/usr/share/doc/libghc-cairo-doc/html/cairo.txt is in libghc-cairo-doc 0.13.1.0-4build1.
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 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 | -- Hoogle documentation, generated by Haddock
-- See Hoogle, http://www.haskell.org/hoogle/
-- | Binding to the Cairo library.
--
-- Cairo is a library to render high quality vector graphics. There exist
-- various backends that allows rendering to Gtk windows, PDF, PS, PNG
-- and SVG documents, amongst others.
@package cairo
@version 0.13.1.0
-- | Matrix math
module Graphics.Rendering.Cairo.Matrix
-- | Representation of a 2-D affine transformation.
--
-- The Matrix type represents a 2x2 transformation matrix along with a
-- translation vector. <tt>Matrix a1 a2 b1 b2 c1 c2</tt> describes the
-- transformation of a point with coordinates x,y that is defined by
--
-- <pre>
-- / x' \ = / a1 b1 \ / x \ + / c1 \
-- \ y' / \ a2 b2 / \ y / \ c2 /
-- </pre>
--
-- or
--
-- <pre>
-- x' = a1 * x + b1 * y + c1
-- y' = a2 * x + b2 * y + c2
-- </pre>
data Matrix
Matrix :: !Double -> !Double -> !Double -> !Double -> !Double -> !Double -> Matrix
type MatrixPtr = Ptr (Matrix)
identity :: Matrix
translate :: Double -> Double -> Matrix -> Matrix
scale :: Double -> Double -> Matrix -> Matrix
rotate :: Double -> Matrix -> Matrix
transformDistance :: Matrix -> (Double, Double) -> (Double, Double)
transformPoint :: Matrix -> (Double, Double) -> (Double, Double)
scalarMultiply :: Double -> Matrix -> Matrix
adjoint :: Matrix -> Matrix
invert :: Matrix -> Matrix
instance GHC.Classes.Eq Graphics.Rendering.Cairo.Matrix.Matrix
instance GHC.Show.Show Graphics.Rendering.Cairo.Matrix.Matrix
instance Foreign.Storable.Storable Graphics.Rendering.Cairo.Matrix.Matrix
instance GHC.Num.Num Graphics.Rendering.Cairo.Matrix.Matrix
-- | The Cairo 2D graphics library.
--
-- Cairo is a 2D graphics library with support for multiple output
-- devices. Currently supported output targets include the X Window
-- System, win32, and image buffers. Experimental backends include OpenGL
-- (through glitz), Quartz, XCB, PostScript and PDF file output.
--
-- Cairo is designed to produce consistent output on all output media
-- while taking advantage of display hardware acceleration when available
-- (eg. through the X Render Extension).
--
-- The cairo API provides operations similar to the drawing operators of
-- PostScript and PDF. Operations in cairo including stroking and filling
-- cubic Bezier splines, transforming and compositing translucent images,
-- and antialiased text rendering. All drawing operations can be
-- transformed by any affine transformation (scale, rotation, shear,
-- etc.)
--
-- Cairo is free software and is available to be redistributed and/or
-- modified under the terms of either the GNU Lesser General Public
-- License (LGPL) version 2.1 or the Mozilla Public License (MPL) version
-- 1.1.
--
-- For more information see <a>http://cairographics.org</a>
--
-- <ul>
-- <li>Note the Haskell bindings do not support all the possible cairo
-- backends because it would require bindings for the associated
-- technology (eg X11, glitz, etc) however bindings to other backends may
-- be implemented externally. For example, Gtk2Hs provides a binding to
-- the backend for X11 (and win32 on Windows).</li>
-- </ul>
module Graphics.Rendering.Cairo
-- | Creates a new Render context with all graphics state parameters set to
-- default values and with the given surface as a target surface. The
-- target surface should be constructed with a backend-specific function
-- such as <a>withImageSurface</a> (or any other
-- with<backend>Surface variant).
renderWith :: (MonadIO m) => Surface -> Render a -> m a
-- | Makes a copy of the current state and saves it on an internal stack of
-- saved states. When <a>restore</a> is called, the saved state is
-- restored. Multiple calls to <a>save</a> and <a>restore</a> can be
-- nested; each call to <a>restore</a> restores the state from the
-- matching paired <a>save</a>.
save :: Render ()
-- | Restores to the state saved by a preceding call to <a>save</a> and
-- removes that state from the stack of saved states.
restore :: Render ()
-- | Ask for the status of the current <a>Render</a> monad.
status :: Render Status
-- | Gets the target surface for the Render context as passed to
-- <a>renderWith</a>.
withTargetSurface :: (Surface -> Render a) -> Render a
-- | Like <tt>pushGroupWithContent ContentColorAlpha</tt>, but more
-- convenient.
pushGroup :: Render ()
-- | Temporarily redirects drawing to an intermediate surface known as a
-- group. The redirection lasts until the group is completed by a call to
-- <a>withGroupPattern</a> or <a>popGroupToSource</a>. These calls
-- provide the result of any drawing to the group as a pattern (either as
-- an explicit object, or set as the source pattern). This group
-- functionality can be convenient for performing intermediate
-- compositing. One common use of a group is to render objects as opaque
-- within the group (so that they occlude each other), and then blend the
-- result with translucence onto the destination.
--
-- Groups can be nested arbitrarily deeply by making balanced calls to
-- <a>pushGroupWithContent</a> and <a>withGroupPattern</a>. As a side
-- effect, <a>pushGroupWithContent</a> calls <a>save</a> and
-- <a>withGroupPattern</a> calls <a>restore</a>, so that any changes to
-- the graphics state will not be visible outside the group.
--
-- As an example, here is how one might fill and stroke a path with
-- translucence, but without any portion of the fill being visible under
-- the stroke:
--
-- <pre>
-- pushGroup
-- setSource fillPattern
-- fillPreserve
-- setSource strokePattern
-- stroke
-- popGroupToSource
-- paintWithAlpha alpha
-- </pre>
pushGroupWithContent :: Content -> Render ()
-- | Like <tt>withGroupPattern setSource</tt>, but more convenient.
popGroupToSource :: Render ()
-- | Sets the source pattern within the context to an opaque color. This
-- opaque color will then be used for any subsequent drawing operation
-- until a new source pattern is set.
--
-- The color components are floating point numbers in the range 0 to 1.
-- If the values passed in are outside that range, they will be clamped.
setSourceRGB :: Double -> Double -> Double -> Render ()
-- | Sets the source pattern within the context to a translucent color.
-- This color will then be used for any subsequent drawing operation
-- until a new source pattern is set.
--
-- The color and alpha components are floating point numbers in the range
-- 0 to 1. If the values passed in are outside that range, they will be
-- clamped.
setSourceRGBA :: Double -> Double -> Double -> Double -> Render ()
-- | Sets the source pattern within the context to source. This pattern
-- will then be used for any subsequent drawing operation until a new
-- source pattern is set.
--
-- Note: The pattern's transformation matrix will be locked to the user
-- space in effect at the time of <a>setSource</a>. This means that
-- further modifications of the current transformation matrix will not
-- affect the source pattern. See <a>setMatrix</a>.
setSource :: Pattern -> Render ()
-- | This is a convenience function for creating a pattern from surface and
-- setting it as the source in the context with <a>setSource</a>.
--
-- The x and y parameters give the user-space coordinate at which the
-- surface origin should appear. (The surface origin is its upper-left
-- corner before any transformation has been applied.) The x and y
-- patterns are negated and then set as translation values in the pattern
-- matrix.
--
-- Other than the initial translation pattern matrix, as described above,
-- all other pattern attributes, (such as its extend mode), are set to
-- the default values as in <tt>patternCreateForSurface</tt>. The
-- resulting pattern can be queried with <a>getSource</a> so that these
-- attributes can be modified if desired, (eg. to create a repeating
-- pattern with <tt>patternSetExtent</tt>.
setSourceSurface :: Surface -> Double -> Double -> Render ()
-- | Gets the current source pattern.
getSource :: Render Pattern
-- | Set the antialiasing mode of the rasterizer used for drawing shapes.
