NAME
SDL2::TTF - TTF Image Loading Library
SYNOPSIS
use SDL2::FFI qw[:all];
DESCRIPTION
This extension to SDL2 can load fonts from TrueType font files, normally ending in .ttf
, though some .fon
files are also valid for use.
General Functions
These may be imported by name or with the :all
tag.
SDL_TTF_VERSION( ... )
Macro to determine compile-time version of the SDL_ttf library.
my $compile_version = SDL2::Version->new;
SDL_TTF_VERSION($compile_version);
printf "compiled with SDL_ttf version: %d.%d.%d\n", $compile_version->major,
$compile_version->minor, $compile_version->patch;
Expected parameters include:
x
- a pointer to a SDL2::Version struct to initialize
SDL_IMAGE_VERSION_ATLEAST( ... )
Evaluates to true if compiled with SDL at least major.minor.patch
.
if ( SDL_TTF_VERSION_ATLEAST( 2, 0, 5 ) ) {
# Some feature that requires 2.0.5+
}
Expected parameters include:
major
minor
patch
TTF_Linked_Version( )
This function gets the version of the dynamically linked SDL_image library.
my $link_version = TTF_Linked_Version();
printf "running with SDL_ttf version: %d.%d.%d\n",
$link_version->major, $link_version->minor, $link_version->patch;
It should NOT be used to fill a version structure, instead you should use the SDL_TTF_VERSION( ... )
macro.
Returns a SDL2::Version object.
TTF_Init( )
Initialize the truetype font API.
if ( TTF_Init( ) == -1 ) {
printf( "could not initialize sdl_ttf: %s\n", TTF_GetError() );
return !1;
}
This must be called before using other functions in this library, except TTF_WasInit( )
. SDL does not have to be initialized before this call.
Returns 0
on success or -1
on failure.
TTF_WasInit( )
Query the initialization status of the truetype font API.
if ( !TTF_WasInit() && TTF_Init() == -1 ) {
printf "TTF_Init: %s\n", TTF_GetError();
exit 1;
}
You may, of course, use this before TTF_Init to avoid initializing twice in a row. Or use this to determine if you need to call TTF_Quit.
Returns 1
if already initialized, 0
if not initialized.
TTF_Quit( )
Shutdown and cleanup the truetype font API.
TTF_Quit( );
After calling this, the SDL_ttf
functions should not be used, excepting TTF_WasInit( )
. You may, of course, use TTF_Init( )
to use the functionality again.
TTF_SetError( ... )
This is really a defined macro for SDL_SetError( ... )
, which sets the error string which may be fetched with TTF_GetError( )
(or SDL_GetError( )
).
sub myfunc ($i) {
TTF_SetError( 'myfunc is not implemented! %d was passed in.', $i );
return -1;
}
TTF_GetError( )
This is really a defined macro for SDL_GetError( )
.
printf 'Oh My Goodness, an error: %s', TTF_GetError();
Use this to tell the user what happened when an error status has been returned from an SDL_ttf
function call.
Returns the last error set by TTF_SetError( ... )
(or SDL_SetError( )
) as a string.
Management Functions
These functions deal with loading and freeing a TTF_Font
.
TTF_OpenFont( ... )
Load file
for use as a font, at ptsize
size.
# load font.ttf at size 16 into font
my $font = TTF_OpenFont( 'font.ttf', 16 );
if ( !$font ) {
printf( "TTF_OpenFont: %s\n", TTF_GetError() );
# handle error
}
This is actually TTF_OpenFontIndex( $file, $ptsize, 0 )
. This can load TTF and FON files.
Expected parameters include:
file
- file name to load font fromptsize
- point size (based on 72 DPI) to load font as; this basically translates to pixel height
Returns a new SDL2::TTF::Font structure on success.
TTF_OpenFontRW( ... )
Load src
for use as a font, at ptsize
size.
# load font.ttf at size 16 into font
my $font = TTF_OpenFontRW( SDL_RWFromFile( 'font.ttf', 'rb' ), 1, 16 );
if ( !$font ) {
printf( "TTF_OpenFontRW: %s\n", TTF_GetError() );
# handle error
}
This is actually TTF_OpenFontIndexRW( $src, $freesrc, $ptsize, 0 )
. This can load TTF and FON formats.
Expected parameters include:
src
- the source SDL2::RWopsfreesrc
- a non-zero value means it will automatically close and free thesrc
for you after it finishes using thesrc
, even if a noncritical error occurredptsize
- point size (based on 72 DPI) to load font as; this basically translates to pixel height
Returns a new SDL2::TTF::Font structure on success.
TTF_OpenFontIndex( ... )
Load file
, face index
, for use as a font, at ptsize
size.
