/usr/share/gtk-doc/html/cairo/cairo-Paths.html is in libcairo2-doc 1.10.2-6.1ubuntu2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 | <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Paths</title>
<meta name="generator" content="DocBook XSL Stylesheets V1.75.2">
<link rel="home" href="index.html" title="Cairo: A Vector Graphics Library">
<link rel="up" href="cairo-drawing.html" title="Drawing">
<link rel="prev" href="cairo-cairo-t.html" title="cairo_t">
<link rel="next" href="cairo-cairo-pattern-t.html" title="cairo_pattern_t">
<meta name="generator" content="GTK-Doc V1.15 (XML mode)">
<link rel="stylesheet" href="style.css" type="text/css">
</head>
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
<table class="navigation" id="top" width="100%" summary="Navigation header" cellpadding="2" cellspacing="2">
<tr valign="middle">
<td><a accesskey="p" href="cairo-cairo-t.html"><img src="left.png" width="24" height="24" border="0" alt="Prev"></a></td>
<td><a accesskey="u" href="cairo-drawing.html"><img src="up.png" width="24" height="24" border="0" alt="Up"></a></td>
<td><a accesskey="h" href="index.html"><img src="home.png" width="24" height="24" border="0" alt="Home"></a></td>
<th width="100%" align="center">Cairo: A Vector Graphics Library</th>
<td><a accesskey="n" href="cairo-cairo-pattern-t.html"><img src="right.png" width="24" height="24" border="0" alt="Next"></a></td>
</tr>
<tr><td colspan="5" class="shortcuts">
<a href="#cairo-Paths.synopsis" class="shortcut">Top</a>
|
<a href="#cairo-Paths.description" class="shortcut">Description</a>
</td></tr>
</table>
<div class="refentry" title="Paths">
<a name="cairo-Paths"></a><div class="titlepage"></div>
<div class="refnamediv"><table width="100%"><tr>
<td valign="top">
<h2><span class="refentrytitle"><a name="cairo-Paths.top_of_page"></a>Paths</span></h2>
<p>Paths — Creating paths and manipulating path data</p>
</td>
<td valign="top" align="right"></td>
</tr></table></div>
<div class="refsynopsisdiv" title="Synopsis">
<a name="cairo-Paths.synopsis"></a><h2>Synopsis</h2>
<pre class="synopsis"> <a class="link" href="cairo-Paths.html#cairo-path-t" title="cairo_path_t">cairo_path_t</a>;
union <a class="link" href="cairo-Paths.html#cairo-path-data-t" title="union cairo_path_data_t">cairo_path_data_t</a>;
enum <a class="link" href="cairo-Paths.html#cairo-path-data-type-t" title="enum cairo_path_data_type_t">cairo_path_data_type_t</a>;
<a class="link" href="cairo-Paths.html#cairo-path-t" title="cairo_path_t"><span class="returnvalue">cairo_path_t</span></a> * <a class="link" href="cairo-Paths.html#cairo-copy-path" title="cairo_copy_path ()">cairo_copy_path</a> (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>);
<a class="link" href="cairo-Paths.html#cairo-path-t" title="cairo_path_t"><span class="returnvalue">cairo_path_t</span></a> * <a class="link" href="cairo-Paths.html#cairo-copy-path-flat" title="cairo_copy_path_flat ()">cairo_copy_path_flat</a> (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>);
<span class="returnvalue">void</span> <a class="link" href="cairo-Paths.html#cairo-path-destroy" title="cairo_path_destroy ()">cairo_path_destroy</a> (<em class="parameter"><code><a class="link" href="cairo-Paths.html#cairo-path-t" title="cairo_path_t"><span class="type">cairo_path_t</span></a> *path</code></em>);
<span class="returnvalue">void</span> <a class="link" href="cairo-Paths.html#cairo-append-path" title="cairo_append_path ()">cairo_append_path</a> (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>,
<em class="parameter"><code>const <a class="link" href="cairo-Paths.html#cairo-path-t" title="cairo_path_t"><span class="type">cairo_path_t</span></a> *path</code></em>);
<a class="link" href="cairo-Types.html#cairo-bool-t" title="cairo_bool_t"><span class="returnvalue">cairo_bool_t</span></a> <a class="link" href="cairo-Paths.html#cairo-has-current-point" title="cairo_has_current_point ()">cairo_has_current_point</a> (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>);
<span class="returnvalue">void</span> <a class="link" href="cairo-Paths.html#cairo-get-current-point" title="cairo_get_current_point ()">cairo_get_current_point</a> (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>,
<em class="parameter"><code><span class="type">double</span> *x</code></em>,
<em class="parameter"><code><span class="type">double</span> *y</code></em>);
<span class="returnvalue">void</span> <a class="link" href="cairo-Paths.html#cairo-new-path" title="cairo_new_path ()">cairo_new_path</a> (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>);
<span class="returnvalue">void</span> <a class="link" href="cairo-Paths.html#cairo-new-sub-path" title="cairo_new_sub_path ()">cairo_new_sub_path</a> (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>);
<span class="returnvalue">void</span> <a class="link" href="cairo-Paths.html#cairo-close-path" title="cairo_close_path ()">cairo_close_path</a> (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>);
<span class="returnvalue">void</span> <a class="link" href="cairo-Paths.html#cairo-arc" title="cairo_arc ()">cairo_arc</a> (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>,
<em class="parameter"><code><span class="type">double</span> xc</code></em>,
<em class="parameter"><code><span class="type">double</span> yc</code></em>,
<em class="parameter"><code><span class="type">double</span> radius</code></em>,
<em class="parameter"><code><span class="type">double</span> angle1</code></em>,
<em class="parameter"><code><span class="type">double</span> angle2</code></em>);
<span class="returnvalue">void</span> <a class="link" href="cairo-Paths.html#cairo-arc-negative" title="cairo_arc_negative ()">cairo_arc_negative</a> (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>,
<em class="parameter"><code><span class="type">double</span> xc</code></em>,
<em class="parameter"><code><span class="type">double</span> yc</code></em>,
<em class="parameter"><code><span class="type">double</span> radius</code></em>,
<em class="parameter"><code><span class="type">double</span> angle1</code></em>,
<em class="parameter"><code><span class="type">double</span> angle2</code></em>);
<span class="returnvalue">void</span> <a class="link" href="cairo-Paths.html#cairo-curve-to" title="cairo_curve_to ()">cairo_curve_to</a> (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>,
<em class="parameter"><code><span class="type">double</span> x1</code></em>,
<em class="parameter"><code><span class="type">double</span> y1</code></em>,
<em class="parameter"><code><span class="type">double</span> x2</code></em>,
<em class="parameter"><code><span class="type">double</span> y2</code></em>,
<em class="parameter"><code><span class="type">double</span> x3</code></em>,
<em class="parameter"><code><span class="type">double</span> y3</code></em>);
<span class="returnvalue">void</span> <a class="link" href="cairo-Paths.html#cairo-line-to" title="cairo_line_to ()">cairo_line_to</a> (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>,
<em class="parameter"><code><span class="type">double</span> x</code></em>,
<em class="parameter"><code><span class="type">double</span> y</code></em>);
<span class="returnvalue">void</span> <a class="link" href="cairo-Paths.html#cairo-move-to" title="cairo_move_to ()">cairo_move_to</a> (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>,
<em class="parameter"><code><span class="type">double</span> x</code></em>,
<em class="parameter"><code><span class="type">double</span> y</code></em>);
