Hey, nice. Lots to learn still, but this is working.

config.nims

@@ -1,5 +1,5 @@
 
-when defined(emscripten):
+when defined( emscripten ):
   --define:GraphicsApiOpenGlEs2
   # --define:NaylibWebResources
   # switch("define", "NaylibWebResourcesPath=resources")
@@ -8,6 +8,12 @@ when defined(emscripten):
   --os:linux
   --cpu:wasm32
   --cc:clang
+  when defined( windows ):
+    --clang.exe:emcc.bat  # Replace C
+    --clang.linkerexe:emcc.bat # Replace C linker
+    --clang.cpp.exe:emcc.bat # Replace C++
+    --clang.cpp.linkerexe:emcc.bat # Replace C++ linker.
+  else:
     --clang.exe:emcc
     --clang.linkerexe:emcc
     --clang.cpp.exe:emcc
@@ -17,11 +23,12 @@ when defined(emscripten):
   --panics:on
   --exceptions:goto
   --define:noSignalHandler
-  --passL:"-03"
+  --passL:"-Oz" # Production build
+  # --passL:"-O0 -gDebug -gsource-map" # Debug build
   # --passL:"-s EXPORT_NAME=Test1Module"
   # --passL:"-s MODULARIZE=1"
   --passL:"-s ASYNCIFY" # async support
   # --passL:"-s JSPI" # async support
-  --passL:"-o index.html"
-  # --passL:"--shell-file minshell.html"
+  --passL:"-o build/index.html"
+  --passL:"--shell-file minshell.html"
 

nim_wasm_test.nimble

@@ -14,9 +14,9 @@ task make, "Native build":
   exec "mkdir -p build && nim c --outdir:build -d:release --opt:speed src/nim_wasm_test.nim"
 
 task makeweb, "Emscripten build":
-  exec "mkdir -p build && nim c --outdir:build -d:emscripten src/nim_wasm_test.nim"
+  exec "mkdir -p build && nim c -d:emscripten -d:release src/nim_wasm_test.nim"
 
 task runweb, "Run a local webserver for the wasm build":
-  exec "nimhttpd -H:'Cross-Origin-Opener-Policy: same-origin' -H:'Cross-Origin-Embedder-Policy: require-corp'"
+  exec "nimhttpd -H:'Cross-Origin-Opener-Policy: same-origin' -H:'Cross-Origin-Embedder-Policy: require-corp' build/"
 
 

src/nim_wasm_test.nim

@@ -4,31 +4,45 @@ import std/os
 import raylib
 
 # Emscripten specific imports
-proc emscripten_set_main_loop(f: proc() {.cdecl.}, a: cint, b: bool) {.importc.}
-proc emscripten_sleep(a: cuint) {.importc.}
+proc emscripten_set_main_loop( f: proc() {.cdecl.}, a: cint, b: bool ) {.importc.}
+proc emscripten_sleep( a: cuint ) {.importc.}
 
+var camera = Camera(
+    position: Vector3(x: 5, y: 5, z: 10),  # Camera position
+    target: Vector3(x: 0, y: 0, z: 0),     # Camera target it looks-at
+    up: Vector3(x: 0, y: 1, z: 0),         # Camera up vector (rotation over its axis)
+    fovy: 45,                              # Camera field-of-view apperture in Y (degrees)
+    projection: Perspective                # Defines projection type, see CameraProjection
+)
 
-proc main() =
+proc mainLoop() {.cdecl.} =
     defer: closeWindow()
 
-    initWindow( 600, 400, "raylib nim playground" )
+    initWindow( 800, 600, "raylib nim playground" )
 
     while not windowShouldClose():
-        if defined(emscripten):
+
+        beginDrawing();
+        clearBackground( RAYWHITE );
+        beginMode3D( camera );
+        drawGrid( 10, 1.0f );
+        endMode3D();
+
+        var col = if isCursorOnScreen(): BLUE else: GRAY
+        drawText( "OH SNAP IT'S WORKING", 10, 10, 20, col );
+        endDrawing();
+
+        if defined( emscripten ):
             emscripten_sleep 10
+            echo "wasm: hi"
         else:
             sleep 10
-
-main()
+            echo "native: hi"
+
+
+if defined( emscripten ):
+    emscripten_set_main_loop( mainLoop, 0, true );
+else:
+    mainLoop()
 
 
-# when defined(emscripten):
-#   # Emscripten can't block so it will call this callback instead.
-#   emscripten_set_main_loop(main_loop, 0, true);
-# else:
-#   # When running native code we can block in an infinite loop.
-#   while windowShouldClose(window) == 0:
-#     mainLoop()
-#     # If you get ESC key quit.
-#     if window.getKey(KEY_ESCAPE) == 1:
-#       window.setWindowShouldClose(1)