Combine Emscripten and GopherJS ?

<p>I am trying to implement Web/HTML5 target for my library here <a href="https://github.com/gen2brain/raylib-go" rel="nofollow">https://github.com/gen2brain/raylib-go</a> , original C library supports emscripten.</p> <p>For now i have this:</p> <p><code>go generate -tags js github.com/gen2brain/raylib-go/raylib</code> will generate <code>raylib.js</code> file (emcc from emscripten must be in PATH).</p> <p>Then, I have implemented bindings for <code>raylib.js</code> in GopherJS here <a href="https://github.com/gen2brain/raylib-go/blob/master/raylib/raylib_js.go" rel="nofollow">https://github.com/gen2brain/raylib-go/blob/master/raylib/raylib_js.go</a> .</p> <p><code>gopherjs build</code> is then used to build project example or game to js. After that, <a href="https://github.com/gen2brain/raylib-go/blob/master/raylib/external/web/index.html" rel="nofollow">https://github.com/gen2brain/raylib-go/blob/master/raylib/external/web/index.html</a> should be edited to include that js file.</p> <p>If I open that index.html in browser, I can see that InitWindow() works, OpenGL ES is active, etc. but per emscripten docs <a href="https://kripken.github.io/emscripten-site/docs/api_reference/emscripten.h.html#c.emscripten_set_main_loop" rel="nofollow">https://kripken.github.io/emscripten-site/docs/api_reference/emscripten.h.html#c.emscripten_set_main_loop</a>, I need to set update()/mainloop() function there and use that in app, raylib also does that, but in C code (and includes emscripten.h).</p> <p>Now, I add with generate script this at the end of raylib.js (with emcc --post-js option):</p> <pre><code>function _emscripten_set_main_loop_go(fps, simulateInfiniteLoop) { if (_go_update_function !== undefined &amp;&amp; typeof _go_update_function == &#39;function&#39;) { _emscripten_set_main_loop(_go_update_function, fps, simulateInfiniteLoop); } } Module[&#34;_emscripten_set_main_loop_go&#34;] = _emscripten_set_main_loop_go; </code></pre> <p>And then I use it in Go like this:</p> <pre><code>func SetMainLoop(fn func(), fps int, infinite bool) { js.Global.Set(&#34;_go_update_function&#34;, fn) js.Global.Get(&#34;Module&#34;).Call(&#34;_emscripten_set_main_loop_go&#34;, fps, infinite) } </code></pre> <p>This results in error <code>Invalid function pointer called with signature &#39;v&#39;. Perhaps this is an invalid value (e.g. caused by calling a virtual method on a NULL pointer)?</code></p> <p>I guess it doesn&#39;t pass properly Go function, but I am kinda lost here who passes what and to whom. Any help and/or pointers are much appreciated.</p> <p>Error details are here <a href="https://github.com/gen2brain/raylib-go/issues/28" rel="nofollow">https://github.com/gen2brain/raylib-go/issues/28</a> .</p> <p>Edit: demo is here <a href="http://81.4.106.254/raylib-go/" rel="nofollow">http://81.4.106.254/raylib-go/</a> , .js files are not optimized/compressed/obfuscated . </p>