sokol: a WebGPU build of the browser player

.github/workflows/build.yml

@@ -1313,3 +1313,117 @@ jobs:
           if-no-files-found: error
           name: "tic80-html-players"
           path: build/players/*
+
+  # === HTML, WebGPU backend ===
+  # A job of its own so a WebGPU-only break cannot keep the GLES3 players off dev.
+  html-webgpu:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: emscripten-core/setup-emsdk@v15
+
+      - uses: actions/checkout@v6
+        with:
+          submodules: recursive
+          fetch-depth: 0
+
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: 2.6
+
+      - name: Install 32-bit build tools
+        run: sudo apt-get update && sudo apt-get install -y gcc-multilib
+
+      # The editorful build, as the site's players are: the loader keeps the name the site asks for.
+      - name: Build per-language WebGPU players
+        shell: bash
+        run: |
+          set -euo pipefail
+          langs=(lua ruby js moon yue fennel scheme squirrel wren wasm janet python miniscript forth gravity)
+          stage="$GITHUB_WORKSPACE/build/players-webgpu"
+          rm -rf "$stage"
+          for lang in "${langs[@]}"; do
+            flags=(-DBUILD_WITH_ALL=OFF)
+            for l in "${langs[@]}"; do
+              up=$(echo "$l" | tr '[:lower:]' '[:upper:]')
+              if [ "$l" = "$lang" ]; then flags+=("-DBUILD_WITH_$up=ON"); else flags+=("-DBUILD_WITH_$up=OFF"); fi
+            done
+            cd "$GITHUB_WORKSPACE/build"
+            emcmake cmake -G Ninja -DBUILD_TOUCH_INPUT=ON -DCMAKE_BUILD_TYPE=Release -DBUILD_EDITORS=ON -DBUILD_SOKOL_WGPU=ON "${flags[@]}" -DTIC80_TARGET="tic80$lang" ..
+            cmake --build . --parallel
+            for f in "bin/tic80$lang.js" "bin/tic80$lang.wasm"; do
+              [ -f "$f" ] || { echo "missing player: build/$f" >&2; exit 1; }
+            done
+            mkdir -p "$stage/$lang/webgpu"
+            cp "bin/tic80$lang.js"   "$stage/$lang/webgpu/tic80.js"
+            cp "bin/tic80$lang.wasm" "$stage/$lang/webgpu/tic80$lang.wasm"
+            rm -f "bin/tic80$lang.js" "bin/tic80$lang.wasm"
+          done
+
+      # The target names the wasm its loader asks for; plain "tic80" would ask for the wrong one.
+      - name: Build universal WebGPU player
+        shell: bash
+        run: |
+          set -euo pipefail
+          stage="$GITHUB_WORKSPACE/build/players-webgpu/webgpu"
+          cd "$GITHUB_WORKSPACE/build"
+          emcmake cmake -G Ninja -DBUILD_TOUCH_INPUT=ON -DCMAKE_BUILD_TYPE=Release -DBUILD_WITH_ALL=ON -DBUILD_SOKOL_WGPU=ON -DTIC80_TARGET=tic80webgpu .. --fresh
+          cmake --build . --parallel
+          mkdir -p "$stage"
+          cp bin/tic80webgpu.js   "$stage/tic80.js"
+          cp bin/tic80webgpu.wasm "$stage/tic80webgpu.wasm"
+          # the page an exported game gets, as the html job's "Build all" copies it
+          cp html/index.html "$stage/index.html"
+
+      # The backend is read from the loader: the wasm carries no such string.
+      - name: Check the builds are what they claim
+        shell: bash
+        run: |
+          set -euo pipefail
+          stage="$GITHUB_WORKSPACE/build/players-webgpu"
+          langs=(lua ruby js moon yue fennel scheme squirrel wren wasm janet python miniscript forth gravity)
+          files=()
+          for lang in "${langs[@]}"; do
+            js="$stage/$lang/webgpu/tic80.js"
+            wasm="$stage/$lang/webgpu/tic80$lang.wasm"
+            for f in "$js" "$wasm"; do
+              [ -f "$f" ] || { echo "missing player file: $f" >&2; exit 1; }
+            done
+            grep -qa "SPRITE EDITOR" "$wasm" ||
+              { echo "player without editors: $wasm — BUILD_EDITORS=ON did not take" >&2; exit 1; }
+            grep -qa "Unable to initialize SDL Video" "$wasm" &&
+              { echo "player on the SDL layer: $wasm — the sokol default did not take" >&2; exit 1; }
+            grep -qa "navigator.gpu" "$js" ||
+              { echo "player without the WebGPU shim: $js — BUILD_SOKOL_WGPU=ON did not take" >&2; exit 1; }
+            grep -qa "tic80$lang.wasm" "$js" ||
+              { echo "player asks for another wasm: $js does not name tic80$lang.wasm — TIC80_TARGET did not take" >&2; exit 1; }
+            files+=("$wasm")
+          done
+          for f in "$stage/webgpu/tic80.js" "$stage/webgpu/tic80webgpu.wasm" "$stage/webgpu/index.html"; do
+            [ -f "$f" ] || { echo "missing universal file: $f" >&2; exit 1; }
+          done
+          grep -qa "SPRITE EDITOR" "$stage/webgpu/tic80webgpu.wasm" ||
+            { echo "the universal build carries no editors" >&2; exit 1; }
+          grep -qa "Unable to initialize SDL Video" "$stage/webgpu/tic80webgpu.wasm" &&
+            { echo "the universal build is on the SDL layer — the sokol default did not take" >&2; exit 1; }
+          grep -qa "navigator.gpu" "$stage/webgpu/tic80.js" ||
+            { echo "the universal build is not WebGPU" >&2; exit 1; }
+          grep -qa "tic80webgpu.wasm" "$stage/webgpu/tic80.js" ||
+            { echo "the universal player asks for another wasm: it does not name tic80webgpu.wasm — TIC80_TARGET did not take" >&2; exit 1; }
+          # a language flag that did not take leaves two builds alike
+          for ((i = 0; i < ${#files[@]}; i++)); do
+            for ((j = i + 1; j < ${#files[@]}; j++)); do
+              if cmp -s "${files[i]}" "${files[j]}"; then
+                echo "duplicate player: $(basename "${files[i]}") == $(basename "${files[j]}") — a language flag did not take" >&2
+                exit 1
+              fi
+            done
+          done
+          echo "checked ${#files[@]} WebGPU players, all distinct, all with editors, all on the WebGPU shim"
+
+      - name: Deploy
+        uses: actions/upload-artifact@v6
+        with:
+          if-no-files-found: error
+          name: "tic80-html-webgpu"
+          path: build/players-webgpu/*

