/lib/pods/SDL/TTF.pod
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1 2=pod 3 4=head1 NAME 5 6SDL::TTF - True Type Font functions (libfreetype) 7 8=head1 CATEGORY 9 10TTF 11 12=head1 CONSTANTS 13 14The constants are exported by default. You can avoid this by doing: 15 16 use SDL::TTF (); 17 18and access them directly: 19 20 SDL::TTF::TTF_HINTING_NORMAL; 21 22Available constants for "hinting": 23 24=over 4 25 26=item * 27 28TTF_HINTING_NORMAL 29 30=item * 31 32TTF_HINTING_LIGHT 33 34=item * 35 36TTF_HINTING_MONO 37 38=item * 39 40TTF_HINTING_NONE 41 42=back 43 44Available constants for "style": 45 46=over 4 47 48=item * 49 50TTF_STYLE_NORMAL 51 52=item * 53 54TTF_STYLE_BOLD 55 56=item * 57 58TTF_STYLE_ITALIC 59 60=item * 61 62TTF_STYLE_UNDERLINE 63 64=item * 65 66TTF_STYLE_STRIKETHROUGH 67 68=back 69 70=head1 METHODS 71 72=head2 General methods 73 74=head3 linked_version 75 76 my $version = SDL::TTF::linked_version(); 77 78This gives you the SDL::Version object which SDL_ttf lib is used on the system. 79No prior initialization needs to be done before these function is called. 80 81Example: 82 83 use SDL::TTF; 84 use SDL::Version; 85 86 my $version = SDL::TTF::linked_version(); 87 88 printf("got version: %d.%d.%d\n", $version->major, $version->minor, $version->patch); 89 90=head3 compile_time_version 91 92 my $version = SDL::TTF::compile_time_version(); 93 94This gives you the SDL::Version object which SDL_ttf was present at compile time. 95 96=head3 init 97 98 my $success = SDL::TTF::init(); 99 100Initialize the truetype font API. 101This 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">. 102SDL does not have to be initialized before this call. 103 104Returns: C<0> on success, C<-1> on any error. 105 106=head3 was_init 107 108 my $was_init = SDL::TTF::was_init(); 109 110Query the initialization status of the truetype font API. 111You 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 112call L<SDL::TTF::quit|SDL::TTF/"quit">. 113 114=head3 quit 115 116 SDL::TTF::quit(); 117 118Shutdown and cleanup the truetype font API. 119After 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 120L<SDL::TTF::init|SDL::TTF/"init"> to use the functionality again 121 122=head2 Management functions 123 124=head3 open_font 125 126 my $font = SDL::TTF::open_font($font_file, $point_size); 127 128Load 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. 129 130Returns: a L<SDL::TTF::Font> object. C<undef> is returned on errors. 131 132Example: 133 134 use SDL::TTF; 135 use SDL::TTF::Font; 136 137 my $font = SDL::TTF::open_font('arial.ttf', 24); 138 139=head3 open_font_index 140 141 my $font = SDL::TTF::open_font($font_file, $point_size, $face_index); 142 143This 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. 144This can load TTF and FON files. 145 146=head3 open_font_RW 147 148 my $font = SDL::TTF::open_font_RW($rwops_object, $free, $point_size); 149 150This is the same as L<SDL::TTF::open_font|SDL::TTF/"open_font">, except you can pass an L<SDL::RWOps>-object. If you pass true as C<$free>, the L<SDL::RWOps>-object 151will be freed by SDL_ttf library. Don't do this, perl will free this object for you. 152 153Example: 154 155 my $font = SDL::TTF::open_font_RW(SDL::RWOps->new_file($font_file, 'r'), 0, 24); 156 157=head3 open_font_index_RW 158 159 my $font = SDL::TTF::open_font_index_RW($rwops_object, $free, $point_size, $face_index); 160 161This is the same as L<SDL::TTF::open_font_index|SDL::TTF/"open_font_index">, except you can pass an L<SDL::RWOps>-object. If you pass true as C<$free>, the 162L<SDL::RWOps>-object will be freed by SDL_ttf library. Don't do this, perl will free this object for you. 163 164=head2 Attributes 165 166=head3 Global attributes 167 168=head4 byte_swapped_unicode 169 170 SDL::TTF::byte_swapped_unicode( $bool ); 171 172This function tells SDL_ttf whether UNICODE (2 bytes per character) text is generally byteswapped. A C<UNICODE_BOM_NATIVE> or 173C<UNICODE_BOM_SWAPPED> character in a string will temporarily override this setting for the remainder of that string, however this setting 174will be restored for the next one. The default mode is non-swapped, native endianness