ioquake3.html replaces Emscripten-generated HTML shell

This enables several things:
* Optionally load pk3 files from a web server at runtime instead of bundling them with Emscripten at build time
* Set command line arguments via URL param
* It's not ugly

Makefile

@@ -1066,17 +1066,52 @@ ifeq ($(PLATFORM),emscripten)
 
   CC=emcc
   ARCH=wasm32
+  BINEXT=.js
   
   # LDFLAGS+=-s MAIN_MODULE is needed for dlopen() in client/server but it causes compile errors
   USE_RENDERER_DLOPEN=0
+  USE_OPENAL_DLOPEN=0
+  USE_CURL=0
+  HAVE_VM_COMPILED=false
+  BUILD_GAME_SO=0
+  BUILD_GAME_QVM=0
+  # Would be interesting to try to get the server working via WebRTC DataChannel.
+  # This would enable P2P play, hosting a server in the browser. Also,
+  # DataChannel is the only way to use UDP in the browser.
+  BUILD_SERVER=0
+
+  CLIENT_EXTRA_FILES+=code/web/ioquake3.html
+
+  CLIENT_CFLAGS+=-s USE_SDL=2
+
+  CLIENT_LDFLAGS+=-s TOTAL_MEMORY=256mb
+  CLIENT_LDFLAGS+=-s STACK_SIZE=5MB
+  # Informing Emscripten which WebGL versions we support makes the JS bundle smaller and faster to load.
+  CLIENT_LDFLAGS+=-s MIN_WEBGL_VERSION=2
+  CLIENT_LDFLAGS+=-s MAX_WEBGL_VERSION=2
+  CLIENT_LDFLAGS+=-s FULL_ES2=1
+  # The HTML file can use these functions to load extra files before the game starts.
+  CLIENT_LDFLAGS+=-s EXPORTED_RUNTIME_METHODS=FS,addRunDependency,removeRunDependency
+  CLIENT_LDFLAGS+=-s EXIT_RUNTIME=1
+  CLIENT_LDFLAGS+=-s EXPORT_ES6
+  CLIENT_LDFLAGS+=-s EXPORT_NAME=ioquake3
+  # Game data files can be packaged by emcc into a .data file that lives next to the wasm bundle
+  # and added to the virtual filesystem before the game starts. This requires the game data to be
+  # present at build time and it can't be changed afterward.
+  # For more flexibility, game data files can be loaded from a web server at runtime by listing
+  # them in ioq3-config.json. This way they don't have to be present at build time and can be
+  # changed later.
+  ifneq ($(wildcard $(BASEGAME)/*),)
+    CLIENT_LDFLAGS+=--preload-file $(BASEGAME)
+    EMSCRIPTEN_PRELOAD_FILE=1
+    CLIENT_EXTRA_FILES+=code/web/empty/ioq3-config.json
+  else
+    CLIENT_EXTRA_FILES+=code/web/$(BASEGAME)/ioq3-config.json
+  endif
 
-  BASE_CFLAGS=-fPIC -s USE_SDL=2
-  LDFLAGS=-s STACK_SIZE=5MB -s TOTAL_MEMORY=256MB -s MAX_WEBGL_VERSION=2 --preload-file $(BASEGAME)
   OPTIMIZEVM = -O3
   OPTIMIZE = $(OPTIMIZEVM) -ffast-math
 
-  FULLBINEXT=.html
-
   SHLIBEXT=wasm
   SHLIBCFLAGS=-fPIC
   SHLIBLDFLAGS=-s SIDE_MODULE
@@ -1129,19 +1164,16 @@ ifneq ($(BUILD_SERVER),0)
   TARGETS += $(B)/$(SERVERBIN)$(FULLBINEXT)
 
   ifeq ($(PLATFORM),emscripten)
-    EMSCRIPTENOBJ += $(B)/$(SERVERBIN).js \
+    EMSCRIPTENOBJ+=$(B)/$(SERVERBIN).wasm
-                     $(B)/$(SERVERBIN).wasm \
+    ifeq ($(EMSCRIPTEN_PRELOAD_FILE),1)
-                     $(B)/$(SERVERBIN).data
+      EMSCRIPTENOBJ+=$(B)/$(SERVERBIN).data
+    endif
   endif
 endif
 