CMakeLists.txt

@@ -55,13 +55,18 @@ endif()
 
 option(BUILD_SDL "SDL Enabled" ${BUILD_SDL_DEFAULT})
 option(BUILD_SOKOL "Sokol Enabled" ${BUILD_SOKOL_DEFAULT})
+option(BUILD_SOKOL_WGPU "Sokol WebGPU backend (browser builds)" OFF)
 if(BUILD_APPLE)
     set(BUILD_SDL OFF)
     set(BUILD_SOKOL OFF)
 endif()
 if(BUILD_SDL AND BUILD_SOKOL)
     message(FATAL_ERROR "BUILD_SDL and BUILD_SOKOL are two system layers: enable exactly one")
 endif()
+# WebGPU is the Emscripten sokol backend; elsewhere it would be silently ignored.
+if(BUILD_SOKOL_WGPU AND NOT (EMSCRIPTEN AND BUILD_SOKOL))
+    message(FATAL_ERROR "BUILD_SOKOL_WGPU is the Emscripten sokol backend: enable it with BUILD_SOKOL, for the browser")
+endif()
 option(BUILD_SDLGPU "SDL GPU Enabled" OFF)
 option(BUILD_LIBRETRO "libretro Enabled" ${BUILD_LIBRETRO_DEFAULT})
 option(BUILD_TOOLS "bin2txt prj2cart" OFF)
@@ -112,6 +117,7 @@ target_compile_definitions(runtime INTERFACE BUILD_DEPRECATED)
 message("PREFER_SYSTEM_LIBRARIES: ${PREFER_SYSTEM_LIBRARIES}")
 message("BUILD_STATIC: ${BUILD_STATIC}")
 message("BUILD_SDLGPU: ${BUILD_SDLGPU}")
+message("BUILD_SOKOL_WGPU: ${BUILD_SOKOL_WGPU}")
 message("BUILD_TOUCH_INPUT: ${BUILD_TOUCH_INPUT}")
 message("BUILD_WITH_ALL: ${BUILD_WITH_ALL}")
 

