SDL::TTF(3) True Type Font functions (libfreetype)

CATEGORY

TTF

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'':

  • TTF_HINTING_NORMAL
  • TTF_HINTING_LIGHT
  • TTF_HINTING_MONO
  • TTF_HINTING_NONE

Available constants for ``style'':

  • TTF_STYLE_NORMAL
  • TTF_STYLE_BOLD
  • TTF_STYLE_ITALIC
  • TTF_STYLE_UNDERLINE
  • TTF_STYLE_STRIKETHROUGH

METHODS

General methods

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);

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.

init 

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

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

Returns: 0 on success, "-1" on any error.

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 SDL::TTF::init to avoid initializing twice in a row. Or use this to determine if you need to call SDL::TTF::quit.

quit 

 SDL::TTF::quit();

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

Management functions

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 "SDL::TTF::open_font_index(..., ..., $index = 0)". This can load TTF, OTF and FON files.

Returns: a SDL::TTF::Font object. "undef" is returned on errors.

Example: 

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

open_font_index 

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

This is the same as 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.

open_font_RW 

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

This is the same as SDL::TTF::open_font, except you can pass an SDL::RWOps-object. If you pass true as $free, the 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);

open_font_index_RW 

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

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

Attributes

Global attributes

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 "UNICODE_BOM_NATIVE" or "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.

Font style

get_font_style 

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

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

  • TTF_STYLE_NORMAL
  • TTF_STYLE_BOLD
  • TTF_STYLE_ITALIC
  • TTF_STYLE_UNDERLINE
  • TTF_STYLE_STRIKETHROUGH (since SDL_ttf 2.0.10)

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;

set_font_style 

 SDL::TTF::set_font_style($font, $style);

Set the rendering style of the loaded font.

Note: "TTF_STYLE_UNDERLINE" may cause surfaces created by "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 "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.

get_font_outline 

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

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

Note: at least SDL_ttf 2.0.10 needed

set_font_outline 

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

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

Note: at least SDL_ttf 2.0.10 needed

Font settings

get_font_hinting 

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

Get the current hinting setting of the loaded font.

Note: at least SDL_ttf 2.0.10 needed

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

  • TTF_HINTING_NORMAL
  • TTF_HINTING_LIGHT
  • TTF_HINTING_MONO
  • TTF_HINTING_NONE

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.

Note: at least SDL_ttf 2.0.10 needed

Example: 

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

get_font_kerning 

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

Get the current kerning setting of the loaded font.

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

Note: at least SDL_ttf 2.0.10 needed

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

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 0 to disable kerning, 1 to enable.

Note: at least SDL_ttf 2.0.10 needed

Font metrics

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 SDL::TTF::font_line_skip as well.

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 "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 );

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 "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 );

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 SDL::TTF::font_height of the font.

Face attributes

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.

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 "glyph_width * string_length".

Returns: ">0" if font is a fixed width font. 0 if not a fixed width font.

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"

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"

Glyphs

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.

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.

Note: at least SDL_ttf 2.0.10 needed

Example: 

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

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

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") };

Text metrics

size_text 

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

Calculate the resulting surface size of the LATIN1 encoded text rendered using $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 SDL::TTF::font_height.

size_utf8 

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

Calculate the resulting surface size of the UTF8 encoded text rendered using $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 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

size_unicode 

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

Calculate the resulting surface size of the UNICODE encoded text rendered using $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 SDL::TTF::font_height.

$text has to be:

UTF16BE without BOM
``hello'' will look like ``\0h\0e\0l\0l\0o''
UTF16BE with BOM
``hello'' will look like ``\xFE\xFF\0h\0e\0l\0l\0o''
UTF16LE with BOM
``hello'' will look like ``\xFF\xFEh\0e\0l\0l\0o\0''

You may use Unicode::String for this.

Font Rendering

Solid

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.

Note: The unicode char has to be passed exactly like for SDL::TTF::size_unicode.

Note: 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

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.

Note: 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);

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.

Note: 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

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.

Note: The unicode test has to be passed exactly like for SDL::TTF::size_unicode.

Note: 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

Shaded

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 $background_color. After that you can blit this surface to your display-surface.

Note: The unicode char has to be passed exactly like for SDL::TTF::size_unicode.

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 $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);

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 $background_color. After that you can blit this surface to your display-surface.

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 $background_color. After that you can blit this surface to your display-surface.

Note: The unicode text has to be passed exactly like for SDL::TTF::size_unicode.

Blended

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.

Note: The unicode char has to be passed exactly like for SDL::TTF::size_unicode.

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);

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.

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.

Note: The unicode char has to be passed exactly like for SDL::TTF::size_unicode.

AUTHORS

See ``AUTHORS'' in SDL.

LAST SEARCHED