openGL-ES support

[umlaeute]

IanniX uses a bit of immediate mode openGL calls to do the actual drawing.
this works fine on most Desktop systems.

However, these days arm architectures are becoming more and more popular (think Raspberry Pi). On these devices you usually only have an implementation of the OpenGL-ES subset of openGL, which does not support any immediate mode rendering.

Because of that Qt5 (i don't know about Qt4) uses openGL-ES on arm architectures (and "normal" openGL on Desktop-oriented architectures).

All this basically means that IanniX fails to build on arm architectures (at least with Qt5).
E.g. cf the build-logs for Debian

[gjacquemin]

Yes, we really need help on this topic because we don't really know how theses "new" versions of OpenGL works… We just know that they'll be outdated, but we don't know how/where to start the migration to OpenGL-ES…

[mxmilkiib]

https://www.khronos.org/opengl/wiki/Legacy_OpenGL

projectM-visualizer/projectm#11 - ProjectM recently changed from intermediate mode to GLES. most of the handy information is on the related pull requests (70, 26, 66)

Edit: see also http://duriansoftware.com/joe/An-intro-to-modern-OpenGL.-Chapter-2.1:-Buffers-and-Textures.html

Edit2: https://spiegelmock.com/2018/07/29/projectm-opengl-and-shader-modernization

[gjacquemin]

Thanks for the link, it's now urgent for us to switch to OpenGL3!