Don't use rayon in examples on wasm

Author: Liamolucko

Cargo.toml

@@ -37,6 +37,16 @@ version = "0.3.55"
 features = ["CanvasRenderingContext2d", "Document", "Element", "HtmlCanvasElement", "ImageData", "Window"]
 
 [dev-dependencies]
+instant = "0.1.12"
 winit = "0.26.1"
+
+[dev-dependencies.image]
+version = "0.23.14"
+# Disable rayon on web
+default-features = false
+features = ["jpeg"]
+
+[target.'cfg(not(target_arch = "wasm32"))'.dev-dependencies]
+# Turn rayon back on everywhere else; creating the separate entry resets the features to default.
 image = "0.23.14"
 rayon = "1.5.1"

examples/animation.rs

@@ -1,5 +1,6 @@
 use std::f64::consts::PI;
-use std::time::Instant;
+use instant::Instant;
+#[cfg(not(target_arch = "wasm32"))]
 use rayon::prelude::*;
 use softbuffer::GraphicsContext;
 use winit::event::{Event, WindowEvent};
@@ -64,7 +65,7 @@ fn main() {
 }
 
 fn pre_render_frames(width: usize, height: usize) -> Vec<Vec<u32>>{
-    (0..60).into_par_iter().map(|frame_id|{
+    let render = |frame_id|{
         let elapsed = ((frame_id as f64)/(60.0))*2.0*PI;
         let buffer = (0..((width * height) as usize))
             .map(|index| {
@@ -81,5 +82,11 @@ fn pre_render_frames(width: usize, height: usize) -> Vec<Vec<u32>>{
             .collect::<Vec<_>>();
 
         buffer
-    }).collect()
+    };
+
+    #[cfg(target_arch = "wasm32")]
+    return (0..60).map(render).collect();
+
+    #[cfg(not(target_arch = "wasm32"))]
+    (0..60).into_par_iter().map(render).collect()
 }

src/error.rs

@@ -16,6 +16,7 @@ pub enum SoftBufferError<W: HasRawWindowHandle> {
     PlatformError(Option<String>, Option<Box<dyn Error>>)
 }
 
+#[allow(unused)] // This isn't used on all platforms
 pub(crate) fn unwrap<T, E: std::error::Error + 'static, W: HasRawWindowHandle>(res: Result<T, E>, str: &str) -> Result<T, SoftBufferError<W>>{
     match res{
         Ok(t) => Ok(t),