 ifneq ($(BUILD_CLIENT),0)
-  TARGETS += $(B)/$(CLIENTBIN)$(FULLBINEXT)
+  ifneq ($(PLATFORM),emscripten)
-
+    TARGETS += $(B)/$(CLIENTBIN)$(FULLBINEXT)
-  ifeq ($(PLATFORM),emscripten)
-    EMSCRIPTENOBJ += $(B)/$(CLIENTBIN).js \
-                     $(B)/$(CLIENTBIN).wasm \
-                     $(B)/$(CLIENTBIN).data
   endif
 
   ifneq ($(USE_RENDERER_DLOPEN),0)
@@ -1154,9 +1186,10 @@ ifneq ($(BUILD_CLIENT),0)
       TARGETS += $(B)/$(CLIENTBIN)_opengl2$(FULLBINEXT)
 
       ifeq ($(PLATFORM),emscripten)
-        EMSCRIPTENOBJ += $(B)/$(CLIENTBIN)_opengl2.js \
+        EMSCRIPTENOBJ+=$(B)/$(CLIENTBIN)_opengl2.wasm32.wasm
-                         $(B)/$(CLIENTBIN)_opengl2.wasm \
+        ifeq ($(EMSCRIPTEN_PRELOAD_FILE),1)
-                         $(B)/$(CLIENTBIN)_opengl2.data
+          EMSCRIPTENOBJ+=$(B)/$(CLIENTBIN)_opengl2.wasm32.data
+        endif
       endif
     endif
   endif
@@ -1504,6 +1537,7 @@ ifneq ($(BUILD_CLIENT),0)
 endif
 
 NAKED_TARGETS=$(shell echo $(TARGETS) | sed -e "s!$(B)/!!g")
+NAKED_EMSCRIPTENOBJ=$(shell echo $(EMSCRIPTENOBJ) | sed -e "s!$(B)/!!g")
 
 print_list=-@for i in $(1); \
      do \
@@ -1559,7 +1593,20 @@ endif
 	@echo ""
 	@echo "  Output:"
 	$(call print_list, $(NAKED_TARGETS))
+	$(call print_list, $(NAKED_EMSCRIPTENOBJ))
 	@echo ""
+ifeq ($(PLATFORM),emscripten)
+ifneq ($(EMSCRIPTEN_PRELOAD_FILE),1)
+	@echo "  Warning: Game files not found in '$(BASEGAME)'."
+	@echo "  They will not be packaged by Emscripten or preloaded."
+	@echo "  To run this build you must serve the game files from a web server"
+	@echo "  and list their paths in ioq3-config.json."
+	@echo "  To make a build that automatically loads the game files, create a"
+	@echo "  directory called '$(BASEGAME)' and copy your game files into it, then"
+	@echo "  'emmake make clean' and rebuild."
+	@echo ""
+endif
+endif
 ifneq ($(TARGETS),)
   ifndef DEBUG_MAKEFILE
 	@$(MAKE) $(TARGETS) $(B).zip V=$(V)
@@ -1575,7 +1622,7 @@ endif
 ifneq ($(PLATFORM),darwin)
   ifdef ARCHIVE
 	@rm -f $@
-	@(cd $(B) && zip -r9 ../../$@ $(NAKED_TARGETS))
+	@(cd $(B) && zip -r9 ../../$@ $(NAKED_TARGETS) $(NAKED_EMSCRIPTENOBJ))
   endif
 endif
 

code/web/baseq3/ioq3-config.json

@@ -0,0 +1,13 @@
+{
+    "files": [
+        {"src": "baseq3/pak0.pk3", "dst": "/baseq3"},
+        {"src": "baseq3/pak1.pk3", "dst": "/baseq3"},
+        {"src": "baseq3/pak2.pk3", "dst": "/baseq3"},
+        {"src": "baseq3/pak3.pk3", "dst": "/baseq3"},
+        {"src": "baseq3/pak4.pk3", "dst": "/baseq3"},
+        {"src": "baseq3/pak5.pk3", "dst": "/baseq3"},
+        {"src": "baseq3/pak6.pk3", "dst": "/baseq3"},
+        {"src": "baseq3/pak7.pk3", "dst": "/baseq3"},
+        {"src": "baseq3/pak8.pk3", "dst": "/baseq3"}
+    ]
+}

