1/*! \page ogsflib GRASS GIS OGSF Library 2<!-- doxygenized from "GRASS 5 Programmer's Manual" 3 by M. Neteler 2/2004 4 Updated by Martin Landa <landa.martin gmail.com> in 6/2011 5 --> 6 7by GRASS Development Team (https://grass.osgeo.org) 8 9\section ogsfintro OGSF Library for OpenGL programming 10 11<b>Overview</b> 12 13The OGSF (gsurf) library, consisting of approximately 27,000 lines of 14C code, contains some 250 public functions and about twice as many 15internal functions for run-time data storage, manipulation, querying, 16and visualization using OpenGL. The library handles all drawing and 17lighting operations, including use of user-defined clipping planes and 18drawing various style "fences" on clipping planes when drawing 19multiple surfaces, and treats datasets as objects which can be used 20for various attributes of the rendering. It allows data sharing 21(%e.g., same data for more than one attribute of same or different 22surfaces), separate masking for each surface, multiple surfaces, 23%vector sets, or %point sets, and will also allow multiple volumes. 24The library provides all query features such as 3D "point on surface", 25keyframe animation routines, and full state saving functionality. 26Database-specific routines for interfacing with the \ref gislib are 27kept isolated for easier library reuse with other databases. The 28gsurf library is not dependent upon any particular interface library, 29and has been used successfully with both Motif, Tcl/Tk or wxPython. It 30is used for Nviz visualization tool. 31 32The library is designed to provide a unique "handle" or identifier 33number to the calling program for each new geographic object added to 34the model. The object could be a surface, %vector set, or %point set, 35which could each be defined by one or more database files. Once 36created, the application only needs to keep track of the "handles" to 37the objects (which are returned by the creation routines); for 38example, to draw a surface the application would make the call: 39 40\subsection ogsfNames Naming Conventions 41 42The following naming conventions for function prefixes are used: 43 44 - <b>GS_</b> - Functions which have to do with loading & 45 manipulating surfaces. Also functions for library 46 initialization, setting global variables, viewer positioning, 47 and lighting. 48 49 - <b>GSU_</b> - Utility functions for distance calculations, common 50 2D & 3D unit %vector operations such as cross product or 51 %vector arithmetic. 52 53 - <b>GV_</b> - Functions which have to do with loading & 54 manipulating %vector sets. 55 56 - <b>GP_</b> - Functions which have to do with loading & 57 manipulating %point sets. 58 59 - <b>GVL_</b> - Functions which have to do with loading & 60 manipulating 3D volumes. 61 62 - <b>GK_</b> - Functions which have to do with setting & 63 manipulating keyframes for viewer position animation (fly-bys). 64 65Programmers' documentation is currently incomplete, but see the 66following for more details of the library design and capabilities in 67the appendix (PLEASE ADD EXPLANATIONS!!): 68 69 - public function prototypes 70 - public include file include/gsurf.h 71 - public include file include/keyframe.h 72 - public color packing utility macros rgbpack.h 73 - private types and defines include/gstypes.h 74 - private utilities gsget.h 75 76\section ogsfTodo Major todos 77 78- remove global variables 79- dynamically allocate items instead of static arrays 80- merge GP_ functions into GV_ 81 82\section ogsfPublic Public function prototypes 83 84\subsection ogsfGs Initialization and positioning surfaces (GS) 85 86Functions which have to do with loading & manipulating surfaces. 87Also functions for library initialization, setting global variables, 88viewer positioning, and lighting. 