15bd8deadSopenharmony_ciXXX - Not complete yet!!! 25bd8deadSopenharmony_ci 35bd8deadSopenharmony_ciName 45bd8deadSopenharmony_ci 55bd8deadSopenharmony_ci SGIX_occlusion_instrument 65bd8deadSopenharmony_ci 75bd8deadSopenharmony_ciName Strings 85bd8deadSopenharmony_ci 95bd8deadSopenharmony_ci GL_SGIX_occlusion_instrument 105bd8deadSopenharmony_ci 115bd8deadSopenharmony_ciVersion 125bd8deadSopenharmony_ci 135bd8deadSopenharmony_ci $Date: 1998/04/21 03:53:34 $ $Revision: 1.1 $ 145bd8deadSopenharmony_ci 155bd8deadSopenharmony_ciNumber 165bd8deadSopenharmony_ci 175bd8deadSopenharmony_ci 151 185bd8deadSopenharmony_ci 195bd8deadSopenharmony_ciDependencies 205bd8deadSopenharmony_ci 215bd8deadSopenharmony_ci SGIX_intruments is required 225bd8deadSopenharmony_ci 235bd8deadSopenharmony_ciOverview 245bd8deadSopenharmony_ci 255bd8deadSopenharmony_ci This extension defines an occlusion instrument that can be used by 265bd8deadSopenharmony_ci applications to determine whether a set of fragments are completely 275bd8deadSopenharmony_ci occluded (i.e., fail the depth test) by fragments already in the 285bd8deadSopenharmony_ci frame buffer. 295bd8deadSopenharmony_ci 305bd8deadSopenharmony_ciIssues 315bd8deadSopenharmony_ci 325bd8deadSopenharmony_ci * This extension is named like this so that developers have a better 335bd8deadSopenharmony_ci idea of what the extension does instead of being obscured by a 345bd8deadSopenharmony_ci device-specific name. The extension encompasses functionality that 355bd8deadSopenharmony_ci is exposed by the bali_r_extension, but it does not try to address 365bd8deadSopenharmony_ci the different mode of retrieving occlusion information. It's 375bd8deadSopenharmony_ci possible that Bali may not be able to support this extension easily. 385bd8deadSopenharmony_ci 395bd8deadSopenharmony_ci 405bd8deadSopenharmony_ciNew Procedures and Functions 415bd8deadSopenharmony_ci 425bd8deadSopenharmony_ci None 435bd8deadSopenharmony_ci 445bd8deadSopenharmony_ciNew Tokens 455bd8deadSopenharmony_ci 465bd8deadSopenharmony_ci Accepted by the <cap> parameter of Enable, Disable and IsEnabled: 475bd8deadSopenharmony_ci 485bd8deadSopenharmony_ci OCCLUSION_INSTRUMENT_SGIX 0x6060 495bd8deadSopenharmony_ci 505bd8deadSopenharmony_ciAdditions to Chapter 2 of the 1.1 Specification (OpenGL Operation) 515bd8deadSopenharmony_ci 525bd8deadSopenharmony_ci None. 535bd8deadSopenharmony_ci 545bd8deadSopenharmony_ciAdditions to Chapter 3 of the 1.1 Specification (Rasterization) 555bd8deadSopenharmony_ci 565bd8deadSopenharmony_ci None. 575bd8deadSopenharmony_ci 585bd8deadSopenharmony_ciAdditions to Chapter 4 of the 1.1 Specification (Per-Fragment Operations 595bd8deadSopenharmony_ciand the Frame Buffer) 605bd8deadSopenharmony_ci 615bd8deadSopenharmony_ci Added to subsection 4.1.5 (Depth buffer test) at the end of the 625bd8deadSopenharmony_ci paragraph which begins "If the depth buffer test fails...": 635bd8deadSopenharmony_ci 645bd8deadSopenharmony_ci If OCCLUSION_INSTRUMENT_SGIX is enabled and instruments have been 655bd8deadSopenharmony_ci started via a call to StartInstrumentSGIX, a flag is maintained 665bd8deadSopenharmony_ci of whether fragments pass or fail the depth test. The flag's initial 675bd8deadSopenharmony_ci state is TRUE and it is set to FALSE whenever a fragment generated 685bd8deadSopenharmony_ci during rasterization passes the depth test. 695bd8deadSopenharmony_ci 705bd8deadSopenharmony_ci The format of the measured occlusion instrument consists of four 715bd8deadSopenharmony_ci words: the occlusion instrument enable enum (OCCLUSION_INSTRUMENT_SGIX); 725bd8deadSopenharmony_ci the size of the measurement (4); the result of the measurement; and 735bd8deadSopenharmony_ci the marker passed in with either StopInstrumentsSGIX or 745bd8deadSopenharmony_ci ReadInstrumentsSGIX. 755bd8deadSopenharmony_ci 765bd8deadSopenharmony_ciAdditions to Chapter 5 of the 1.1 Specification (Special Functions) 775bd8deadSopenharmony_ci 785bd8deadSopenharmony_ciAdditions to Chapter 6 of the 1.1 Specification (State and State Requests) 795bd8deadSopenharmony_ci 805bd8deadSopenharmony_ciAdditions to the GLX Specification 815bd8deadSopenharmony_ci 825bd8deadSopenharmony_ci 835bd8deadSopenharmony_ciErrors 845bd8deadSopenharmony_ci 855bd8deadSopenharmony_ciNew State 865bd8deadSopenharmony_ci 875bd8deadSopenharmony_ciNew Implementation Dependent State 885bd8deadSopenharmony_ci 89