of the CPU. 175 176=head3 Font style 177 178=head4 get_font_style 179 180 SDL::TTF::get_font_style($font); 181 182Returns: The style as a bitmask composed of the following masks: 183 184=over 4 185 186=item * 187 188TTF_STYLE_NORMAL 189 190=item * 191 192TTF_STYLE_BOLD 193 194=item * 195 196TTF_STYLE_ITALIC 197 198=item * 199 200TTF_STYLE_UNDERLINE 201 202=item * 203 204TTF_STYLE_STRIKETHROUGH (since SDL_ttf 2.0.10) 205 206=back 207 208Example: 209 210 my $style = SDL::TTF::get_font_style($font); 211 212 print("normal\n") if $style == TTF_STYLE_NORMAL; 213 print("bold\n") if $style & TTF_STYLE_BOLD; 214 print("italic\n") if $style & TTF_STYLE_ITALIC; 215 print("underline\n") if $style & TTF_STYLE_UNDERLINE; 216 print("strikethrough\n") if $style & TTF_STYLE_STRIKETHROUGH; 217 218=head4 set_font_style 219 220 SDL::TTF::set_font_style($font, $style); 221 222Set the rendering style of the loaded font. 223 224B<Note>: C<TTF_STYLE_UNDERLINE> may cause surfaces created by C<SDL::TTF::render_glyph_*> functions to be extended vertically, downward only, 225to 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 226to place a glyph using glyph metrics. 227On the other hand C<TTF_STYLE_STRIKETHROUGH> doesn't extend the glyph, since this would invalidate the metrics used to position the glyph when 228blitting, because they would likely be extended vertically upward. There is perhaps a workaround, but it would require programs to be smarter 229about glyph blitting math than they are currently designed for. 230Still, sometimes the underline or strikethrough may be outside of the generated surface, and thus not visible when blitted to the screen. In 231this case, you should probably turn off these styles and draw your own strikethroughs and underlines. 232 233=head4 get_font_outline 234 235 my $outline = SDL::TTF::get_font_outline($font); 236 237Get the current outline width of the font, in pixels. 238 239B<Note>: at least SDL_ttf 2.0.10 needed 240 241=head4 set_font_outline 242 243 SDL::TTF::set_font_outline($font, $outline); 244 245Set the outline pixel width of the loaded font. Use C<0>(zero) to turn off outlining. 246 247B<Note>: at least SDL_ttf 2.0.10 needed 248 249=head3 Font settings 250 251=head4 get_font_hinting 252 253 my $hinting = SDL::TTF::get_font_hinting($font); 254 255Get the current hinting setting of the loaded font. 256 257B<Note>: at least SDL_ttf 2.0.10 needed 258 259Returns the hinting type matching one of the following defined values: 260 261=over 4 262 263=item * 264 265TTF_HINTING_NORMAL 266 267=item * 268 269TTF_HINTING_LIGHT 270 271=item * 272 273TTF_HINTING_MONO 274 275=item * 276 277TTF_HINTING_NONE 278 279=back 280 281=head4 set_font_hinting 282 283 SDL::TTF::set_font_hinting($font, $hinting); 284 285Set the hinting of the loaded font. You should experiment with this setting if you know which font you are using beforehand, especially when 286using smaller sized fonts. If the user is selecting a font, you may wish to let them select the hinting mode for that font as well. 287 288B<Note>: at least SDL_ttf 2.0.10 needed 289 290Example: 291 292 SDL::TTF::set_font_hinting($font, TTF_HINTING_LIGHT); 293 294=head4 get_font_kerning 295 296 my $kerning_enabled = SDL::TTF::get_font_kerning($font); 297 298Get the current kerning setting of the loaded font. 299 300Returns: 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>). 301 302B<Note>: at least SDL_ttf 2.0.10 needed 303 304B<Note>: This function returns wrong values: See L<http://bugzilla.libsdl.org/show_bug.cgi?id=973> 305 306=head4 set_font_kerning 307 308 SDL::TTF::set_font_kerning($font, $kerning_enabled); 309 310Set whether to use kerning when rendering the loaded font. This has no effect on individual glyphs, but rather when rendering whole strings of 311characters, 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 312overlapping glyphs or abnormal spacing within words. 313 314Pass C<0> to disable kerning, 1 to enable. 