Hi list, Multiple driver support in EGL is hard to get right, if not impossible. On Linux desktop, we almost always want to use egl_dri2. It allows EGL to loads DRI2 drivers, thus allowing it to share DRI2 drivers with libGL.
In one case where the app wants to use OpenVG, libEGL needs to load egl_gallium instead. The problem comes from that we cannot know that an OpenVG context is to be created until it is created. But before a context can be created, EGL needs to be initialized and an EGLConfig needs to be chosen. So when EGL is to be initialized, we need to load and initilaize all EGL drivers. When an EGLConfig is to be picked, we need to pick it from all drivers. But this also introduces new problems. For example, when the vendor string or the extension string is queried, whose string of all EGL drivers should be returned? My proposal is to simply drop multiple driver support from EGL. Instead, we will provide four libEGL implementations: - libEGL_dri2: derived from egl_dri2 - libEGL_gallium: derived from egl_gallium - libEGL_glx: derived from egl_glx - libEGL_loader: see below All of them are conformant EGL implementations. That is, any one of them can be installed as /usr/lib/libEGL.so. libEGL_loader is new. It is basically a wrapper that loads another implementation to do the real work. As such, the problems we face with multiple driver support will remain in libEGL_loader. Distros may choose to install libEGL_loader as libEGL and let it pick the real implementation. Or they may choose to have the first three installed as libEGL, and package them separately. Thoughts? -- o...@lunarg.com _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
