GLREADBUFFER(3G) |
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GLREADBUFFER(3G) |
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 GL_AUXi, where i is between 0 and GL_AUX_BUFFERS -1.
DESCRIPTION
glReadBuffer specifies a color buffer as the source for subsequent
glReadPixels,
glCopyTexImage1D,
glCopyTexImage2D,
glCopyTexSubImage1D,
glCopyTexSubImage2D,
glCopyTexSubImage3D, and
glCopyPixels commands.
mode accepts one of twelve or more predefined values. (
GL_AUX0 through
GL_AUX3 are always defined.) 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.
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.
GL_INVALID_OPERATION is generated if glReadBuffer is executed between the execution of glBegin and the corresponding execution of glEnd.
ASSOCIATED GETS
glGet with argument GL_READ_BUFFER
SEE ALSO
glCopyPixels(3G), glCopyTexImage1D(3G), glCopyTexImage2D(3G), glCopyTexSubImage1D(3G), glCopyTexSubImage2D(3G), glCopyTexSubImage3D(3G), glDrawBuffer(3G), glReadPixels(3G)