-- This value is a hint, and a particular backend may or may not support
-- a particular value. At the current time, no backend supports
-- <a>AntialiasSubpixel</a> when drawing shapes.
--
-- Note that this option does not affect text rendering, instead see
-- <tt>fontOptionsSetAntilias</tt>.
setAntialias :: Antialias -> Render ()
-- | Sets the dash pattern to be used by <a>stroke</a>. A dash pattern is
-- specified by dashes, a list of positive values. Each value provides
-- the user-space length of altenate "on" and "off" portions of the
-- stroke. The offset specifies an offset into the pattern at which the
-- stroke begins.
--
-- If <tt>dashes</tt> is <tt>[]</tt> then dashing is disabled.
setDash :: [Double] -> Double -> Render ()
-- | Set the current fill rule within the cairo context. The fill rule is
-- used to determine which regions are inside or outside a complex
-- (potentially self-intersecting) path. The current fill rule affects
-- both <a>fill</a> and <a>clip</a>. See <a>FillRule</a> for details on
-- the semantics of each available fill rule.
setFillRule :: FillRule -> Render ()
-- | Gets the current fill rule, as set by <tt>setFillrule</tt>.
getFillRule :: Render FillRule
-- | Sets the current line cap style within the cairo context. See
-- <a>LineCap</a> for details about how the available line cap styles are
-- drawn.
--
-- As with the other stroke parameters, the current line cap style is
-- examined by <a>stroke</a>, <a>strokeExtents</a>, and
-- <tt>strokeToPath</tt>, but does not have any effect during path
-- construction.
setLineCap :: LineCap -> Render ()
-- | Gets the current line cap style, as set by <a>setLineCap</a>.
getLineCap :: Render LineCap
-- | Sets the current line join style within the cairo context. See
-- <a>LineJoin</a> for details about how the available line join styles
-- are drawn.
--
-- As with the other stroke parameters, the current line join style is
-- examined by <a>stroke</a>, <a>strokeExtents</a>, and
-- <tt>strokeToPath</tt>, but does not have any effect during path
-- construction.
setLineJoin :: LineJoin -> Render ()
-- | Gets the current line join style, as set by <a>setLineJoin</a>.
getLineJoin :: Render LineJoin
-- | Sets the current line width within the cairo context. The line width
-- specifies the diameter of a pen that is circular in user-space.
--
-- As with the other stroke parameters, the current line cap style is
-- examined by <a>stroke</a>, <a>strokeExtents</a>, and
-- <tt>strokeToPath</tt>, but does not have any effect during path
-- construction.
setLineWidth :: Double -> Render ()
-- | Gets the current line width, as set by <a>setLineWidth</a>.
getLineWidth :: Render Double
setMiterLimit :: Double -> Render ()
-- | Gets the current miter limit, as set by <a>setMiterLimit</a>.
getMiterLimit :: Render Double
-- | Sets the compositing operator to be used for all drawing operations.
-- See <a>Operator</a> for details on the semantics of each available
-- compositing operator.
setOperator :: Operator -> Render ()
-- | Gets the current compositing operator for a cairo context.
getOperator :: Render Operator
-- | Sets the tolerance used when converting paths into trapezoids. Curved
-- segments of the path will be subdivided until the maximum deviation
-- between the original path and the polygonal approximation is less than
-- tolerance. The default value is 0.1. A larger value will give better
-- performance, a smaller value, better appearance. (Reducing the value
-- from the default value of 0.1 is unlikely to improve appearance
-- significantly.)
setTolerance :: Double -> Render ()
-- | Gets the current tolerance value, as set by <a>setTolerance</a>.
getTolerance :: Render Double
-- | Establishes a new clip region by intersecting the current clip region
-- with the current path as it would be filled by <a>fill</a> and
-- according to the current fill rule (see <a>setFillRule</a>).
--
-- After <a>clip</a>, the current path will be cleared from the cairo
-- context.
--
-- The current clip region affects all drawing operations by effectively
-- masking out any changes to the surface that are outside the current
-- clip region.
--
-- Calling <a>clip</a> can only make the clip region smaller, never
-- larger. But the current clip is part of the graphics state, so a
-- temporary restriction of the clip region can be achieved by calling
-- <a>clip</a> within a 'save'/'restore' pair. The only other means of
-- increasing the size of the clip region is <a>resetClip</a>.
clip :: Render ()
-- | Establishes a new clip region by intersecting the current clip region
-- with the current path as it would be filled by <a>fill</a> and
-- according to the current fill rule (see <a>setFillRule</a>).
--
-- Unlike <a>clip</a>, cairoClipPreserve preserves the path within the
-- cairo context.
--
-- The current clip region affects all drawing operations by effectively
-- masking out any changes to the surface that are outside the current
-- clip region.
--
-- Calling <a>clip</a> can only make the clip region smaller, never
-- larger. But the current clip is part of the graphics state, so a
-- temporary restriction of the clip region can be achieved by calling
-- <a>clip</a> within a 'save'/'restore' pair. The only other means of
-- increasing the size of the clip region is <a>resetClip</a>.
clipPreserve :: Render ()
-- | Computes a bounding box in user coordinates covering the area inside
-- the current clip.
clipExtents :: Render (Double, Double, Double, Double)
-- | Reset the current clip region to its original, unrestricted state.
-- That is, set the clip region to an infinitely large shape containing
-- the target surface. Equivalently, if infinity is too hard to grasp,
-- one can imagine the clip region being reset to the exact bounds of the
-- target surface.
--
-- Note that code meant to be reusable should not call <a>resetClip</a>
-- as it will cause results unexpected by higher-level code which calls
-- <a>clip</a>. Consider using <a>save</a> and <a>restore</a> around
-- <a>clip</a> as a more robust means of temporarily restricting the clip
-- region.
resetClip :: Render ()
-- | A drawing operator that fills the current path according to the
-- current fill rule, (each sub-path is implicitly closed before being
-- filled). After <a>fill</a>, the current path will be cleared from the
-- cairo context.
--
-- See <a>setFillRule</a> and <a>fillPreserve</a>.
fill :: Render ()
-- | A drawing operator that fills the current path according to the
-- current fill rule, (each sub-path is implicitly closed before being
-- filled). Unlike <a>fill</a>, <a>fillPreserve</a> preserves the path
-- within the cairo context.
--
-- See <a>setFillRule</a> and <a>fill</a>.
fillPreserve :: Render ()
fillExtents :: Render (Double, Double, Double, Double)
inFill :: Double -> Double -> Render Bool
-- | A drawing operator that paints the current source using the alpha
-- channel of pattern as a mask. (Opaque areas of mask are painted with
-- the source, transparent areas are not painted.)
mask :: Pattern -> Render ()
-- | A drawing operator that paints the current source using the alpha
-- channel of surface as a mask. (Opaque areas of surface are painted
-- with the source, transparent areas are not painted.)
maskSurface :: Surface -> Double -> Double -> Render ()
-- | A drawing operator that paints the current source everywhere within
-- the current clip region.
paint :: Render ()
-- | A drawing operator that paints the current source everywhere within
-- the current clip region using a mask of constant alpha value alpha.
-- The effect is similar to <a>paint</a>, but the drawing is faded out
-- using the alpha value.
paintWithAlpha :: Double -> Render ()
-- | A drawing operator that strokes the current path according to the
-- current line width, line join, line cap, and dash settings. After
-- issuing <a>stroke</a>, the current path will be cleared from the
-- <a>Render</a> monad.
--
-- See <a>setLineWidth</a>, <a>setLineJoin</a>, <a>setLineCap</a>,
-- <a>setDash</a>, and <a>strokePreserve</a>.
stroke :: Render ()
-- | A drawing operator that strokes the current path according to the
-- current line width, line join, line cap, and dash settings. Unlike
-- <a>stroke</a>, <a>strokePreserve</a> preserves the path within the
-- <a>Render</a> monad.
