An Introduction to EGL - Praise for OpenGL ES 30 Programming Guide - page 51

Letting EGL Choose the Coniguration

To have EGL make the choice of matching EGLConfigs , use this function:

EGLBoolean eglChooseConfig (EGLDisplay display ,
const EGLint * attribList ,
EGLConfig * configs ,
EGLint maxReturnConfigs ,
EGLint * numConfigs )

display

specifies the EGL display connection

attribList

specifies the list of attributes to match by configs

configs

specifies the list of configurations

maxReturnConfigs

specifies the size of configurations

numConfigs

specifies the size of configurations returned

This function returns EGL_TRUE if the call succeeded. On failure,
EGL_FALSE is returned, and an EGL_BAD_ATTRIBUTE error is posted if
attribList contains an undefined EGL attribute or an attribute value
that is unrecognized or out of range.

You need to provide a list of the attributes, with associated preferred
values for all the attributes that are important for the correct operation of
your application. For example, if you need an EGLConfig that supports
a rendering surface having five bits red and blue, and six bits green (the
commonly used “RGB 565” format); a depth buffer; and OpenGL ES 3.0,
you might declare the array shown in Example 3-2.

For values that are not explicitly specified in the attribute list, EGL will use the
default values shown in Table 3-1. Additionally, when specifying a numeric
value for an attribute, EGL will guarantee the returned configuration has at
least that value at a minimum if there is a matching EGLConfig available.

Example 3-2 Specifying EGL Attributes

EGLint attribList[] =
{
EGL_RENDERABLE_TYPE, EGL_OPENGL_ES3_BIT_KHR,
EGL_RED_SIZE, 5,
EGL_GREEN_SIZE, 6,
EGL_BLUE_SIZE, 5,
EGL_DEPTH_SIZE, 1,
EGL_NONE
};