<span class="returnvalue">void</span> <a class="link" href="cairo-Paths.html#cairo-rectangle" title="cairo_rectangle ()">cairo_rectangle</a> (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>,
<em class="parameter"><code><span class="type">double</span> x</code></em>,
<em class="parameter"><code><span class="type">double</span> y</code></em>,
<em class="parameter"><code><span class="type">double</span> width</code></em>,
<em class="parameter"><code><span class="type">double</span> height</code></em>);
<span class="returnvalue">void</span> <a class="link" href="cairo-Paths.html#cairo-glyph-path" title="cairo_glyph_path ()">cairo_glyph_path</a> (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>,
<em class="parameter"><code>const <a class="link" href="cairo-text.html#cairo-glyph-t" title="cairo_glyph_t"><span class="type">cairo_glyph_t</span></a> *glyphs</code></em>,
<em class="parameter"><code><span class="type">int</span> num_glyphs</code></em>);
<span class="returnvalue">void</span> <a class="link" href="cairo-Paths.html#cairo-text-path" title="cairo_text_path ()">cairo_text_path</a> (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>,
<em class="parameter"><code>const <span class="type">char</span> *utf8</code></em>);
<span class="returnvalue">void</span> <a class="link" href="cairo-Paths.html#cairo-rel-curve-to" title="cairo_rel_curve_to ()">cairo_rel_curve_to</a> (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>,
<em class="parameter"><code><span class="type">double</span> dx1</code></em>,
<em class="parameter"><code><span class="type">double</span> dy1</code></em>,
<em class="parameter"><code><span class="type">double</span> dx2</code></em>,
<em class="parameter"><code><span class="type">double</span> dy2</code></em>,
<em class="parameter"><code><span class="type">double</span> dx3</code></em>,
<em class="parameter"><code><span class="type">double</span> dy3</code></em>);
<span class="returnvalue">void</span> <a class="link" href="cairo-Paths.html#cairo-rel-line-to" title="cairo_rel_line_to ()">cairo_rel_line_to</a> (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>,
<em class="parameter"><code><span class="type">double</span> dx</code></em>,
<em class="parameter"><code><span class="type">double</span> dy</code></em>);
<span class="returnvalue">void</span> <a class="link" href="cairo-Paths.html#cairo-rel-move-to" title="cairo_rel_move_to ()">cairo_rel_move_to</a> (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>,
<em class="parameter"><code><span class="type">double</span> dx</code></em>,
<em class="parameter"><code><span class="type">double</span> dy</code></em>);
<span class="returnvalue">void</span> <a class="link" href="cairo-Paths.html#cairo-path-extents" title="cairo_path_extents ()">cairo_path_extents</a> (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>,
<em class="parameter"><code><span class="type">double</span> *x1</code></em>,
<em class="parameter"><code><span class="type">double</span> *y1</code></em>,
<em class="parameter"><code><span class="type">double</span> *x2</code></em>,
<em class="parameter"><code><span class="type">double</span> *y2</code></em>);
</pre>
</div>
<div class="refsect1" title="Description">
<a name="cairo-Paths.description"></a><h2>Description</h2>
<p>
Paths are the most basic drawing tools and are primarily used to implicitly
generate simple masks.
</p>
</div>
<div class="refsect1" title="Details">
<a name="cairo-Paths.details"></a><h2>Details</h2>
<div class="refsect2" title="cairo_path_t">
<a name="cairo-path-t"></a><h3>cairo_path_t</h3>
<pre class="programlisting">typedef struct {
cairo_status_t status;
cairo_path_data_t *data;
int num_data;
} cairo_path_t;
</pre>
<p>
A data structure for holding a path. This data structure serves as
the return value for <a class="link" href="cairo-Paths.html#cairo-copy-path" title="cairo_copy_path ()"><code class="function">cairo_copy_path()</code></a> and
<a class="link" href="cairo-Paths.html#cairo-copy-path-flat" title="cairo_copy_path_flat ()"><code class="function">cairo_copy_path_flat()</code></a> as well the input value for
<a class="link" href="cairo-Paths.html#cairo-append-path" title="cairo_append_path ()"><code class="function">cairo_append_path()</code></a>.
</p>
<p>
See <a class="link" href="cairo-Paths.html#cairo-path-data-t" title="union cairo_path_data_t"><span class="type">cairo_path_data_t</span></a> for hints on how to iterate over the
actual data within the path.
</p>
<p>
The num_data member gives the number of elements in the data
array. This number is larger than the number of independent path
portions (defined in <a class="link" href="cairo-Paths.html#cairo-path-data-type-t" title="enum cairo_path_data_type_t"><span class="type">cairo_path_data_type_t</span></a>), since the data
includes both headers and coordinates for each portion.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><a class="link" href="cairo-Error-handling.html#cairo-status-t" title="enum cairo_status_t"><span class="type">cairo_status_t</span></a> <em class="structfield"><code><a name="cairo-path-t.status"></a>status</code></em>;</span></p></td>
<td>the current error status
</td>
</tr>
<tr>
<td><p><span class="term"><a class="link" href="cairo-Paths.html#cairo-path-data-t" title="union cairo_path_data_t"><span class="type">cairo_path_data_t</span></a> *<em class="structfield"><code><a name="cairo-path-t.data"></a>data</code></em>;</span></p></td>
<td>the elements in the path
</td>
</tr>
<tr>
<td><p><span class="term"><span class="type">int</span> <em class="structfield"><code><a name="cairo-path-t.num-data"></a>num_data</code></em>;</span></p></td>
<td>the number of elements in the data array
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" title="union cairo_path_data_t">
<a name="cairo-path-data-t"></a><h3>union cairo_path_data_t</h3>
<pre class="programlisting"></pre>
<p>
<a class="link" href="cairo-Paths.html#cairo-path-data-t" title="union cairo_path_data_t"><span class="type">cairo_path_data_t</span></a> is used to represent the path data inside a
<a class="link" href="cairo-Paths.html#cairo-path-t" title="cairo_path_t"><span class="type">cairo_path_t</span></a>.
</p>
<p>
The data structure is designed to try to balance the demands of
efficiency and ease-of-use. A path is represented as an array of
<a class="link" href="cairo-Paths.html#cairo-path-data-t" title="union cairo_path_data_t"><span class="type">cairo_path_data_t</span></a>, which is a union of headers and points.
</p>
<p>
Each portion of the path is represented by one or more elements in
the array, (one header followed by 0 or more points). The length
value of the header is the number of array elements for the current
portion including the header, (ie. length == 1 + # of points), and
where the number of points for each element type is as follows:
</p>
<p>
</p>
<pre class="programlisting">
%CAIRO_PATH_MOVE_TO: 1 point
%CAIRO_PATH_LINE_TO: 1 point
%CAIRO_PATH_CURVE_TO: 3 points
%CAIRO_PATH_CLOSE_PATH: 0 points
</pre>
<p>
</p>
<p>
The semantics and ordering of the coordinate values are consistent
with <a class="link" href="cairo-Paths.html#cairo-move-to" title="cairo_move_to ()"><code class="function">cairo_move_to()</code></a>, <a class="link" href="cairo-Paths.html#cairo-line-to" title="cairo_line_to ()"><code class="function">cairo_line_to()</code></a>, <a class="link" href="cairo-Paths.html#cairo-curve-to" title="cairo_curve_to ()"><code class="function">cairo_curve_to()</code></a>, and
<a class="link" href="cairo-Paths.html#cairo-close-path" title="cairo_close_path ()"><code class="function">cairo_close_path()</code></a>.
