Emscripten platform + WebAssembly 32 / 64-bit option

[danoli3]

PG side of openframeworks/openFrameworks#8558 (PROJECT_EMSCRIPTEN_WASM = 32 | 64 in config.emscripten.default.mk) and openframeworks/openFrameworks#8586 (CMake, same option name).

Emscripten platform

• Emscripten is now a platform, "Emscripten (Web) (Make)". It still works as a template for osx / linux / linux64.
• CLI: -pemscripten builds on the vscode base (Makefile, .vscode) and overlays scripts/templates/emscripten (Makefile, config.make, emmake.sh). No desktop platform is needed.
• Template list: emscripten isn't added to platformsOptions. That list only drives allplatforms and the template filter, so adding it would block the template.
• GUI: with the platform or the template selected, the WebGL / WebAssembly fields show, and after generating you get Build & Preview instead of "Open in IDE".

WebAssembly 32 / 64-bit

• Option: CLI -W32 / -W64 (--emscripten-wasm=64). In the GUI it's the "WebAssembly (Emscripten)" dropdown, under Advanced options:
  • 32-bit (default) (MEMORY32)
  • 64-bit (WASM64) (MEMORY64)
• 64: writes PROJECT_EMSCRIPTEN_WASM = 64 to config.make.
• 32: writes nothing, so the makefile default applies and existing projects are unchanged. A legacy EMSCRIPTEN_MEMORY64 line is commented out.
• No flag: keeps the project's value. It's read before the template copy can replace config.make. A legacy EMSCRIPTEN_MEMORY64 = 1 counts as 64.
• Invalid values: a warning, and the project is left unchanged.
• GUI on existing projects: opening one selects its value from config.make / CMakeLists.txt. New projects reset to 32.
• Missing WASM64 libs: at 64, if no libs/*/lib/emscripten/WASM64 exists, PG warns to run BITS=64 scripts/emscripten/download_libs.sh, which replaces the installed lib/emscripten libs. The GUI shows the same note.
• Addon libs: PG doesn't resolve emscripten addon libs itself. make / CMake pick WASM or WASM64, so the two are never mixed.

CMake template (openFrameworks#8586)

• Template: -tcmake (GUI: Templates → "CMake (CMakeLists.txt)") copies scripts/templates/cmake/CMakeLists.txt if the project has none. An existing one is kept.
• Edits: PG only edits a CMakeLists.txt that includes OF's openFrameworks.cmake:
  • the OF_ROOT default is set relative to the project, or absolute when the project is outside OF;
  • at 64, set(PROJECT_EMSCRIPTEN_WASM 64) goes before the include (a normal variable, so a stale cached 32 can't override it);
  • at 32 the line is removed.
• Missing template: if OF has no scripts/templates/cmake, PG logs a warning.

Translations

• All new strings are in the 9 locales.
• Rebased on master after Add MSYS2 environment selector for msys2 / VSCode targets #648 (MSYS2 environment). The -k / -W options, the GUI fields and the 9 locales were merged by keeping both sides: 161 keys per locale, no duplicates. -pmsys2 -kclangarm64 and -pemscripten -W64 both still work.
• Versions: commandLine 0.110.0, GUI 0.102.0.

Tested

• CLI config.make:
  • new project at 64, then regenerated without the flag: kept;
  • switched to 32: removed;
  • legacy EMSCRIPTEN_MEMORY64 = 1: read as 64;
  • invalid value: warning, unchanged;
  • -posx -temscripten still works.
• CMake files: at 64 / 32 the CMakeLists.txt was correct, the value was kept on reopen and removed when switched to 32, and OF_ROOT was absolute for a project outside OF.
• Builds (OF #8586 branch, emsdk 6.0.9):
  • 32-bit: emcmake cmake + cmake --build and emmake make both build bin/em/<app>/index.html.
  • 64-bit: configure puts the core in lib/emscripten/WASM64 and compiles everything with -sMEMORY64=1 -mwasm64. The link then fails on third-party symbols, because there are no wasm64 libs yet. That's expected until apothecary ships real wasm64 emscripten_64 packages.
• GUI:
  • the Emscripten platform shows the fields and Build & Preview;
  • opening 64 / 32 / CMake-only projects selects the right value;
  • new projects go back to 32;
  • generating at 64 writes the line.