From 9c819ae67d17171340f4dda578c3a7726e9b737d Mon Sep 17 00:00:00 2001
From: Elie Michel <elie.michel@exppad.com>
Date: Wed, 16 Oct 2024 00:43:40 +0200
Subject: [PATCH] Adapt CMakeLists to emscripten

---
 .github/workflows/cmake.yml | 44 ++++++-------------------------------
 examples/CMakeLists.txt     | 30 +++++++++++++++----------
 2 files changed, 26 insertions(+), 48 deletions(-)

diff --git a/.github/workflows/cmake.yml b/.github/workflows/cmake.yml
index b84508c..6c6b131 100644
--- a/.github/workflows/cmake.yml
+++ b/.github/workflows/cmake.yml
@@ -42,6 +42,13 @@ jobs:
         - system: MacOS-x64
           runner: macos-13
 
+        - system: emscripten
+          runner: ubuntu-latest
+          webgpu-backend: EMSCRIPTEN
+          link-type: STATIC
+          build-type: Release
+          cmake-wrapper: emcmake
+
         # Latest version of Dawn to not support static linking
         exclude:
         - webgpu-backend: DAWN
@@ -109,40 +116,3 @@ jobs:
         cmake
         --build build
         --config ${{ matrix.build-type }}
-
-  # Was too annoying to put emscripten in the matrix, so here it is, on its own:
-  build-web:
-    strategy:
-      fail-fast: false
-      matrix:
-        system: [ emscripten ]
-        build-type: [ Debug, Release ]
-        emsdk-version: [ 3.1.61 ]
-
-    runs-on: ubuntu-latest
-
-    steps:
-    - uses: actions/checkout@v4
-    
-    - name: Install dependencies
-      if: ${{ matrix.install-deps }}
-      run: ${{ matrix.install-deps }}
-
-    - name: Setup emscripten
-      if: ${{ matrix.emsdk-version }}
-      uses: mymindstorm/setup-emsdk@v14
-      with:
-        version: ${{ matrix.emsdk-version }}
-
-    - name: Configure CMake
-      run: >
-        emcmake cmake
-        -S examples
-        -B build
-        -DCMAKE_BUILD_TYPE=${{ matrix.build-type }}
-
-    - name: Build
-      run: >
-        cmake
-        --build build
-        --config ${{ matrix.build-type }}
diff --git a/examples/CMakeLists.txt b/examples/CMakeLists.txt
index f22c7b1..9bb8257 100644
--- a/examples/CMakeLists.txt
+++ b/examples/CMakeLists.txt
@@ -6,17 +6,25 @@ include(FetchContent)
 include(utils.cmake)
 
 # Dependencies
-FetchContent_Declare(
-  glfw-light
-  URL      https://eliemichel.github.io/LearnWebGPU/_downloads/6873a344e35ea9f5e4fc7e5cc85d3ab8/glfw-3.4.0-light.zip
-  URL_HASH MD5=e6684142080457e9227e4f78a6f84fc2
-)
-FetchContent_Declare(
-  webgpu
-  GIT_REPOSITORY https://github.com/eliemichel/WebGPU-distribution.git
-  GIT_TAG        7ed61fb96d972a4c61ccc79af1139eba2a0ce4c4  # fetch
-)
-FetchContent_MakeAvailable(glfw-light webgpu)
+if (NOT EMSCRIPTEN)
+  FetchContent_Declare(
+    glfw-light
+    URL      https://eliemichel.github.io/LearnWebGPU/_downloads/6873a344e35ea9f5e4fc7e5cc85d3ab8/glfw-3.4.0-light.zip
+    URL_HASH MD5=e6684142080457e9227e4f78a6f84fc2
+  )
+  FetchContent_Declare(
+    webgpu
+    GIT_REPOSITORY https://github.com/eliemichel/WebGPU-distribution.git
+    GIT_TAG        7ed61fb96d972a4c61ccc79af1139eba2a0ce4c4  # fetch
+  )
+  FetchContent_MakeAvailable(glfw-light webgpu)
+else()
+    # Emscripten has built-in support for GLFW but requires the `-sUSE_GLFW=3` link option:
+    add_library(glfw-light INTERFACE)
+    target_link_options(glfw-light INTERFACE -sUSE_GLFW=3)
+    add_library(webgpu INTERFACE)
+    target_link_options(webgpu INTERFACE -sUSE_WEBGPU=1)
+endif()
 
 # The glfw3webgpu target
 # NB: We specify a second argument only because this is an out-of-tree