Hello everyone, I'm working on a 2d component oriented game engine in c++ that aims to be deployed in various platforms, including web browsers thanks to Emscripten. The things implemented until now works apparently well after compiling with Emscripten, the component systems works ok, and the translation of OpenGL calls to WebGL from the rendering system it's doing the job, with some warning that must be polished, but transforms and renders the scene as expected.

Now it's time for scripting (the behaviour components) and i started to test Angelscript with Emscripten, but while the desktop build works apparently well, the javascript version don't. I successfully compile Angelscript and tests with emscripten but when I try to run RegisterGlobalFunction from the example in the users guide it returns a -7 error. Apparently asCreateScriptEngine, SetMessageCallback, RegisterStdString and the initialization of CScriptBuilder, doesn't give me any error, so i don't understand what's happening, and of course this doesn't happen in the descktop build.

So, my question is, anyone here has tried to embed Angelscript runtime and have had success running it, using Emscripten compiler? From my point of view is like building it for a new platform, so i tried to create a "configuration" in as_config.h but i'm totally lost here and there are a lot of flags that i don't know if must be defined or not for Emscripten. I will appreciate if someone can help me to configure it and give me some advice of how to use it when dealing with Emscripten, or in the case that it is impossible to do, explain me why and if there are some alternatives (like Lua, that comes with Emscripten examples).

Thanks.

I'm not familiar with Emscripten, but from what you describe it seems to translate native C++ code into javascript so that it can run on any platform that support javascript. Is that it?

There wouldn't be support for native calling conventions when this is done, as native calling conventions require assembler to properly set up the stack and CPU registers. Instead you need to use the generic calling convention when registering the functions and object methods. If you take a look at the implementation of RegisterStdString() you'll see that when the library is compiled without support for native calling conventions it choses a different path that uses the generic calling convention, which is why it is able to successfully the string type.

You shouldn't need to change the configurations in as_config.h to get this to work. It will already assume AS_MAX_PORTABILITY when it doesn't recognize the target platform to support native calling conventions.

Yo dawg, we heard you like script engines.... :)