--
-- See <a>setLineWidth</a>, <a>setLineJoin</a>, <a>setLineCap</a>,
-- <a>setDash</a>, and <a>strokePreserve</a>.
strokePreserve :: Render ()
strokeExtents :: Render (Double, Double, Double, Double)
inStroke :: Double -> Double -> Render Bool
copyPage :: Render ()
showPage :: Render ()
-- | Gets the current point of the current path, which is conceptually the
-- final point reached by the path so far.
--
-- The current point is returned in the user-space coordinate system. If
-- there is no defined current point then x and y will both be set to
-- 0.0.
--
-- Most path construction functions alter the current point. See the
-- following for details on how they affect the current point:
-- <a>newPath</a>, <a>moveTo</a>, <a>lineTo</a>, <a>curveTo</a>,
-- <a>arc</a>, <a>relMoveTo</a>, <a>relLineTo</a>, <a>relCurveTo</a>,
-- <a>arcNegative</a>, <a>textPath</a>, <tt>strokeToPath</tt>.
getCurrentPoint :: Render (Double, Double)
-- | Clears the current path. After this call there will be no current
-- point.
newPath :: Render ()
-- | Adds a line segment to the path from the current point to the
-- beginning of the current subpath, (the most recent point passed to
-- <a>moveTo</a>), and closes this subpath.
--
-- The behavior of <a>closePath</a> is distinct from simply calling
-- <a>lineTo</a> with the equivalent coordinate in the case of stroking.
-- When a closed subpath is stroked, there are no caps on the ends of the
-- subpath. Instead, their is a line join connecting the final and
-- initial segments of the subpath.
closePath :: Render ()
-- | Adds a circular arc of the given radius to the current path. The arc
-- is centered at (<tt>xc</tt>, <tt>yc</tt>), begins at <tt>angle1</tt>
-- and proceeds in the direction of increasing angles to end at
-- <tt>angle2</tt>. If <tt>angle2</tt> is less than <tt>angle1</tt> it
-- will be progressively increased by <tt>2*pi</tt> until it is greater
-- than <tt>angle1</tt>.
--
-- 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.
--
-- Angles are measured in radians. An angle of 0 is in the direction of
-- the positive X axis (in user-space). An angle of <tt>pi/2</tt> 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.
--
-- (To convert from degrees to radians, use <tt>degrees * (pi /
-- 180)</tt>.)
--
-- This function gives the arc in the direction of increasing angles; see
-- <a>arcNegative</a> to get the arc in the direction of decreasing
-- angles.
--
-- 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 x, y, width, height:
--
-- <pre>
-- save
-- translate (x + width / 2) (y + height / 2)
-- scale (1 / (height / 2.)) (1 / (width / 2))
-- arc 0 0 1 0 (2 * pi)
-- restore
-- </pre>
arc :: Double -> Double -> Double -> Double -> Double -> Render ()
-- | Adds a circular arc of the given radius to the current path. The arc
-- is centered at (<tt>xc</tt>, <tt>yc</tt>), begins at <tt>angle1</tt>
-- and proceeds in the direction of decreasing angles to end at
-- <tt>angle2</tt>. If <tt>angle2</tt> is greater than <tt>angle1</tt> it
-- will be progressively decreased by 2*<tt>pi</tt> until it is greater
-- than <tt>angle1</tt>.
--
-- See <a>arc</a> for more details. This function differs only in the
-- direction of the arc between the two angles.
arcNegative :: Double -> Double -> Double -> Double -> Double -> Render ()
-- | Adds a cubic Bezier spline to the path from the current point to
-- position (<tt>x3</tt>, <tt>y3</tt>) in user-space coordinates, using
-- (<tt>x1</tt>, <tt>y1</tt>) and (<tt>x2</tt>, <tt>y2</tt>) as the
-- control points. After this call the current point will be
-- (<tt>x3</tt>, <tt>y3</tt>).
curveTo :: Double -> Double -> Double -> Double -> Double -> Double -> Render ()
-- | Adds a line to the path from the current point to position
-- (<tt>x</tt>, <tt>y</tt>) in user-space coordinates. After this call
-- the current point will be (<tt>x</tt>, <tt>y</tt>).
lineTo :: Double -> Double -> Render ()
-- | If the current subpath is not empty, begin a new subpath. After this
-- call the current point will be (<tt>x</tt>, <tt>y</tt>).
moveTo :: Double -> Double -> Render ()
-- | Adds a closed-subpath rectangle of the given size to the current path
-- at position (<tt>x</tt>, <tt>y</tt>) in user-space coordinates.
rectangle :: Double -> Double -> Double -> Double -> Render ()
-- | Render text at the current path.
--
-- <ul>
-- <li>See <a>showText</a> for why you should use Gtk functions.</li>
-- </ul>
textPath :: CairoString string => string -> Render ()
-- | Relative-coordinate version of <a>curveTo</a>. All offsets are
-- relative to the current point. Adds a cubic Bezier spline to the path
-- from the current point to a point offset from the current point by
-- (<tt>dx3</tt>, <tt>dy3</tt>), using points offset by (<tt>dx1</tt>,
-- <tt>dy1</tt>) and (<tt>dx2</tt>, <tt>dy2</tt>) as the control points.
-- After this call the current point will be offset by (<tt>dx3</tt>,
-- <tt>dy3</tt>).
--
-- Given a current point of (x, y), relCurveTo <tt>dx1</tt> <tt>dy1</tt>
-- <tt>dx2</tt> <tt>dy2</tt> <tt>dx3</tt> <tt>dy3</tt> is logically
-- equivalent to curveTo (x + <tt>dx1</tt>) (y + <tt>dy1</tt>) (x +
-- <tt>dx2</tt>) (y + <tt>dy2</tt>) (x + <tt>dx3</tt>) (y +
-- <tt>dy3</tt>).
relCurveTo :: Double -> Double -> Double -> Double -> Double -> Double -> Render ()
-- | Relative-coordinate version of <a>lineTo</a>. Adds a line to the path
-- from the current point to a point that is offset from the current
-- point by (<tt>dx</tt>, <tt>dy</tt>) in user space. After this call the
-- current point will be offset by (<tt>dx</tt>, <tt>dy</tt>).
--
-- Given a current point of (x, y), relLineTo <tt>dx</tt> <tt>dy</tt> is
-- logically equivalent to lineTo (x + <tt>dx</tt>) (y + <tt>dy</tt>).
relLineTo :: Double -> Double -> Render ()
-- | If the current subpath is not empty, begin a new subpath. After this
-- call the current point will offset by (x, y).
--
-- Given a current point of (x, y), relMoveTo <tt>dx</tt> <tt>dy</tt> is
-- logically equivalent to moveTo (x + <tt>dx</tt>) (y + <tt>dy</tt>)
relMoveTo :: Double -> Double -> Render ()
-- | Creates a new <a>Pattern</a> corresponding to an opaque color. The
-- color components are floating point numbers in the range 0 to 1. If
-- the values passed in are outside that range, they will be clamped.
--
-- For example to create a solid red pattern:
--
-- <pre>
-- withRBGPattern 1 0 0 $ do
-- ...
-- ...
-- </pre>
withRGBPattern :: Double -> Double -> Double -> (Pattern -> Render a) -> Render a
-- | Creates a new <a>Pattern</a> corresponding to a translucent color. The
-- color components are floating point numbers in the range 0 to 1. If
-- the values passed in are outside that range, they will be clamped.
--
-- For example to create a solid red pattern at 50% transparency:
--
-- <pre>
-- withRBGPattern 1 0 0 0.5 $ do
-- ...
-- ...
-- </pre>
withRGBAPattern :: Double -> Double -> Double -> Double -> (Pattern -> Render a) -> Render a
-- | Create a new <a>Pattern</a> for the given surface.
withPatternForSurface :: Surface -> (Pattern -> Render a) -> Render a
-- | Pop the current group from the group stack and use it as a pattern.
-- The group should be populated first by calling <a>pushGroup</a> or
-- <a>pushGroupWithContent</a> and doing some drawing operations. This
-- also calls <a>restore</a> to balance the <a>save</a> called in
-- <a>pushGroup</a>.
withGroupPattern :: (Pattern -> Render a) -> Render a
-- | Create a new linear gradient <a>Pattern</a> along the line defined by
-- <tt>(x0, y0)</tt> and <tt>(x1, y1)</tt>. Before using the gradient
-- pattern, a number of color stops should be defined using
-- <a>patternAddColorStopRGB</a> and <a>patternAddColorStopRGBA</a>.