# load font.ttf at size 16 into font
my $font = TTF_OpenFontIndex( 'font.ttf', 16, 0 );
if ( !$font ) {
printf( "TTF_OpenFontIndex: %s\n", TTF_GetError() );
# handle error
}
This is actually TTF_OpenFontIndexRW( SDL_RWFromFile($src, 'rb'), $freesrc, $ptsize, $index )
.
Expected parameters include:
src
- the source SDL2::RWopsptsize
- point size (based on 72 DPI) to load font as; this basically translates to pixel heightindex
- choose a font face from a file containing multiple font faces
Returns a new SDL2::TTF::Font structure on success.
TTF_OpenFontIndexRW( ... )
Load src
, face index
, for use as a font, at ptsize
size.
# load font.ttf at size 16 into font
my $font = TTF_OpenFontIndexRW( SDL_RWFromFile( 'font.ttf', 'rb' ), 1, 16, 0 );
if ( !$font ) {
printf( "TTF_OpenFontIndexRW: %s\n", TTF_GetError() );
# handle error
}
Expected parameters include:
src
- the source SDL2::RWopsfreesrc
- a non-zero value means it will automatically close and free thesrc
for you after it finishes using thesrc
, even if a noncritical error occurredptsize
- point size (based on 72 DPI) to load font as; this basically translates to pixel heightindex
- choose a font face from a file containing multiple font faces
Returns a new SDL2::TTF::Font structure on success.
TTF_CloseFont( ... )
Free the memory used by font
, and free font
itself as well. Do not use font
after this without loading a new font to it.
# free the font
TTF_CloseFont( $font );
undef $font; # to be safe...
Expected parameters include:
font
- pointer to the TTF_Font to free
Attribute Functions
These functions deal with SDL2::TTF::Font and global attributes.
TTF_ByteSwappedUNICODE( ... )
This function tells SDL_ttf
whether UNICODE (Uint16 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.
# Turn on byte swapping for UNICODE text
TTF_ByteSwappedUNICODE( 1 );
Expected parameters include:
swapped
TTF_GetFontStyle( ... )
Get the rendering style of the loaded font
.
# get the loaded font's style
my $font = TTF_OpenFontIndex( 'your.ttf', 16, 0 );
my $style = TTF_GetFontStyle($font);
print 'The font style is: ' . ( $style == TTF_STYLE_NORMAL ? 'normal' :
$style & TTF_STYLE_BOLD ? 'bold' :
$style & TTF_STYLE_ITALIC ? 'italic' :
$style & TTF_STYLE_UNDERLINE ? 'underline' :
$style & TTF_STYLE_STRIKETHROUGH ? 'strikethrough' :
'unknown' );
Expected parameters include:
Returns the style as a bitmask composed of the following masks:
TTF_STYLE_BOLD
TTF_STYLE_ITALIC
TTF_STYLE_UNDERLINE
TTF_STYLE_STRIKETHROUGH
If no style is set then TTF_STYLE_NORMAL
is returned.
TTF_SetFontStyle( ... )
Set the rendering style of the loaded font
.
# set the loaded font's style to bold italics
TTF_SetFontStyle( $font, TTF_STYLE_BOLD | TTF_STYLE_ITALIC );
# ...render some text in bold italics...
# set the loaded font's style back to normal
TTF_SetFontStyle( $font, TTF_STYLE_NORMAL );
Expected parameters include:
font
- the loaded font to set the style ofstyle
- the style as a bitmask composed of the following masks:-
TTF_STYLE_BOLD
TTF_STYLE_ITALIC
TTF_STYLE_UNDERLINE
TTF_STYLE_STRIKETHROUGH
If no style is desired then use
TTF_STYLE_NORMAL
, which is the default.
Notes:
Passing an undefined
font
into this function will cause a segfault.This will flush the internal cache of previously rendered glyphs, even if there is no change in style, so it may be best to check the current style using TTF_GetFontStyle first.
TTF_STYLE_UNDERLINE
may cause surfaces created byTTF_RenderGlyph_*
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.
TTF_GetFontOutline( ... )
Get the current outline size of the loaded font
.
# get the loaded font's outline width
my $outline = TTF_GetFontOutline( $font );
printf 'The font outline width is %d pixels', $outline;
Expected parameters include:
Note: Passing an undefined font
into this function will cause a segfault.
Returns the size of the outline currently set on the font, in pixels.
TTF_SetFontOutline( ... )
Set the outline pixel width of the loaded font
.
# set the loaded font's outline to 1 pixel wide
TTF_SetFontOutline( $font, 1 );
# render some outlined text...
# set the loaded font's outline back to normal
TTF_SetFontOutline( $font, 0 );
Expected parameters include:
font
- the loaded font to set the outline size ofoutline
- the size of outline desired, in pixels. Use zero (0
) to turn off outlining.