</p>
<p>
Here is sample code for iterating through a <a class="link" href="cairo-Paths.html#cairo-path-t" title="cairo_path_t"><span class="type">cairo_path_t</span></a>:
</p>
<p>
</p>
<div class="informalexample"><pre class="programlisting">
int i;
cairo_path_t *path;
cairo_path_data_t *data;
path = cairo_copy_path (cr);
for (i=0; i < path->num_data; i += path->data[i].header.length) {
data = &path->data[i];
switch (data->header.type) {
case CAIRO_PATH_MOVE_TO:
do_move_to_things (data[1].point.x, data[1].point.y);
break;
case CAIRO_PATH_LINE_TO:
do_line_to_things (data[1].point.x, data[1].point.y);
break;
case CAIRO_PATH_CURVE_TO:
do_curve_to_things (data[1].point.x, data[1].point.y,
data[2].point.x, data[2].point.y,
data[3].point.x, data[3].point.y);
break;
case CAIRO_PATH_CLOSE_PATH:
do_close_path_things ();
break;
}
}
cairo_path_destroy (path);
</pre></div>
<p>
</p>
<p>
As of cairo 1.4, cairo does not mind if there are more elements in
a portion of the path than needed. Such elements can be used by
users of the cairo API to hold extra values in the path data
structure. For this reason, it is recommended that applications
always use <code class="literal">data->header.length</code> to
iterate over the path data, instead of hardcoding the number of
elements for each element type.
</p>
</div>
<hr>
<div class="refsect2" title="enum cairo_path_data_type_t">
<a name="cairo-path-data-type-t"></a><h3>enum cairo_path_data_type_t</h3>
<pre class="programlisting">typedef enum _cairo_path_data_type {
CAIRO_PATH_MOVE_TO,
CAIRO_PATH_LINE_TO,
CAIRO_PATH_CURVE_TO,
CAIRO_PATH_CLOSE_PATH
} cairo_path_data_type_t;
</pre>
<p>
<a class="link" href="cairo-Paths.html#cairo-path-data-t" title="union cairo_path_data_t"><span class="type">cairo_path_data_t</span></a> is used to describe the type of one portion
of a path when represented as a <a class="link" href="cairo-Paths.html#cairo-path-t" title="cairo_path_t"><span class="type">cairo_path_t</span></a>.
See <a class="link" href="cairo-Paths.html#cairo-path-data-t" title="union cairo_path_data_t"><span class="type">cairo_path_data_t</span></a> for details.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><a name="CAIRO-PATH-MOVE-TO:CAPS"></a><span class="term"><code class="literal">CAIRO_PATH_MOVE_TO</code></span></p></td>
<td>A move-to operation
</td>
</tr>
<tr>
<td><p><a name="CAIRO-PATH-LINE-TO:CAPS"></a><span class="term"><code class="literal">CAIRO_PATH_LINE_TO</code></span></p></td>
<td>A line-to operation
</td>
</tr>
<tr>
<td><p><a name="CAIRO-PATH-CURVE-TO:CAPS"></a><span class="term"><code class="literal">CAIRO_PATH_CURVE_TO</code></span></p></td>
<td>A curve-to operation
</td>
</tr>
<tr>
<td><p><a name="CAIRO-PATH-CLOSE-PATH:CAPS"></a><span class="term"><code class="literal">CAIRO_PATH_CLOSE_PATH</code></span></p></td>
<td>A close-path operation
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" title="cairo_copy_path ()">
<a name="cairo-copy-path"></a><h3>cairo_copy_path ()</h3>
<pre class="programlisting"><a class="link" href="cairo-Paths.html#cairo-path-t" title="cairo_path_t"><span class="returnvalue">cairo_path_t</span></a> * cairo_copy_path (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>);</pre>
<p>
Creates a copy of the current path and returns it to the user as a
<a class="link" href="cairo-Paths.html#cairo-path-t" title="cairo_path_t"><span class="type">cairo_path_t</span></a>. See <a class="link" href="cairo-Paths.html#cairo-path-data-t" title="union cairo_path_data_t"><span class="type">cairo_path_data_t</span></a> for hints on how to iterate
over the returned data structure.
</p>
<p>
This function will always return a valid pointer, but the result
will have no data (<code class="literal">data==<a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a></code> and
<code class="literal">num_data==0</code>), if either of the following
conditions hold:
</p>
<p>
</p>
<div class="orderedlist"><ol class="orderedlist" type="1">
<li class="listitem">If there is insufficient memory to copy the path. In this
case <code class="literal">path->status</code> will be set to
<a class="link" href="cairo-Error-handling.html#CAIRO-STATUS-NO-MEMORY:CAPS"><code class="literal">CAIRO_STATUS_NO_MEMORY</code></a>.</li>
<li class="listitem">If <em class="parameter"><code>cr</code></em> is already in an error state. In this case
<code class="literal">path->status</code> will contain the same status that
would be returned by <a class="link" href="cairo-cairo-t.html#cairo-status" title="cairo_status ()"><code class="function">cairo_status()</code></a>.</li>
</ol></div>
<p>
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>cr</code></em> :</span></p></td>
<td>a cairo context
</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
<td> the copy of the current path. The caller owns the
returned object and should call <a class="link" href="cairo-Paths.html#cairo-path-destroy" title="cairo_path_destroy ()"><code class="function">cairo_path_destroy()</code></a> when finished
with it.
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" title="cairo_copy_path_flat ()">
<a name="cairo-copy-path-flat"></a><h3>cairo_copy_path_flat ()</h3>
<pre class="programlisting"><a class="link" href="cairo-Paths.html#cairo-path-t" title="cairo_path_t"><span class="returnvalue">cairo_path_t</span></a> * cairo_copy_path_flat (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>);</pre>
<p>
Gets a flattened copy of the current path and returns it to the
user as a <a class="link" href="cairo-Paths.html#cairo-path-t" title="cairo_path_t"><span class="type">cairo_path_t</span></a>. See <a class="link" href="cairo-Paths.html#cairo-path-data-t" title="union cairo_path_data_t"><span class="type">cairo_path_data_t</span></a> for hints on
how to iterate over the returned data structure.
</p>
<p>
This function is like <a class="link" href="cairo-Paths.html#cairo-copy-path" title="cairo_copy_path ()"><code class="function">cairo_copy_path()</code></a> except that any curves
in the path will be approximated with piecewise-linear
approximations, (accurate to within the current tolerance
value). That is, the result is guaranteed to not have any elements
of type <a class="link" href="cairo-Paths.html#CAIRO-PATH-CURVE-TO:CAPS"><code class="literal">CAIRO_PATH_CURVE_TO</code></a> which will instead be replaced by a
series of <a class="link" href="cairo-Paths.html#CAIRO-PATH-LINE-TO:CAPS"><code class="literal">CAIRO_PATH_LINE_TO</code></a> elements.
