GLCLIPPLANE



GLCLIPPLANE

NAME
C SPECIFICATION
PARAMETERS
DESCRIPTION
NOTES
ERRORS
ASSOCIATED GETS
SEE ALSO

NAME

glClipPlane − specify a plane against which all geometry is clipped

C SPECIFICATION

void glClipPlane( GLenum plane,

const GLdouble *equation )

PARAMETERS

plane

Specifies which clipping plane is being positioned. Symbolic names of the form GL_CLIP_PLANEi, where i is an integer between 0 and GL_MAX_CLIP_PLANES$^-^1$, are accepted.

equation

Specifies the address of an array of four double-precision floating-point values. These values are interpreted as a plane equation.

DESCRIPTION

Geometry is always clipped against the boundaries of a six-plane frustum in x, y, and z. glClipPlane allows the specification of additional planes, not necessarily perpendicular to the x, y, or z axis, against which all geometry is clipped. To determine the maximum number of additional clipping planes, call glGetIntegerv with argument GL_MAX_CLIP_PLANES. All implementations support at least six such clipping planes. Because the resulting clipping region is the intersection of the defined half-spaces, it is always convex.

glClipPlane specifies a half-space using a four-component plane equation. When glClipPlane is called, equation is transformed by the inverse of the modelview matrix and stored in the resulting eye coordinates. Subsequent changes to the modelview matrix have no effect on the stored plane-equation components. If the dot product of the eye coordinates of a vertex with the stored plane equation components is positive or zero, the vertex is in with respect to that clipping plane. Otherwise, it is out.

To enable and disable clipping planes, call glEnable and glDisable with the argument GL_CLIP_PLANEi, where i is the plane number.

All clipping planes are initially defined as (0, 0, 0, 0) in eye coordinates and are disabled.

NOTES

It is always the case that GL_CLIP_PLANE$i$ = GL_CLIP_PLANE0$~+~i$.

ERRORS

GL_INVALID_ENUM is generated if plane is not an accepted value.

GL_INVALID_OPERATION is generated if glClipPlane is executed between the execution of glBegin and the corresponding execution of glEnd.

ASSOCIATED GETS

glGetClipPlane
glIsEnabled
with argument GL_CLIP_PLANEi

SEE ALSO

glEnable(3G)






Opportunity


Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.

Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.





Free Software


Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.


Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.





Free Books


The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.


Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.





Education


Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.


Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.