libsdl-perl 2.546-3build1 / usr / lib / x86_64-linux-gnu / perl5 / 5.26 / pods / SDL / TTF.pod

=pod

=head1 NAME

SDL::TTF - True Type Font functions (libfreetype)

=head1 CATEGORY

TTF

=head1 CONSTANTS

The constants are exported by default. You can avoid this by doing:

 use SDL::TTF ();

and access them directly:

 SDL::TTF::TTF_HINTING_NORMAL;

Available constants for "hinting":

=over 4

=item *

TTF_HINTING_NORMAL

=item *

TTF_HINTING_LIGHT

=item *

TTF_HINTING_MONO

=item *

TTF_HINTING_NONE

=back

Available constants for "style":

=over 4

=item *

TTF_STYLE_NORMAL

=item *

TTF_STYLE_BOLD

=item *

TTF_STYLE_ITALIC

=item *

TTF_STYLE_UNDERLINE

=item *

TTF_STYLE_STRIKETHROUGH

=back

=head1 METHODS

=head2 General methods

=head3 linked_version

 my $version = SDL::TTF::linked_version();

This gives you the SDL::Version object which SDL_ttf lib is used on the system.
No prior initialization needs to be done before these function is called. 

Example:

 use SDL::TTF;
 use SDL::Version;
 
 my $version = SDL::TTF::linked_version();
 
 printf("got version: %d.%d.%d\n", $version->major, $version->minor, $version->patch);

=head3 compile_time_version

 my $version = SDL::TTF::compile_time_version();

This gives you the SDL::Version object which SDL_ttf was present at compile time.

=head3 init

 my $success = SDL::TTF::init();

Initialize the truetype font API.
This must be called before using other functions in this library, except L<SDL::TTF::was_init|SDL::TTF/"was_init"> and L<SDL::TTF::linked_version|SDL::TTF/"linked_version">.
SDL does not have to be initialized before this call.

Returns: C<0> on success, C<-1> on any error.

=head3 was_init

 my $was_init = SDL::TTF::was_init();

Query the initialization status of the truetype font API.
You may, of course, use this before L<SDL::TTF::init|SDL::TTF/"init"> to avoid initializing twice in a row. Or use this to determine if you need to 
call L<SDL::TTF::quit|SDL::TTF/"quit">.

=head3 quit

 SDL::TTF::quit();

Shutdown and cleanup the truetype font API.
After calling this the SDL::TTF functions should not be used, excepting L<SDL::TTF::was_init|SDL::TTF/"was_init">. You may, of course, use 
L<SDL::TTF::init|SDL::TTF/"init"> to use the functionality again

=head2 Management functions

=head3 open_font

 my $font = SDL::TTF::open_font($font_file, $point_size);

Load file for use as a font, at the given size. This is actually C<SDL::TTF::open_font_index(..., ..., $index = 0)>. This can load TTF, OTF and FON files.

Returns: a L<SDL::TTF::Font> object. C<undef> is returned on errors.

Example:

 use SDL::TTF;
 use SDL::TTF::Font;
 
 my $font = SDL::TTF::open_font('arial.ttf', 24);

=head3 open_font_index

 my $font = SDL::TTF::open_font($font_file, $point_size, $face_index);

This is the same as L<SDL::TTF::open_font|SDL::TTF/"open_font">, except you can specify the face index of a font file containing multiple faces. 
This can load TTF and FON files. 

=head3 open_font_RW

 my $font = SDL::TTF::open_font_RW($rwops_object, $free, $point_size);

This is the same as L<SDL::TTF::open_font|SDL::TTF/"open_font">, except you can pass an L<SDL::RWOps>-object. If you pass true as C<$free>, the L<SDL::RWOps>-object
will be freed by SDL_ttf library. Don't do this, perl will free this object for you.

Example:

 my $font = SDL::TTF::open_font_RW(SDL::RWOps->new_file($font_file, 'r'), 0, 24);

=head3 open_font_index_RW

 my $font = SDL::TTF::open_font_index_RW($rwops_object, $free, $point_size, $face_index);

This is the same as L<SDL::TTF::open_font_index|SDL::TTF/"open_font_index">, except you can pass an L<SDL::RWOps>-object. If you pass true as C<$free>, the 
L<SDL::RWOps>-object will be freed by SDL_ttf library. Don't do this, perl will free this object for you.

