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diff --git a/nx-X11/extras/ogl-sample/main/doc/man/mangl/standard/blendequation.gl b/nx-X11/extras/ogl-sample/main/doc/man/mangl/standard/blendequation.gl new file mode 100644 index 000000000..f3c49cda3 --- /dev/null +++ b/nx-X11/extras/ogl-sample/main/doc/man/mangl/standard/blendequation.gl @@ -0,0 +1,163 @@ +_C_ License Applicability. Except to the extent portions of this file are +_C_ made subject to an alternative license as permitted in the SGI Free +_C_ Software License B, Version 1.1 (the "License"), the contents of this +_C_ file are subject only to the provisions of the License. You may not use +_C_ this file except in compliance with the License. You may obtain a copy +_C_ of the License at Silicon Graphics, Inc., attn: Legal Services, 1600 +_C_ Amphitheatre Parkway, Mountain View, CA 94043-1351, or at: +_C_ +_C_ http://oss.sgi.com/projects/FreeB +_C_ +_C_ Note that, as provided in the License, the Software is distributed on an +_C_ "AS IS" basis, with ALL EXPRESS AND IMPLIED WARRANTIES AND CONDITIONS +_C_ DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND +_C_ CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A +_C_ PARTICULAR PURPOSE, AND NON-INFRINGEMENT. +_C_ +_C_ Original Code. The Original Code is: OpenGL Sample Implementation, +_C_ Version 1.2.1, released January 26, 2000, developed by Silicon Graphics, +_C_ Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc. +_C_ Copyright in any portions created by third parties is as indicated +_C_ elsewhere herein. All Rights Reserved. +_C_ +_C_ Additional Notice Provisions: The application programming interfaces +_C_ established by SGI in conjunction with the Original Code are The +_C_ OpenGL(R) Graphics System: A Specification (Version 1.2.1), released +_C_ April 1, 1999; The OpenGL(R) Graphics System Utility Library (Version +_C_ 1.3), released November 4, 1998; and OpenGL(R) Graphics with the X +_C_ Window System(R) (Version 1.3), released October 19, 1998. This software +_C_ was created using the OpenGL(R) version 1.2.1 Sample Implementation +_C_ published by SGI, but has not been independently verified as being +_C_ compliant with the OpenGL(R) version 1.2.1 Specification. +_C_ +_C_ The first character in this file must be an '_'! +_C_ Anything on a line after _C_ is ignored +_define(_filters,tbl|eqn)_C_ +_C_ eqn is automatically replaced with neqn for nroff +_header(BlendEquation, set the blend equation) +_names(BlendEquation) +.EQ +delim $$ +.EN +.SH PARAMETERS +_phead(_param1) +specifies how source and destination colors are combined. +It must be _const(FUNC_ADD), _const(FUNC_SUBTRACT), +_const(FUNC_REVERSE_SUBTRACT), _const(MIN), _const(MAX). + +.SH DESCRIPTION +The blend equation determines how a new pixel (the ``source'' color) +is combined with a pixel already in the framebuffer (the ``destination'' +color). +.TP +_const(MIN) +sets the blend equation so that each component of the result color +is the minimum of the corresponding components of the source and destination +colors. +.TP +_const(MAX) +sets the blend equation so that each component of the result color +is the maximum of the corresponding components of the source and destination +colors. +.P +The remaining blend equations use the source and destination blend factors +specified by _cmnd(BlendFunc). +See _cmnd(BlendFunc) for a description of the various blend factors. +.P +In the equations that follow, source and destination +color components are referred to as +$(R sub s, G sub s, B sub s, A sub s )$ +and +$(R sub d, G sub d, B sub d, A sub d )$, +respectively. +The result color is referred to as +$(R sub r, G sub r, B sub r, A sub r )$. +The source and destination blend factors are denoted +$(s sub R, s sub G, s sub B, s sub A )$ and +$(d sub R, d sub G, d sub B, d sub A )$, respectively. +For these equations all color components are understood to have values +in the range [0,\ 1]. +.TP +_const(FUNC_ADD) +sets the blend equation so that the source and destination +data are added. +Each component of the source color is +multiplied by the corresponding source factor, then +each component of the destination color is multiplied +by the corresponding destination factor. +The result is the componentwise sum of the two products, clamped to the +range [0,\ 1]. +.P +.RS +.nf +.IP +$Rr ~=~ mark min (1, ~R sub s~s sub R ~+~ R sub d~d sub R )$ +$Gr ~=~ lineup min (1, ~G sub s~s sub G ~+~ G sub d~d sub G )$ +$Br ~=~ lineup min (1, ~B sub s~s sub B ~+~ B sub d~d sub B )$ +$Ar ~=~ lineup min (1, ~A sub s~s sub A ~+~ A sub d~d sub A )$ +.fi +.RE +.TP +_const(FUNC_SUBTRACT) +Is like _const(FUNC_ADD) except the product of the destination factor and +the destination color is componentwise subtracted from the product of the +source factor and the source color. +The result is clamped to the range [0,\ 1]. +.RS +.nf +.IP +$Rr ~=~ mark max (0 , ~R sub s~s sub R ~-~ R sub d~d sub R )$ +$Gr ~=~ lineup max (0 , ~G sub s~s sub G ~-~ G sub d~d sub G )$ +$Br ~=~ lineup max (0 , ~B sub s~s sub B ~-~ B sub d~d sub B )$ +$Ar ~=~ lineup max (0 , ~A sub s~s sub A ~-~ A sub d~d sub A )$ +.fi +.RE +.TP +_const(FUNC_REVERSE_SUBTRACT) +Is like _const(FUNC_ADD) except the product of the source factor and the +source color is componentwise subtracted from the product of the destination +factor and the destination color. +The result is clamped to the range [0,\ 1]. +.RS +.nf +.IP +$Rr ~=~ mark max (0 , ~R sub d~d sub R ~-~ R sub s~s sub R )$ +$Gr ~=~ lineup max (0 , ~G sub d~d sub G ~-~ G sub s~s sub G )$ +$Br ~=~ lineup max (0 , ~B sub d~d sub B ~-~ B sub s~s sub B )$ +$Ar ~=~ lineup max (0 , ~A sub d~d sub A ~-~ A sub s~s sub A )$ +.fi +.RE +.P +The _const(MIN) and _const(MAX) equations are useful for applications +that analyze +.br +image data (image thresholding against a constant color, +for example). +The _const(FUNC_ADD) equation is useful +for antialiasing and transparency, among other things. +.P +Initially, the blend equation is set to _const(FUNC_ADD). +.P +.SH NOTES +_cmnd is part of the _arbstring(imaging) subset. _cmnd is present only +if _arbstring(imaging) is returned when _cmnd(GetString) is called with +_const(EXTENSIONS) as its argument. +.P +The _const(MIN), and _const(MAX) equations do not use +the source or destination factors, only the source and destination colors. +.P +.SH ERRORS +_const(INVALID_ENUM) is generated if _param1 is not one of +_const(FUNC_ADD), _const(FUNC_SUBTRACT), _const(FUNC_REVERSE_SUBTRACT), +_const(MAX), or _const(MIN). +.P +_const(INVALID_OPERATION) is generated if _cmnd is executed +between the execution of _cmnd(Begin) and the corresponding +execution of _cmnd(End). +.SH ASSOCIATED GETS +.TP +_cmnd(Get) with an argument of _const(BLEND_EQUATION) +.SH SEE ALSO +_cmnd(GetString), +_cmnd(BlendColor), +_cmnd(BlendFunc) |