315 316B<Note>: at least SDL_ttf 2.0.10 needed 317 318=head3 Font metrics 319 320=head4 font_height 321 322 my $font_height = SDL::TTF::font_height($font); 323 324Get the maximum pixel height of all glyphs of the loaded font. You may use this height for rendering text as close together vertically as 325possible, 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 326printing, so you are responsible for line spacing, see the L<SDL::TTF::font_line_skip|SDL::TTF/"font_line_skip"> as well. 327 328=head4 font_ascent 329 330 my $font_ascent = SDL::TTF::font_ascent($font); 331 332Get 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 333baseline. 334It 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 335of the rectangle used when blitting the glyph on the screen. 336 337Example: 338 339 my ($minx, $maxx, $miny, $maxy, $advance) = @{ SDL::TTF::glyph_metrics($font, "\0M") }; 340 341 $rect->y( $top + SDL::TTF::font_ascent($font) - $maxy ); 342 343=head4 font_descent 344 345 my $font_descent = SDL::TTF::font_descent($font); 346 347Get 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 348the font. 349It 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 350of the rectangle used when blitting the glyph on the screen. 351 352Example: 353 354 my ($minx, $maxx, $miny, $maxy, $advance) = @{ SDL::TTF::glyph_metrics($font, "\0M") }; 355 356 $rect->y( $bottom - SDL::TTF::font_descent($font) - $maxy ); 357 358=head4 font_line_skip 359 360 my $font_line_skip = SDL::TTF::font_line_skip($font); 361 362Get 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 363font. 364 365=head3 Face attributes 366 367=head4 font_faces 368 369 my $font_faces = SDL::TTF::font_faces($font); 370 371Get 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 372and other typographical features perhaps) contained in the font itself. 373 374=head4 font_face_is_fixed_width 375 376 my $font_face_is_fixed_width = SDL::TTF::font_face_is_fixed_width($font); 377 378Test if the current font face of the loaded font is a fixed width font. Fixed width fonts are monospace, meaning every character that exists 379in 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>. 380 381Returns: C<E<gt>0> if font is a fixed width font. C<0> if not a fixed width font. 382 383=head4 font_face_family_name 384 385 my $font_face_family_name = SDL::TTF::font_face_family_name($font); 386 387Get the current font face family name from the loaded font. This information is not for every font available. 388 389Example: 390 391 my $font = SDL::TTF::open_font('arialuni.ttf', 8); 392 393 printf("%s\n", SDL::TTF::font_face_family_name($font)); # will print "Arial Unicode MS" 394 395=head4 font_face_style_name 396 397 my $font_face_style_name = SDL::TTF::font_face_style_name($font); 398 399Get the current font face style name from the loaded font. This information is not for every font available. 400 401Example: 402 403 my $font = SDL::TTF::open_font('arialuni.ttf', 8); 404 405 printf("%s\n", SDL::TTF::font_face_style_name($font)); # will print "Regular" 406 407=head3 Glyphs 408 409=head4 glyph_is_provided 410 411 my $glyph_is_provided = SDL::TTF::glyph_is_provided($font, $unicode_char); 412 413Get the status of the availability of the glyph from the loaded font. 414 415Returns: the index of the glyph in font, or 0 for an undefined character code. 416 417B<Note>: You have to pass this unicode character either as UTF16/UCS-2 big endian without BOM, or with BOM as UTF16/UCS-2 big/little endian. 418 419B<Note>: at least SDL_ttf 2.0.10 needed 420 421Example: 422 423 print("We have this char!\n") if SDL::TTF::glyph_is_provided($font, "\0M"); 424 425=head4 glyph_metrics 426 427 my @glyph_metrics = @{ SDL::TTF::glyph_metrics($font, $unicode_char) }; 428 429Get desired glyph metrics of the UNICODE char from the loaded font. 430 431See also: L<The FreeType2 Documentation Tutorial|http://freetype.sourceforge.net/freetype2/docs/tutorial/step2.html> 432 433B<Note>: You have to pass this unicode character either as UTF16/UCS-2 big endian without BOM, or with BOM as UTF16/UCS-2 big/little endian. 434 435Example: 436 437 my ($minx, $maxx, $miny, $maxy, $advance) = @{ SDL::TTF::glyph_metrics($font, "\0M") }; 438 439=head3 Text metrics 440 441=head4 size_text 442 443 my ($width, $height) = @{ SDL::TTF::size_text($font, $text) }; 444 445Calculate the resulting surface size of the LATIN1 encoded text rendered using C<$font>. No actual rendering is done, however correct kerning 446is 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">. 