=head2 Attributes

=head3 Global attributes

=head4 byte_swapped_unicode

 SDL::TTF::byte_swapped_unicode( $bool );

This function tells SDL_ttf whether UNICODE (2 bytes per character) text is generally byteswapped. A C<UNICODE_BOM_NATIVE> or 
C<UNICODE_BOM_SWAPPED> character in a string will temporarily override this setting for the remainder of that string, however this setting 
will be restored for the next one. The default mode is non-swapped, native endianness of the CPU.

=head3 Font style

=head4 get_font_style

 SDL::TTF::get_font_style($font);

Returns: The style as a bitmask composed of the following masks:

=over 4

=item *

TTF_STYLE_NORMAL

=item *

TTF_STYLE_BOLD

=item *

TTF_STYLE_ITALIC

=item *

TTF_STYLE_UNDERLINE

=item *

TTF_STYLE_STRIKETHROUGH (since SDL_ttf 2.0.10)

=back

Example:

 my $style = SDL::TTF::get_font_style($font);
 
 print("normal\n")        if $style == TTF_STYLE_NORMAL;
 print("bold\n")          if $style  & TTF_STYLE_BOLD;
 print("italic\n")        if $style  & TTF_STYLE_ITALIC;
 print("underline\n")     if $style  & TTF_STYLE_UNDERLINE;
 print("strikethrough\n") if $style  & TTF_STYLE_STRIKETHROUGH;

=head4 set_font_style

 SDL::TTF::set_font_style($font, $style);
 
Set the rendering style of the loaded font.

B<Note>: C<TTF_STYLE_UNDERLINE> may cause surfaces created by C<SDL::TTF::render_glyph_*> functions to be extended vertically, downward only, 
to encompass the underline if the original glyph metrics didn't allow for the underline to be drawn below. This does not change the math used 
to place a glyph using glyph metrics.
On the other hand C<TTF_STYLE_STRIKETHROUGH> doesn't extend the glyph, since this would invalidate the metrics used to position the glyph when 
blitting, because they would likely be extended vertically upward. There is perhaps a workaround, but it would require programs to be smarter 
about glyph blitting math than they are currently designed for.
Still, sometimes the underline or strikethrough may be outside of the generated surface, and thus not visible when blitted to the screen. In 
this case, you should probably turn off these styles and draw your own strikethroughs and underlines. 

=head4 get_font_outline

 my $outline = SDL::TTF::get_font_outline($font);

Get the current outline width of the font, in pixels.

B<Note>: at least SDL_ttf 2.0.10 needed

=head4 set_font_outline

 SDL::TTF::set_font_outline($font, $outline);

Set the outline pixel width of the loaded font. Use C<0>(zero) to turn off outlining.

B<Note>: at least SDL_ttf 2.0.10 needed

=head3 Font settings

=head4 get_font_hinting

 my $hinting = SDL::TTF::get_font_hinting($font);

Get the current hinting setting of the loaded font.

B<Note>: at least SDL_ttf 2.0.10 needed

Returns the hinting type matching one of the following defined values:

=over 4

=item *

TTF_HINTING_NORMAL

=item *

TTF_HINTING_LIGHT

=item *

TTF_HINTING_MONO

=item *

TTF_HINTING_NONE

=back

=head4 set_font_hinting

 SDL::TTF::set_font_hinting($font, $hinting);

Set the hinting of the loaded font. You should experiment with this setting if you know which font you are using beforehand, especially when 
using smaller sized fonts. If the user is selecting a font, you may wish to let them select the hinting mode for that font as well.

B<Note>: at least SDL_ttf 2.0.10 needed

Example:

 SDL::TTF::set_font_hinting($font, TTF_HINTING_LIGHT);

=head4 get_font_kerning

 my $kerning_enabled = SDL::TTF::get_font_kerning($font);

Get the current kerning setting of the loaded font.

Returns: C<0>(zero) if kerning is disabled. A non-zero value is returned when enabled. The default for a newly loaded font is enabled(C<1>). 

B<Note>: at least SDL_ttf 2.0.10 needed

B<Note>: This function returns wrong values: See L<http://bugzilla.libsdl.org/show_bug.cgi?id=973>

=head4 set_font_kerning

 SDL::TTF::set_font_kerning($font, $kerning_enabled);

Set whether to use kerning when rendering the loaded font. This has no effect on individual glyphs, but rather when rendering whole strings of 
characters, at least a word at a time. Perhaps the only time to disable this is when kerning is not working for a specific font, resulting in 
overlapping glyphs or abnormal spacing within words.

Pass C<0> to disable kerning, 1 to enable.