Notes:
Passing an undefined
font
into this function will cause a segfault.This will flush the internal cache of previously rendered glyphs, even if there is no change in outline size, so it may be best to check the current outline size using
TTF_GetFontOutline
first.
TTF_GetFontHinting( ... )
Get the current hinting setting from the loaded font
.
# get the loaded font's hinting setting
my $hinting = TTF_GetFontHinting($font);
printf 'The font hinting is currently set to %s',
$hinting == TTF_HINTING_NORMAL ? 'Normal' :
$hinting == TTF_HINTING_LIGHT ? 'Light' :
$hinting == TTF_HINTING_MONO ? 'Mono' :
$hinting == TTF_HINTING_NONE ? 'None' :
'Unknonwn';
Expected parameters include:
Note: Passing an undefined font
into this function will cause a segfault.
Returns the hinting type matching one of the following defined values:
TTF_HINTING_NORMAL
TTF_HINTING_LIGHT
TTF_HINTING_MONO
TTF_HINTING_NONE
If no hinting is set then TTF_HINTING_NORMAL
is returned.
TTF_SetFontHinting( ... )
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.
# set the loaded font's hinting to optimized for monochrome rendering
TTF_SetFontHinting( $font, TTF_HINTING_MONO );
# render some monochrome text...
# set the loaded font's hinting back to normal
TTF_SetFontHinting( $font, TTF_HINTING_NORMAL );
Expected parameters include:
font
- the loaded font to set the hinting ofhinting
- the hinting setting desired, which is one of:-
TTF_HINTING_NORMAL
TTF_HINTING_LIGHT
TTF_HINTING_MONO
TTF_HINTING_NONE
The default is
TTF_HINTING_NORMAL
.
Notes:
Passing an undefined
font
into this function will cause a segfault.This will flush the internal cache of previously rendered glyphs, even if there is no change in hinting, so it may be best to check the current hinting by using
TTF_GetFontHinting( ... )
first.
TTF_GetFontKerning( ... )
Get the current kerning setting of the loaded font
.
# get the loaded font's kerning setting
my $kerning = TTF_GetFontKerning( $font );
printf 'The font kerning is currently %sabled', $kerning ? 'en' : 'dis';
The default for a newly loaded font is enabled.
Expected parameters include:
Note: Passing an undefined font
into this function will cause a segfault.
Returns zero (0
) if kerning is disabled. A non-zero value is returned when enabled.
TTF_SetFontKerning( ... )
Set whether to use kerning when rendering the loaded font.
# turn off kerning on the loaded font
TTF_SetFontKerning( $font, 0 );
# render some text string...
# turn kerning back on for the loaded font
TTF_SetFontKerning( $font, 1 );
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.
Expected parameters include:
font
- the loaded font to set the kerning value ofallowed
-0
to disable kerning; a non-zero value to enable kerning
Note: Passing an undefined font
into this function will cause a segfault.
TTF_FontHeight( ... )
Get the maximum pixel height of all glyphs of the loaded font.
printf "The font max height is: %d\n", TTF_FontHeight( $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 TTF_FontLineSkip( ... )
as well.
Expected parameters include:
Note: Passing an undefined font
into this function will cause a segfault.
Returns the maximum pixel height of all glyphs in the font.
TTF_FontAscent( ... )
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.
printf "The font ascent is: %d\n", TTF_FontAscent( $font );
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.
$rect->y( $top + TTF_FontAscent($font) - $glyph_metric->maxy );
Expected parameters include:
Note: Passing an undefined font
into this function will cause a segfault.
Returns the maximum pixel ascent of all glyphs in the font.
TTF_FontDescent( ... )
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.
printf "The font descent is: %d\n", TTF_FontDescent( $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.
$rect->y( $bottom - TTF_FontDescent($font) - $glyph_metric->maxy );
Expected parameters include:
Note: Passing an undefined font
into this function will cause a segfault.
Returns the maximum pixel height of all glyphs in the font.
TTF_FontLineSkip( ... )
Get the recommended pixel height of a rendered line of text of the loaded font
. This is usually larger than the TTF_FontHeight( ... )
of the font
.
printf "The font line skip is: %d\n", TTF_FontLineSkip( $font );
Expected parameters include:
Note: Passing an undefined font
into this function will cause a segfault.
Returns the recommended pixel height.
TTF_FontFaces( ... )
Get the number of faces ("sub-fonts") available in the loaded font
.
printf "The number of faces in the font is: %ld\n", TTF_FontFaces($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. It seems to be a useless fact to know, since it can't be applied in any other SDL_ttf
functions.
Expected parameters include:
Note: Passing an undefined font
into this function will cause a segfault.
Returns the number of faces in the font
.
