no gles support for gtk host

[dougcooper]

The software appears to have the hooks in place for gles support, however:

• the gtk interface pulls in the GL libraries not the GLES libraries
• we modified the uno lib to pull in the expected libs but still received an error: glDrawBuffer() not found which means something in the lower layers is trying to make a call that is implementation dependent.

The opengl docs do confirm that this is an unsupported call for GLES.

[jeromelaban]

Thanks. The code you're mentioning does import the OpenGL ES portions (the using at the top indicates that), though we're still having issues with the autodetection of the appropriate OpenGL flavor to use.

Try using this to explicitly use the ES flavor:

var host = new GtkHost(() => new App());
host.RenderSurfaceType = RenderSurfaceType.OpenGLES;

[dougcooper]

im not sure what using statement your referring to. the OpenGLESRenderSurface constructor explicitly uses GLCoreLibraryNameContainer instead of OpenGLESLibraryNameContainer which brings in the non-gles lib versions. After making that change we also had to ensure GDK_GL=gles was set and symlink to a non-versioned shared object and it detected just fine.

[jeromelaban]

Indeed, you're right, the resolved that is incorrect. Interestingly, we did not detect this in our validations, meaning that something was changing the outcome. Are you testing on Linux directly?

[dougcooper]

yes...directly on an embedded device

[jeromelaban]

Thanks. We'll take a look. It also looks similar to #9099.

[dougcooper]

A little backstory...the app was running fine on the embedded device except for some stuttering during a small animation as compared to a non-embedded version of the app. We initially tried forcing RenderSurfaceType as you suggested which caused the app to fail except for the Software type.