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. Furthermore, 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.
glReadBufferspecifies 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. Furthermore, 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.