Allow OpenGL ES renderer by configure

[warpme]

OpenGL ES configurability works in following way: there is new configure switch: —enable-opengles

Overall logic: OpenGL ES is disabled by default (if no switch passed to configure or —disable-opengles passed to configure)

If —enable-opengles is passed to configure, configure will detect all required and set conditional USING_OPENGLES if all is OK. If anything is missing in system - configure will exit with error.

[warpme]

Patch for configure to add gles configurability

[warpme]

patch to get working gles

[mspieth]

Looks good.

It would be nice to auto set opengles in configure if target is android.

[Peter Bennett]

With these patches both applied, configure fails on android. Normally android build has these:

	--enable-opengl-video \
	--enable-opengl \

I tried two ways, one by changing the enable-opengl to enable-opengles and the other way by having both enable-opengl and enable-opengles. Both ways fail with ERROR: OpenGL not found! It also fails with the same error if I leave just enable-opengl and enable-opengl-video.

[warpme]

v2 for setups where OS has only GLES

[warpme]

v2 with removed some android conditionals as now GLES conditional does things

[warpme]

Mark,

thx for looking on this.

This was somehow expected as my initial patches are for case where OS has OpenGL Desktop _and_ OpenGL ES.

I believe Android is case where OS has only OpenGL ES.

V2 should address such case - assuming I'm guessing right placement of libs/*h files in Android.

pls test.

[Peter Bennett]

With the new patches

Android build with no change (still using --enable-opengl) - the config is successful and reports opengl enabled and opengles disabled. Build then fails this way

In file included from mythrender_opengl.cpp:24:0:
mythrender_opengl1.h:7:19: fatal error: GL/gl.h: No such file or directory
 #include <GL/gl.h>
                   ^
compilation terminated.

I changed --enable-opengl to --enable-opengles and then config gives error -

ERROR: OpenGL ES not found!

[warpme]

Peter, One of my goals when working on this was proper detection of opengles.

Previously, configure wrongly allows to set opengles on system where opengles isn't properly installed from configure point of view (configure can't see required *.h and *.so files) or there is lack of pkg-config .pc files related to opengles.

Now configure is addressing this, and if system hasn't properly installed opengles - configure output reflects this.

Issue You see is because: GLES2/gl2.h or EGL/egl.h or libglesv2.so or libegl.so are unseen by configure or system is lacking pkg-config's glesv2.pc or egl.pc files.

I think proper approach on android build system should be addressing root caue: make GLES2/gl2.h and EGL/egl.h and libglesv2.so and libegl.so seen by configure or provide proper glesv2.pc an egl.pc files.

Alternative is breaking configure to wrongly report opengles is OK on system where is might be not OK....

[Mark Kendall]

Piotr - I'm assuming this is now irrelevant:)