447 448=head4 size_utf8 449 450 my ($width, $height) = @{ SDL::TTF::size_utf8($font, $text) }; 451 452Calculate the resulting surface size of the UTF8 encoded text rendered using C<$font>. No actual rendering is done, however correct kerning is 453done 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">. 454 455Note that the first example uses the same text as in the LATIN1 example, that is because plain ASCII is UTF8 compatible. 456 457Examples: 458 459 ($width, $height) = @{ SDL::TTF::size_utf8($font, 'Hello World!') }; # plain text, if your script is in utf8 or ansi-format 460 461 # or 462 463 ($width, $height) = @{ SDL::TTF::size_utf8($font, "\xE4\xBB\x8A\xE6\x97\xA5\xE3\x81\xAF") }; # utf8 hex-data 464 465 # or 466 467 use Unicode::String; 468 my $unicode = utf8($data_from_somewhere); 469 ($width, $height) = @{ SDL::TTF::size_utf8($font, $unicode->utf8) }; # utf8 via Unicode::String 470 471=head4 size_unicode 472 473 my ($width, $height) = @{ SDL::TTF::size_unicode($font, $text) }; 474 475Calculate the resulting surface size of the UNICODE encoded text rendered using C<$font>. No actual rendering is done, however correct kerning 476is 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">. 477 478C<$text> has to be: 479 480=over 4 481 482=item UTF16BE without BOM 483 484"hello" will look like "\0h\0e\0l\0l\0o" 485 486=item UTF16BE with BOM 487 488"hello" will look like "\xFE\xFF\0h\0e\0l\0l\0o" 489 490=item UTF16LE with BOM 491 492"hello" will look like "\xFF\xFEh\0e\0l\0l\0o\0" 493 494=back 495 496You may use Unicode::String for this. 497 498=head2 Font Rendering 499 500=head3 Solid 501 502=head4 render_glyph_solid 503 504 my $surface = SDL::TTF::render_glyph_solid($font, $char, $color); 505 506Render the unicode encoded char onto a new surface, using the Solid mode. After that you can blit this surface to your display-surface. 507 508B<Note>: The unicode char has to be passed exactly like for L<SDL::TTF::size_unicode|SDL::TTF/"size_unicode">. 509 510B<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 2.3.5 511 512=head4 render_text_solid 513 514 my $surface = SDL::TTF::render_text_solid($font, $text, $color); 515 516Render the LATIN1 encoded text onto a new surface, using the Solid mode. After that you can blit this surface to your display-surface. 517 518B<Note>: L<See space-character bug|http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=374062>. You have to upgrade libfreetype2 to at least 519version 2.3.5 520 521Example: 522 523 use SDL; 524 use SDL::Rect; 525 use SDL::Video; 526 use SDL::Color; 527 use SDL::TTF; 528 use SDL::TTF::Font; 529 530 SDL::init(SDL_INIT_VIDEO); 531 SDL::TTF::init(); 532 my $display = SDL::Video::set_video_mode(640, 480, 32, SDL_SWSURFACE); 533 my $font = SDL::TTF::open_font('somefont.ttf', '24'); 534 die 'Coudnt make font '. SDL::get_error if !$font; 535 my $surface = SDL::TTF::render_text_solid($font, 'Hello!', SDL::Color->new(0xFF,0xFF,0xFF)); 536 SDL::Video::blit_surface($surface, SDL::Rect->new(0, 0, 640, 480), $display, SDL::Rect->new(10, 10, 640, 480)); 537 SDL::Video::update_rect($display, 0, 0, 0, 0); 538 SDL::delay(5000); 539 540=head4 render_utf8_solid 541 542 my $surface = SDL::TTF::render_utf8_solid($font, $text, $color); 543 544Render the UTF8 encoded text onto a new surface, using the Solid mode. After that you can blit this surface to your display-surface. 545 546B<Note>: L<See space-character bug|http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=374062>. You have to upgrade libfreetype2 to at least 547version 2.3.5 548 549=head4 render_unicode_solid 550 551 my $surface = SDL::TTF::render_unicode_solid($font, $text, $color); 552 553Render the unicode encoded text onto a new surface, using the Solid mode. After that you can blit this surface to your display-surface. 554 555B<Note>: The unicode test has to be passed exactly like for L<SDL::TTF::size_unicode|SDL::TTF/"size_unicode">. 