Choose your own font and size (#1154)

* Refactor text layout: don't need &Fonts in all functions
* Replace indexing in Fonts with member function
* Wrap Fonts in a Mutex
* Remove mutex for Font::glyph_info_cache
* Remove RwLock around Font::characters
* Put FontsImpl and GalleyCache behind the same Mutex
* Round font sizes to whole pixels before deduplicating them
* Make TextStyle !Copy
* Implement user-named TextStyle:s
* round font size earlier
* Cache fonts based on family and size
* Move TextStyle into egui and Style
* Remove body_text_style
* Query graphics about max texture size and use that as font atlas size
* Recreate texture atlas when it is getting full

egui_glium/src/epi_backend.rs

@@ -47,6 +47,7 @@ pub fn run(app: Box<dyn epi::App>, native_options: &epi::NativeOptions) -> ! {
     let mut painter = crate::Painter::new(&display);
     let mut integration = egui_winit::epi::EpiIntegration::new(
         "egui_glium",
+        painter.max_texture_side(),
         display.gl_window().window(),
         repaint_signal,
         persistence,