</p>
<p>
This function will always return a valid pointer, but the result
will have no data (<code class="literal">data==<a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a></code> and
<code class="literal">num_data==0</code>), if either of the following
conditions hold:
</p>
<p>
</p>
<div class="orderedlist"><ol class="orderedlist" type="1">
<li class="listitem">If there is insufficient memory to copy the path. In this
case <code class="literal">path->status</code> will be set to
<a class="link" href="cairo-Error-handling.html#CAIRO-STATUS-NO-MEMORY:CAPS"><code class="literal">CAIRO_STATUS_NO_MEMORY</code></a>.</li>
<li class="listitem">If <em class="parameter"><code>cr</code></em> is already in an error state. In this case
<code class="literal">path->status</code> will contain the same status that
would be returned by <a class="link" href="cairo-cairo-t.html#cairo-status" title="cairo_status ()"><code class="function">cairo_status()</code></a>.</li>
</ol></div>
<p>
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>cr</code></em> :</span></p></td>
<td>a cairo context
</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
<td> the copy of the current path. The caller owns the
returned object and should call <a class="link" href="cairo-Paths.html#cairo-path-destroy" title="cairo_path_destroy ()"><code class="function">cairo_path_destroy()</code></a> when finished
with it.
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" title="cairo_path_destroy ()">
<a name="cairo-path-destroy"></a><h3>cairo_path_destroy ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span> cairo_path_destroy (<em class="parameter"><code><a class="link" href="cairo-Paths.html#cairo-path-t" title="cairo_path_t"><span class="type">cairo_path_t</span></a> *path</code></em>);</pre>
<p>
Immediately releases all memory associated with <em class="parameter"><code>path</code></em>. After a call
to <a class="link" href="cairo-Paths.html#cairo-path-destroy" title="cairo_path_destroy ()"><code class="function">cairo_path_destroy()</code></a> the <em class="parameter"><code>path</code></em> pointer is no longer valid and
should not be used further.
</p>
<p>
Note: <a class="link" href="cairo-Paths.html#cairo-path-destroy" title="cairo_path_destroy ()"><code class="function">cairo_path_destroy()</code></a> should only be called with a
pointer to a <a class="link" href="cairo-Paths.html#cairo-path-t" title="cairo_path_t"><span class="type">cairo_path_t</span></a> returned by a cairo function. Any path
that is created manually (ie. outside of cairo) should be destroyed
manually as well.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody><tr>
<td><p><span class="term"><em class="parameter"><code>path</code></em> :</span></p></td>
<td>a path previously returned by either <a class="link" href="cairo-Paths.html#cairo-copy-path" title="cairo_copy_path ()"><code class="function">cairo_copy_path()</code></a> or
<a class="link" href="cairo-Paths.html#cairo-copy-path-flat" title="cairo_copy_path_flat ()"><code class="function">cairo_copy_path_flat()</code></a>.
</td>
</tr></tbody>
</table></div>
</div>
<hr>
<div class="refsect2" title="cairo_append_path ()">
<a name="cairo-append-path"></a><h3>cairo_append_path ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span> cairo_append_path (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>,
<em class="parameter"><code>const <a class="link" href="cairo-Paths.html#cairo-path-t" title="cairo_path_t"><span class="type">cairo_path_t</span></a> *path</code></em>);</pre>
<p>
Append the <em class="parameter"><code>path</code></em> onto the current path. The <em class="parameter"><code>path</code></em> may be either the
return value from one of <a class="link" href="cairo-Paths.html#cairo-copy-path" title="cairo_copy_path ()"><code class="function">cairo_copy_path()</code></a> or
<a class="link" href="cairo-Paths.html#cairo-copy-path-flat" title="cairo_copy_path_flat ()"><code class="function">cairo_copy_path_flat()</code></a> or it may be constructed manually. See
<a class="link" href="cairo-Paths.html#cairo-path-t" title="cairo_path_t"><span class="type">cairo_path_t</span></a> for details on how the path data structure should be
initialized, and note that <code class="literal">path->status</code> must be
initialized to <a class="link" href="cairo-Error-handling.html#CAIRO-STATUS-SUCCESS:CAPS"><code class="literal">CAIRO_STATUS_SUCCESS</code></a>.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>cr</code></em> :</span></p></td>
<td>a cairo context
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>path</code></em> :</span></p></td>
<td>path to be appended
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" title="cairo_has_current_point ()">
<a name="cairo-has-current-point"></a><h3>cairo_has_current_point ()</h3>
<pre class="programlisting"><a class="link" href="cairo-Types.html#cairo-bool-t" title="cairo_bool_t"><span class="returnvalue">cairo_bool_t</span></a> cairo_has_current_point (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>);</pre>
<p>
Returns whether a current point is defined on the current path.
See <a class="link" href="cairo-Paths.html#cairo-get-current-point" title="cairo_get_current_point ()"><code class="function">cairo_get_current_point()</code></a> for details on the current point.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>cr</code></em> :</span></p></td>
<td>a cairo context
</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
<td> whether a current point is defined.
</td>
</tr>
</tbody>
</table></div>
<p class="since">Since 1.6</p>
</div>
<hr>
<div class="refsect2" title="cairo_get_current_point ()">
<a name="cairo-get-current-point"></a><h3>cairo_get_current_point ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span> cairo_get_current_point (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>,
<em class="parameter"><code><span class="type">double</span> *x</code></em>,
<em class="parameter"><code><span class="type">double</span> *y</code></em>);</pre>
<p>
Gets the current point of the current path, which is
conceptually the final point reached by the path so far.
</p>
<p>
The current point is returned in the user-space coordinate
system. If there is no defined current point or if <em class="parameter"><code>cr</code></em> is in an
error status, <em class="parameter"><code>x</code></em> and <em class="parameter"><code>y</code></em> will both be set to 0.0. It is possible to
check this in advance with <a class="link" href="cairo-Paths.html#cairo-has-current-point" title="cairo_has_current_point ()"><code class="function">cairo_has_current_point()</code></a>.
</p>
<p>
Most path construction functions alter the current point. See the
following for details on how they affect the current point:
<a class="link" href="cairo-Paths.html#cairo-new-path" title="cairo_new_path ()"><code class="function">cairo_new_path()</code></a>, <a class="link" href="cairo-Paths.html#cairo-new-sub-path" title="cairo_new_sub_path ()"><code class="function">cairo_new_sub_path()</code></a>,
<a class="link" href="cairo-Paths.html#cairo-append-path" title="cairo_append_path ()"><code class="function">cairo_append_path()</code></a>, <a class="link" href="cairo-Paths.html#cairo-close-path" title="cairo_close_path ()"><code class="function">cairo_close_path()</code></a>,
<a class="link" href="cairo-Paths.html#cairo-move-to" title="cairo_move_to ()"><code class="function">cairo_move_to()</code></a>, <a class="link" href="cairo-Paths.html#cairo-line-to" title="cairo_line_to ()"><code class="function">cairo_line_to()</code></a>, <a class="link" href="cairo-Paths.html#cairo-curve-to" title="cairo_curve_to ()"><code class="function">cairo_curve_to()</code></a>,
<a class="link" href="cairo-Paths.html#cairo-rel-move-to" title="cairo_rel_move_to ()"><code class="function">cairo_rel_move_to()</code></a>, <a class="link" href="cairo-Paths.html#cairo-rel-line-to" title="cairo_rel_line_to ()"><code class="function">cairo_rel_line_to()</code></a>, <a class="link" href="cairo-Paths.html#cairo-rel-curve-to" title="cairo_rel_curve_to ()"><code class="function">cairo_rel_curve_to()</code></a>,
<a class="link" href="cairo-Paths.html#cairo-arc" title="cairo_arc ()"><code class="function">cairo_arc()</code></a>, <a class="link" href="cairo-Paths.html#cairo-arc-negative" title="cairo_arc_negative ()"><code class="function">cairo_arc_negative()</code></a>, <a class="link" href="cairo-Paths.html#cairo-rectangle" title="cairo_rectangle ()"><code class="function">cairo_rectangle()</code></a>,
<a class="link" href="cairo-Paths.html#cairo-text-path" title="cairo_text_path ()"><code class="function">cairo_text_path()</code></a>, <a class="link" href="cairo-Paths.html#cairo-glyph-path" title="cairo_glyph_path ()"><code class="function">cairo_glyph_path()</code></a>, <code class="function">cairo_stroke_to_path()</code>.
