doodle/wasm
Noah Petherbridge 3d08291bc5 Demo Running Level as Title Screen Wallpaper
* Load SDL2 fonts from go-bindata storage so we don't have to ship
  external font files on disk.
* Dedupe names of doodads so we don't show double on the front-end
  (go-bindata bundled doodads + those on local filesystem)
* Use go-bindata for accessing wallpaper images.
* Better flashed messages walking you through the Link Tool.
* Stylize the title screen (MainScene) by rendering a live example level
  as the background wallpaper, with mobile doodads in motion.
2019-06-27 22:59:36 -07:00
..
index.html Initial WebAssembly Build Target 2019-06-26 18:40:40 -07:00
main_wasm.go Texture Caching for WASM Canvas Engine 2019-06-26 22:44:08 -07:00
Makefile Initial WebAssembly Build Target 2019-06-26 18:40:40 -07:00
README.md Initial WebAssembly Build Target 2019-06-26 18:40:40 -07:00
server.go Demo Running Level as Title Screen Wallpaper 2019-06-27 22:59:36 -07:00
wasm_exec.js Initial WebAssembly Build Target 2019-06-26 18:40:40 -07:00

WebAssembly Port

Build and Test

Change to the wasm/ folder and type make to build doodle.wasm

To test it with a local Go server, cd to the wasm/ folder and run go run server.go and visit http://localhost:8080/

Copy the fonts and assets folders from the project root to the wasm/ directory so they're available over HTTP.

wasm_exec.js

To update the wasm_exec.js to match your version of Go:

# Fedora: install golang-misc
sudo dnf install golang-misc

# Copy the wasm_exec.js
cp $(go env GOROOT)/misc/wasm/wasm_exec.js ./

Font Support

Fonts are implemented as CSS embedded fonts configured in wasm/index.html

The font family name should match the filename, sans .ttf extension, for example "DejaVuSans-Bold". Doodle's internal logic converts a FontFilename string like "./fonts/DejaVuSans.ttf" into the base name to use as the font family. It also has fallbacks for sans-serif and serif in case of any problems.

Known Bugs and Limitations

  • github.com/kirsle/golog
    • The detection of an interactive terminal is broken in WASM.
    • terminal.IsTerminal(int(os.Stdout.Fd()))
    • As a workaround, comment it out and hardcode to false
  • Userdir
    • For WASM we'll want to use localStorage to store user drawings instead of the userdir.
  • Wallpaper support
    • WASM can't use os.Open to read the wallpaper image, so will need another method to load the image.
    • Texture caching support isn't implemented yet to hold the four corner textures of a wallpaper.
    • As a workaround, added a wallpaper.ready boolean and relevant functions exit early for WASM so wallpapers don't render at all.