15bd8deadSopenharmony_ciXXX - Not complete yet!!! But pretty close. 25bd8deadSopenharmony_ci 35bd8deadSopenharmony_ciName 45bd8deadSopenharmony_ci 55bd8deadSopenharmony_ci SGIX_blend_alpha_minmax 65bd8deadSopenharmony_ci 75bd8deadSopenharmony_ciName Strings 85bd8deadSopenharmony_ci 95bd8deadSopenharmony_ci GL_SGIX_blend_alpha_minmax 105bd8deadSopenharmony_ci 115bd8deadSopenharmony_ciVersion 125bd8deadSopenharmony_ci 135bd8deadSopenharmony_ci $Date: 1998/03/31 00:55:21 $ $Revision: 1.3 $ 145bd8deadSopenharmony_ci 155bd8deadSopenharmony_ciNumber 165bd8deadSopenharmony_ci 175bd8deadSopenharmony_ci 119 185bd8deadSopenharmony_ci 195bd8deadSopenharmony_ciDependencies 205bd8deadSopenharmony_ci 215bd8deadSopenharmony_ci EXT_blend_minmax is required 225bd8deadSopenharmony_ci EXT_blend_subtract affects the number of values of BLEND_EQUATION_EXT 235bd8deadSopenharmony_ci 245bd8deadSopenharmony_ciOverview 255bd8deadSopenharmony_ci 265bd8deadSopenharmony_ci Two additional blending equations are specified using the interface 275bd8deadSopenharmony_ci defined by EXT_blend_minmax. These equations are similar to the 285bd8deadSopenharmony_ci MIN_EXT and MAX_EXT blending equations, but the outcome for all four 295bd8deadSopenharmony_ci color components is determined by a comparison of just the alpha 305bd8deadSopenharmony_ci component's source and destination values. These equations are useful 315bd8deadSopenharmony_ci in image processing and advanced shading algorithms. 325bd8deadSopenharmony_ci 335bd8deadSopenharmony_ciNew Procedures and Functions 345bd8deadSopenharmony_ci 355bd8deadSopenharmony_ci None 365bd8deadSopenharmony_ci 375bd8deadSopenharmony_ciNew Tokens 385bd8deadSopenharmony_ci 395bd8deadSopenharmony_ci Accepted by the <mode> parameter of BlendEquationEXT: 405bd8deadSopenharmony_ci 415bd8deadSopenharmony_ci ALPHA_MIN_SGIX 0x8320 425bd8deadSopenharmony_ci ALPHA_MAX_SGIX 0x8321 435bd8deadSopenharmony_ci 445bd8deadSopenharmony_ciAdditions to Chapter 2 of the GL Specification (OpenGL Operation) 455bd8deadSopenharmony_ci 465bd8deadSopenharmony_ci None 475bd8deadSopenharmony_ci 485bd8deadSopenharmony_ciAdditions to Chapter 3 of the GL Specification (Rasterization) 495bd8deadSopenharmony_ci 505bd8deadSopenharmony_ci None 515bd8deadSopenharmony_ci 525bd8deadSopenharmony_ciAdditions to Chapter 4 of the GL Specification (Per-Fragment Operations 535bd8deadSopenharmony_ciand the Framebuffer) 545bd8deadSopenharmony_ci 555bd8deadSopenharmony_ci Two additional blending equations are defined. If BlendEquationEXT is 565bd8deadSopenharmony_ci called with <mode> set to ALPHA_MIN_EXT, the blending equation becomes 575bd8deadSopenharmony_ci 585bd8deadSopenharmony_ci / Cs As < Ad 595bd8deadSopenharmony_ci C' = ( 605bd8deadSopenharmony_ci \ Cd As >= Ad 615bd8deadSopenharmony_ci 625bd8deadSopenharmony_ci where C' is the color resulting from the blending operation, 635bd8deadSopenharmony_ci Cs and Cd are the source and destination colors, and As and Ad 645bd8deadSopenharmony_ci are the source and destination alpha in particular. 655bd8deadSopenharmony_ci 665bd8deadSopenharmony_ci If BlendEquationEXT is called with <mode> set to ALPHA_MAX_SGIX, the 675bd8deadSopenharmony_ci blending equation becomes 685bd8deadSopenharmony_ci 695bd8deadSopenharmony_ci / Cs As > Ad 705bd8deadSopenharmony_ci C' = ( 715bd8deadSopenharmony_ci \ Cd As <= Ad 725bd8deadSopenharmony_ci 735bd8deadSopenharmony_ci In both cases the blending equation is evaluated separately for each 745bd8deadSopenharmony_ci color component in a quadruplet. 755bd8deadSopenharmony_ci 765bd8deadSopenharmony_ciAdditions to Chapter 5 of the GL Specification (Special Functions) 775bd8deadSopenharmony_ci 785bd8deadSopenharmony_ci None 795bd8deadSopenharmony_ci 805bd8deadSopenharmony_ciAdditions to Chapter 6 of the GL Specification (State and State Requests) 815bd8deadSopenharmony_ci 825bd8deadSopenharmony_ci None 835bd8deadSopenharmony_ci 845bd8deadSopenharmony_ciAdditions to the GLX Specification 855bd8deadSopenharmony_ci 865bd8deadSopenharmony_ci None 875bd8deadSopenharmony_ci 885bd8deadSopenharmony_ciGLX Protocol 895bd8deadSopenharmony_ci 905bd8deadSopenharmony_ci None 915bd8deadSopenharmony_ci 925bd8deadSopenharmony_ciDependencies on EXT_blend_minmax 935bd8deadSopenharmony_ci 945bd8deadSopenharmony_ci EXT_blend_minmax is required. 955bd8deadSopenharmony_ci 965bd8deadSopenharmony_ciErrors 975bd8deadSopenharmony_ci 985bd8deadSopenharmony_ci INVALID_ENUM is generated by BlendEquationEXT if its single parameter 995bd8deadSopenharmony_ci is not FUNC_ADD_EXT, MIN_EXT, MAX_EXT, FUNC_SUBTRACT_EXT, 1005bd8deadSopenharmony_ci FUNC_REVERSE_SUBTRACT_EXT, ALPHA_MIN_SGIX, or ALPHA_MAX_SGIX. 1015bd8deadSopenharmony_ci 1025bd8deadSopenharmony_ci INVALID_OPERATION is generated if BlendEquationEXT is executed between 1035bd8deadSopenharmony_ci the execution of Begin and the corresponding execution to End. 1045bd8deadSopenharmony_ci 1055bd8deadSopenharmony_ciNew State 1065bd8deadSopenharmony_ci 1075bd8deadSopenharmony_ci Two new values of BLEND_EQUATION_EXT: 1085bd8deadSopenharmony_ci 1095bd8deadSopenharmony_ci Get Value Get Command Type Initial Value Attribute 1105bd8deadSopenharmony_ci --------- ----------- ---- ------------- --------- 1115bd8deadSopenharmony_ci BLEND_EQUATION_EXT GetIntegerv Z7 FUNC_ADD_EXT color-buffer 1125bd8deadSopenharmony_ci 1135bd8deadSopenharmony_ciNew Implementation Dependent State 1145bd8deadSopenharmony_ci 1155bd8deadSopenharmony_ci None 116