B<Note>: at least SDL_ttf 2.0.10 needed

=head3 Font metrics

=head4 font_height

 my $font_height = SDL::TTF::font_height($font);

Get the maximum pixel height of all glyphs of the loaded font. You may use this height for rendering text as close together vertically as 
possible, though adding at least one pixel height to it will space it so they can't touch. Remember that SDL_ttf doesn't handle multiline 
printing, so you are responsible for line spacing, see the L<SDL::TTF::font_line_skip|SDL::TTF/"font_line_skip"> as well.

=head4 font_ascent

 my $font_ascent = SDL::TTF::font_ascent($font);

Get the maximum pixel ascent of all glyphs of the loaded font. This can also be interpreted as the distance from the top of the font to the 
baseline.
It could be used when drawing an individual glyph relative to a top point, by combining it with the glyph's C<maxy> metric to resolve the top 
of the rectangle used when blitting the glyph on the screen.

Example:

 my ($minx, $maxx, $miny, $maxy, $advance) = @{ SDL::TTF::glyph_metrics($font, "\0M") };

 $rect->y( $top + SDL::TTF::font_ascent($font) - $maxy );

=head4 font_descent

 my $font_descent = SDL::TTF::font_descent($font);

Get the maximum pixel descent of all glyphs of the loaded font. This can also be interpreted as the distance from the baseline to the bottom of 
the font.
It could be used when drawing an individual glyph relative to a bottom point, by combining it with the glyph's C<maxy> metric to resolve the top 
of the rectangle used when blitting the glyph on the screen.

Example:

 my ($minx, $maxx, $miny, $maxy, $advance) = @{ SDL::TTF::glyph_metrics($font, "\0M") };

 $rect->y( $bottom - SDL::TTF::font_descent($font) - $maxy );

=head4 font_line_skip

 my $font_line_skip = SDL::TTF::font_line_skip($font);
 
Get the recommended pixel height of a rendered line of text of the loaded font. This is usually larger than the L<SDL::TTF::font_height|SDL::TTF/"font_height"> of the 
font.

=head3 Face attributes

=head4 font_faces

 my $font_faces = SDL::TTF::font_faces($font);

Get the number of faces ("sub-fonts") available in the loaded font. This is a count of the number of specific fonts (based on size and style 
and other typographical features perhaps) contained in the font itself.

=head4 font_face_is_fixed_width

 my $font_face_is_fixed_width = SDL::TTF::font_face_is_fixed_width($font);

Test if the current font face of the loaded font is a fixed width font. Fixed width fonts are monospace, meaning every character that exists 
in the font is the same width, thus you can assume that a rendered string's width is going to be the result of C<glyph_width * string_length>.

Returns: C<E<gt>0> if font is a fixed width font. C<0> if not a fixed width font. 

=head4 font_face_family_name

 my $font_face_family_name = SDL::TTF::font_face_family_name($font);

Get the current font face family name from the loaded font. This information is not for every font available.

Example:

 my $font = SDL::TTF::open_font('arialuni.ttf', 8);
 
 printf("%s\n", SDL::TTF::font_face_family_name($font)); # will print "Arial Unicode MS"

=head4 font_face_style_name

 my $font_face_style_name = SDL::TTF::font_face_style_name($font);

Get the current font face style name from the loaded font. This information is not for every font available. 

Example:

 my $font = SDL::TTF::open_font('arialuni.ttf', 8);
 
 printf("%s\n", SDL::TTF::font_face_style_name($font)); # will print "Regular"

=head3 Glyphs

=head4 glyph_is_provided

 my $glyph_is_provided = SDL::TTF::glyph_is_provided($font, $unicode_char);

Get the status of the availability of the glyph from the loaded font.

Returns: the index of the glyph in font, or 0 for an undefined character code.

B<Note>: You have to pass this unicode character either as UTF16/UCS-2 big endian without BOM, or with BOM as UTF16/UCS-2 big/little endian.

B<Note>: at least SDL_ttf 2.0.10 needed

Example:

 print("We have this char!\n") if SDL::TTF::glyph_is_provided($font, "\0M");

=head4 glyph_metrics

 my @glyph_metrics = @{ SDL::TTF::glyph_metrics($font, $unicode_char) };

Get desired glyph metrics of the UNICODE char from the loaded font.

See also: L<The FreeType2 Documentation Tutorial|http://freetype.sourceforge.net/freetype2/docs/tutorial/step2.html>

B<Note>: You have to pass this unicode character either as UTF16/UCS-2 big endian without BOM, or with BOM as UTF16/UCS-2 big/little endian.