--
-- <ul>
-- <li>Note: The coordinates here are in pattern space. For a new
-- pattern, pattern space is identical to user space, but the
-- relationship between the spaces can be changed with
-- <a>patternSetMatrix</a>.</li>
-- </ul>
withLinearPattern :: Double -> Double -> Double -> Double -> (Pattern -> Render a) -> Render a
-- | Creates a new radial gradient <a>Pattern</a> between the two circles
-- defined by <tt>(x0, y0, c0)</tt> and <tt>(x1, y1, c0)</tt>. Before
-- using the gradient pattern, a number of color stops should be defined
-- using <a>patternAddColorStopRGB</a> or <a>patternAddColorStopRGBA</a>.
--
-- <ul>
-- <li>Note: The coordinates here are in pattern space. For a new
-- pattern, pattern space is identical to user space, but the
-- relationship between the spaces can be changed with
-- <a>patternSetMatrix</a>.</li>
-- </ul>
withRadialPattern :: Double -> Double -> Double -> Double -> Double -> Double -> (Pattern -> Render a) -> Render a
-- | Adds an opaque color stop to a gradient pattern. The offset specifies
-- the location along the gradient's control vector. For example, a
-- linear gradient's control vector is from (x0,y0) to (x1,y1) while a
-- radial gradient's control vector is from any point on the start circle
-- to the corresponding point on the end circle.
--
-- The color is specified in the same way as in <a>setSourceRGB</a>.
--
-- Note: If the pattern is not a gradient pattern, (eg. a linear or
-- radial pattern), then the pattern will be put into an error status
-- with a status of <a>StatusPatternTypeMismatch</a>.
patternAddColorStopRGB :: MonadIO m => Pattern -> Double -> Double -> Double -> Double -> m ()
-- | Adds a translucent color stop to a gradient pattern. The offset
-- specifies the location along the gradient's control vector. For
-- example, a linear gradient's control vector is from (x0,y0) to (x1,y1)
-- while a radial gradient's control vector is from any point on the
-- start circle to the corresponding point on the end circle.
--
-- The color is specified in the same way as in setSourceRGBA.
--
-- Note: If the pattern is not a gradient pattern, (eg. a linear or
-- radial pattern), then the pattern will be put into an error status
-- with a status of <a>StatusPatternTypeMismatch</a>.
patternAddColorStopRGBA :: MonadIO m => Pattern -> Double -> Double -> Double -> Double -> Double -> m ()
-- | Sets the pattern's transformation matrix to matrix. This matrix is a
-- transformation from user space to pattern space.
--
-- When a pattern is first created it always has the identity matrix for
-- its transformation matrix, which means that pattern space is initially
-- identical to user space.
--
-- Important: Please note that the direction of this transformation
-- matrix is from user space to pattern space. This means that if you
-- imagine the flow from a pattern to user space (and on to device
-- space), then coordinates in that flow will be transformed by the
-- inverse of the pattern matrix.
--
-- Also, please note the discussion of the user-space locking semantics
-- of <a>setSource</a>.
patternSetMatrix :: MonadIO m => Pattern -> Matrix -> m ()
-- | Get the pattern's transformation matrix.
patternGetMatrix :: MonadIO m => Pattern -> m Matrix
patternSetExtend :: MonadIO m => Pattern -> Extend -> m ()
patternGetExtend :: MonadIO m => Pattern -> m Extend
patternSetFilter :: MonadIO m => Pattern -> Filter -> m ()
patternGetFilter :: MonadIO m => Pattern -> m Filter
-- | Modifies the current transformation matrix (CTM) by translating the
-- user-space origin by <tt>(tx, ty)</tt>. This offset is interpreted as
-- a user-space coordinate according to the CTM in place before the new
-- call to <a>translate</a>. In other words, the translation of the
-- user-space origin takes place after any existing transformation.
translate :: Double -> Double -> Render ()
-- | Modifies the current transformation matrix (CTM) by scaling the X and
-- Y user-space axes by sx and sy respectively. The scaling of the axes
-- takes place after any existing transformation of user space.
scale :: Double -> Double -> Render ()
-- | Modifies the current transformation matrix (CTM) by rotating the
-- user-space axes by <tt>angle</tt> radians. The rotation of the axes
-- takes places after any existing transformation of user space. The
-- rotation direction for positive angles is from the positive X axis
-- toward the positive Y axis.
rotate :: Double -> Render ()
-- | Modifies the current transformation matrix (CTM) by applying matrix as
-- an additional transformation. The new transformation of user space
-- takes place after any existing transformation.
transform :: Matrix -> Render ()
-- | Modifies the current transformation matrix (CTM) by setting it equal
-- to <tt>matrix</tt>.
setMatrix :: Matrix -> Render ()
-- | Gets the current transformation matrix, as set by <a>setMatrix</a>.
getMatrix :: Render Matrix
-- | Resets the current transformation matrix (CTM) by setting it equal to
-- the identity matrix. That is, the user-space and device-space axes
-- will be aligned and one user-space unit will transform to one
-- device-space unit.
identityMatrix :: Render ()
-- | Transform a coordinate from user space to device space by multiplying
-- the given point by the current transformation matrix (CTM).
userToDevice :: Double -> Double -> Render (Double, Double)
-- | Transform a distance vector from user space to device space. This
-- function is similar to <a>userToDevice</a> except that the translation
-- components of the CTM will be ignored when transforming
-- <tt>(dx,dy)</tt>.
userToDeviceDistance :: Double -> Double -> Render (Double, Double)
-- | Transform a coordinate from device space to user space by multiplying
-- the given point by the inverse of the current transformation matrix
-- (CTM).
deviceToUser :: Double -> Double -> Render (Double, Double)
-- | Transform a distance vector from device space to user space. This
-- function is similar to <a>deviceToUser</a> except that the translation
-- components of the inverse CTM will be ignored when transforming
-- <tt>(dx,dy)</tt>.
deviceToUserDistance :: Double -> Double -> Render (Double, Double)
-- | Selects a family and style of font from a simplified description as a
-- <tt>family</tt> name, <tt>slant</tt> and <tt>weight</tt>. This
-- function is meant to be used only for applications with simple font
-- needs: Cairo doesn't provide for operations such as listing all
-- available fonts on the system, and it is expected that most
-- applications will need to use a more comprehensive font handling and
-- text layout library in addition to cairo.
selectFontFace :: CairoString string => string -> FontSlant -> FontWeight -> Render ()
-- | Sets the current font matrix to a scale by a factor of <tt>size</tt>,
-- replacing any font matrix previously set with <a>setFontSize</a> or
-- <a>setFontMatrix</a>. This results in a font size of size user space
-- units. (More precisely, this matrix will result in the font's
-- em-square being a size by size square in user space.)
setFontSize :: Double -> Render ()
-- | Sets the current font matrix to <tt>matrix</tt>. The font matrix gives
-- a transformation from the design space of the font (in this space, the
-- em-square is 1 unit by 1 unit) to user space. Normally, a simple scale
-- is used (see <a>setFontSize</a>), but a more complex font matrix can
-- be used to shear the font or stretch it unequally along the two axes.
setFontMatrix :: Matrix -> Render ()
-- | Gets the current font matrix, as set by <a>setFontMatrix</a>
getFontMatrix :: Render Matrix
-- | Sets a set of custom font rendering options. Rendering options are
-- derived by merging these options with the options derived from
-- underlying surface; if the value in <tt>options</tt> has a default
-- value (like <a>AntialiasDefault</a>), then the value from the surface
-- is used.
setFontOptions :: FontOptions -> Render ()
-- | A drawing operator that generates the shape from a string of Unicode
-- characters, rendered according to the current font face, font size
-- (font matrix), and font options.
--
-- This function first computes a set of glyphs for the string of text.
-- The first glyph is placed so that its origin is at the current point.
