a furia di smanettamente ho caricato il context GLES in emulazione....

peccato che cmq non funziona in GLES openbor
il log è evidente e il context GLES c'era...

direi che a fronte di tutte queste prove la versione migliore è quindi quella dove compila il motore in SDL e usa la mali senza GL per i filtri... non è quello che volevo ma cmq funziona molto bene!
p.s. solo per vedere ecco il log
LIBGL: Initialising gl4es
LIBGL: v1.0.9 built on Sep 10 2018 19:42:08
LIBGL: Using GLES 2.0 backend
LIBGL: Disable usage of Depth Textures
LIBGL:loaded: libvcos.so
LIBGL:loaded: libGLESv2.so
LIBGL:loaded: libEGL.so
LIBGL: Using GLES 2.0 backend
LIBGL: Hardware Limited NPOT detected and used
LIBGL: Extension GL_EXT_blend_minmax detected and used
LIBGL: FBO are in core, and so used
LIBGL: PointSprite are in core, and so used
LIBGL: CubeMap are in core, and so used
LIBGL: BlendColor is in core, and so used
LIBGL: Blend Substract is in core, and so used
LIBGL: Blend Function and Equation Separation is in core, and so used
LIBGL: Texture Mirrored Repeat is in core, and so used
LIBGL: Extension GL_OES_packed_depth_stencil detected and used
LIBGL: Extension GL_OES_depth24 detected and used
LIBGL: Extension GL_EXT_texture_format_BGRA8888 detected and used
LIBGL: Max vertex attrib: 16
LIBGL: Extension GL_OES_standard_derivatives detected and used
LIBGL: Max texture size: 4096
LIBGL: Max Varying Vector: 12
LIBGL: Texture Units: 8(8), Max lights: 8, Max planes: 6
LIBGL: Hardware vendor is ARM
LIBGL: Recycling of FBO enabled
LIBGL: Targeting OpenGL 2.0
LIBGL: Forcing NPOT support by disabling MIPMAP support for NPOT textures
LIBGL: glXMakeCurrent FBO workaround enabled
LIBGL: Current folder is:/storage/roms/openbor/Avengers United Battle Force [2018] [build 4432].pak