TTF_FontFaceIsFixedWidth( ... )
Test if the current font face of the loaded font is a fixed width font
.
if(TTF_FontFaceIsFixedWidth($font)) {
printf "The font is fixed width.\n";
}
else {
print "The font is not fixed width.\n";
}
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 a simple calculation:
$glyph_width * length( $string )
Expected parameters include:
Note: Passing an undefined font
into this function will cause a segfault.
Returns 0
if the font is not fixed width. Otherwise, a value greater than zero is returned.
TTF_FontFaceFamilyName( ... )
Get the current font face family name from the loaded font.
my $fam = TTF_FontFaceFamilyName( $font );
print 'The family name of the face in the font is ' . $fam if defined $fam;
Expected parameters include:
Note: Passing an undefined font
into this function will cause a segfault.
Returns the current family name of the font face if defined.
TTF_FontFaceStyleName( ... )
Get the current font face style name from the loaded font.
my $style = TTF_FontFaceStyleName( $font );
print 'The style name of the face in the font is ' . $style if defined $style;
Expected parameters include:
Note: Passing an undefined font
into this function will cause a segfault.
Returns the current style name of the font face if defined.
TTF_GlyphIsProvided( ... )
Get the status of the availability of the glyph for ch from the loaded font
.
my $index = TTF_GlyphIsProvided( $font, 'g' );
printf "There is no 'g' in the loaded font!\n" if !$index;
Expected parameters include:
Note: Passing an undefined font
into this function will cause a segfault.
Returns the index of the glyph for ch
in font
, or 0
for an undefined character code.
TTF_GlyphMetrics( ... )
Get desired glyph metrics of the UNICODE char given in ch
from the loaded font
.
# get the glyph metric for the letter 'g' in a loaded font
my ( $minx, $maxx, $miny, $maxy, $advance );
if ( TTF_GlyphMetrics( $font, 'g', \$minx, \$maxx, \$miny, \$maxy, \$advance ) == -1 ) {
printf "%s\n", TTF_GetError();
}
else {
warn;
printf "minx : %d\n", $minx;
printf "maxx : %d\n", $maxx;
printf "miny : %d\n", $miny;
printf "maxy : %d\n", $maxy;
printf "advance : %d\n", $advance;
}
Expected parameters include:
font
- the loaded font to querych
- the Unicode character to test glyph metrics ofminx
- pointer to int to store the returned minimum X offset into, orundef
when no return value desiredmaxx
- pointer to int to store the returned maximum X offset into, orundef
when no return value desiredminy
- pointer to int to store the returned minimum Y offset into, orundef
when no return value desiredmaxy
- pointer to int to store the returned maximum X offset into, orundef
when no return value desiredadvance
- pointer to int to store the returned advance offset into, orundef
when no return value desired.
Note: Passing an undefined font
into this function will cause a segfault.
Returns 0
on success, with all defined parameters set to the glyph metric as appropriate. -1
on errors, such as when the glyph named by ch does not exist in the font.
Notes
This diagram shows the relationships between the values:
Here's how the numbers look:
TTF_FontHeight : 53
TTF_FontAscent : 38
TTF_FontDescent : -14
TTF_FontLineSkip : 55
TTF_GlyphMetrics('g') :
minx = 1
maxx = 15
miny = -7
maxy = 15
advance = 16
We see from the Line Skip that each line of text is 55 pixels high, including spacing for this font.
The Ascent-Descent=52
, so there seems to be 3 pixels worth of space between lines for this font.
Let's say we want to draw the surface of glyph 'g' (retrieved via TTF_RenderGlyph_Solid( ... )
or a similar function), at coordinates (X,Y) for the top left corner of the desired location. Here's the math using glyph metrics:
# $glyph, $screen, $rect
my ($minx, $maxy, $advance);
TTF_GlyphMetrics( $font, 'g', \$minx, undef, undef, \$maxy, \$advance );
$rect->x( $X + $minx );
$rect->y( $Y + TTF_FontAscent($font) - $maxy );
SDL_BlitSurface( $glyph, undef, $screen, $rect );
$X += $advance;
Let's say we want to draw the same glyph at coordinates (X,Y) for the origin (on the baseline) of the desired location. Here's the math using glyph metrics:
my ( $minx, $maxy, $advance );
TTF_GlyphMetrics( $font, 'g', \$minx, undef, undef, \$maxy, \$advance );
rect->x( $X + $minx );
rect->y( $Y - $maxy );
SDL_BlitSurface( $glyph, undef, $screen, $rect);
$X += $advance;
Notes:
The only difference between these example is the
TTF_FontAscent( $font )
used in the top-left corner algorithm.These examples assume that 'g' is present in the font!