556 557B<Note>: L<See space-character bug|http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=374062>. You have to upgrade libfreetype2 to at least 558version 2.3.5 559 560=head3 Shaded 561 562=head4 render_glyph_shaded 563 564 my $surface = SDL::TTF::render_glyph_shaded($font, $char, $color, $background_color); 565 566Render the unicode encoded char onto a new surface. The surface is filled with C<$background_color>. After that you can blit this surface to 567your display-surface. 568 569B<Note>: The unicode char has to be passed exactly like for L<SDL::TTF::size_unicode|SDL::TTF/"size_unicode">. 570 571=head4 render_text_shaded 572 573 my $surface = SDL::TTF::render_text_shaded($font, $text, $color, $background_color); 574 575Render the LATIN1 encoded text onto a new surface. The surface is filled with C<$background_color>. After that you can blit this surface to 576your display-surface. 577 578Example: 579 580 use SDL; 581 use SDL::Video; 582 use SDL::Color; 583 use SDL::TTF; 584 use SDL::TTF::Font; 585 586 SDL::init(SDL_INIT_VIDEO); 587 588 SDL::TTF::init(); 589 590 my $display = SDL::Video::set_video_mode(640, 480, 32, SDL_SWSURFACE); 591 my $font = SDL::TTF::open_font('arial.ttf', '24'); 592 my $white = SDL::Color->new(0xFF, 0xFF, 0xFF); 593 my $black = SDL::Color->new(0x00, 0x00, 0x00); 594 my $surface = SDL::TTF::render_text_solid($font, 'Hello!', $white, $black); 595 596 SDL::Video::blit_surface($surface, SDL::Rect->new(0, 0, 640, 480), $display, SDL::Rect->new(10, 10, 640, 480)); 597 SDL::Video::update_rect($display, 0, 0, 0, 0); 598 599 SDL::delay(5000); 600 601=head4 render_utf8_shaded 602 603 my $surface = SDL::TTF::render_utf8_shaded($font, $text, $color, $background_color); 604 605Render the UTF8 encoded text onto a new surface. The surface is filled with C<$background_color>. After that you can blit this surface to 606your display-surface. 607 608=head4 render_unicode_shaded 609 610 my $surface = SDL::TTF::render_unicode_shaded($font, $text, $color, $background_color); 611 612Render the unicode encoded text onto a new surface. The surface is filled with C<$background_color>. After that you can blit this surface to 613your display-surface. 614 615B<Note>: The unicode text has to be passed exactly like for L<SDL::TTF::size_unicode|SDL::TTF/"size_unicode">. 616 617=head3 Blended 618 619=head4 render_glyph_blended 620 621 my $surface = SDL::TTF::render_glyph_blended($font, $char, $color); 622 623Render the unicode encoded char onto a new surface. After that you can blit this surface to your display-surface. 624 625B<Note>: The unicode char has to be passed exactly like for L<SDL::TTF::size_unicode|SDL::TTF/"size_unicode">. 626 627=head4 render_text_blended 628 629 my $surface = SDL::TTF::render_text_blended($font, $text, $color); 630 631Render the LATIN1 encoded text onto a new surface. After that you can blit this surface to your display-surface. 632 633Example: 634 635 use SDL; 636 use SDL::Video; 637 use SDL::Color; 638 use SDL::TTF; 639 use SDL::TTF::Font; 640 641 SDL::init(SDL_INIT_VIDEO); 642 643 SDL::TTF::init(); 644 645 my $display = SDL::Video::set_video_mode(640, 480, 32, SDL_SWSURFACE); 646 my $font = SDL::TTF::open_font('arial.ttf', '24'); 647 my $surface = SDL::TTF::render_text_blended($font, 'Hello!', SDL::Color->new(0xFF,0xFF,0xFF)); 648 649 SDL::Video::blit_surface($surface, SDL::Rect->new(0, 0, 640, 480), $display, SDL::Rect->new(10, 10, 640, 480)); 650 SDL::Video::update_rect($display, 0, 0, 0, 0); 651 652 SDL::delay(5000); 653 654=head4 render_utf8_blended 655 656 my $surface = SDL::TTF::render_utf8_blended($font, $text, $color); 657 658Render the UTF8 encoded text onto a new surface. After that you can blit this surface to your display-surface. 659 660=head4 render_unicode_blended 661 662 my $surface = SDL::TTF::render_unicode_blended($font, $text, $color); 663 664Render the unicode encoded text onto a new surface. After that you can blit this surface to your display-surface. 665 666B<Note>: The unicode char has to be passed exactly like for L<SDL::TTF::size_unicode|SDL::TTF/"size_unicode">. 667 668=head1 AUTHORS 669 670See L<SDL/AUTHORS>. 671 672=head1 SEE ALSO 673 674L<SDL::TTF::Font>, L<Unicode::String>, L<SDL::Video>, L<SDL::Surface> 675 676=cut