3);
24

DESCRIPTION

26       GD::Text::Align provides an object that draws a string aligned to a
27       coordinate at an angle.
28
29       For builtin fonts only two angles are valid: 0 and PI/2. All other
30       angles will be converted to one of these two.
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METHODS

33       This class inherits everything from GD::Text. I will only discuss the
34       methods and attributes here that are not discussed there, or that have
35       a different interface or behaviour. Methods directly inherited include
36       "set_text" and "set_font".
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38       GD::Text::Align->new($gd_object, attrib => value, ...)
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40       Create a new object. The first argument to new has to be a valid
41       GD::Image object. The other arguments will be passed on to the set
42       method.
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44       $align->set(attrib => value, ...)
45
46       Set an attribute. Valid attributes are the ones discussed in GD::Text
47       and:
48
49       valign, halign
50           Vertical and horizontal alignment of the string. See also
51           set_valign and set_halign.
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53       colour, color
54           Synonyms. The colour to use to draw the string. This should be the
55           index of the colour in the GD::Image object's palette. The default
56           value is the last colour in the GD object's palette at the time of
57           the creation of $align.
58
59       $align->get(attribute)
60
61       Get the value of an attribute.  Valid attributes are all the attributes
62       mentioned in GD::Text, the attributes mentioned under the "set" method
63       and
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65       x, y and angle
66           The x and y coordinate and the angle to be used. You can only do
67           this after a call to the draw or bounding_box methods. Note that
68           these coordinates are not necessarily the same ones that were
69           passed in.  Instead, they are the coordinates from where the GD
70           methods will start drawing. I doubt that this is very useful to
71           anyone.
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73       Note that while you can set the colour with both 'color' and 'colour',
74       you can only get it as 'colour'. Sorry, but such is life in Australia.
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76       $align->set_valign(value)
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78       Set the vertical alignment of the string to one of 'top', 'center',
79       'base' or 'bottom'. For builtin fonts the last two are the same. The
80       value 'base' denotes the baseline of a TrueType font.  Returns true on
81       success, false on failure.
82
83       $align->set_halign(value)
84
85       Set the horizontal alignment of the string to one of 'left', 'center',
86       or 'right'.  Returns true on success, false on failure.
87
88       $align->set_align(valign, halign)
89
90       Set the vertical and horizontal alignment. Just here for convenience.
91       See also "set_valign" and "set_halign".  Returns true on success, false
92       on failure.
93
94       $align->draw(x, y, angle)
95
96       Draw the string at coordinates x, y at an angle angle in radians. The x
97       and y coordinate become the pivot around which the string rotates.
98
99       Note that for the builtin GD fonts the only two valid angles are 0 and
100       PI/2.
101
102       Returns the bounding box of the drawn string (see "bounding_box()").
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104       $align->bounding_box(x, y, angle)
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106       Return the bounding box of the string to draw. This returns an eight-
107       element list (exactly like the GD::Image->stringTTF method):
108
109         (x1,y1) lower left corner
110         (x2,y2) lower right corner
111         (x3,y3) upper right corner
112         (x4,y4) upper left corner
113
114       Note that upper, lower, left and right are relative to the string, not
115       to the canvas.
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117       The bounding box can be used to make decisions about whether to move
118       the string or change the font size prior to actually drawing the
119       string.
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NOTES

122       As with all Modules for Perl: Please stick to using the interface. If
123       you try to fiddle too much with knowledge of the internals of this mod‐
124       ule, you may get burned. I may change them at any time.
125
126       You can only use TrueType fonts with version of GD > 1.20, and then
127       only if compiled with support for this. If you attempt to do it anyway,
128       you will get errors.
129
130       In the following, terms like 'top', 'upper', 'left' and the like are
131       all relative to the string to be drawn, not to the canvas.
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BUGS

134       Any bugs inherited from GD::Text.
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COPYRIGHT

137       copyright 1999 Martien Verbruggen (mgjv@comdyn.com.au)
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