In practice you may want to also subtract
TTF_GetFontOutline( $font )
from your X and Y coordinates to keep the glyphs in the same place no matter what outline size is set.
See the web page at The FreeType2 Documentation Tutorial for more.
Any glyph based rendering calculations will not result in accurate kerning between adjacent glyphs.
TTF_SizeText( ... )
Calculate the resulting surface size of the LATIN1 encoded text
rendered using font
.
# get the width and height of a string as it would be rendered in a loaded font
my ($w, $h);
if( TTF_SizeText( $font, 'Hello World!', \$w, \$h ) ) {
# perhaps print the current TTF_GetError(), the string can't be rendered...
}
else {
printf( "width=%d height=%d\n", $w, $h );
}
No actual rendering is done, however correct kerning is done to get the actual width. The height returned in h
is the same as you can get using TTF_FontHeight( ... )
.
Expected parameters include:
font
- the loaded font to use to calculate the size of the string withtext
- The LATIN1 string to size upw
- pointer to int in which to fill the text width, orundef
for no desired return valueh
- pointer to int in which to fill the text height, orundef
for no desired return value
Notes:
Passing a
undef
font into this function will cause a segfaultPassing a
undef
text into this function will result in undefined behavior
Returns 0
on success with the variables pointed to by w
and h
set as appropriate, if they are not undef
. -1
is returned on errors, such as a glyph in the string not being found.
TTF_SizeUNICODE( ... )
Calculate the resulting surface size of the UNICODE encoded text
rendered using font
.
# get the width and height of a string as it would be rendered in a loaded font
my ($w, $h);
if( TTF_SizeUNICODE( $font, 'Hello World!', \$w, \$h ) ) {
# perhaps print the current TTF_GetError(), the string can't be rendered...
}
else {
printf( "width=%d height=%d\n", $w, $h );
}
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 TTF_FontHeight( ... )
.
Expected parameters include:
font
- the loaded font to use to calculate the size of the string withtext
- The UNICODE string to size upw
- pointer to int in which to fill the text width, orundef
for no desired return valueh
- pointer to int in which to fill the text height, orundef
for no desired return value
Notes:
Passing a
undef
font into this function will cause a segfaultPassing a
undef
text into this function will result in undefined behavior
Returns 0
on success with the variables pointed to by w
and h
set as appropriate, if they are not undef
. -1
is returned on errors, such as a glyph in the string not being found.
Render Functions
These functions render text using a SDL2::TTF::Font.
There are three modes of rendering:
- Solid: Quick and Dirty
-
Create an 8-bit palletized surface and render the given text at fast quality with the given font and color. The pixel value of 0 is the colorkey, giving a transparent background when blitted. Pixel and colormap value 1 is set to the text foreground color. This allows you to change the color without having to render the text again. Palette index 0 is of course not drawn when blitted to another surface, since it is the colorkey, and thus transparent, though its actual color is 255 minus each of the RGB components of the foreground color. This is the fastest rendering speed of all the rendering modes. This results in no box around the text, but the text is not as smooth. The resulting surface should blit faster than the Blended one. Use this mode for FPS and other fast changing updating text displays.
- Shaded: Slow and Nice, but with a Solid Box
-
Create an 8-bit palletized surface and render the given text at high quality with the given font and colors. The 0 pixel value is background, while other pixels have varying degrees of the foreground color from the background color. This results in a box of the background color around the text in the foreground color. The text is antialiased. This will render slower than Solid, but in about the same time as Blended mode. The resulting surface should blit as fast as Solid, once it is made. Use this when you need nice text, and can live with a box.
- Blended: Slow Slow Slow, but Ultra Nice over another image
-
Create a 32-bit ARGB surface and render the given text at high quality, using alpha blending to dither the font with the given color. This results in a surface with alpha transparency, so you don't have a solid colored box around the text. The text is antialiased. This will render slower than Solid, but in about the same time as Shaded mode. The resulting surface will blit slower than if you had used Solid or Shaded. Use this when you want high quality, and the text isn't changing too fast.
TTF_RenderText_Solid( ... )
Render the LATIN1 encoded text
using font
with fg
color onto a new surface, using the Solid mode. The caller (you!) is responsible for freeing any returned surface.
# Render some text in solid black to a new surface
# then blit to the upper left of the screen
# then free the text surface
my $color = SDL2::Color->new({r => 0, g => 0, b => 0});
if(!(my $text_surface = TTF_RenderText_Solid( $font,"Hello World!", $color))) {
# handle error here, perhaps print TTF_GetError at least
}
else {
SDL_BlitSurface( $text_surface, undef, $screen, undef );
# perhaps we can reuse it, but I assume not for simplicity.
SDL_FreeSurface( $text_surface );
}
Expected parameters include:
font
- font to render the text withtext
- the LATIN1 string to renderfg
- the color to render the text in; this becomes colormap index 1
Notes:
Passing a
undef
font into this function will cause a segfaultPassing a
undef
text into this function will result in undefined behavior
Returns a new SDL2::Surface on success.