89 90- GS_alldraw_cplane_fences() 91 92- GS_alldraw_surf() 93 94- GS_alldraw_wire() 95 96- GS_check_cancel() 97 98- GS_clear() 99 100- GS_coordpair_repeats() 101 102- GS_delete_list() 103 104- GS_delete_surface() 105 106- GS_distance() 107 108- GS_done_draw() 109 110- GS_draw_all_list() 111 112- GS_draw_cplane() 113 114- GS_draw_cplane_fence() 115 116- GS_draw_flowline_at_xy() 117 118- GS_draw_fringe() 119 120- GS_draw_legend() 121 122- GS_draw_lighting_model() 123 124- GS_draw_lighting_model1() 125 126- GS_draw_line_onsurf() 127 128- GS_draw_nline_onsurf() 129 130- GS_draw_surf() 131 132- GS_draw_wire() 133 134- GS_draw_X() 135 136- GS_dv3norm() 137 138- GS_geodistance() 139 140- GS_get_aspect() 141 142- GS_get_att() 143 144- GS_get_cat_at_xy() 145 146- GS_Get_ClientData() 147 148- GS_get_dims() 149 150- GS_get_distance_alongsurf() 151 152- GS_get_drawmode() 153 154- GS_get_drawres() 155 156- GS_get_exag_guess() 157 158- GS_get_fencecolor() 159 160- GS_get_focus() 161 162- GS_get_fov() 163 164- GS_get_from() 165 166- GS_get_from_real() 167 168- GS_getlight_ambient() 169 170- GS_getlight_color() 171 172- GS_getlight_position() 173 174- GS_get_longdim() 175 176- GS_get_maskmode() 177 178- GS_get_modelposition() 179 180- GS_get_modelposition1() 181 182- GS_get_norm_at_xy() 183 184- GS_get_nozero() 185 186- GS_get_region() 187 188- GS_get_scale() 189 190- GS_get_SDscale() 191 192- GS_get_SDsurf() 193 194- GS_get_selected_point_on_surface() 195 196- GS_get_surf_list() 197 198- GS_get_to() 199 200- GS_get_to_real() 201 202- GS_get_trans() 203 204- GS_get_twist() 205 206- GS_get_val_at_xy() 207 208- GS_get_viewdir() 209 210- GS_get_wire_color() 211 212- GS_get_zextents() 213 214- GS_get_zrange() 215 216- GS_get_zrange_nz() 217 218- GS_global_exag() 219 220- GS_has_transparency() 221 222- GS_init_view() 223 224- GS_is_masked() 225 226- GS_libinit() 227 228- GS_lights_off() 229 230- GS_lights_on() 231 232- GS_load_3dview() 233 234- GS_load_att_map() 235 236- GS_look_here() 237 238- GS_moveto() 239 240- GS_moveto_real() 241 242- GS_new_light() 243 244- GS_new_surface() 245 246- GS_num_surfs() 247 248- GS_P2distance() 249 250- GS_ready_draw() 251 252- GS_save_3dview() 253 254- GS_setall_drawmode() 255 256- GS_setall_drawres() 257 258- GS_set_att_const() 259 260- GS_set_att_defaults() 261 262- GS_set_cancel() 263 264- GS_Set_ClientData() 265 266- GS_set_cplane() 267 268- GS_set_cplane_rot() 269 270- GS_set_cplane_trans() 271 272- GS_set_cxl_func() 273 274- GS_set_draw() 275 276- GS_set_drawmode() 277 278- GS_set_drawres() 279 280- GS_set_exag() 281 282- GS_set_fencecolor() 283 284- GS_set_focus() 285 286- GS_set_focus_center_map() 287 288- GS_set_focus_real() 289 290- GS_set_fov() 291 292- GS_set_global_exag() 293 294- GS_set_infocus() 295 296- GS_setlight_ambient() 297 298- GS_setlight_color() 299 300- GS_setlight_position() 301 302- GS_set_maskmode() 303 304- GS_set_Narrow() 305 306- GS_set_nofocus() 307 308- GS_set_nozero() 309 310- GS_set_SDscale() 311 312- GS_set_SDsurf() 313 314- GS_set_trans() 315 316- GS_set_twist() 317 318- GS_set_viewdir() 319 320- GS_set_viewport() 321 322- GS_set_wire_color() 323 324- GS_surf_exists() 325 326- GS_switchlight() 327 328- GS_transp_is_set() 329 330- GS_unset_att() 331 332- GS_unset_cplane() 333 334- GS_unset_SDsurf() 335 336- GS_update_curmask() 337 338- GS_update_normals() 339 340- GS_util.c() 341 342- GS_v2dir() 343 344- GS_v2norm() 345 346- GS_v3add() 347 348- GS_v3cross() 349 350- GS_v3dir() 351 352- GS_v3eq() 353 354- GS_v3mag() 355 356- GS_v3mult() 357 358- GS_v3norm() 359 360- GS_v3normalize() 361 362- GS_v3sub() 363 364- GS_write_ppm() 365 366- GS_write_tif() 367 368- GS_write_zoom() 369 370- GS_zoom_setup() 371 372\subsection ogsfGv Loading and manipulation of vector maps (GV) 373 374Functions which have to do with loading & manipulating %vector 375sets. 376 377- GV_alldraw_fastvect() 378 379- GV_alldraw_vect() 380 381- GV_delete_vector() 382 383- GV_draw_fastvect() 384 385- GV_draw_vect() 386 387- GV_Get_ClientData() 388 389- GV_get_trans() 390 391- GV_get_vect_list() 392 393- GV_get_style() 394 395- GV_get_vectname() 396 397- GV_load_vector() 398 399- GV_new_vector() 400 401- GV_num_vects() 402 403- GV_select_surf() 404 405- GV_Set_ClientData() 406 407- GV_set_trans() 408 409- GV_set_style() 410 411- GV_surf_is_selected() 412 413- GV_unselect_surf() 414 415- GV_vect_exists() 416 417\subsection ogsfGp Loading and manipulation of vector point maps (GP) 418 419Functions which have to do with loading & manipulating %point 420sets. 421 422- GP_alldraw_site() 423 424- GP_attmode_color() 425 