make the glow and glium backends toggleable at build-time

ezgui/Cargo.toml

@@ -5,7 +5,9 @@ authors = ["Dustin Carlino <dabreegster@gmail.com>"]
 edition = "2018"
 
 [features]
-default = []
+default = ["glium-backend"]
+glium-backend = ["glium"]
+glow-backend = ["glow"]
 profiler = ["cpuprofiler"]
 
 [dependencies]
@@ -13,8 +15,8 @@ abstutil = { path = "../abstutil" }
 # backtrace = "0.3.40"
 cpuprofiler = { version = "0.0.3", optional = true }
 geom = { path = "../geom" }
-#glium = "0.26.0"
-glow = "0.4.0"
+glium = { version = "0.26.0", optional = true }
+glow = { version = "0.4.0", optional = true }
 glutin = "0.23.0"
 htmlescape = "0.3.1"
 image = "0.22.2"

ezgui/src/backend_glium.rs

@@ -155,7 +155,7 @@ impl<'a> GfxCtxInnards<'a> {
         });
     }
 
-    pub fn disable_clipping(&mut self) {
+    pub fn disable_clipping(&mut self, _: &Canvas) {
         assert!(self.params.scissor.is_some());
         self.params.scissor = None;
     }
@@ -194,7 +194,7 @@ pub struct PrerenderInnards {
     program: glium::Program,
 
     // TODO Prerender doesn't know what things are temporary and permanent. Could make the API more
-    // detailed (and use the corresponding persistent glium types).
+    // detailed.
     pub total_bytes_uploaded: Cell<usize>,
 
     // Kind of a weird place for this, but ah well.
@@ -330,4 +330,6 @@ impl PrerenderInnards {
                 .push(Texture2dArray::new(&self.display, raw_data).unwrap());
         }
     }
+
+    pub fn window_resized(&self, _: f64, _: f64) {}
 }

ezgui/src/backend_glow.rs

@@ -172,7 +172,7 @@ pub struct PrerenderInnards {
     program: <glow::Context as glow::HasContext>::Program,
 
     // TODO Prerender doesn't know what things are temporary and permanent. Could make the API more
-    // detailed (and use the corresponding persistent glium types).
+    // detailed.
     pub total_bytes_uploaded: Cell<usize>,
 
     // Kind of a weird place for this, but ah well.

ezgui/src/drawing.rs

@@ -1,5 +1,5 @@
 use crate::assets::Assets;
-use crate::backend_glow::{GfxCtxInnards, PrerenderInnards};
+use crate::backend::{GfxCtxInnards, PrerenderInnards};
 use crate::svg;
 use crate::{
     Canvas, Color, Drawable, EventCtx, HorizontalAlignment, ScreenDims, ScreenPt, ScreenRectangle,

ezgui/src/lib.rs

@@ -1,4 +1,7 @@
 mod assets;
+#[cfg(feature = "glium-backend")]
+mod backend_glium;
+#[cfg(feature = "glow-backend")]
 mod backend_glow;
 mod canvas;
 mod color;
@@ -14,7 +17,7 @@ mod svg;
 mod text;
 mod widgets;
 
-pub use crate::backend_glow::Drawable;
+pub use crate::backend::Drawable;
 pub use crate::canvas::{Canvas, HorizontalAlignment, VerticalAlignment};
 pub use crate::color::Color;
 pub use crate::drawing::{GeomBatch, GfxCtx, Prerender, RewriteColor};
@@ -35,3 +38,11 @@ pub enum InputResult<T: Clone> {
     StillActive,
     Done(String, T),
 }
+
+mod backend {
+    #[cfg(feature = "glium-backend")]
+    pub use crate::backend_glium::*;
+
+    #[cfg(feature = "glow-backend")]
+    pub use crate::backend_glow::*;
+}

ezgui/src/runner.rs

@@ -159,7 +159,7 @@ impl Settings {
 }
 
 pub fn run<G: 'static + GUI, F: FnOnce(&mut EventCtx) -> G>(settings: Settings, make_gui: F) -> ! {
-    let (prerender_innards, event_loop) = crate::backend_glow::setup(&settings.window_title);
+    let (prerender_innards, event_loop) = crate::backend::setup(&settings.window_title);
 
     let window_size = event_loop.primary_monitor().size();
     let mut canvas = Canvas::new(window_size.width.into(), window_size.height.into());

game/Cargo.toml

@@ -12,6 +12,7 @@ chrono = "0.4.10"
 counter = "0.4.3"
 downcast-rs = "1.0.4"
 ezgui = { path = "../ezgui" }
+#ezgui = { path = "../ezgui", default-features=false, features=["glow-backend"] }
 geom = { path = "../geom" }
 kml = { path = "../kml" }
 map_model = { path = "../map_model" }