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diff --git a/nx-X11/extras/ogl-sample/main/doc/man/mangl/standard/texparameter.gl b/nx-X11/extras/ogl-sample/main/doc/man/mangl/standard/texparameter.gl new file mode 100644 index 000000000..47863ba2a --- /dev/null +++ b/nx-X11/extras/ogl-sample/main/doc/man/mangl/standard/texparameter.gl @@ -0,0 +1,335 @@ +_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(TexParameter, set texture parameters) +_names(TexParameter,[fi]) +.EQ +delim $$ +.EN +.SH PARAMETERS +_phead(_param1) +Specifies the target texture, +which must be either _const(TEXTURE_1D), _const(TEXTURE_2D), or +_const(TEXTURE_3D). +_phead(_param2) +Specifies the symbolic name of a single-valued texture parameter. +_param2 can be one of the following: +_const(TEXTURE_MIN_FILTER), +_const(TEXTURE_MAG_FILTER), +_const(TEXTURE_MIN_LOD), +_const(TEXTURE_MAX_LOD), +_const(TEXTURE_BASE_LEVEL), +_const(TEXTURE_MAX_LEVEL), +_const(TEXTURE_WRAP_S), +_const(TEXTURE_WRAP_T), +_const(TEXTURE_WRAP_R), or +_const(TEXTURE_PRIORITY). +_phead(_param3) +Specifies the value of _param2. +_names(TexParameter,[fi]v) +.SH PARAMETERS +_phead(_param1) +Specifies the target texture, +which must be either _const(TEXTURE_1D), _const(TEXTURE_2D) or +_const(TEXTURE_3D). +_phead(_param2) +Specifies the symbolic name of a texture parameter. +_param2 can be one of the following: +_const(TEXTURE_MIN_FILTER), +_const(TEXTURE_MAG_FILTER), +_const(TEXTURE_MIN_LOD), +_const(TEXTURE_MAX_LOD), +_const(TEXTURE_BASE_LEVEL), +_const(TEXTURE_MAX_LEVEL), +_const(TEXTURE_WRAP_S), +_const(TEXTURE_WRAP_T), +_const(TEXTURE_WRAP_R), +_const(TEXTURE_BORDER_COLOR), or +_const(TEXTURE_PRIORITY). +_phead(_param3) +Specifies a pointer to an array where the value or values of _param2 +are stored. +.SH DESCRIPTION +Texture mapping is a technique that applies an image onto an object's surface +as if the image were a decal or cellophane shrink-wrap. +The image is created in texture space, +with an ($s$, $t$) coordinate system. +A texture is a one- or two-dimensional image and a set of parameters +that determine how samples are derived from the image. +.P +_cmnd assigns the value or values in _param3 to the texture parameter +specified as _param2. +_param1 defines the target texture, +either _const(TEXTURE_1D), _const(TEXTURE_2D), or _const(TEXTURE_3D). +The following symbols are accepted in _param2: +.TP 10 +_const(TEXTURE_MIN_FILTER) +The texture minifying function is used whenever the pixel being textured +maps to an area greater than one texture element. +There are six defined minifying functions. +Two of them use the nearest one or nearest four texture elements +to compute the texture value. +The other four use mipmaps. +.IP +A mipmap is an ordered set of arrays representing the same image +at progressively lower resolutions. +If the texture has dimensions $2 sup n ~times~ 2 sup m$, there are +$ bold max ( n, m ) + 1 $ mipmaps. +The first mipmap is the original texture, +with dimensions $2 sup n ~times~ 2 sup m$. +Each subsequent mipmap has dimensions $2 sup { k - 1 } ~times~ 2 sup { l - 1 }$, +where $2 sup k ~times~ 2 sup l$ are the dimensions of the previous mipmap, +until either $k ~=~ 0$ or $l~=~0$. +At that point, +subsequent mipmaps have dimension $ 1 ~times~ 2 sup { l - 1 } $ +or $ 2 sup { k - 1} ~times~ 1 $ until the final mipmap, +which has dimension $1 ~times~ 1$. +To define the mipmaps, call _cmnd(TexImage1D), _cmnd(TexImage2D), +_cmnd(TexImage3D), +_cmnd(CopyTexImage1D), or _cmnd(CopyTexImage2D) +with the \f2level\fP argument indicating the order of the mipmaps. +Level 0 is the original texture; +level $ bold max ( n, m ) $ is the final $1 ~times~ 1$ mipmap. +.IP +_param3 supplies a function for minifying the texture as one of the following: +.RS 10 +.TP 10 +_const(NEAREST) +Returns the value of the texture element that is nearest +(in Manhattan