From f4092abdf94af6a99aff944d6264bc1284e8bdd4 Mon Sep 17 00:00:00 2001 From: Reinhard Tartler Date: Mon, 10 Oct 2011 17:43:39 +0200 Subject: Imported nx-X11-3.1.0-1.tar.gz Summary: Imported nx-X11-3.1.0-1.tar.gz Keywords: Imported nx-X11-3.1.0-1.tar.gz into Git repository --- .../main/doc/man/mangl/standard/lightmodel.gl | 172 +++++++++++++++++++++ 1 file changed, 172 insertions(+) create mode 100644 nx-X11/extras/ogl-sample/main/doc/man/mangl/standard/lightmodel.gl (limited to 'nx-X11/extras/ogl-sample/main/doc/man/mangl/standard/lightmodel.gl') diff --git a/nx-X11/extras/ogl-sample/main/doc/man/mangl/standard/lightmodel.gl b/nx-X11/extras/ogl-sample/main/doc/man/mangl/standard/lightmodel.gl new file mode 100644 index 000000000..15e6ef1de --- /dev/null +++ b/nx-X11/extras/ogl-sample/main/doc/man/mangl/standard/lightmodel.gl @@ -0,0 +1,172 @@ +_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(LightModel,set the lighting model parameters) +_names(LightModel,[fi]) +.EQ +delim $$ +.EN +.SH PARAMETERS +_phead(_param1) +Specifies a single-valued lighting model parameter. +_const(LIGHT_MODEL_LOCAL_VIEWER), +_const(LIGHT_MODEL_COLOR_CONTROL), and +_const(LIGHT_MODEL_TWO_SIDE) are accepted. +_phead(_param2) +Specifies the value that _param2 will be set to. +_names(LightModel,[fi]v) +.SH PARAMETERS +_phead(_param1) +Specifies a lighting model parameter. +_const(LIGHT_MODEL_AMBIENT), +_const(LIGHT_MODEL_COLOR_CONTROL), +_const(LIGHT_MODEL_LOCAL_VIEWER), and +_const(LIGHT_MODEL_TWO_SIDE) are accepted. +_phead(_param2) +Specifies a pointer to the value or values that _param2 will be set to. +.SH DESCRIPTION +_cmnd sets the lighting model parameter. +_param1 names a parameter and _param2 gives the new value. +There are three lighting model parameters: +.TP 10 +_const(LIGHT_MODEL_AMBIENT) +_param2 contains four integer or floating-point values that specify +the ambient RGBA intensity of the entire scene. +Integer values are mapped linearly such that the most positive representable +value maps to 1.0, +and the most negative representable value maps to \-1.0. +Floating-point values are mapped directly. +Neither integer nor floating-point values are clamped. +The initial ambient scene intensity is (0.2, 0.2, 0.2, 1.0). +.TP +_const(LIGHT_MODEL_COLOR_CONTROL) +_param2 must be either _const(SEPARATE_SPECULAR_COLOR) or +_const(SINGLE_COLOR). +_const(SINGLE_COLOR) specifies that a single color is generated from the +lighting computation for a vertex. _const(SEPARATE_SPECULAR_COLOR) +specifies that the specular color computation of lighting be stored +separately from the remainder of the lighting computation. The specular +color is summed into the generated fragment's color after the application +of texture mapping (if enabled). The initial value is _const(SINGLE_COLOR). +.TP +_const(LIGHT_MODEL_LOCAL_VIEWER) +_param2 is a single integer or floating-point value that specifies +how specular reflection angles are computed. +If _param2 is 0 (or 0.0), specular reflection angles take the +view direction to be parallel to and in the direction of the -\f2z\fP axis, +regardless of the location of the vertex in eye coordinates. +Otherwise, specular reflections are computed from the origin +of the eye coordinate system. +The initial value is 0. +.TP +_const(LIGHT_MODEL_TWO_SIDE) +_param2 is a single integer or floating-point value that specifies +whether one- or two-sided lighting calculations are done for polygons. +It has no effect on the lighting calculations for points, +lines, +or bitmaps. +If _param2 is 0 (or 0.0), one-sided lighting is specified, +and only the \f2front\fP material parameters are used in the +lighting equation. +Otherwise, two-sided lighting is specified. +In this case, vertices of back-facing polygons are lighted using the +\f2back\fP material parameters, +and have their normals reversed before the lighting equation is evaluated. +Vertices of front-facing polygons are always lighted using the +\f2front\fP material parameters, +with no change to their normals. The initial value is 0. +.P +In RGBA mode, the lighted color of a vertex is the sum of +the material emission intensity, +the product of the material ambient reflectance and the lighting model full-scene +ambient intensity, +and the contribution of each enabled light source. +Each light source contributes the sum of three terms: +ambient, diffuse, and specular. +The ambient light source contribution is the product of the material ambient +reflectance and the light's ambient intensity. +The diffuse light source contribution is the product of the material diffuse +reflectance, +the light's diffuse intensity, +and the dot product of the vertex's normal with the normalized vector from +the vertex to the light source. +The specular light source contribution is the product of the material specular +reflectance, +the light's specular intensity, +and the dot product of the normalized vertex-to-eye and vertex-to-light +vectors, +raised to the power of the shininess of the material. +All three light source contributions are attenuated equally based on +the distance from the vertex to the light source and on light source +direction, spread exponent, and spread cutoff angle. +All dot products are replaced with 0 if they evaluate to a negative value. +.P +The alpha component of the resulting lighted color is set to the alpha value +of the material diffuse reflectance. +.P +In color index mode, +the value of the lighted index of a vertex ranges from the ambient +to the specular values passed to _cmnd(Material) using _const(COLOR_INDEXES). +Diffuse and specular coefficients, +computed with a (.30, .59, .11) weighting of the lights' colors, +the shininess of the material, +and the same reflection and attenuation equations as in the RGBA case, +determine how much above ambient the resulting index is. +.SH NOTES +_const(LIGHT_MODEL_COLOR_CONTROL) is available only if the GL version is +1.2 or greater. +.SH ERRORS +_const(INVALID_ENUM) is generated if _param1 is not an accepted value. +.P +_const(INVALID_ENUM) is generated if _param1 is +_const(LIGHT_MODEL_COLOR_CONTROL) and _param2 is not one of +_const(SINGLE_COLOR) or _const(SEPARATE_SPECULAR_COLOR). +.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(Get) with argument _const(LIGHT_MODEL_AMBIENT) +.br +_cmnd(Get) with argument _const(LIGHT_MODEL_COLOR_CONTROL) +.br +_cmnd(Get) with argument _const(LIGHT_MODEL_LOCAL_VIEWER) +.br +_cmnd(Get) with argument _const(LIGHT_MODEL_TWO_SIDE) +.br +_cmnd(IsEnabled) with argument _const(LIGHTING) +.SH SEE ALSO +_cmnd(Light), +_cmnd(Material) -- cgit v1.2.3