Add GitHub Actions release workflow: multi-platform builds uploaded as release assets

.github/workflows/c-cpp.yml

@@ -34,21 +34,3 @@ jobs:
             build/bin/openwarcraft3
             build/lib/
           if-no-files-found: error
-
-      - name: Create release archive
-        if: startsWith(github.ref, 'refs/tags/')
-        run: |
-          mkdir -p release
-          cp build/bin/openwarcraft3 release/
-          cp -r build/lib/. release/
-          tar -czf openwarcraft3-linux-x64.tar.gz -C release .
-
-      - name: Create GitHub Release
-        if: startsWith(github.ref, 'refs/tags/')
-        env:
-          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-        run: |
-          gh release create "${{ github.ref_name }}" \
-            openwarcraft3-linux-x64.tar.gz \
-            --title "OpenWarcraft3 ${{ github.ref_name }}" \
-            --generate-notes

.github/workflows/release.yml

@@ -0,0 +1,69 @@
+name: Release
+
+on:
+  release:
+    types: [published]
+  workflow_dispatch:
+    inputs:
+      tag:
+        description: 'Release tag to attach assets to (e.g. v0.0.1-alpha)'
+        required: true
+
+jobs:
+  build:
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - os: ubuntu-latest
+            name: linux-x64
+          - os: macos-latest
+            name: macos-x64
+
+    runs-on: ${{ matrix.os }}
+    permissions:
+      contents: write
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install dependencies (Linux)
+        if: runner.os == 'Linux'
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y \
+            libgles2-mesa-dev \
+            libsdl2-dev \
+            libjpeg-dev \
+            libstorm-dev
+
+      - name: Install dependencies (macOS)
+        if: runner.os == 'macOS'
+        run: brew install sdl2 libjpeg stormlib
+
+      - name: Build
+        run: make build
+
+      - name: Create release archive
+        run: |
+          mkdir -p release
+          cp build/bin/openwarcraft3 release/
+          cp -r build/lib/. release/
+          tar -czf openwarcraft3-${{ matrix.name }}.tar.gz -C release .
+
+      - name: Determine release tag
+        id: get_tag
+        run: |
+          if [ "${{ github.event_name }}" = "workflow_dispatch" ]; then
+            echo "tag=${{ github.event.inputs.tag }}" >> "$GITHUB_OUTPUT"
+          else
+            echo "tag=${{ github.ref_name }}" >> "$GITHUB_OUTPUT"
+          fi
+
+      - name: Upload release asset
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          gh release upload "${{ steps.get_tag.outputs.tag }}" \
+            "openwarcraft3-${{ matrix.name }}.tar.gz" \
+            --clobber

README.md

@@ -8,10 +8,34 @@ It was developed using War3.mpq from Warcraft III v1.0 as reference, with ongoin
 
 ## Download
 
-Pre-built Linux binaries are available on the [Releases page](https://github.com/corepunch/openwarcraft3/releases/latest).
+Pre-built binaries for Linux and macOS are available on the [Releases page](https://github.com/corepunch/openwarcraft3/releases/latest).
 
 You can also download the latest build artifact from the [CI workflow runs](https://github.com/corepunch/openwarcraft3/actions/workflows/c-cpp.yml) (click the most recent successful run and download `openwarcraft3-linux-x64`).
 
+## Releases
+
+Release assets (compiled executables) are produced automatically by the [Release workflow](.github/workflows/release.yml).
+
+### How releases are produced
+
+When a new GitHub Release is **published**, the Release workflow runs automatically and:
+1. Builds the project on `ubuntu-latest` and `macos-latest`.
+2. Packages each build as a `.tar.gz` archive containing the `openwarcraft3` binary and shared libraries.
+3. Uploads the archives as release assets:
+   - `openwarcraft3-linux-x64.tar.gz`
+   - `openwarcraft3-macos-x64.tar.gz`
+
+### Re-running the workflow for an existing release
+
+To attach assets to an existing release (e.g. `v0.0.1-alpha`) without creating a new one:
+
+1. Go to **Actions → Release** in GitHub.
+2. Click **Run workflow**.
+3. Enter the tag name (e.g. `v0.0.1-alpha`) in the **tag** input field.
+4. Click **Run workflow**.
+
+The workflow will build for both platforms and upload (or overwrite) the assets on the specified release.
+
 <p align="center">
   <img src="https://github.com/user-attachments/assets/c76a93af-1801-402e-83bc-b3e0a4462312" width="31%" style="margin-right:2%;" />
   <img src="https://github.com/corepunch/openwarcraft3/assets/83646194/643c7aa7-2b91-469c-857e-0f6910c939af" width="31%" style="margin-right:2%;" />