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diff --git a/nx-X11/extras/ogl-sample/main/doc/man/mangl/standard/texgen.gl b/nx-X11/extras/ogl-sample/main/doc/man/mangl/standard/texgen.gl new file mode 100644 index 000000000..66e29f1be --- /dev/null +++ b/nx-X11/extras/ogl-sample/main/doc/man/mangl/standard/texgen.gl @@ -0,0 +1,243 @@ +_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,eqn)_C_ +_C_ eqn is automatically replaced with neqn for nroff +_header(TexGen,control the generation of texture coordinates) +_names(TexGen,[ifd]) +.EQ +delim $$ +.EN +.SH PARAMETERS +_phead(_param1) +Specifies a texture coordinate. +Must be one of _const(S), _const(T), _const(R), or _const(Q). +_phead(_param2) +Specifies the symbolic name of the texture-coordinate generation function. +Must be _const(TEXTURE_GEN_MODE). +_phead(_param3) +Specifies a single-valued texture generation parameter, +one of _const(OBJECT_LINEAR), _const(EYE_LINEAR), or _const(SPHERE_MAP). +_names(TexGen,[ifd]v) +.SH PARAMETERS +_phead(_param1) +Specifies a texture coordinate. +Must be one of _const(S), _const(T), _const(R), or _const(Q). +_phead(_param2) +Specifies the symbolic name of the texture-coordinate generation function +or function parameters. +Must be +_const(TEXTURE_GEN_MODE), +_const(OBJECT_PLANE), or +_const(EYE_PLANE). +_phead(_param3) +Specifies a pointer to an array of texture generation parameters. +If _param2 is _const(TEXTURE_GEN_MODE), +then the array must contain a single symbolic constant, +one of +_const(OBJECT_LINEAR), +_const(EYE_LINEAR), or +_const(SPHERE_MAP). +Otherwise, +_param3 holds the coefficients for the texture-coordinate generation function +specified by _param2. +.SH DESCRIPTION +_cmnd selects a texture-coordinate generation function +or supplies coefficients for one of the functions. +_param1 names one of the (\f2s\fP, \f2t\fP, \f2r\fP, \f2q\fP) texture +coordinates; it must be one of the symbols +_const(S), +_const(T), +_const(R), or +_const(Q). +_param2 must be one of three symbolic constants: +_const(TEXTURE_GEN_MODE), +_const(OBJECT_PLANE), or +_const(EYE_PLANE). +If _param2 is _const(TEXTURE_GEN_MODE), +then _param3 chooses a mode, +one of +_const(OBJECT_LINEAR), +_const(EYE_LINEAR), or +_const(SPHERE_MAP). +If _param2 is either _const(OBJECT_PLANE) or _const(EYE_PLANE), +_param3 contains coefficients for the corresponding +texture generation function. +.P +If the texture generation function is _const(OBJECT_LINEAR), +the function +.P +.ce +$g ~=~ p sub 1^x sub o ~+~ p sub 2^y sub o ~+~ p sub 3^z sub o ~+~ p sub 4^w sub o$ +.P +.br +is used, where $g$ is the value computed for the coordinate named in _param1, +$p sub 1$, +$p sub 2$, +$p sub 3$, +and +$p sub 4$ are the four values supplied in _param3, and +$x sub o$, +$y sub o$, +$z sub o$, and +$w sub o$ are the object coordinates of the vertex. +This function can be used, for example, to texture-map terrain using sea level +as a reference plane +(defined by $p sub 1$, $p sub 2$, $p sub 3$, and $p sub 4$). +The altitude of a terrain vertex is computed by the _const(OBJECT_LINEAR) +coordinate generation function as its distance from sea level; +that altitude can then be used to index the texture image to map white snow +onto peaks and green grass onto foothills. +.P +If the texture generation function is _const(EYE_LINEAR), the function +.P +.ce +$g ~=~ p sub 1 sup prime ^x sub e ~+~ p sub 2 sup prime ^y sub e ~+~ p sub 3 sup prime ^z sub e ~+~ p sub 4 sup prime ^w sub e$ +.P +.br +is used, where +.P +.ce +$( p sub 1 sup