-- The origin of each subsequent glyph is offset from that of the
-- previous glyph by the advance values of the previous glyph.
--
-- 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 easy display of a single logical
-- string with multiple calls to <a>showText</a>.
--
-- NOTE: The <a>showText</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 the
-- most serious of text-using applications.
showText :: CairoString string => string -> Render ()
-- | Gets the font extents for the currently selected font.
fontExtents :: Render FontExtents
-- | Gets the extents for a string of text. The extents describe a
-- user-space rectangle that encloses the "inked" portion of the text,
-- (as it would be drawn by <a>showText</a>). Additionally, the
-- <a>textExtentsXadvance</a> and <a>textExtentsYadvance</a> values
-- indicate the amount by which the current point would be advanced by
-- <a>showText</a>.
--
-- Note that whitespace characters do not directly contribute to the size
-- of the rectangle (<a>textExtentsWidth</a> and
-- <a>textExtentsHeight</a>). They do contribute indirectly by changing
-- the position of non-whitespace characters. In particular, trailing
-- whitespace characters are likely to not affect the size of the
-- rectangle, though they will affect the <a>textExtentsXadvance</a> and
-- <a>textExtentsYadvance</a> values.
textExtents :: CairoString string => string -> Render TextExtents
-- | Allocates a new font options object with all options initialized to
-- default values.
fontOptionsCreate :: MonadIO m => m FontOptions
-- | Allocates a new font options object copying the option values from
-- <tt>original</tt>.
fontOptionsCopy :: MonadIO m => FontOptions -> m FontOptions
-- | Merges non-default options from <tt>other</tt> into <tt>options</tt>,
-- replacing existing values. This operation can be thought of as
-- somewhat similar to compositing <tt>other</tt> onto <tt>options</tt>
-- with the operation of <tt>OperationOver</tt>.
fontOptionsMerge :: MonadIO m => FontOptions -> FontOptions -> m ()
-- | Compute a hash for the font options object; this value will be useful
-- when storing an object containing a <a>FontOptions</a> in a hash
-- table.
fontOptionsHash :: MonadIO m => FontOptions -> m Int
-- | Compares two font options objects for equality.
fontOptionsEqual :: MonadIO m => FontOptions -> FontOptions -> m Bool
-- | Sets the antiliasing mode for the font options object. This specifies
-- the type of antialiasing to do when rendering text.
fontOptionsSetAntialias :: MonadIO m => FontOptions -> Antialias -> m ()
-- | Gets the antialising mode for the font options object.
fontOptionsGetAntialias :: MonadIO m => FontOptions -> m Antialias
-- | Sets the subpixel order for the font options object. The subpixel
-- order specifies the order of color elements within each pixel on the
-- display device when rendering with an antialiasing mode of
-- <a>AntialiasSubpixel</a>. See the documentation for
-- <a>SubpixelOrder</a> for full details.
fontOptionsSetSubpixelOrder :: MonadIO m => FontOptions -> SubpixelOrder -> m ()
-- | Gets the subpixel order for the font options object. See the
-- documentation for <a>SubpixelOrder</a> for full details.
fontOptionsGetSubpixelOrder :: MonadIO m => FontOptions -> m SubpixelOrder
-- | Sets the hint style for font outlines for the font options object.
-- This controls whether to fit font outlines to the pixel grid, and if
-- so, whether to optimize for fidelity or contrast. See the
-- documentation for <a>HintStyle</a> for full details.
fontOptionsSetHintStyle :: MonadIO m => FontOptions -> HintStyle -> m ()
-- | Gets the hint style for font outlines for the font options object. See
-- the documentation for <a>HintStyle</a> for full details.
fontOptionsGetHintStyle :: MonadIO m => FontOptions -> m HintStyle
-- | Sets the metrics hinting mode for the font options object. This
-- controls whether metrics are quantized to integer values in device
-- units. See the documentation for <a>HintMetrics</a> for full details.
fontOptionsSetHintMetrics :: MonadIO m => FontOptions -> HintMetrics -> m ()
-- | Gets the metrics hinting mode for the font options object. See the
-- documentation for <a>HintMetrics</a> for full details.
fontOptionsGetHintMetrics :: MonadIO m => FontOptions -> m HintMetrics
-- | Create a temporary surface that is as compatible as possible with an
-- existing surface. The new surface will use the same backend as other
-- unless that is not possible for some reason.
withSimilarSurface :: Surface -> Content -> Int -> Int -> (Surface -> IO a) -> IO a
-- | Like <a>withSimilarSurface</a> but creates a Surface that is managed
-- by the Haskell memory manager rather than only being temporaily
-- allocated. This is more flexible and allows you to create surfaces
-- that persist, which can be very useful, for example to cache static
-- elements in an animation.
--
-- However you should be careful because surfaces can be expensive
-- resources and the Haskell memory manager cannot guarantee when it will
-- release them. You can manually release the resources used by a surface
-- with <a>surfaceFinish</a>.
createSimilarSurface :: Surface -> Content -> Int -> Int -> IO Surface
-- | Create a temporary surface that is compatible with the current target
-- surface (like a combination of <a>withTargetSurface</a> and
-- <a>withSimilarSurface</a>).
--
-- This is useful for drawing to a temporary surface and then compositing
-- it into the main suface. For example, the following code draws to a
-- temporary surface and then uses that as a mask:
--
-- <pre>
-- renderWithSimilarSurface ContentAlpha 200 200 $ \tmpSurface -> do
-- renderWith tmpSurface $ do
-- ... -- draw onto the temporary surface
--
-- -- use the temporary surface as a mask, filling it with the
-- -- current source which in this example is transparent red.
-- setSourceRGBA 1 0 0 0.5
-- setOperator Operator{something} -- think of something clever to do
-- maskSurface tmpSurface 0 0)
-- </pre>
renderWithSimilarSurface :: Content -> Int -> Int -> (Surface -> Render a) -> Render a
-- | Retrieves the default font rendering options for the surface. This
-- allows display surfaces to report the correct subpixel order for
-- rendering on them, print surfaces to disable hinting of metrics and so
-- forth. The result can then be used with <tt>scaledFontCreate</tt>.
surfaceGetFontOptions :: Surface -> Render FontOptions
-- | This function finishes the surface and drops all references to
-- external resources. For example, for the Xlib backend it means that
-- cairo will no longer access the drawable, which can be freed. After
-- calling <a>surfaceFinish</a> the only valid operations on a surface
-- are getting and setting user data and referencing and destroying it.
-- Further drawing to the surface will not affect the surface but will
-- instead trigger a <a>StatusSurfaceFinished</a> error.
--
-- When the last call to <tt>surfaceDestroy</tt> decreases the reference
-- count to zero, cairo will call <a>surfaceFinish</a> if it hasn't been
-- called already, before freeing the resources associated with the
-- surface.
surfaceFinish :: MonadIO m => Surface -> m ()
-- | Do any pending drawing for the surface and also restore any temporary
-- modification's cairo has made to the surface's state. This function
-- must be called before switching from drawing on the surface with cairo
-- to drawing on it directly with native APIs. If the surface doesn't
-- support direct access, then this function does nothing.
surfaceFlush :: MonadIO m => Surface -> m ()
-- | Tells cairo that drawing has been done to surface using means other
-- than cairo, and that cairo should reread any cached areas. Note that
-- you must call <a>surfaceFlush</a> before doing such drawing.
surfaceMarkDirty :: MonadIO m => Surface -> m ()
-- | Like <a>surfaceMarkDirty</a>, but drawing has been done only to the
-- specified rectangle, so that cairo can retain cached contents for
-- other parts of the surface.
surfaceMarkDirtyRectangle :: MonadIO m => Surface -> Int -> Int -> Int -> Int -> m ()
-- | Sets an offset that is added to the device coordinates determined by
-- the CTM when drawing to surface. One use case for this function is
-- when we want to create a <a>Surface</a> that redirects drawing for a
-- portion of an onscreen surface to an offscreen surface in a way that
-- is completely invisible to the user of the cairo API. Setting a
-- transformation via <a>translate</a> isn't sufficient to do this, since
-- functions like <a>deviceToUser</a> will expose the hidden offset.