426- GP_attmode_none() 427 428- GP_delete_site() 429 430- GP_draw_site() 431 432- GP_Get_ClientData() 433 434- GP_get_site_list() 435 436- GP_get_sitename() 437 438- GP_get_style() 439 440- GP_get_trans() 441 442- GP_get_zmode() 443 444- GP_load_site() 445 446- GP_new_site() 447 448- GP_num_sites() 449 450- GP_select_surf() 451 452- GP_Set_ClientData() 453 454- GP_set_style() 455 456- GP_set_style_thematic() 457 458- GP_set_trans() 459 460- GP_set_zmode() 461 462- GP_site_exists() 463 464- GP_str_to_marker() 465 466- GP_surf_is_selected() 467 468- GP_unselect_surf() 469 470\subsection ogsf ogsfGk Keyframe animation 471 472Functions which have to do with setting & manipulating keyframes 473for viewer position animation (fly-bys). 474 475- GK_add_key() 476 477- GK_clear_keys() 478 479- GK_delete_key() 480 481- GK_do_framestep() 482 483- GK_move_key() 484 485- GK_print_keys() 486 487- GK_set_interpmode() 488 489- GK_set_numsteps() 490 491- GK_set_tension() 492 493- GK_show_list() 494 495- GK_show_path() 496 497- GK_show_site() 498 499- GK_showtension_start() 500 501- GK_showtension_stop() 502 503- GK_show_vect() 504 505- GK_show_vol() 506 507- GK_update_frames() 508 509- GK_update_tension() 510 511 512\subsection ogsfGvl Loading and manipulation of volume maps (GVL) 513 514Functions which have to do with loading & manipulating 3D volumes. 515 516- GVL_alldraw_vol() 517 518- GVL_alldraw_wire() 519 520- GVL_delete_vol() 521 522- GVL_draw_vol() 523 524- GVL_draw_wire() 525 526- GVL_Get_ClientData() 527 528- GVL_get_dims() 529 530- GVL_get_region() 531 532- GVL_get_trans() 533 534- GVL_get_vol_list() 535 536- GVL_get_volname() 537 538- GVL_get_window() 539 540- GVL_isosurf_add() 541 542- GVL_isosurf_del() 543 544- GVL_isosurf_get_att() 545 546- GVL_isosurf_get_drawmode() 547 548- GVL_isosurf_get_drawres() 549 550- GVL_isosurf_get_flags() 551 552- GVL_isosurf_get_maskmode() 553 554- GVL_isosurf_move_down() 555 556- GVL_isosurf_move_up() 557 558- GVL_isosurf_num_isosurfs() 559 560- GVL_isosurf_set_att_const() 561 562- GVL_isosurf_set_att_map() 563 564- GVL_isosurf_set_drawmode() 565 566- GVL_isosurf_set_drawres() 567 568- GVL_isosurf_set_flags() 569 570- GVL_isosurf_set_maskmode() 571 572- GVL_isosurf_unset_att() 573 574- GVL_libinit() 575 576- GVL_load_vol() 577 578- GVL_new_vol() 579 580- GVL_num_vols() 581 582- GVL_Set_ClientData() 583 584- GVL_set_focus_center_map() 585 586- GVL_set_trans() 587 588- GVL_slice_add() 589 590- GVL_slice_del() 591 592- GVL_slice_get_drawmode() 593 594- GVL_slice_get_drawres() 595 596- GVL_slice_get_pos() 597 598- GVL_slice_get_transp() 599 600- GVL_slice_move_down() 601 602- GVL_slice_move_up() 603 604- GVL_slice_num_slices() 605 606- GVL_slice_set_drawmode() 607 608- GVL_slice_set_drawres() 609 610- GVL_slice_set_pos() 611 612- GVL_slice_set_transp() 613 614- GVL_vol_exists() 615 616\subsection ogsfGvlIso Loading and manipulation of isosurfaces (GVL) 617 618Functions which have to do with loading & manipulating 619isosurfaces. 620 621- GVL_isosurf_add() 622 623- GVL_isosurf_del() 624 625- GVL_isosurf_get_att() 626 627- GVL_isosurf_get_drawmode() 628 629- GVL_isosurf_get_drawres() 630 631- GVL_isosurf_get_flags() 632 633- GVL_isosurf_get_maskmode() 634 635- GVL_isosurf_move_down() 636 637- GVL_isosurf_move_up() 638 639- GVL_isosurf_num_isosurfs() 640 641- GVL_isosurf_set_att_const() 642 643- GVL_isosurf_set_att_map() 644 645- GVL_isosurf_set_drawmode() 646 647- GVL_isosurf_set_drawres() 648 649- GVL_isosurf_set_flags() 650 651- GVL_isosurf_set_maskmode() 652 653- GVL_isosurf_unset_att() 654 655\subsection ogsfGvlSlice Loading and manipulation of slices (GVL) 656 657Functions which have to do with loading & manipulating slices. 658 659- GVL_slice_add() 660 661- GVL_slice_del() 662 663- GVL_slice_get_drawmode() 664 665- GVL_slice_get_drawres() 666 667- GVL_slice_get_pos() 668 669- GVL_slice_get_transp() 670 671- GVL_slice_move_down() 672 673- GVL_slice_move_up() 674 675- GVL_slice_num_slices() 676 677- GVL_slice_set_drawmode() 678 679- GVL_slice_set_drawres() 680 681- GVL_slice_set_pos() 682 683- GVL_slice_set_transp() 684 685\section authors Authors 686 687 Bill Brown GMSL/University of Illinois 688 689*/ 690