Support for --target wasm32-unknown-emscripten

gfx-rs · Dec 7, 2021 · 8eb6fa8 · 8eb6fa8
1 parent d51f70e
commit 8eb6fa8
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Showing 13 changed files with 298 additions and 86 deletions.
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
@@ -94,6 +94,14 @@ jobs:
             tool: clippy
             kind: web
 
+          # Emscripten WebGL
+          - name: WebAssembly emscripten
+            os: ubuntu-20.04
+            channel: stable
+            target: wasm32-unknown-emscripten
+            tool: clippy
+            kind: webgl-em
+
     name: Check ${{ matrix.name }}
     runs-on: ${{ matrix.os }}
 
@@ -164,6 +172,15 @@ jobs:
           # build docs
           cargo doc --target ${{ matrix.target }} -p wgpu --no-deps
 
+      - name: check web-em
+        if: matrix.kind == 'webgl-em'
+        run: |
+          # check with no features
+          cargo ${{matrix.tool}} --target ${{ matrix.target }} -p wgpu -p wgpu-core
+
+          # build docs
+          cargo doc --target ${{ matrix.target }} -p wgpu -p wgpu-core --no-deps
+
       - name: check native
         if: matrix.kind == 'local' || matrix.kind == 'other'
         run: |

diff --git a/Cargo.lock b/Cargo.lock
diff --git a/run-wasm-emscripten-example.sh b/run-wasm-emscripten-example.sh
@@ -0,0 +1,33 @@
+#!/usr/bin/env bash
+
+set -e
+
+set -- hello-triangle
+echo "Compiling..."
+EMMAKEN_CFLAGS="-g -s ERROR_ON_UNDEFINED_SYMBOLS=0 --no-entry -s FULL_ES3=1" cargo build --example $1 --target wasm32-unknown-emscripten
+
+mkdir -p target/wasm-examples/$1/
+cp target/wasm32-unknown-emscripten/debug/examples/* target/wasm-examples/$1
+cat wasm-resources/index.em.template.html | sed "s/{{example}}/$1/g" > target/wasm-examples/$1/index.html
+
+# Find a serving tool to host the example
+SERVE_CMD=""
+SERVE_ARGS=""
+if which basic-http-server; then
+    SERVE_CMD="basic-http-server"
+    SERVE_ARGS="target/wasm-examples/$1 -a 127.0.0.1:1234"
+elif which miniserve && python3 -m http.server --help > /dev/null; then
+    SERVE_CMD="miniserve"
+    SERVE_ARGS="target/wasm-examples/$1 -p 1234 --index index.html"
+elif python3 -m http.server --help > /dev/null; then
+    SERVE_CMD="python3"
+    SERVE_ARGS="-m http.server --directory target/wasm-examples/$1 1234"
+fi
+
+# Exit if we couldn't find a tool to serve the example with
+if [ "$SERVE_CMD" = "" ]; then
+    echo "Couldn't find a utility to use to serve the example web page. You can serve the `target/wasm-examples/$1` folder yourself using any simple static http file server."
+fi
+
+echo "Serving example with $SERVE_CMD at http://localhost:1234"
+$SERVE_CMD $SERVE_ARGS
diff --git a/wasm-resources/index.em.template.html b/wasm-resources/index.em.template.html
@@ -0,0 +1,15 @@
+<html>
+  <head>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+  </head>
+  <body>
+    <canvas id="canvas" width="640" height="400"></canvas>
+    <script>
+        var Module = {
+            canvas: document.getElementById("canvas"),
+        };
+    </script>
+    <script src="{{example}}.js"></script>
+  </body>
+</html>
diff --git a/wgpu-hal/Cargo.toml b/wgpu-hal/Cargo.toml
@@ -43,7 +43,7 @@ gpu-descriptor = { version = "0.2", optional = true }
 inplace_it = { version ="0.3.3", optional = true }
 
 # backend: Gles
-glow = { version = "0.11", optional = true }
+glow = { git = "https://github.com/grovesNL/glow", rev = "b6eb0ba", optional = true }
 
 # backend: Dx12
 bit-set = { version = "0.5", optional = true }
@@ -59,6 +59,10 @@ egl = { package = "khronos-egl", version = "4.1", features = ["dynamic"], option
 #Note: it's only unused on Apple platforms
 libloading = { version = "0.7", optional = true }
 
+[target.'cfg(target_os = "emscripten")'.dependencies]
+egl = { package = "khronos-egl", version = "4.1", features = ["static", "no-pkg-config"], optional = true }
+libloading = { version = "0.7", optional = true }
+
 [target.'cfg(windows)'.dependencies]
 winapi = { version = "0.3", features = ["libloaderapi", "windef", "winuser"] }
 native = { package = "d3d12", version = "0.4.1", features = ["libloading"], optional = true }
@@ -68,7 +72,7 @@ mtl = { package = "metal", version = "0.23.1" }
 objc = "0.2.5"
 core-graphics-types = "0.1"
 
-[target.'cfg(target_arch = "wasm32")'.dependencies]
+[target.'cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))'.dependencies]
 wasm-bindgen = { version = "0.2" }
 web-sys = { version = "0.3", features = ["Window", "HtmlCanvasElement", "WebGl2RenderingContext"] }
 js-sys = { version = "0.3" }
@@ -86,4 +90,6 @@ features = ["wgsl-in"]
 
 [dev-dependencies]
 env_logger = "0.8"
+
+[target.'cfg(not(target_os = "emscripten"))'.dev-dependencies]
 winit = "0.26"
diff --git a/wgpu-hal/src/gles/device.rs b/wgpu-hal/src/gles/device.rs
@@ -1096,6 +1096,8 @@ impl crate::Device<super::Api> for super::Device {
         #[cfg_attr(target_arch = "wasm32", allow(clippy::needless_borrow))]
         Ok(fence.get_latest(&self.shared.context.lock()))
     }
+
+    #[cfg_attr(target_os = "emscripten", allow(unreachable_code, unused_variables))]
     unsafe fn wait(
         &self,
         fence: &super::Fence,
@@ -1114,6 +1116,12 @@ impl crate::Device<super::Api> for super::Device {
                 .iter()
                 .find(|&&(value, _)| value >= wait_value)
                 .unwrap();
+
+            // for some reason signature of glow's client_wait_sync didn't match to emscripten's client_wait_sync
+            // however it should be noop in emscripten
+            #[cfg(target_os = "emscripten")]
+            return Ok(true);
+
             match gl.client_wait_sync(sync, glow::SYNC_FLUSH_COMMANDS_BIT, timeout_ns as i32) {
                 // for some reason firefox returns WAIT_FAILED, to investigate
                 #[cfg(target_arch = "wasm32")]