Example:

 my ($minx, $maxx, $miny, $maxy, $advance) = @{ SDL::TTF::glyph_metrics($font, "\0M") };

=head3 Text metrics

=head4 size_text

 my ($width, $height) = @{ SDL::TTF::size_text($font, $text) };

Calculate the resulting surface size of the LATIN1 encoded text rendered using C<$font>. No actual rendering is done, however correct kerning 
is done to get the actual width. The height returned is the same as you can get using L<SDL::TTF::font_height|SDL::TTF/"font_height">.

=head4 size_utf8

 my ($width, $height) = @{ SDL::TTF::size_utf8($font, $text) };

Calculate the resulting surface size of the UTF8 encoded text rendered using C<$font>. No actual rendering is done, however correct kerning is 
done to get the actual width. The height returned in h is the same as you can get using L<SDL::TTF::font_height|SDL::TTF/"font_height">.

Note that the first example uses the same text as in the LATIN1 example, that is because plain ASCII is UTF8 compatible.

Examples:

 ($width, $height) = @{ SDL::TTF::size_utf8($font, 'Hello World!') }; # plain text, if your script is in utf8 or ansi-format
 
 # or
 
 ($width, $height) = @{ SDL::TTF::size_utf8($font, "\xE4\xBB\x8A\xE6\x97\xA5\xE3\x81\xAF") }; # utf8 hex-data
 
 # or
 
 use Unicode::String;
 my $unicode       = utf8($data_from_somewhere);
 ($width, $height) = @{ SDL::TTF::size_utf8($font, $unicode->utf8) }; # utf8 via Unicode::String

=head4 size_unicode

 my ($width, $height) = @{ SDL::TTF::size_unicode($font, $text) };

Calculate the resulting surface size of the UNICODE encoded text rendered using C<$font>. No actual rendering is done, however correct kerning 
is done to get the actual width. The height returned in h is the same as you can get using L<SDL::TTF::font_height|SDL::TTF/"font_height">.

C<$text> has to be:

=over 4

=item UTF16BE without BOM

"hello" will look like "\0h\0e\0l\0l\0o"

=item UTF16BE with BOM

"hello" will look like "\xFE\xFF\0h\0e\0l\0l\0o"

=item UTF16LE with BOM

"hello" will look like "\xFF\xFEh\0e\0l\0l\0o\0"

=back

You may use Unicode::String for this.

=head2 Font Rendering

=head3 Solid

=head4 render_glyph_solid

 my $surface = SDL::TTF::render_glyph_solid($font, $char, $color);

Render the unicode encoded char onto a new surface, using the Solid mode. After that you can blit this surface to your display-surface.

B<Note>: The unicode char has to be passed exactly like for L<SDL::TTF::size_unicode|SDL::TTF/"size_unicode">.

B<Note>: L<See space-character bug|http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=374062>. You have to upgrade libfreetype2 to at least version 2.3.5

=head4 render_text_solid

 my $surface = SDL::TTF::render_text_solid($font, $text, $color);

Render the LATIN1 encoded text onto a new surface, using the Solid mode. After that you can blit this surface to your display-surface.

B<Note>: L<See space-character bug|http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=374062>. You have to upgrade libfreetype2 to at least 
version 2.3.5

Example:

 use SDL;
 use SDL::Rect;
 use SDL::Video;
 use SDL::Color;
 use SDL::TTF;
 use SDL::TTF::Font;

 SDL::init(SDL_INIT_VIDEO);
 SDL::TTF::init();
 my $display = SDL::Video::set_video_mode(640, 480, 32, SDL_SWSURFACE);
 my $font    = SDL::TTF::open_font('somefont.ttf', '24');
 die 'Coudnt make font '. SDL::get_error if !$font;
 my $surface = SDL::TTF::render_text_solid($font, 'Hello!', SDL::Color->new(0xFF,0xFF,0xFF));
 SDL::Video::blit_surface($surface, SDL::Rect->new(0, 0, 640, 480), $display, SDL::Rect->new(10, 10, 640, 480));
 SDL::Video::update_rect($display, 0, 0, 0, 0);
 SDL::delay(5000);

=head4 render_utf8_solid

 my $surface = SDL::TTF::render_utf8_solid($font, $text, $color);

Render the UTF8 encoded text onto a new surface, using the Solid mode. After that you can blit this surface to your display-surface.

B<Note>: L<See space-character bug|http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=374062>. You have to upgrade libfreetype2 to at least 
version 2.3.5

=head4 render_unicode_solid

 my $surface = SDL::TTF::render_unicode_solid($font, $text, $color);

Render the unicode encoded text onto a new surface, using the Solid mode. After that you can blit this surface to your display-surface.

B<Note>: The unicode test has to be passed exactly like for L<SDL::TTF::size_unicode|SDL::TTF/"size_unicode">.