distance) +to the center of the pixel being textured. +.TP +_const(LINEAR) +Returns the weighted average of the four texture elements +that are closest to the center of the pixel being textured. +These can include border texture elements, +depending on the values of _const(TEXTURE_WRAP_S) and _const(TEXTURE_WRAP_T), +and on the exact mapping. +.TP +_const(NEAREST_MIPMAP_NEAREST) +Chooses the mipmap that most closely matches the size of the pixel +being textured and uses the _const(NEAREST) criterion +(the texture element nearest to the center of the pixel) +to produce a texture value. +.TP +_const(LINEAR_MIPMAP_NEAREST) +Chooses the mipmap that most closely matches the size of the pixel +being textured and uses the _const(LINEAR) criterion +(a weighted average of the four texture elements that are closest +to the center of the pixel) +to produce a texture value. +.TP +_const(NEAREST_MIPMAP_LINEAR) +Chooses the two mipmaps that most closely match the size of the pixel +being textured and uses the _const(NEAREST) criterion +(the texture element nearest to the center of the pixel) +to produce a texture value from each mipmap. +The final texture value is a weighted average of those two values. +.TP +_const(LINEAR_MIPMAP_LINEAR) +Chooses the two mipmaps that most closely match the size of the pixel +being textured and uses the _const(LINEAR) criterion +(a weighted average of the four texture elements that are closest +to the center of the pixel) +to produce a texture value from each mipmap. +The final texture value is a weighted average of those two values. +.RE +.IP +As more texture elements are sampled in the minification process, +fewer aliasing artifacts will be apparent. +While the _const(NEAREST) and _const(LINEAR) minification functions can be +faster than the other four, +they sample only one or four texture elements to determine the texture value +of the pixel being rendered and can produce moire patterns +or ragged transitions. +The initial value of _const(TEXTURE_MIN_FILTER) is +_const(NEAREST_MIPMAP_LINEAR). +.TP 10 +_const(TEXTURE_MAG_FILTER) +The texture magnification function is used when the pixel being textured +maps to an area less than or equal to one texture element. +It sets the texture magnification function to either _const(NEAREST) +or _const(LINEAR) (see below). _const(NEAREST) is generally faster +than _const(LINEAR), +but it can produce textured images with sharper edges +because the transition between texture elements is not as smooth. +The initial value of _const(TEXTURE_MAG_FILTER) is _const(LINEAR). +.RS 10 +.TP 10 +_const(NEAREST) +Returns the value of the texture element that is nearest +(in Manhattan distance) +to the center of the pixel being textured. +.TP +_const(LINEAR) +Returns the weighted average of the four texture elements +that are closest to the center of the pixel being textured. +These can include border texture elements, +depending on the values of _const(TEXTURE_WRAP_S) and _const(TEXTURE_WRAP_T), +and on the exact mapping. +.P +.RE +.P +.TP 10 +_const(TEXTURE_MIN_LOD) +Sets the minimum level-of-detail parameter. This floating-point value +limits the selection of highest resolution mipmap (lowest mipmap +level). The initial value is -1000. +.P +.TP 10 +_const(TEXTURE_MAX_LOD) +Sets the maximum level-of-detail parameter. This floating-point value +limits the selection of the lowest resolution mipmap (highest mipmap +level). The initial value is 1000. +.P +.TP 10 +_const(TEXTURE_BASE_LEVEL) +Specifies the index of the lowest defined mipmap level. This is an +integer value. The initial value is 0. +.P +.TP 10 +_const(TEXTURE_MAX_LEVEL) +Sets the index of the highest defined mipmap level. This is an integer +value. The initial value is 1000. +.P +.TP 10 +_const(TEXTURE_WRAP_S) +Sets the wrap parameter for texture coordinate $s$ to either +_const(CLAMP), _const(CLAMP_TO_EDGE), or _const(REPEAT). +_const(CLAMP) causes $s$ coordinates to be clamped to the range [0,1] +and is useful for preventing wrapping artifacts when mapping +a single image onto an object. +_const(CLAMP_TO_EDGE) causes $s$ coordinates to be clamped to the range +$left [ {1 over 2N}, 1 - {1 over 2N} right ]$, where $N$ is the size +of the texture in the direction of clamping. +_const(REPEAT) causes the integer part of the $s$ coordinate to be ignored; +the GL uses only the fractional part, +thereby creating a repeating pattern. +Border texture elements are accessed only if wrapping is set to _const(CLAMP). +Initially, _const(TEXTURE_WRAP_S) is set to _const(REPEAT). +.P +.TP 10 +_const(TEXTURE_WRAP_T) +Sets the wrap parameter for texture coordinate $t$ to either +_const(CLAMP), _const(CLAMP_TO_EDGE), or _const(REPEAT). +See the discussion under _const(TEXTURE_WRAP_S). +Initially, _const(TEXTURE_WRAP_T) is set to _const(REPEAT). +.TP 10 +_const(TEXTURE_WRAP_R) +Sets the wrap parameter for texture coordinate $r$ to either +_const(CLAMP), _const(CLAMP_TO_EDGE), or _const(REPEAT). +See the discussion under _const(TEXTURE_WRAP_S). +Initially, _const(TEXTURE_WRAP_R) is set to _const(REPEAT). +.TP +_const(TEXTURE_BORDER_COLOR) +Sets a border color. +_param3 contains four values that comprise the RGBA color +of the texture border. +Integer color components are interpreted linearly such that the most +positive integer maps to 1.0, +and the most negative integer maps to -1.0. +The values are clamped to the range [0,1] when they are specified. +Initially, the border color is (0, 0, 0, 0). +.TP 10 +_const(TEXTURE_PRIORITY) +Specifies the texture residence priority of the currently bound texture. +Permissible values are in the range [0,\ 1]. +See _cmnd(PrioritizeTextures) and _cmnd(BindTexture) for more information. +.SH NOTES +_const(TEXTURE_3D), _const(TEXTURE_MIN_LOD), _const(TEXTURE_MAX_LOD), +_const(TEXTURE_BASE_LEVEL), and _const(TEXTURE_MAX_LEVEL) are only +available if the GL version is 1.2 or greater. +.P +Suppose that a program has enabled texturing +(by calling _cmnd(Enable) +with argument _const(TEXTURE_1D), _const(TEXTURE_2D), or _const(TEXTURE_3D)) +and has set _const(TEXTURE_MIN_FILTER) to one of the functions +that requires a mipmap. +If either the dimensions of the texture images currently defined +(with previous calls to _cmnd(TexImage1D), _cmnd(TexImage2D), +_cmnd(TexImage3D), +_cmnd(CopyTexImage1D), or _cmnd(CopyTexImage2D)) +do not follow the proper sequence for mipmaps +(described above), +or there are fewer texture images defined than are needed, +or the set of texture images have differing numbers of texture components, +then it is as if texture mapping were disabled. +.P +Linear filtering accesses the four nearest texture elements only in 2D +textures. +In 1D textures, linear filtering accesses the two nearest texture +elements. +.P +When the _arbstring(multitexture) extension is supported, _cmnd +specifies the texture parameters for the active texture unit, specified +by calling _cmnd(ActiveTextureARB). +.SH ERRORS +_const(INVALID_ENUM) is generated if _param1 or _param2 is not +one of the accepted defined values. +.P +_const(INVALID_ENUM) is generated if _param3 should have a defined +constant value (based on the value of _param2) and does not. +.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(GetTexParameter) +.br +_cmnd(GetTexLevelParameter) +.SH SEE ALSO +_cmnd(ActiveTextureARB), +_cmnd(BindTexture), +_cmnd(CopyPixels), +_cmnd(CopyTexImage1D), +_cmnd(CopyTexImage2D), +_cmnd(CopyTexSubImage1D), +_cmnd(CopyTexSubImage2D), +_cmnd(CopyTexSubImage3D), +_cmnd(DrawPixels), +_cmnd(PixelStore), +_cmnd(PixelTransfer), +_cmnd(PrioritizeTextures), +_cmnd(TexEnv), +_cmnd(TexGen), +_cmnd(TexImage1D), +_cmnd(TexImage2D), +_cmnd(TexImage3D), +_cmnd(TexSubImage1D), +_cmnd(TexSubImage2D), +_cmnd(TexSubImage3D) + + |