</p>
<p>
Some functions use and alter the current point but do not
otherwise change current path:
<a class="link" href="cairo-text.html#cairo-show-text" title="cairo_show_text ()"><code class="function">cairo_show_text()</code></a>.
</p>
<p>
Some functions unset the current path and as a result, current point:
<a class="link" href="cairo-cairo-t.html#cairo-fill" title="cairo_fill ()"><code class="function">cairo_fill()</code></a>, <a class="link" href="cairo-cairo-t.html#cairo-stroke" title="cairo_stroke ()"><code class="function">cairo_stroke()</code></a>.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>cr</code></em> :</span></p></td>
<td>a cairo context
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>x</code></em> :</span></p></td>
<td>return value for X coordinate of the current point
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>y</code></em> :</span></p></td>
<td>return value for Y coordinate of the current point
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" title="cairo_new_path ()">
<a name="cairo-new-path"></a><h3>cairo_new_path ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span> cairo_new_path (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>);</pre>
<p>
Clears the current path. After this call there will be no path and
no current point.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody><tr>
<td><p><span class="term"><em class="parameter"><code>cr</code></em> :</span></p></td>
<td>a cairo context
</td>
</tr></tbody>
</table></div>
</div>
<hr>
<div class="refsect2" title="cairo_new_sub_path ()">
<a name="cairo-new-sub-path"></a><h3>cairo_new_sub_path ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span> cairo_new_sub_path (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>);</pre>
<p>
Begin a new sub-path. Note that the existing path is not
affected. After this call there will be no current point.
</p>
<p>
In many cases, this call is not needed since new sub-paths are
frequently started with <a class="link" href="cairo-Paths.html#cairo-move-to" title="cairo_move_to ()"><code class="function">cairo_move_to()</code></a>.
</p>
<p>
A call to <a class="link" href="cairo-Paths.html#cairo-new-sub-path" title="cairo_new_sub_path ()"><code class="function">cairo_new_sub_path()</code></a> is particularly useful when
beginning a new sub-path with one of the <a class="link" href="cairo-Paths.html#cairo-arc" title="cairo_arc ()"><code class="function">cairo_arc()</code></a> calls. This
makes things easier as it is no longer necessary to manually
compute the arc's initial coordinates for a call to
<a class="link" href="cairo-Paths.html#cairo-move-to" title="cairo_move_to ()"><code class="function">cairo_move_to()</code></a>.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody><tr>
<td><p><span class="term"><em class="parameter"><code>cr</code></em> :</span></p></td>
<td>a cairo context
</td>
</tr></tbody>
</table></div>
<p class="since">Since 1.2</p>
</div>
<hr>
<div class="refsect2" title="cairo_close_path ()">
<a name="cairo-close-path"></a><h3>cairo_close_path ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span> cairo_close_path (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>);</pre>
<p>
Adds a line segment to the path from the current point to the
beginning of the current sub-path, (the most recent point passed to
<a class="link" href="cairo-Paths.html#cairo-move-to" title="cairo_move_to ()"><code class="function">cairo_move_to()</code></a>), and closes this sub-path. After this call the
current point will be at the joined endpoint of the sub-path.
</p>
<p>
The behavior of <a class="link" href="cairo-Paths.html#cairo-close-path" title="cairo_close_path ()"><code class="function">cairo_close_path()</code></a> is distinct from simply calling
<a class="link" href="cairo-Paths.html#cairo-line-to" title="cairo_line_to ()"><code class="function">cairo_line_to()</code></a> with the equivalent coordinate in the case of
stroking. When a closed sub-path is stroked, there are no caps on
the ends of the sub-path. Instead, there is a line join connecting
the final and initial segments of the sub-path.
</p>
<p>
If there is no current point before the call to <a class="link" href="cairo-Paths.html#cairo-close-path" title="cairo_close_path ()"><code class="function">cairo_close_path()</code></a>,
this function will have no effect.
</p>
<p>
Note: As of cairo version 1.2.4 any call to <a class="link" href="cairo-Paths.html#cairo-close-path" title="cairo_close_path ()"><code class="function">cairo_close_path()</code></a> will
place an explicit MOVE_TO element into the path immediately after
the CLOSE_PATH element, (which can be seen in <a class="link" href="cairo-Paths.html#cairo-copy-path" title="cairo_copy_path ()"><code class="function">cairo_copy_path()</code></a> for
example). This can simplify path processing in some cases as it may
not be necessary to save the "last move_to point" during processing
as the MOVE_TO immediately after the CLOSE_PATH will provide that
point.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody><tr>
<td><p><span class="term"><em class="parameter"><code>cr</code></em> :</span></p></td>
<td>a cairo context
</td>
</tr></tbody>
</table></div>
</div>
<hr>
<div class="refsect2" title="cairo_arc ()">
<a name="cairo-arc"></a><h3>cairo_arc ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span> cairo_arc (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>,
<em class="parameter"><code><span class="type">double</span> xc</code></em>,
<em class="parameter"><code><span class="type">double</span> yc</code></em>,
<em class="parameter"><code><span class="type">double</span> radius</code></em>,
<em class="parameter"><code><span class="type">double</span> angle1</code></em>,
<em class="parameter"><code><span class="type">double</span> angle2</code></em>);</pre>
<p>
Adds a circular arc of the given <em class="parameter"><code>radius</code></em> to the current path. The
arc is centered at (<em class="parameter"><code>xc</code></em>, <em class="parameter"><code>yc</code></em>), begins at <em class="parameter"><code>angle1</code></em> and proceeds in
the direction of increasing angles to end at <em class="parameter"><code>angle2</code></em>. If <em class="parameter"><code>angle2</code></em> is
less than <em class="parameter"><code>angle1</code></em> it will be progressively increased by 2*M_PI
until it is greater than <em class="parameter"><code>angle1</code></em>.
</p>
<p>
If there is a current point, an initial line segment will be added
to the path to connect the current point to the beginning of the
arc. If this initial line is undesired, it can be avoided by
calling <a class="link" href="cairo-Paths.html#cairo-new-sub-path" title="cairo_new_sub_path ()"><code class="function">cairo_new_sub_path()</code></a> before calling <a class="link" href="cairo-Paths.html#cairo-arc" title="cairo_arc ()"><code class="function">cairo_arc()</code></a>.