B<Note>: L<See space-character bug|http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=374062>. You have to upgrade libfreetype2 to at least 
version 2.3.5

=head3 Shaded

=head4 render_glyph_shaded

 my $surface = SDL::TTF::render_glyph_shaded($font, $char, $color, $background_color);

Render the unicode encoded char onto a new surface. The surface is filled with C<$background_color>. After that you can blit this surface to 
your display-surface.

B<Note>: The unicode char has to be passed exactly like for L<SDL::TTF::size_unicode|SDL::TTF/"size_unicode">.

=head4 render_text_shaded

 my $surface = SDL::TTF::render_text_shaded($font, $text, $color, $background_color);

Render the LATIN1 encoded text onto a new surface. The surface is filled with C<$background_color>. After that you can blit this surface to 
your display-surface.

Example:

 use SDL;
 use SDL::Video;
 use SDL::Color;
 use SDL::TTF;
 use SDL::TTF::Font;
 
 SDL::init(SDL_INIT_VIDEO);
 
 SDL::TTF::init();

 my $display = SDL::Video::set_video_mode(640, 480, 32, SDL_SWSURFACE);
 my $font    = SDL::TTF::open_font('arial.ttf', '24');
 my $white   = SDL::Color->new(0xFF, 0xFF, 0xFF);
 my $black   = SDL::Color->new(0x00, 0x00, 0x00);
 my $surface = SDL::TTF::render_text_solid($font, 'Hello!', $white, $black);
 
 SDL::Video::blit_surface($surface, SDL::Rect->new(0, 0, 640, 480), $display, SDL::Rect->new(10, 10, 640, 480));
 SDL::Video::update_rect($display, 0, 0, 0, 0);
 
 SDL::delay(5000);

=head4 render_utf8_shaded

 my $surface = SDL::TTF::render_utf8_shaded($font, $text, $color, $background_color);

Render the UTF8 encoded text onto a new surface. The surface is filled with C<$background_color>. After that you can blit this surface to 
your display-surface.

=head4 render_unicode_shaded

 my $surface = SDL::TTF::render_unicode_shaded($font, $text, $color, $background_color);

Render the unicode encoded text onto a new surface. The surface is filled with C<$background_color>. After that you can blit this surface to 
your display-surface.

B<Note>: The unicode text has to be passed exactly like for L<SDL::TTF::size_unicode|SDL::TTF/"size_unicode">.

=head3 Blended

=head4 render_glyph_blended

 my $surface = SDL::TTF::render_glyph_blended($font, $char, $color);

Render the unicode encoded char onto a new surface. After that you can blit this surface to your display-surface.

B<Note>: The unicode char has to be passed exactly like for L<SDL::TTF::size_unicode|SDL::TTF/"size_unicode">.

=head4 render_text_blended

 my $surface = SDL::TTF::render_text_blended($font, $text, $color);

Render the LATIN1 encoded text onto a new surface. After that you can blit this surface to your display-surface.

Example:

 use SDL;
 use SDL::Video;
 use SDL::Color;
 use SDL::TTF;
 use SDL::TTF::Font;
 
 SDL::init(SDL_INIT_VIDEO);
 
 SDL::TTF::init();
 
 my $display = SDL::Video::set_video_mode(640, 480, 32, SDL_SWSURFACE);
 my $font    = SDL::TTF::open_font('arial.ttf', '24');
 my $surface = SDL::TTF::render_text_blended($font, 'Hello!', SDL::Color->new(0xFF,0xFF,0xFF));
 
 SDL::Video::blit_surface($surface, SDL::Rect->new(0, 0, 640, 480), $display, SDL::Rect->new(10, 10, 640, 480));
 SDL::Video::update_rect($display, 0, 0, 0, 0);
 
 SDL::delay(5000);

=head4 render_utf8_blended

 my $surface = SDL::TTF::render_utf8_blended($font, $text, $color);

Render the UTF8 encoded text onto a new surface. After that you can blit this surface to your display-surface.

=head4 render_unicode_blended

 my $surface = SDL::TTF::render_unicode_blended($font, $text, $color);

Render the unicode encoded text onto a new surface. After that you can blit this surface to your display-surface.

B<Note>: The unicode char has to be passed exactly like for L<SDL::TTF::size_unicode|SDL::TTF/"size_unicode">.

=head1 AUTHORS

See L<SDL/AUTHORS>.

=head1 SEE ALSO

L<SDL::TTF::Font>, L<Unicode::String>, L<SDL::Video>, L<SDL::Surface>

=cut