TTF_RenderUTF8_Solid( ... )
Render the UTF8 encoded text
using font
with fg
color onto a new surface, using the Solid mode. The caller (you!) is responsible for freeing any returned surface.
# Render some text in solid black to a new surface
# then blit to the upper left of the screen
# then free the text surface
my $color = SDL2::Color->new({r => 0, g => 0, b => 0});
if(!(my $text_surface = TTF_RenderUTF8_Solid( $font,"Hello World!", $color))) {
# handle error here, perhaps print TTF_GetError at least
}
else {
SDL_BlitSurface( $text_surface, undef, $screen, undef );
# perhaps we can reuse it, but I assume not for simplicity.
SDL_FreeSurface( $text_surface );
}
Expected parameters include:
font
- font to render the text withtext
- the UTF8 string to renderfg
- the color to render the text in; this becomes colormap index 1
Notes:
Passing a
undef
font into this function will cause a segfaultPassing a
undef
text into this function will result in undefined behavior
Returns a new SDL2::Surface on success.
TTF_RenderUNICODE_Solid( ... )
Render the UNICODE encoded text
using font
with fg
color onto a new surface, using the Solid mode. The caller (you!) is responsible for freeing any returned surface.
# Render some text in solid black to a new surface
# then blit to the upper left of the screen
# then free the text surface
my $color = SDL2::Color->new({r => 0, g => 0, b => 0});
if(!(my $text_surface = TTF_RenderUNICODE_Solid( $font,"Hello World!", $color))) {
# handle error here, perhaps print TTF_GetError at least
}
else {
SDL_BlitSurface( $text_surface, undef, $screen, undef );
# perhaps we can reuse it, but I assume not for simplicity.
SDL_FreeSurface( $text_surface );
}
Expected parameters include:
font
- font to render the text withtext
- the UNICODE string to renderfg
- the color to render the text in; this becomes colormap index 1
Notes:
Passing a
undef
font into this function will cause a segfaultPassing a
undef
text into this function will result in undefined behavior
Returns a new SDL2::Surface on success.
TTF_RenderGlyph_Solid( ... )
Render the glyph for the UNICODE ch
using font
with fg
color onto a new surface, using the Solid mode. The caller (you!) is responsible for freeing any returned surface.
# Render and cache all printable ASCII characters in solid black
my @glyph_cache;
for my $ord ( 0 .. 127 ) {
push @glyph_cache, TTF_RenderGlyph_Solid( $font, chr $ord, $color );
}
Expected parameters include:
font
- font to render the text withch
- the glyph to renderfg
- the color to render the glyph in; this becomes colormap index 1
Note: Passing a undef
font into this function will cause a segfault.
Returns a new SDL2::Surface on success. undef
is returned on errors, such as when the glyph is not available in the font.
Combined with a cache of the glyph metrics (minx, miny, and advance), you might make a fast text rendering routine that prints directly to the screen, but with inaccurate kerning.
TTF_RenderText_Shaded( ... )
Render the LATIN1 encoded text
using font
with fg
color onto a new surface filled with the bg
color, using the Shaded mode. The caller (you!) is responsible for freeing any returned surface.
# Render some text in shaded black on white to a new surface
# then blit to the upper left of the screen
# then free the text surface
my $color = SDL2::Color->new({r => 0, g => 0, b => 0});
my $bgcolor = SDL2::Color->new({r => 0xff, g => 0xff, b => 0xff});
if(!(my $text_surface = TTF_RenderText_Shaded( $font,"Hello World!", $color, $bgcolor))) {
# handle error here, perhaps print TTF_GetError at least
}
else {
SDL_BlitSurface( $text_surface, undef, $screen, undef );
# perhaps we can reuse it, but I assume not for simplicity.
SDL_FreeSurface( $text_surface );
}
Expected parameters include:
font
- font to render the text withtext
- the LATIN1 string to renderfg
- the color to render the text in; this becomes colormap index 1bg
- the color to render the background box in; this becomes colormap index 0
Notes:
Passing a
undef
font into this function will cause a segfaultPassing a
undef
text into this function will result in undefined behavior
Returns a new SDL2::Surface on success.
TTF_RenderUTF8_Shaded( ... )
Render the UTF8 encoded text
using font
with fg
color onto a new surface filled with the bg
color, using the Shaded mode. The caller (you!) is responsible for freeing any returned surface.
