Introduction to OpenGL ES 3.0 - Praise for OpenGL ES 30 Programming Guide - page 23

GLenum glGetError (void)

Returns the current error code and resets the current error code to
GL_NO_ERROR . If GL_NO_ERROR is returned, there has been no detectable
error since the last call to glGetError .

Table 1-3 lists the basic error codes and their description. Other error codes
besides the basic ones listed in this table are described in the chapters that
cover OpenGL ES commands that generate these specific errors.

Table 1-3 OpenGL ES Basic Error Codes

Error Code Description

GL_NO_ERROR No error has been generated since the last

call to glGetError .

GL_INVALID_ENUM

A GLenum argument is out of range. The
command that generated the error is ignored.

GL_INVALID_VALUE

A numeric argument is out of range. The
command that generated the error is ignored.

GL_INVALID_OPERATION

The specific command cannot be performed
in the current OpenGL ES state. The
command that generated the error is ignored.

GL_OUT_OF_MEMORY

There is insufficient memory to execute
this command. The state of the OpenGL ES
pipeline is considered to be undefined if this
error is encountered except for the current
error code.

Basic State Management

Figure 1-1 showed the various pipeline stages in OpenGL ES 3.0. Each
pipeline stage has a state that can be enabled or disabled and appropriate
state values that are maintained per context. Examples of states are
blending enable, blend factors, cull enable, and cull face. The state is
initialized with default values when an OpenGL ES context ( EGLContext )
is initialized. The state enables can be set using the glEnable and
glDisable commands.