</p>
<p>
Angles are measured in radians. An angle of 0.0 is in the direction
of the positive X axis (in user space). An angle of <code class="literal">M_PI</code>/2.0 radians
(90 degrees) is in the direction of the positive Y axis (in
user space). Angles increase in the direction from the positive X
axis toward the positive Y axis. So with the default transformation
matrix, angles increase in a clockwise direction.
</p>
<p>
(To convert from degrees to radians, use <code class="literal">degrees * (M_PI /
180.)</code>.)
</p>
<p>
This function gives the arc in the direction of increasing angles;
see <a class="link" href="cairo-Paths.html#cairo-arc-negative" title="cairo_arc_negative ()"><code class="function">cairo_arc_negative()</code></a> to get the arc in the direction of
decreasing angles.
</p>
<p>
The arc is circular in user space. To achieve an elliptical arc,
you can scale the current transformation matrix by different
amounts in the X and Y directions. For example, to draw an ellipse
in the box given by <em class="parameter"><code>x</code></em>, <em class="parameter"><code>y</code></em>, <em class="parameter"><code>width</code></em>, <em class="parameter"><code>height</code></em>:
</p>
<p>
</p>
<div class="informalexample"><pre class="programlisting">
cairo_save (cr);
cairo_translate (cr, x + width / 2., y + height / 2.);
cairo_scale (cr, width / 2., height / 2.);
cairo_arc (cr, 0., 0., 1., 0., 2 * M_PI);
cairo_restore (cr);
</pre></div>
<p>
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>cr</code></em> :</span></p></td>
<td>a cairo context
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>xc</code></em> :</span></p></td>
<td>X position of the center of the arc
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>yc</code></em> :</span></p></td>
<td>Y position of the center of the arc
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>radius</code></em> :</span></p></td>
<td>the radius of the arc
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>angle1</code></em> :</span></p></td>
<td>the start angle, in radians
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>angle2</code></em> :</span></p></td>
<td>the end angle, in radians
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" title="cairo_arc_negative ()">
<a name="cairo-arc-negative"></a><h3>cairo_arc_negative ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span> cairo_arc_negative (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>,
<em class="parameter"><code><span class="type">double</span> xc</code></em>,
<em class="parameter"><code><span class="type">double</span> yc</code></em>,
<em class="parameter"><code><span class="type">double</span> radius</code></em>,
<em class="parameter"><code><span class="type">double</span> angle1</code></em>,
<em class="parameter"><code><span class="type">double</span> angle2</code></em>);</pre>
<p>
Adds a circular arc of the given <em class="parameter"><code>radius</code></em> to the current path. The
arc is centered at (<em class="parameter"><code>xc</code></em>, <em class="parameter"><code>yc</code></em>), begins at <em class="parameter"><code>angle1</code></em> and proceeds in
the direction of decreasing angles to end at <em class="parameter"><code>angle2</code></em>. If <em class="parameter"><code>angle2</code></em> is
greater than <em class="parameter"><code>angle1</code></em> it will be progressively decreased by 2*M_PI
until it is less than <em class="parameter"><code>angle1</code></em>.
</p>
<p>
See <a class="link" href="cairo-Paths.html#cairo-arc" title="cairo_arc ()"><code class="function">cairo_arc()</code></a> for more details. This function differs only in the
direction of the arc between the two angles.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>cr</code></em> :</span></p></td>
<td>a cairo context
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>xc</code></em> :</span></p></td>
<td>X position of the center of the arc
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>yc</code></em> :</span></p></td>
<td>Y position of the center of the arc
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>radius</code></em> :</span></p></td>
<td>the radius of the arc
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>angle1</code></em> :</span></p></td>
<td>the start angle, in radians
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>angle2</code></em> :</span></p></td>
<td>the end angle, in radians
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" title="cairo_curve_to ()">
<a name="cairo-curve-to"></a><h3>cairo_curve_to ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span> cairo_curve_to (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>,
<em class="parameter"><code><span class="type">double</span> x1</code></em>,
<em class="parameter"><code><span class="type">double</span> y1</code></em>,
<em class="parameter"><code><span class="type">double</span> x2</code></em>,
<em class="parameter"><code><span class="type">double</span> y2</code></em>,
<em class="parameter"><code><span class="type">double</span> x3</code></em>,
<em class="parameter"><code><span class="type">double</span> y3</code></em>);</pre>
<p>
Adds a cubic Bézier spline to the path from the current point to
position (<em class="parameter"><code>x3</code></em>, <em class="parameter"><code>y3</code></em>) in user-space coordinates, using (<em class="parameter"><code>x1</code></em>, <em class="parameter"><code>y1</code></em>) and
(<em class="parameter"><code>x2</code></em>, <em class="parameter"><code>y2</code></em>) as the control points. After this call the current point
will be (<em class="parameter"><code>x3</code></em>, <em class="parameter"><code>y3</code></em>).
</p>
<p>
If there is no current point before the call to <a class="link" href="cairo-Paths.html#cairo-curve-to" title="cairo_curve_to ()"><code class="function">cairo_curve_to()</code></a>
this function will behave as if preceded by a call to
cairo_move_to(<em class="parameter"><code>cr</code></em>, <em class="parameter"><code>x1</code></em>, <em class="parameter"><code>y1</code></em>).
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>cr</code></em> :</span></p></td>
<td>a cairo context
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>x1</code></em> :</span></p></td>
<td>the X coordinate of the first control point
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>y1</code></em> :</span></p></td>
<td>the Y coordinate of the first control point
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>x2</code></em> :</span></p></td>
<td>the X coordinate of the second control point
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>y2</code></em> :</span></p></td>
<td>the Y coordinate of the second control point
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>x3</code></em> :</span></p></td>
<td>the X coordinate of the end of the curve
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>y3</code></em> :</span></p></td>
<td>the Y coordinate of the end of the curve
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" title="cairo_line_to ()">
<a name="cairo-line-to"></a><h3>cairo_line_to ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span> cairo_line_to (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>,
<em class="parameter"><code><span class="type">double</span> x</code></em>,
<em class="parameter"><code><span class="type">double</span> y</code></em>);</pre>
<p>
Adds a line to the path from the current point to position (<em class="parameter"><code>x</code></em>, <em class="parameter"><code>y</code></em>)
in user-space coordinates. After this call the current point
will be (<em class="parameter"><code>x</code></em>, <em class="parameter"><code>y</code></em>).
</p>
<p>
If there is no current point before the call to <a class="link" href="cairo-Paths.html#cairo-line-to" title="cairo_line_to ()"><code class="function">cairo_line_to()</code></a>
this function will behave as cairo_move_to(<em class="parameter"><code>cr</code></em>, <em class="parameter"><code>x</code></em>, <em class="parameter"><code>y</code></em>).
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>cr</code></em> :</span></p></td>
<td>a cairo context
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>x</code></em> :</span></p></td>
<td>the X coordinate of the end of the new line
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>y</code></em> :</span></p></td>
<td>the Y coordinate of the end of the new line
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" title="cairo_move_to ()">
<a name="cairo-move-to"></a><h3>cairo_move_to ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span> cairo_move_to (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>,
<em class="parameter"><code><span class="type">double</span> x</code></em>,
<em class="parameter"><code><span class="type">double</span> y</code></em>);</pre>
<p>
Begin a new sub-path. After this call the current point will be (<em class="parameter"><code>x</code></em>,
<em class="parameter"><code>y</code></em>).