cmake/sokol.cmake

@@ -28,6 +28,9 @@ if(BUILD_SOKOL)
         target_compile_definitions(sokol PUBLIC SOKOL_METAL)
     elseif(WIN32)
         target_compile_definitions(sokol PUBLIC SOKOL_D3D11 UNICODE)
+    elseif(EMSCRIPTEN AND BUILD_SOKOL_WGPU)
+        # The browser's other backend: sokol_app owns the WebGPU device and swapchain.
+        target_compile_definitions(sokol PUBLIC SOKOL_WGPU)
     elseif(EMSCRIPTEN)
         target_compile_definitions(sokol PUBLIC SOKOL_GLES3)
     elseif(USE_GLES2)
@@ -124,7 +127,22 @@ if(BUILD_SOKOL)
         # The same runtime shape the SDL web target asks for — memory growth,
         # fetch, the 4M stack a deep cart needs, the page's file hooks — with
         # WebGL2 in place of SDL's GL.
-        set_target_properties(${TIC80_TARGET} PROPERTIES LINK_FLAGS "-s WASM=1 -s ALLOW_MEMORY_GROWTH=1 -s FETCH=1 -s STACK_SIZE=4194304 -s EXPORTED_FUNCTIONS=_main,_malloc,_free -s EXPORTED_RUNTIME_METHODS=UTF8ToString -s MIN_WEBGL_VERSION=2 -s MAX_WEBGL_VERSION=2 --pre-js ${CMAKE_SOURCE_DIR}/build/html/prejs.js -lidbfs.js")
+        set(TIC80_LINK_FLAGS "-s WASM=1 -s ALLOW_MEMORY_GROWTH=1 -s FETCH=1 -s STACK_SIZE=4194304 -s EXPORTED_FUNCTIONS=_main,_malloc,_free -s EXPORTED_RUNTIME_METHODS=UTF8ToString --pre-js ${CMAKE_SOURCE_DIR}/build/html/prejs.js -lidbfs.js")
+
+        if(BUILD_SOKOL_WGPU)
+
+            # WebGPU in place of WebGL2; the port carries the header, so it is on compile and link.
+            set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} --use-port=emdawnwebgpu")
+            # Named because the port's C++ drops them from the default set; unnamed they die in callMain.
+            set(TIC80_LINK_FLAGS "${TIC80_LINK_FLAGS} --use-port=emdawnwebgpu -sDEFAULT_TO_CXX -sEXPORTED_FUNCTIONS=_main,_malloc,_free,__emscripten_stack_alloc,_emscripten_stack_get_current,__emscripten_stack_restore")
+
+        else()
+
+            set(TIC80_LINK_FLAGS "${TIC80_LINK_FLAGS} -s MIN_WEBGL_VERSION=2 -s MAX_WEBGL_VERSION=2")
+
+        endif()
+
+        set_target_properties(${TIC80_TARGET} PROPERTIES LINK_FLAGS "${TIC80_LINK_FLAGS}")
 
     endif()