code/web/empty/ioq3-config.json

@@ -0,0 +1,3 @@
+{
+    "files": []
+}

code/web/ioquake3.html

@@ -0,0 +1,70 @@
+<!DOCTYPE html><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1">
+<title>ioquake3 Emscripten demo</title>
+<style>
+html, body { margin: 0; padding: 0; width: 100%; height: 100%; overflow: hidden; background: rgb(0, 0, 0); display:flex; align-items: center; justify-content: center; }
+canvas { max-width: 100%; max-height: 100%; min-width: 100%; min-height: 100%; object-fit: contain; }
+</style>
+
+<canvas id=canvas></canvas>
+
+<script type=module>
+if (window.location.protocol === 'file:') throw new Error('Unfortunately browser security restrictions prevent loading wasm from a file: URL. This file must be loaded from a web server. The easiest way to do this is probably to use Python\'s built-in web server by running `python3 -m http.server` in the top level ioq3 directory and then navigating to http://localhost:8000/code/web/ioquake3.html');
+
+// First set up the command line arguments and the Emscripten filesystem.
+const urlParams = new URLSearchParams(window.location.search);
+const basegame = urlParams.get('basegame') || 'baseq3';
+let generatedArguments = `
+    +set net_enabled 0
+    +set r_mode -2
+    +set fs_game ${basegame}
+`;
+// Note that unfortunately "+" needs to be encoded as "%2b" in URL query strings or it will be stripped by the browser.
+const queryArgs = urlParams.get('args');
+if (queryArgs) generatedArguments += ` ${queryArgs} `;
+
+// If buildPath is not specified, try to find a build in one of a few default paths.
+let buildPath = urlParams.get('buildPath');
+if (buildPath && !buildPath.endsWith('/')) buildPath += '/';
+const buildPaths = buildPath ? [buildPath] : ['../../build/debug-emscripten-wasm32/', '../../build/release-emscripten-wasm32/', './'];
+const scriptPaths = buildPaths.map(buildPath => buildPath + 'ioquake3_opengl2.wasm32.js');
+const scriptResponses = await Promise.all(scriptPaths.map(p => fetch(p, {method: 'HEAD'})));
+const validBuilds = scriptResponses.filter(r => r.ok).length;
+const goodURL = (newPath) => {
+    const url = new URL(window.location);
+    url.searchParams.set('buildPath', newPath);
+    return url.toString().replace(/%2f/gi, '/');
+};
+if (validBuilds === 0) throw new Error(`Didn't find any wasm builds. Run \`emmake make debug\` to build one, or use the buildPath query parameter to specify a directory containing ioquake3_opengl2.wasm32.[js,wasm,data], e.g. ${goodURL('../../build/debug-emscripten-wasm32/')}`);
+if (validBuilds > 1) throw new Error(`Found multiple valid builds at the following paths: [${buildPaths.filter((path, i)=>scriptResponses[i].ok)}]. Please specify which one to run by adding a buildPath query parameter to the URL, e.g. ${goodURL(buildPaths.filter((path, i)=>scriptResponses[i].ok)[0])}`);
+const buildIndex = scriptResponses.findIndex(r => r.ok);
+const selectedScript = scriptPaths[buildIndex];
+buildPath = buildPaths[buildIndex];
+const buildURL = new URL(buildPath, location.origin + location.pathname);
+
+const configPromise = fetch(buildPath + 'ioq3-config.json').then(r => r.ok ? r.json() : {files: []});
+
+const ioquake3 = (await import(selectedScript)).default;
+ioquake3({
+    canvas: canvas,
+    arguments: generatedArguments.trim().split(/\s+/),
+    locateFile: (file) => buildPath + file,
+    preRun: [async (module) => {
+        module.addRunDependency('setup-ioq3-filesystem');
+        try {
+            const config = await configPromise;
+            const fetches = config.files.map(file => fetch(new URL(file.src, buildURL)));
+            for (let i = 0; i < config.files.length; i++) {
+                const response = await fetches[i];
+                if (!response.ok) continue;
+                const data = await response.arrayBuffer();
+                let name = config.files[i].src.match(/[^/]+$/)[0];
+                let dir = config.files[i].dst;
+                module.FS.mkdirTree(dir);
+                module.FS.writeFile(`${dir}/${name}`, new Uint8Array(data));
+            }
+        } finally {
+            module.removeRunDependency('setup-ioq3-filesystem');
+        }
+    }],
+});
+</script>