# Render some text in shaded black on white to a new surface
# then blit to the upper left of the screen
# then free the text surface
my $color = SDL2::Color->new({r => 0, g => 0, b => 0});
my $bgcolor = SDL2::Color->new({r => 0xff, g => 0xff, b => 0xff});
if(!(my $text_surface = TTF_RenderUTF8_Shaded( $font,"Hello World!", $color, $bgcolor))) {
# handle error here, perhaps print TTF_GetError at least
}
else {
SDL_BlitSurface( $text_surface, undef, $screen, undef );
# perhaps we can reuse it, but I assume not for simplicity.
SDL_FreeSurface( $text_surface );
}
Expected parameters include:
font
- font to render the text withtext
- the UTF8 string to renderfg
- the color to render the text in; this becomes colormap index 1bg
- the color to render the background box in; this becomes colormap index 0
Notes:
Passing a
undef
font into this function will cause a segfaultPassing a
undef
text into this function will result in undefined behavior
Returns a new SDL2::Surface on success.
TTF_RenderUNICODE_Shaded( ... )
Render the UNICODE encoded text
using font
with fg
color onto a new surface filled with the bg
color, using the Shaded mode. The caller (you!) is responsible for freeing any returned surface.
# Render some text in shaded black on white to a new surface
# then blit to the upper left of the screen
# then free the text surface
my $color = SDL2::Color->new({r => 0, g => 0, b => 0});
my $bgcolor = SDL2::Color->new({r => 0xff, g => 0xff, b => 0xff});
if(!(my $text_surface = TTF_RenderUNICODE_Shaded( $font,"Hello World!", $color, $bgcolor))) {
# handle error here, perhaps print TTF_GetError at least
}
else {
SDL_BlitSurface( $text_surface, undef, $screen, undef );
# perhaps we can reuse it, but I assume not for simplicity.
SDL_FreeSurface( $text_surface );
}
Expected parameters include:
font
- font to render the text withtext
- the UNICODE string to renderfg
- the color to render the text in; this becomes colormap index 1bg
- the color to render the background box in; this becomes colormap index 0
Notes:
Passing a
undef
font into this function will cause a segfaultPassing a
undef
text into this function will result in undefined behavior
Returns a new SDL2::Surface on success.
TTF_RenderGlyph_Shaded( ... )
Render the glyph for the UNICODE ch
using font
with fg
color onto a new surface, using the Shaded mode. The caller (you!) is responsible for freeing any returned surface.
# Render and cache all printable ASCII characters in solid black
my @glyph_cache;
for my $ord ( 0 .. 127 ) {
push @glyph_cache, TTF_RenderGlyph_Shaded( $font, chr $ord, $color, $bgcolor );
}
Expected parameters include:
font
- font to render the text withch
- the glyph to renderfg
- the color to render the glyph in; this becomes colormap index 1
Note: Passing a undef
font into this function will cause a segfault.
Returns a new SDL2::Surface on success. undef
is returned on errors, such as when the glyph is not available in the font.
Combined with a cache of the glyph metrics (minx, miny, and advance), you might make a fast text rendering routine that prints directly to the screen, but with inaccurate kerning.
TTF_RenderText_Blended( ... )
Render the LATIN1 encoded text
using font
with fg
color onto a new surface, using the Blended mode. The caller (you!) is responsible for freeing any returned surface.
# Render some text in blended black to a new surface
# then blit to the upper left of the screen
# then free the text surface
my $color = SDL2::Color->new({r => 0, g => 0, b => 0});
if(!(my $text_surface = TTF_RenderText_Blended( $font,"Hello World!", $color ))) {
# handle error here, perhaps print TTF_GetError at least
}
else {
SDL_BlitSurface( $text_surface, undef, $screen, undef );
# perhaps we can reuse it, but I assume not for simplicity.
SDL_FreeSurface( $text_surface );
}
Expected parameters include:
font
- font to render the text withtext
- the LATIN1 string to renderfg
- the color to render the text in; pixels are blended between transparent and this color to draw the antialiased glyphs
Notes:
Passing a
undef
font into this function will cause a segfaultPassing a
undef
text into this function will result in undefined behavior
Returns a new SDL2::Surface on success.
TTF_RenderUTF8_Blended( ... )
Render the UTF8 encoded text
using font
with fg
color onto a new surface, using the Blended mode. The caller (you!) is responsible for freeing any returned surface.
# Render some text in blended black to a new surface
# then blit to the upper left of the screen
# then free the text surface
my $color = SDL2::Color->new({r => 0, g => 0, b => 0});
if(!(my $text_surface = TTF_RenderUTF8_Blended( $font,"Hello World!", $color ))) {
# handle error here, perhaps print TTF_GetError at least
}
else {
SDL_BlitSurface( $text_surface, undef, $screen, undef );
# perhaps we can reuse it, but I assume not for simplicity.
SDL_FreeSurface( $text_surface );
}
Expected parameters include:
font
- font to render the text withtext
- the UTF8 string to renderfg
- the color to render the text in; pixels are blended between transparent and this color to draw the antialiased glyphs
Notes:
Passing a
undef
font into this function will cause a segfaultPassing a
undef
text into this function will result in undefined behavior
Returns a new SDL2::Surface on success.
