NAME¶
glReadBuffer - select a color buffer source for pixels
C SPECIFICATION¶
void
glReadBuffer(GLenum mode);
PARAMETERS¶
mode
Specifies a color buffer. Accepted values are
GL_FRONT_LEFT, GL_FRONT_RIGHT, GL_BACK_LEFT,
GL_BACK_RIGHT, GL_FRONT, GL_BACK, GL_LEFT,
GL_RIGHT, and the constants
GL_COLOR_ATTACHMENTi.
DESCRIPTION¶
glReadBuffer specifies a color buffer as the source for subsequent
glReadPixels(),
glCopyTexImage1D(),
glCopyTexImage2D(),
glCopyTexSubImage1D(),
glCopyTexSubImage2D(), and
glCopyTexSubImage3D() commands.
mode accepts one of twelve or
more predefined values. In a fully configured system,
GL_FRONT,
GL_LEFT, and
GL_FRONT_LEFT all name the front left buffer,
GL_FRONT_RIGHT and
GL_RIGHT name the front right buffer, and
GL_BACK_LEFT and
GL_BACK name the back left buffer. Further
more, the constants
GL_COLOR_ATTACHMENTi may be used to
indicate the
ith color attachment where
i ranges from zero to
the value of
GL_MAX_COLOR_ATTACHMENTS minus one.
Nonstereo double-buffered configurations have only a front left and a back left
buffer. Single-buffered configurations have a front left and a front right
buffer if stereo, and only a front left buffer if nonstereo. It is an error to
specify a nonexistent buffer to
glReadBuffer.
mode is initially
GL_FRONT in single-buffered configurations and
GL_BACK in double-buffered configurations.
ERRORS¶
GL_INVALID_ENUM is generated if
mode is not one of the twelve (or
more) accepted values.
GL_INVALID_OPERATION is generated if
mode specifies a buffer that
does not exist.
ASSOCIATED GETS¶
glGet() with argument
GL_READ_BUFFER
SEE ALSO¶
glCopyTexImage1D(),
glCopyTexImage2D(),
glCopyTexSubImage1D(),
glCopyTexSubImage2D(),
glCopyTexSubImage3D(),
glDrawBuffer(),
glReadPixels()
COPYRIGHT¶
Copyright © 1991-2006 Silicon Graphics, Inc. Copyright © 2011 Khronos
Group. This document is licensed under the SGI Free Software B License. For
details, see
http://oss.sgi.com/projects/FreeB/.
