EGL example for voxl2

[John Keller]

I saw that the voxl2 supports OpenGLES 3.1 and I would like to port over some of our OpenGL code to run on the voxl2. I am starting off by trying to get EGL to initialize with the following program but it is failing on the call to eglInitialize with error 0x3001 which is EGL_NOT_INITIALIZED. I am building with gcc egl-query.c -o egl-query -lEGL.

Is there any examples of using EGL/OpenGL or does anyone know how to get this working?

Thank you

#include <EGL/egl.h>
#include <EGL/eglext.h>
#include <stdio.h>

int main(void)
{
    EGLDisplay display;
    EGLint major, minor;

    display = eglGetDisplay(EGL_DEFAULT_DISPLAY);
    if (display == EGL_NO_DISPLAY) {
        printf("eglGetDisplay failed\n");
        return 1;
    }

    if (!eglInitialize(display, &major, &minor)) {
        EGLint err = eglGetError();
        printf("eglInitialize failed (0x%x)\n", err);
        return 1;
    }

    printf("EGL initialized successfully\n");
    printf("EGL version: %d.%d\n", major, minor);

    const char* vendor     = eglQueryString(display, EGL_VENDOR);
    const char* version    = eglQueryString(display, EGL_VERSION);
    const char* extensions = eglQueryString(display, EGL_EXTENSIONS);
    const char* clientapis = eglQueryString(display, EGL_CLIENT_APIS);

    printf("EGL_VENDOR:      %s\n", vendor ? vendor : "(null)");
    printf("EGL_VERSION:     %s\n", version ? version : "(null)");
    printf("EGL_CLIENT_APIS: %s\n", clientapis ? clientapis : "(null)");
    printf("EGL_EXTENSIONS:\n%s\n", extensions ? extensions : "(null)");

    eglTerminate(display);
    return 0;
}

[Andrew Jong]

Bump on this, if anyone might know how we can use OpenGL. Thanks!

[Alex Kushleyev]

@Andrew-Jong , we are able to reproduce the error that you are seeing. I believe that you may need to set up a virtual display in order to get this to work. You could try doing so using Weston compositor, which would normally run if the display was available. Please try it and let us know if you are able to get it to work (or not).

You would need to create a config file /etc/xdg/weston/weston.ini

and try running it manually like this :

weston --idle-time=0 --config=/etc/xdg/weston/weston.ini

a sample config file might look something like this:

# configuration file for Weston
[core]
idle-time=0
repaint-window=15

[output]
name=virtual-1
mode=on

We have not tested this yet, but hopefully it's a good start.

Alex