prime +~~p sub 2 sup prime~~p sub 3 sup prime~~ +{ p sub 4 sup prime}) ~=~ ( p sub 1~~ p sub 2~~ p sub 3~~ p sub 4 ) ~M sup -1$ +.P +.br +and +$x sub e$, +$y sub e$, +$z sub e$, and +$w sub e$ are the eye coordinates of the vertex, +$p sub 1$, +$p sub 2$, +$p sub 3$, +and +$p sub 4$ are the values supplied in _param3, and +$M$ is the modelview matrix when _cmnd is invoked. +If $M$ is poorly conditioned or singular, +texture coordinates generated by the resulting function may be inaccurate +or undefined. +.P +Note that the values in _param3 define a reference plane in eye coordinates. +The modelview matrix that is applied to them may not be the same one +in effect when the polygon vertices are transformed. +This function establishes a field of texture coordinates +that can produce dynamic contour lines on moving objects. +.P +If _param2 is _const(SPHERE_MAP) and _param1 is either +_const(S) or +_const(T), +$s$ and $t$ texture coordinates are generated as follows. +Let \f2u\fP be the unit vector pointing from the origin to the polygon vertex +(in eye coordinates). +Let \f2n\fP sup prime be the current normal, +after transformation to eye coordinates. +Let +.P +.ce +$f ~=~ ( f sub x~~f sub y~~f sub z ) sup T$ +be the reflection vector such that +.P +.ce +$f ~=~ u ~-~ 2 n sup prime n sup prime sup T u$ +.br +.P +Finally, let $ m ~=~ 2 sqrt { f sub x sup {~2} ~+~ f sub y sup {~2} ~+~ (f sub z ~+~ 1 ) sup 2}$. +Then the values assigned to the $s$ and $t$ texture coordinates are +.P +.ce 1 +$s ~=~ f sub x over m ~+~ 1 over 2$ +.sp +.ce 1 +$t ~=~ f sub y over m ~+~ 1 over 2$ +.P +To enable or disable a texture-coordinate generation function, call +_cmnd(Enable) or _cmnd(Disable) +with one of the symbolic texture-coordinate names +(_const(TEXTURE_GEN_S), +_const(TEXTURE_GEN_T), +_const(TEXTURE_GEN_R), or +_const(TEXTURE_GEN_Q)) as the argument. +When enabled, +the specified texture coordinate is computed +according to the generating function associated with that coordinate. +When disabled, +subsequent vertices take the specified texture coordinate +from the current set of texture coordinates. Initially, all texture +generation functions are set to _const(EYE_LINEAR) and are disabled. +Both $s$ plane equations are (1, 0, 0, 0), +both $t$ plane equations are (0, 1, 0, 0), +and all $r$ and $q$ plane equations are (0, 0, 0, 0). +.P +When the _arbstring(multitexture) extension is supported, _cmnd set the +texture generation parameters for the currently active texture unit, +selected with _cmnd(ActiveTextureARB). +.SH ERRORS +_const(INVALID_ENUM) is generated when _param1 or _param2 is not an +accepted defined value, +or when _param2 is _const(TEXTURE_GEN_MODE) and _param3 is not an +accepted defined value. +.P +_const(INVALID_ENUM) is generated when _param2 is _const(TEXTURE_GEN_MODE), +_param3 is _const(SPHERE_MAP), +and _param1 is either _const(R) or _const(Q). +.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 +_cmnd(GetTexGen) +.br +_cmnd(IsEnabled) with argument _const(TEXTURE_GEN_S) +.br +_cmnd(IsEnabled) with argument _const(TEXTURE_GEN_T) +.br +_cmnd(IsEnabled) with argument _const(TEXTURE_GEN_R) +.br +_cmnd(IsEnabled) with argument _const(TEXTURE_GEN_Q) +.SH SEE ALSO +_cmnd(ActiveTextureARB), +_cmnd(CopyPixels), +_cmnd(CopyTexImage2D), +_cmnd(CopyTexSubImage1D), +_cmnd(CopyTexSubImage2D), +_cmnd(CopyTexSubImage3D), +_cmnd(TexEnv), +_cmnd(TexImage1D), +_cmnd(TexImage2D), +_cmnd(TexImage3D), +_cmnd(TexParameter), +_cmnd(TexSubImage1D), +_cmnd(TexSubImage2D), +_cmnd(TexSubImage3D) |