--
-- Note that the offset only affects drawing to the surface, not using
-- the surface in a surface pattern.
surfaceSetDeviceOffset :: MonadIO m => Surface -> Double -> Double -> m ()
-- | Creates an image surface of the specified format and dimensions. The
-- initial contents of the surface is undefined; you must explicitely
-- clear the buffer, using, for example, <a>rectangle</a> and <a>fill</a>
-- if you want it cleared.
withImageSurface :: Format -> Int -> Int -> (Surface -> IO a) -> IO a
-- | Like <a>withImageSurface</a> but creating a surface to target external
-- data pointed to by <a>PixelData</a>.
withImageSurfaceForData :: PixelData -> Format -> Int -> Int -> Int -> (Surface -> IO a) -> IO a
-- | This function provides a stride value that will respect all alignment
-- requirements of the accelerated image-rendering code within cairo.
formatStrideForWidth :: Format -> Int -> Int
-- | Like <a>createImageSurface</a> but creating a surface to target
-- external data pointed to by <a>PixelData</a>.
createImageSurfaceForData :: PixelData -> Format -> Int -> Int -> Int -> IO Surface
-- | Like <a>withImageSurface</a> but creates a Surface that is managed by
-- the Haskell memory manager rather than only being temporaily
-- allocated. This is more flexible and allows you to create surfaces
-- that persist, which can be very useful, for example to cache static
-- elements in an animation.
--
-- However you should be careful because surfaces can be expensive
-- resources and the Haskell memory manager cannot guarantee when it will
-- release them. You can manually release the resources used by a surface
-- with <a>surfaceFinish</a>.
createImageSurface :: Format -> Int -> Int -> IO Surface
-- | Get the width of the image surface in pixels.
imageSurfaceGetWidth :: MonadIO m => Surface -> m Int
-- | Get the height of the image surface in pixels.
imageSurfaceGetHeight :: MonadIO m => Surface -> m Int
-- | Get the format of the surface.
imageSurfaceGetFormat :: MonadIO m => Surface -> m Format
-- | Get the number of bytes from the start of one row to the start of the
-- next. If the image data contains no padding, then this is equal to the
-- pixel depth * the width.
imageSurfaceGetStride :: MonadIO m => Surface -> m Int
-- | Return a ByteString of the image data for a surface. In order to
-- remain safe the returned ByteString is a copy of the data. This is a
-- little slower than returning a pointer into the image surface object
-- itself, but much safer
imageSurfaceGetData :: Surface -> IO ByteString
-- | An array that stores the raw pixel data of an image <a>Surface</a>.
data SurfaceData i e
-- | Retrieve the internal array of raw image data.
--
-- <ul>
-- <li>Image data in an image surface is stored in memory in
-- uncompressed, packed format. Rows in the image are stored top to
-- bottom, and in each row pixels are stored from left to right. There
-- may be padding at the end of a row. The value returned by
-- <a>imageSurfaceGetStride</a> indicates the number of bytes between
-- rows.</li>
-- <li>The returned array is a flat representation of a three dimensional
-- array: x-coordiante, y-coordinate and several channels for each color.
-- The format depends on the <a>Format</a> of the surface:</li>
-- </ul>
--
-- <a>FormatARGB32</a>: each pixel is 32 bits with alpha in the upper 8
-- bits, followed by 8 bits for red, green and blue. Pre-multiplied alpha
-- is used. (That is, 50% transparent red is 0x80800000, not 0x80ff0000.)
--
-- <a>FormatRGB24</a>: each pixel is 32 bits with the upper 8 bits being
-- unused, followed by 8 bits for red, green and blue.
--
-- <a>FormatA8</a>: each pixel is 8 bits holding an alpha value
--
-- <a>FormatA1</a>: each pixel is one bit where pixels are packed into 32
-- bit quantities. The ordering depends on the endianes of the platform.
-- On a big-endian machine, the first pixel is in the uppermost bit, on a
-- little-endian machine the first pixel is in the least-significant bit.
--
-- <ul>
-- <li>To read or write a specific pixel (and assuming
-- <a>FormatARGB32</a> or <a>FormatRGB24</a>), use the formula: <tt>p = y
-- * (rowstride <a>div</a> 4) + x</tt> for the pixel and force the array
-- to have 32-bit words or integers.</li>
-- <li>Calling this function without explicitly giving it a type will
-- often lead to a compiler error since the type parameter <tt>e</tt> is
-- underspecified. If this happens the function can be explicitly typed:
-- <tt>surData <- (imageSurfaceGetPixels pb :: IO (SurfaceData Int
-- Word32))</tt></li>
-- <li>If modifying an image through Haskell's array interface is not
-- fast enough, it is possible to use <a>unsafeRead</a> and
-- <a>unsafeWrite</a> which have the same type signatures as
-- <tt>readArray</tt> and <tt>writeArray</tt>. Note that these are
-- internal functions that might change with GHC.</li>
-- <li>After each write access to the array, you need to inform Cairo
-- about the area that has changed using <a>surfaceMarkDirty</a>.</li>
-- <li>The function will return an error if the surface is not an image
-- surface or if <a>surfaceFinish</a> has been called on the
-- surface.</li>
-- </ul>
imageSurfaceGetPixels :: Storable e => Surface -> IO (SurfaceData Int e)
-- | Creates a new image surface and initializes the contents to the given
-- PNG file.
withImageSurfaceFromPNG :: FilePath -> (Surface -> IO a) -> IO a
imageSurfaceCreateFromPNG :: FilePath -> IO Surface
-- | Writes the contents of surface to a new file <tt>filename</tt> as a
-- PNG image.
surfaceWriteToPNG :: Surface -> FilePath -> IO ()
-- | Creates a PostScript surface of the specified size in points to be
-- written to <tt>filename</tt>.
--
-- Note that the size of individual pages of the PostScript output can
-- vary. See <a>psSurfaceSetSize</a>.
withPDFSurface :: FilePath -> Double -> Double -> (Surface -> IO a) -> IO a
-- | Changes the size of a PDF surface for the current (and subsequent)
-- pages.
--
-- This function should only be called before any drawing operations have
-- been performed on the current page. The simplest way to do this is to
-- call this function immediately after creating the surface or
-- immediately after completing a page with either <a>showPage</a> or
-- <a>copyPage</a>.
pdfSurfaceSetSize :: MonadIO m => Surface -> Double -> Double -> m ()
-- | Creates a PostScript surface of the specified size in points to be
-- written to <tt>filename</tt>.
--
-- Note that the size of individual pages of the PostScript output can
-- vary. See <a>psSurfaceSetSize</a>.
withPSSurface :: FilePath -> Double -> Double -> (Surface -> IO a) -> IO a
-- | Changes the size of a PostScript surface for the current (and
-- subsequent) pages.
--
-- This function should only be called before any drawing operations have
-- been performed on the current page. The simplest way to do this is to
-- call this function immediately after creating the surface or
-- immediately after completing a page with either <a>showPage</a> or
-- <a>copyPage</a>.
psSurfaceSetSize :: MonadIO m => Surface -> Double -> Double -> m ()
-- | Creates a SVG surface of the specified size in points be written to
-- <tt>filename</tt>.
withSVGSurface :: FilePath -> Double -> Double -> (Surface -> IO a) -> IO a
-- | Allocates a new empty region object.
regionCreate :: MonadIO m => m Region
-- | Allocates a new region object containing <tt>rectangle</tt>.
regionCreateRectangle :: MonadIO m => RectangleInt -> m Region
-- | Allocates a new region object containing the union of all given
-- <tt>rects</tt>.
regionCreateRectangles :: MonadIO m => [RectangleInt] -> m Region
-- | Allocates a new region object copying the area from <tt>original</tt>.
regionCopy :: MonadIO m => Region -> m Region
-- | Gets the bounding rectangle of <tt>region</tt> as a RectanglInt.
regionGetExtents :: MonadIO m => Region -> m RectangleInt
-- | Returns the number of rectangles contained in <tt>region</tt>.