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>cr</code></em> :</span></p></td>
<td>a cairo context
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>x</code></em> :</span></p></td>
<td>the X coordinate of the new position
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>y</code></em> :</span></p></td>
<td>the Y coordinate of the new position
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" title="cairo_rectangle ()">
<a name="cairo-rectangle"></a><h3>cairo_rectangle ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span> cairo_rectangle (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>,
<em class="parameter"><code><span class="type">double</span> x</code></em>,
<em class="parameter"><code><span class="type">double</span> y</code></em>,
<em class="parameter"><code><span class="type">double</span> width</code></em>,
<em class="parameter"><code><span class="type">double</span> height</code></em>);</pre>
<p>
Adds a closed sub-path rectangle of the given size to the current
path at position (<em class="parameter"><code>x</code></em>, <em class="parameter"><code>y</code></em>) in user-space coordinates.
</p>
<p>
This function is logically equivalent to:
</p>
<div class="informalexample"><pre class="programlisting">
cairo_move_to (cr, x, y);
cairo_rel_line_to (cr, width, 0);
cairo_rel_line_to (cr, 0, height);
cairo_rel_line_to (cr, -width, 0);
cairo_close_path (cr);
</pre></div>
<p>
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>cr</code></em> :</span></p></td>
<td>a cairo context
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>x</code></em> :</span></p></td>
<td>the X coordinate of the top left corner of the rectangle
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>y</code></em> :</span></p></td>
<td>the Y coordinate to the top left corner of the rectangle
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>width</code></em> :</span></p></td>
<td>the width of the rectangle
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>height</code></em> :</span></p></td>
<td>the height of the rectangle
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" title="cairo_glyph_path ()">
<a name="cairo-glyph-path"></a><h3>cairo_glyph_path ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span> cairo_glyph_path (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>,
<em class="parameter"><code>const <a class="link" href="cairo-text.html#cairo-glyph-t" title="cairo_glyph_t"><span class="type">cairo_glyph_t</span></a> *glyphs</code></em>,
<em class="parameter"><code><span class="type">int</span> num_glyphs</code></em>);</pre>
<p>
Adds closed paths for the glyphs to the current path. The generated
path if filled, achieves an effect similar to that of
<a class="link" href="cairo-text.html#cairo-show-glyphs" title="cairo_show_glyphs ()"><code class="function">cairo_show_glyphs()</code></a>.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>cr</code></em> :</span></p></td>
<td>a cairo context
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>glyphs</code></em> :</span></p></td>
<td>array of glyphs to show
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>num_glyphs</code></em> :</span></p></td>
<td>number of glyphs to show
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" title="cairo_text_path ()">
<a name="cairo-text-path"></a><h3>cairo_text_path ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span> cairo_text_path (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>,
<em class="parameter"><code>const <span class="type">char</span> *utf8</code></em>);</pre>
<p>
Adds closed paths for text to the current path. The generated
path if filled, achieves an effect similar to that of
<a class="link" href="cairo-text.html#cairo-show-text" title="cairo_show_text ()"><code class="function">cairo_show_text()</code></a>.
</p>
<p>
Text conversion and positioning is done similar to <a class="link" href="cairo-text.html#cairo-show-text" title="cairo_show_text ()"><code class="function">cairo_show_text()</code></a>.
</p>
<p>
Like <a class="link" href="cairo-text.html#cairo-show-text" title="cairo_show_text ()"><code class="function">cairo_show_text()</code></a>, After this call the current point is
moved to the origin of where the next glyph would be placed in
this same progression. That is, the current point will be at
the origin of the final glyph offset by its advance values.
This allows for chaining multiple calls to to <a class="link" href="cairo-Paths.html#cairo-text-path" title="cairo_text_path ()"><code class="function">cairo_text_path()</code></a>
without having to set current point in between.
</p>
<p>
Note: The <a class="link" href="cairo-Paths.html#cairo-text-path" title="cairo_text_path ()"><code class="function">cairo_text_path()</code></a> function call is part of what the cairo
designers call the "toy" text API. It is convenient for short demos
and simple programs, but it is not expected to be adequate for
serious text-using applications. See <a class="link" href="cairo-Paths.html#cairo-glyph-path" title="cairo_glyph_path ()"><code class="function">cairo_glyph_path()</code></a> for the
"real" text path API in cairo.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>cr</code></em> :</span></p></td>
<td>a cairo context
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>utf8</code></em> :</span></p></td>
<td>a NUL-terminated string of text encoded in UTF-8, or <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a>
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" title="cairo_rel_curve_to ()">
<a name="cairo-rel-curve-to"></a><h3>cairo_rel_curve_to ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span> cairo_rel_curve_to (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>,
<em class="parameter"><code><span class="type">double</span> dx1</code></em>,
<em class="parameter"><code><span class="type">double</span> dy1</code></em>,
<em class="parameter"><code><span class="type">double</span> dx2</code></em>,
<em class="parameter"><code><span class="type">double</span> dy2</code></em>,
<em class="parameter"><code><span class="type">double</span> dx3</code></em>,
<em class="parameter"><code><span class="type">double</span> dy3</code></em>);</pre>
<p>
Relative-coordinate version of <a class="link" href="cairo-Paths.html#cairo-curve-to" title="cairo_curve_to ()"><code class="function">cairo_curve_to()</code></a>. All offsets are
relative to the current point. Adds a cubic Bézier spline to the
path from the current point to a point offset from the current
point by (<em class="parameter"><code>dx3</code></em>, <em class="parameter"><code>dy3</code></em>), using points offset by (<em class="parameter"><code>dx1</code></em>, <em class="parameter"><code>dy1</code></em>) and
(<em class="parameter"><code>dx2</code></em>, <em class="parameter"><code>dy2</code></em>) as the control points. After this call the current
point will be offset by (<em class="parameter"><code>dx3</code></em>, <em class="parameter"><code>dy3</code></em>).
</p>
<p>
Given a current point of (x, y), cairo_rel_curve_to(<em class="parameter"><code>cr</code></em>, <em class="parameter"><code>dx1</code></em>,
<em class="parameter"><code>dy1</code></em>, <em class="parameter"><code>dx2</code></em>, <em class="parameter"><code>dy2</code></em>, <em class="parameter"><code>dx3</code></em>, <em class="parameter"><code>dy3</code></em>) is logically equivalent to
cairo_curve_to(<em class="parameter"><code>cr</code></em>, x+<em class="parameter"><code>dx1</code></em>, y+<em class="parameter"><code>dy1</code></em>, x+<em class="parameter"><code>dx2</code></em>, y+<em class="parameter"><code>dy2</code></em>, x+<em class="parameter"><code>dx3</code></em>, y+<em class="parameter"><code>dy3</code></em>).