TTF_RenderUNICODE_Blended( ... )
Render the UNICODE encoded text
using font
with fg
color onto a new surface, using the Blended mode. The caller (you!) is responsible for freeing any returned surface.
# Render some text in blended black to a new surface
# then blit to the upper left of the screen
# then free the text surface
my $color = SDL2::Color->new({r => 0, g => 0, b => 0});
if(!(my $text_surface = TTF_RenderUNICODE_Blended( $font,"Hello World!", $color ))) {
# handle error here, perhaps print TTF_GetError at least
}
else {
SDL_BlitSurface( $text_surface, undef, $screen, undef );
# perhaps we can reuse it, but I assume not for simplicity.
SDL_FreeSurface( $text_surface );
}
Expected parameters include:
font
- font to render the text withtext
- the UNICODE string to renderfg
- the color to render the text in; pixels are blended between transparent and this color to draw the antialiased glyphs
Notes:
Passing a
undef
font into this function will cause a segfaultPassing a
undef
text into this function will result in undefined behavior
Returns a new SDL2::Surface on success.
TTF_RenderGlyph_Blended( ... )
Render the glyph for the UNICODE ch
using font
with fg
color onto a new surface, using the Blended mode. The caller (you!) is responsible for freeing any returned surface.
# Render and cache all printable ASCII characters in blended black
my @glyph_cache;
for my $ord ( 0 .. 127 ) {
push @glyph_cache, TTF_RenderGlyph_Blended( $font, chr $ord, $color );
}
Expected parameters include:
font
- font to render the text withch
- the glyph to renderfg
- the color to render the glyph in; pixels are blended between transparent and this color to draw the antialiased glyph
Note: Passing a undef
font into this function will cause a segfault.
Returns a new SDL2::Surface on success. undef
is returned on errors, such as when the glyph is not available in the font.
Combined with a cache of the glyph metrics (minx, miny, and advance), you might make a fast text rendering routine that prints directly to the screen, but with inaccurate kerning.
Defined Values
These may be imported by name or with the :all
tag.
TTF_MAJOR_VERSION
-
SDL_ttf library major number at compilation time.
TTF_MINOR_VERSION
-
SDL_ttf library minor number at compilation time.
TTF_PATCHLEVEL
-
SDL_ttf library patch level at compilation time.
UNICODE_BOM_NATIVE
-
This allows you to switch byte-order of UNICODE text data to native order, meaning the mode of your CPU. This is meant to be used in a UNICODE string that you are using with the SDL_ttf API.
UNICODE_BOM_SWAPPED
-
This allows you to switch byte-order of UNICODE text data to swapped order, meaning the reversed mode of your CPU. So if your CPU is LSB, then the data will be interpreted as MSB. This is meant to be used in a UNICODE string that you are using with the SDL_ttf API.
TTF_STYLE_NORMAL
-
Used to indicate regular, normal, plain rendering style.
TTF_STYLE_BOLD
-
Used to indicate bold rendering style. This is used in a bitmask along with other styles.
TTF_STYLE_ITALIC
-
Used to indicate italicized rendering style. This is used in a bitmask along with other styles.
TTF_STYLE_UNDERLINE
-
Used to indicate underlined rendering style. This is used in a bitmask along with other styles.
TTF_STYLE_STRIKETHROUGH
-
Used to indicate strikethrough rendering style. This is used in a bitmask along with other styles.
TTF_HINTING_NORMAL
-
This corresponds to the default hinting algorithm, optimized for standard gray-level rendering
TTF_HINTING_LIGHT
-
A lighter hinting algorithm for non-monochrome modes. Many generated glyphs are more fuzzy but better resemble its original shape. A bit like rendering on Mac OS X.
TTF_HINTING_MONO
-
Strong hinting algorithm that should only be used for monochrome output. The result is probably unpleasant if the glyph is rendered in non-monochrome modes.
TTF_HINTING_NONE
-
No hinting is used so the font may become very blurry or messy at smaller sizes.
TTF_HINTING_LIGHT_SUBPIXEL
-
A grayscale subpixel hinting algorithm.
LICENSE
Copyright (C) Sanko Robinson.
This library is free software; you can redistribute it and/or modify it under the terms found in the Artistic License 2. Other copyrights, terms, and conditions may apply to data transmitted through this module.
AUTHOR
Sanko Robinson <sanko@cpan.org>