.github/workflows/build.yaml: setup release steps

.github/workflows/build.yaml

@@ -1,6 +1,12 @@
 name: Build for Windows
 
-on: [push, pull_request]
+on:
+  push:
+  workflow_dispatch:
+    inputs:
+      tag:
+        description: 'which tag to upload to'
+        default: ''
 
 jobs:
   build:
@@ -75,3 +81,22 @@ jobs:
         path: |
           builddir/*.dll
 
+    - name: Compress artifact for release
+      if: github.event_name == 'workflow_dispatch' && github.event.inputs.tag != ''
+      shell: cmd
+      run: |
+        cd builddir
+        mkdir vs-fft3dfilter-windows-${{ github.event.inputs.tag }}
+        xcopy fft3dfilter.dll vs-fft3dfilter-wimdows-${{ github.event.inputs.tag }} /f
+        7z a -t7z -mx=9 ../vs-fft3dfilter-windows-${{ github.event.inputs.tag }}.7z vs-fft3dfilter-windows-${{ github.event.inputs.tag }}
+    
+    - name: Release
+      uses: softprops/action-gh-release@v1
+      if: github.event_name == 'workflow_dispatch' && github.event.inputs.tag != ''
+      with:
+        tag_name: ${{ github.event.inputs.tag }}
+        files: |
+          vs-fft3dfilter-windows-${{ github.event.inputs.tag }}.7z
+        fail_on_unmatched_files: true
+        generate_release_notes: false
+        prerelease: true