</p>
<p>
It is an error to call this function with no current point. Doing
so will cause <em class="parameter"><code>cr</code></em> to shutdown with a status of
<a class="link" href="cairo-Error-handling.html#CAIRO-STATUS-NO-CURRENT-POINT:CAPS"><code class="literal">CAIRO_STATUS_NO_CURRENT_POINT</code></a>.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>cr</code></em> :</span></p></td>
<td>a cairo context
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>dx1</code></em> :</span></p></td>
<td>the X offset to the first control point
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>dy1</code></em> :</span></p></td>
<td>the Y offset to the first control point
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>dx2</code></em> :</span></p></td>
<td>the X offset to the second control point
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>dy2</code></em> :</span></p></td>
<td>the Y offset to the second control point
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>dx3</code></em> :</span></p></td>
<td>the X offset to the end of the curve
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>dy3</code></em> :</span></p></td>
<td>the Y offset to the end of the curve
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" title="cairo_rel_line_to ()">
<a name="cairo-rel-line-to"></a><h3>cairo_rel_line_to ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span> cairo_rel_line_to (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>,
<em class="parameter"><code><span class="type">double</span> dx</code></em>,
<em class="parameter"><code><span class="type">double</span> dy</code></em>);</pre>
<p>
Relative-coordinate version of <a class="link" href="cairo-Paths.html#cairo-line-to" title="cairo_line_to ()"><code class="function">cairo_line_to()</code></a>. Adds a line to the
path from the current point to a point that is offset from the
current point by (<em class="parameter"><code>dx</code></em>, <em class="parameter"><code>dy</code></em>) in user space. After this call the
current point will be offset by (<em class="parameter"><code>dx</code></em>, <em class="parameter"><code>dy</code></em>).
</p>
<p>
Given a current point of (x, y), cairo_rel_line_to(<em class="parameter"><code>cr</code></em>, <em class="parameter"><code>dx</code></em>, <em class="parameter"><code>dy</code></em>)
is logically equivalent to cairo_line_to(<em class="parameter"><code>cr</code></em>, x + <em class="parameter"><code>dx</code></em>, y + <em class="parameter"><code>dy</code></em>).
</p>
<p>
It is an error to call this function with no current point. Doing
so will cause <em class="parameter"><code>cr</code></em> to shutdown with a status of
<a class="link" href="cairo-Error-handling.html#CAIRO-STATUS-NO-CURRENT-POINT:CAPS"><code class="literal">CAIRO_STATUS_NO_CURRENT_POINT</code></a>.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>cr</code></em> :</span></p></td>
<td>a cairo context
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>dx</code></em> :</span></p></td>
<td>the X offset to the end of the new line
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>dy</code></em> :</span></p></td>
<td>the Y offset to the end of the new line
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" title="cairo_rel_move_to ()">
<a name="cairo-rel-move-to"></a><h3>cairo_rel_move_to ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span> cairo_rel_move_to (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>,
<em class="parameter"><code><span class="type">double</span> dx</code></em>,
<em class="parameter"><code><span class="type">double</span> dy</code></em>);</pre>
<p>
Begin a new sub-path. After this call the current point will offset
by (<em class="parameter"><code>x</code></em>, <em class="parameter"><code>y</code></em>).
</p>
<p>
Given a current point of (x, y), cairo_rel_move_to(<em class="parameter"><code>cr</code></em>, <em class="parameter"><code>dx</code></em>, <em class="parameter"><code>dy</code></em>)
is logically equivalent to cairo_move_to(<em class="parameter"><code>cr</code></em>, x + <em class="parameter"><code>dx</code></em>, y + <em class="parameter"><code>dy</code></em>).
</p>
<p>
It is an error to call this function with no current point. Doing
so will cause <em class="parameter"><code>cr</code></em> to shutdown with a status of
<a class="link" href="cairo-Error-handling.html#CAIRO-STATUS-NO-CURRENT-POINT:CAPS"><code class="literal">CAIRO_STATUS_NO_CURRENT_POINT</code></a>.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>cr</code></em> :</span></p></td>
<td>a cairo context
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>dx</code></em> :</span></p></td>
<td>the X offset
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>dy</code></em> :</span></p></td>
<td>the Y offset
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" title="cairo_path_extents ()">
<a name="cairo-path-extents"></a><h3>cairo_path_extents ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span> cairo_path_extents (<em class="parameter"><code><a class="link" href="cairo-cairo-t.html#cairo-t" title="cairo_t"><span class="type">cairo_t</span></a> *cr</code></em>,
<em class="parameter"><code><span class="type">double</span> *x1</code></em>,
<em class="parameter"><code><span class="type">double</span> *y1</code></em>,
<em class="parameter"><code><span class="type">double</span> *x2</code></em>,
<em class="parameter"><code><span class="type">double</span> *y2</code></em>);</pre>
<p>
Computes a bounding box in user-space coordinates covering the
points on the current path. If the current path is empty, returns
an empty rectangle ((0,0), (0,0)). Stroke parameters, fill rule,
surface dimensions and clipping are not taken into account.
</p>
<p>
Contrast with <a class="link" href="cairo-cairo-t.html#cairo-fill-extents" title="cairo_fill_extents ()"><code class="function">cairo_fill_extents()</code></a> and <a class="link" href="cairo-cairo-t.html#cairo-stroke-extents" title="cairo_stroke_extents ()"><code class="function">cairo_stroke_extents()</code></a> which
return the extents of only the area that would be "inked" by
the corresponding drawing operations.
</p>
<p>
The result of <a class="link" href="cairo-Paths.html#cairo-path-extents" title="cairo_path_extents ()"><code class="function">cairo_path_extents()</code></a> is defined as equivalent to the
limit of <a class="link" href="cairo-cairo-t.html#cairo-stroke-extents" title="cairo_stroke_extents ()"><code class="function">cairo_stroke_extents()</code></a> with <a class="link" href="cairo-cairo-t.html#CAIRO-LINE-CAP-ROUND:CAPS"><code class="literal">CAIRO_LINE_CAP_ROUND</code></a> as the
line width approaches 0.0, (but never reaching the empty-rectangle
returned by <a class="link" href="cairo-cairo-t.html#cairo-stroke-extents" title="cairo_stroke_extents ()"><code class="function">cairo_stroke_extents()</code></a> for a line width of 0.0).
</p>
<p>
Specifically, this means that zero-area sub-paths such as
<a class="link" href="cairo-Paths.html#cairo-move-to" title="cairo_move_to ()"><code class="function">cairo_move_to()</code></a>;<a class="link" href="cairo-Paths.html#cairo-line-to" title="cairo_line_to ()"><code class="function">cairo_line_to()</code></a> segments, (even degenerate cases
where the coordinates to both calls are identical), will be
considered as contributing to the extents. However, a lone
<a class="link" href="cairo-Paths.html#cairo-move-to" title="cairo_move_to ()"><code class="function">cairo_move_to()</code></a> will not contribute to the results of
<a class="link" href="cairo-Paths.html#cairo-path-extents" title="cairo_path_extents ()"><code class="function">cairo_path_extents()</code></a>.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>cr</code></em> :</span></p></td>
<td>a cairo context
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>x1</code></em> :</span></p></td>
<td>left of the resulting extents
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>y1</code></em> :</span></p></td>
<td>top of the resulting extents
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>x2</code></em> :</span></p></td>
<td>right of the resulting extents
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>y2</code></em> :</span></p></td>
<td>bottom of the resulting extents
</td>
</tr>
</tbody>
</table></div>
<p class="since">Since 1.6</p>
</div>
</div>
</div>
<div class="footer">
<hr>
Generated by GTK-Doc V1.15</div>
</body>
</html>
|