When we initialize OpenGL, check whether we have OpenGL 2.0 or later; if not, check whether we have the 'GL_ARB_shader_objects' extension, since we must be able to support shaders if using OpenGL for GTK. If we don't support shaders, as some Windows graphics drivers do not support OpenGL adequately, notably older Intel drivers, reject and destroy the GL context that we created, and so fallback to the Cairo GSK renderer, so that things continue to run, albeit with an expected warning message that the GL context cannot be realized. Also, when we could not make the created dummy WGL context current during initialization, make sure that we destroy the dummy WGL context as well. Fixes issue #4165.
16 KiB
16 KiB