regionNumRectangles :: MonadIO m => Region -> m Int
-- | Gets the <tt>nth</tt> rectangle from the <tt>region</tt>.
regionGetRectangle :: MonadIO m => Region -> Int -> m RectangleInt
-- | Checks whether <tt>region</tt> is empty.
regionIsEmpty :: MonadIO m => Region -> m Bool
-- | Checks whether (<tt>x</tt>, <tt>y</tt>) is contained in
-- <tt>region</tt>.
regionContainsPoint :: MonadIO m => Region -> Int -> Int -> m Bool
-- | Checks whether <tt>rectangle</tt> is inside, outside or partially
-- contained in <tt>region</tt>.
regionContainsRectangle :: MonadIO m => Region -> RectangleInt -> m RegionOverlap
-- | Compares whether <tt>region_a</tt> is equivalent to <tt>region_b</tt>.
regionEqual :: MonadIO m => Region -> Region -> m Bool
-- | Translates <tt>region</tt> by (<tt>dx</tt>, <tt>dy</tt>).
regionTranslate :: MonadIO m => Region -> Int -> Int -> m ()
-- | Computes the intersection of <tt>dst</tt> with <tt>other</tt> and
-- places the result in <tt>dst</tt>.
regionIntersect :: MonadIO m => Region -> Region -> m ()
-- | Computes the intersection of <tt>dst</tt> with <tt>rectangle</tt> and
-- places the result in <tt>dst</tt>.
regionIntersectRectangle :: MonadIO m => Region -> RectangleInt -> m ()
-- | Subtracts <tt>other</tt> from <tt>dst</tt> and places the result in
-- <tt>dst</tt>.
regionSubtract :: MonadIO m => Region -> Region -> m ()
-- | Subtracts <tt>rectangle</tt> from <tt>dst</tt> and places the result
-- in <tt>dst</tt>.
regionSubtractRectangle :: MonadIO m => Region -> RectangleInt -> m ()
-- | Computes the union of <tt>dst</tt> with <tt>other</tt> and places the
-- result in <tt>dst</tt>.
regionUnion :: MonadIO m => Region -> Region -> m ()
-- | Computes the union of <tt>dst</tt> with <tt>rectangle</tt> and places
-- the result in <tt>dst</tt>.
regionUnionRectangle :: MonadIO m => Region -> RectangleInt -> m ()
-- | Computes the exclusive difference of <tt>dst</tt> with <tt>other</tt>
-- and places the result in <tt>dst</tt>. That is, <tt>dst</tt> will be
-- set to contain all areas that are either in <tt>dst</tt> or in
-- <tt>other</tt>, but not in both.
regionXor :: MonadIO m => Region -> Region -> m ()
-- | Computes the exclusive difference of <tt>dst</tt> with
-- <tt>rectangle</tt> and places the result in <tt>dst</tt>. That is,
-- <tt>dst</tt> will be set to contain all areas that are either in
-- <tt>dst</tt> or in <tt>rectangle</tt>, but not in both
regionXorRectangle :: MonadIO m => Region -> RectangleInt -> m ()
-- | Lift a computation from the <a>IO</a> monad.
liftIO :: MonadIO m => forall a. IO a -> m a
-- | Returns the version of the cairo library encoded in a single integer.
version :: Int
-- | Returns the version of the cairo library as a human-readable string of
-- the form "X.Y.Z".
versionString :: String
class CairoString s
-- | The Render monad. All drawing operations take place in a Render
-- context. You can obtain a Render context for a <a>Surface</a> using
-- <tt>renderWith</tt>.
data Render m
-- | Representation of a 2-D affine transformation.
--
-- The Matrix type represents a 2x2 transformation matrix along with a
-- translation vector. <tt>Matrix a1 a2 b1 b2 c1 c2</tt> describes the
-- transformation of a point with coordinates x,y that is defined by
--
-- <pre>
-- / x' \ = / a1 b1 \ / x \ + / c1 \
-- \ y' / \ a2 b2 / \ y / \ c2 /
-- </pre>
--
-- or
--
-- <pre>
-- x' = a1 * x + b1 * y + c1
-- y' = a2 * x + b2 * y + c2
-- </pre>
data Matrix
-- | The medium to draw on.
data Surface
-- | Patterns can be simple solid colors, various kinds of gradients or
-- bitmaps. The current pattern for a <tt>Render</tt> context is used by
-- the <tt>stroke</tt>, <tt>fill</tt> and paint operations. These
-- operations composite the current pattern with the target surface using
-- the currently selected <a>Operator</a>.
data Pattern
-- | Cairo status.
--
-- <ul>
-- <li><a>Status</a> is used to indicate errors that can occur when using
-- Cairo. In some cases it is returned directly by functions. When using
-- <a>Render</a>, the last error, if any, is stored in the monad and can
-- be retrieved with <a>status</a>.</li>
-- </ul>
data Status
StatusSuccess :: Status
StatusNoMemory :: Status
StatusInvalidRestore :: Status
StatusInvalidPopGroup :: Status
StatusNoCurrentPoint :: Status
StatusInvalidMatrix :: Status
StatusInvalidStatus :: Status
StatusNullPointer :: Status
StatusInvalidString :: Status
StatusInvalidPathData :: Status
StatusReadError :: Status
StatusWriteError :: Status
StatusSurfaceFinished :: Status
StatusSurfaceTypeMismatch :: Status
StatusPatternTypeMismatch :: Status
StatusInvalidContent :: Status
StatusInvalidFormat :: Status
StatusInvalidVisual :: Status
StatusFileNotFound :: Status
StatusInvalidDash :: Status
StatusInvalidDscComment :: Status
StatusInvalidIndex :: Status
StatusClipNotRepresentable :: Status
StatusTempFileError :: Status
StatusInvalidStride :: Status
StatusFontTypeMismatch :: Status
StatusUserFontImmutable :: Status
StatusUserFontError :: Status
StatusNegativeCount :: Status
StatusInvalidClusters :: Status
StatusInvalidSlant :: Status
StatusInvalidWeight :: Status
StatusInvalidSize :: Status
StatusUserFontNotImplemented :: Status
StatusDeviceTypeMismatch :: Status
StatusDeviceError :: Status
StatusInvalidMeshConstruction :: Status
StatusDeviceFinished :: Status
StatusJbig2GlobalMissing :: Status
StatusLastStatus :: Status
-- | Composition operator for all drawing operations.
data Operator
OperatorClear :: Operator
OperatorSource :: Operator
OperatorOver :: Operator
OperatorIn :: Operator
OperatorOut :: Operator
OperatorAtop :: Operator
OperatorDest :: Operator
OperatorDestOver :: Operator
OperatorDestIn :: Operator
OperatorDestOut :: Operator
OperatorDestAtop :: Operator
OperatorXor :: Operator
OperatorAdd :: Operator
OperatorSaturate :: Operator
OperatorMultiply :: Operator
OperatorScreen :: Operator
OperatorOverlay :: Operator
OperatorDarken :: Operator
OperatorLighten :: Operator
OperatorColorDodge :: Operator
OperatorColorBurn :: Operator
OperatorHardLight :: Operator
OperatorSoftLight :: Operator
OperatorDifference :: Operator
OperatorExclusion :: Operator
OperatorHslHue :: Operator
OperatorHslSaturation :: Operator
OperatorHslColor :: Operator
OperatorHslLuminosity :: Operator
-- | Specifies the type of antialiasing to do when rendering text or shapes
--
-- <ul>
-- <li><i><a>AntialiasDefault</a></i> Use the default antialiasing for
-- the subsystem and target device.</li>
-- <li><i><a>AntialiasNone</a></i> Use a bilevel alpha mask.</li>
-- <li><i><a>AntialiasGray</a></i> Perform single-color antialiasing
-- (using shades of gray for black text on a white background, for
-- example).</li>
-- <li><i><a>AntialiasSubpixel</a></i> Perform antialiasing by taking
-- advantage of the order of subpixel elements on devices such as LCD
-- panels.</li>
-- </ul>
data Antialias
AntialiasDefault :: Antialias
AntialiasNone :: Antialias
AntialiasGray :: Antialias
AntialiasSubpixel :: Antialias
AntialiasFast :: Antialias
AntialiasGood :: Antialias
AntialiasBest :: Antialias
-- | Specify how paths are filled.
--
-- <ul>
-- <li>For both fill rules, whether or not a point is included in the
-- fill is determined by taking a ray from that point to infinity and
-- looking at intersections with the path. The ray can be in any
-- direction, as long as it doesn't pass through the end point of a
-- segment or have a tricky intersection such as intersecting tangent to
-- the path. (Note that filling is not actually implemented in this way.
-- This is just a description of the rule that is applied.)</li>
-- </ul>
--
-- <ul>
-- <li><i><a>FillRuleWinding</a></i> If the path crosses the ray from
-- left-to-right, counts +1. If the path crosses the ray from right to
-- left, counts -1. (Left and right are determined from the perspective
-- of looking along the ray from the starting point.) If the total count
-- is non-zero, the point will be filled.</li>
-- <li><i><a>FillRuleEvenOdd</a></i> Counts the total number of
-- intersections, without regard to the orientation of the contour. If
-- the total number of intersections is odd, the point will be
-- filled.</li>
-- </ul>
data FillRule
FillRuleWinding :: FillRule
FillRuleEvenOdd :: FillRule
-- | Specify line endings.
--
-- <ul>
-- <li><i><a>LineCapButt</a></i> Start(stop) the line exactly at the
-- start(end) point.</li>
-- <li><i><a>LineCapRound</a></i> Use a round ending, the center of the
-- circle is the end point.</li>
-- <li><i><a>LineCapSquare</a></i> Use squared ending, the center of the
-- square is the end point</li>
-- </ul>
data LineCap
LineCapButt :: LineCap
LineCapRound :: LineCap
LineCapSquare :: LineCap
-- | Specify how lines join.
data LineJoin
LineJoinMiter :: LineJoin
LineJoinRound :: LineJoin
LineJoinBevel :: LineJoin
data ScaledFont
data FontFace
data Glyph
-- | Specify the extents of a text.
data TextExtents
TextExtents :: Double -> Double -> Double -> Double -> Double -> Double -> TextExtents
[textExtentsXbearing] :: TextExtents -> Double
[textExtentsYbearing] :: TextExtents -> Double
[textExtentsWidth] :: TextExtents -> Double
[textExtentsHeight] :: TextExtents -> Double
[textExtentsXadvance] :: TextExtents -> Double
[textExtentsYadvance] :: TextExtents -> Double
-- | Result of querying the font extents.
data FontExtents
FontExtents :: Double -> Double -> Double -> Double -> Double -> FontExtents
[fontExtentsAscent] :: FontExtents -> Double
[fontExtentsDescent] :: FontExtents -> Double
[fontExtentsHeight] :: FontExtents -> Double
[fontExtentsMaxXadvance] :: FontExtents -> Double
[fontExtentsMaxYadvance] :: FontExtents -> Double
-- | Specify font slant.
data FontSlant
FontSlantNormal :: FontSlant
FontSlantItalic :: FontSlant
FontSlantOblique :: FontSlant
-- | Specify font weight.
data FontWeight
FontWeightNormal :: FontWeight
FontWeightBold :: FontWeight
-- | The subpixel order specifies the order of color elements within each
-- pixel on the display device when rendering with an antialiasing mode
-- of <a>AntialiasSubpixel</a>.
--
-- <ul>
-- <li><i><a>SubpixelOrderDefault</a></i> Use the default subpixel order
-- for for the target device</li>
-- <li><i><a>SubpixelOrderRgb</a></i> Subpixel elements are arranged
-- horizontally with red at the left</li>
-- <li><i><a>SubpixelOrderBgr</a></i> Subpixel elements are arranged
-- horizontally with blue at the left</li>
-- <li><i><a>SubpixelOrderVrgb</a></i> Subpixel elements are arranged
-- vertically with red at the top</li>
-- <li><i><a>SubpixelOrderVbgr</a></i> Subpixel elements are arranged
-- vertically with blue at the top</li>
-- </ul>
data SubpixelOrder
SubpixelOrderDefault :: SubpixelOrder
SubpixelOrderRgb :: SubpixelOrder
SubpixelOrderBgr :: SubpixelOrder
SubpixelOrderVrgb :: SubpixelOrder
SubpixelOrderVbgr :: SubpixelOrder
-- | Specifies the type of hinting to do on font outlines.
--
-- Hinting is the process of fitting outlines to the pixel grid in order
-- to improve the appearance of the result. Since hinting outlines
-- involves distorting them, it also reduces the faithfulness to the
-- original outline shapes. Not all of the outline hinting styles are
-- supported by all font backends.
--
-- <ul>
-- <li><i><a>HintStyleDefault</a></i> Use the default hint style for for
-- font backend and target device</li>
-- <li><i><a>HintStyleNone</a></i> Do not hint outlines</li>
-- <li><i><a>HintStyleSlight</a></i> Hint outlines slightly to improve
-- contrast while retaining good fidelity to the original shapes.</li>
-- <li><i><a>HintStyleMedium</a></i> Hint outlines with medium strength
-- giving a compromise between fidelity to the original shapes and
-- contrast</li>
-- <li><i><a>HintStyleFull</a></i> Hint outlines to maximize
-- contrast</li>
-- </ul>
data HintStyle
HintStyleDefault :: HintStyle
HintStyleNone :: HintStyle
HintStyleSlight :: HintStyle
HintStyleMedium :: HintStyle
HintStyleFull :: HintStyle
-- | Specifies whether to hint font metrics.
--
-- Hinting font metrics means quantizing them so that they are integer
-- values in device space. Doing this improves the consistency of letter
-- and line spacing, however it also means that text will be laid out
-- differently at different zoom factors.
--
-- <ul>
-- <li><i><a>HintMetricsDefault</a></i> Hint metrics in the default
-- manner for the font backend and target device</li>
-- <li><i><a>HintMetricsOff</a></i> Do not hint font metrics</li>
-- <li><i><a>HintMetricsOn</a></i> Hint font metrics</li>
-- </ul>
data HintMetrics
HintMetricsDefault :: HintMetrics
HintMetricsOff :: HintMetrics
HintMetricsOn :: HintMetrics
-- | Specifies how to render text.
data FontOptions
-- | A Cairo path.
--
-- <ul>
-- <li>A path is a sequence of drawing operations that are accumulated
-- until <a>stroke</a> is called. Using a path is particularly useful
-- when drawing lines with special join styles and <a>closePath</a>.</li>
-- </ul>
data Path
-- | A data structure for holding a rectangle with integer coordinates.
data RectangleInt
RectangleInt :: Int -> Int -> Int -> Int -> RectangleInt
[x] :: RectangleInt -> Int
[y] :: RectangleInt -> Int
[width] :: RectangleInt -> Int
[height] :: RectangleInt -> Int
-- | Used as the return value for regionContainsRectangle.
data RegionOverlap
RegionOverlapIn :: RegionOverlap
RegionOverlapOut :: RegionOverlap
RegionOverlapPart :: RegionOverlap
-- | A Cairo region. Represents a set of integer-aligned rectangles.
--
-- It allows set-theoretical operations like regionUnion and
-- regionIntersect to be performed on them.
data Region
data Content
ContentColor :: Content
ContentAlpha :: Content
ContentColorAlpha :: Content
data Format
FormatARGB32 :: Format
FormatRGB24 :: Format
FormatA8 :: Format
FormatA1 :: Format
-- | FIXME: We should find out about this.
data Extend
ExtendNone :: Extend
ExtendRepeat :: Extend
ExtendReflect :: Extend
ExtendPad :: Extend
-- | Specify how filtering is done.
data Filter
FilterFast :: Filter
FilterGood :: Filter
FilterBest :: Filter
FilterNearest :: Filter
FilterBilinear :: Filter
FilterGaussian :: Filter
instance Foreign.Storable.Storable e => Data.Array.Base.MArray Graphics.Rendering.Cairo.SurfaceData e GHC.Types.IO
|