From ee514710c5446154c0440a2b8a2bce7a4c7798d3 Mon Sep 17 00:00:00 2001
From: smallmodel <15067410+smallmodel@users.noreply.github.com>
Date: Fri, 26 Jul 2024 23:57:35 +0200
Subject: [PATCH] Add Emscripten implementation from ioquake3 upstream

---
 code/qcommon/q_platform.h   |  16 ++++
 code/sdl/sdl_glimp.c        | 141 ++++++++++++++++++++++++++----------
 code/web/client-config.json |  47 ++++++++++++
 code/web/client.html        | 116 +++++++++++++++++++++++++++++
 4 files changed, 280 insertions(+), 40 deletions(-)
 create mode 100644 code/web/client-config.json
 create mode 100644 code/web/client.html

diff --git a/code/qcommon/q_platform.h b/code/qcommon/q_platform.h
index bc4960c5..a47f6739 100644
--- a/code/qcommon/q_platform.h
+++ b/code/qcommon/q_platform.h
@@ -355,6 +355,22 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 
 #endif
 
+//================================================================== EMSCRIPTEN ===
+
+#ifdef __EMSCRIPTEN__
+
+#define OS_STRING "emscripten"
+#define ID_INLINE inline
+#define PATH_SEP '/'
+
+#define ARCH_STRING "wasm32"
+
+#define Q3_LITTLE_ENDIAN
+
+#define DLL_EXT ".wasm"
+
+#endif
+
 //================================================================== Q3VM ===
 
 #ifdef Q3_VM
diff --git a/code/sdl/sdl_glimp.c b/code/sdl/sdl_glimp.c
index 528f3a06..af653d70 100644
--- a/code/sdl/sdl_glimp.c
+++ b/code/sdl/sdl_glimp.c
@@ -52,6 +52,7 @@ cvar_t *r_allowSoftwareGL; // Don't abort out if a hardware visual can't be obta
 cvar_t *r_allowResize; // make window resizable
 cvar_t *r_centerWindow;
 cvar_t *r_sdlDriver;
+cvar_t *r_useOpenGLES;
 
 int qglMajorVersion, qglMinorVersion;
 int qglesMajorVersion, qglesMinorVersion;
@@ -230,6 +231,27 @@ static void GLimp_DetectAvailableModes(void)
 	SDL_free( modes );
 }
 
+/*
+===============
+OpenGL ES compatibility
+===============
+*/
+static void APIENTRY GLimp_GLES_ClearDepth( GLclampd depth ) {
+	qglClearDepthf( depth );
+}
+
+static void APIENTRY GLimp_GLES_DepthRange( GLclampd near_val, GLclampd far_val ) {
+	qglDepthRangef( near_val, far_val );
+}
+
+static void APIENTRY GLimp_GLES_DrawBuffer( GLenum mode ) {
+	// unsupported
+}
+
+static void APIENTRY GLimp_GLES_PolygonMode( GLenum face, GLenum mode ) {
+	// unsupported
+}
+
 /*
 ===============
 GLimp_GetProcAddresses
@@ -293,6 +315,7 @@ static qboolean GLimp_GetProcAddresses( qboolean fixedFunction ) {
 		} else {
 			Com_Error( ERR_FATAL, "Unsupported OpenGL Version (%s), OpenGL 1.1 is required", version );
 		}
+		// Add compression-related GL functions for the renderer
 		if ( QGL_VERSION_ATLEAST( 1, 3 ) ) {
 			QGL_1_3_PROCS;
 		}
@@ -309,8 +332,11 @@ static qboolean GLimp_GetProcAddresses( qboolean fixedFunction ) {
 			QGL_1_3_PROCS;
 			QGL_1_5_PROCS;
 			QGL_2_0_PROCS;
-			// error so this doesn't segfault due to NULL desktop GL functions being used
-			Com_Error( ERR_FATAL, "Unsupported OpenGL Version: %s", version );
+
+			qglClearDepth = GLimp_GLES_ClearDepth;
+			qglDepthRange = GLimp_GLES_DepthRange;
+			qglDrawBuffer = GLimp_GLES_DrawBuffer;
+			qglPolygonMode = GLimp_GLES_PolygonMode;
 		} else {
 			Com_Error( ERR_FATAL, "Unsupported OpenGL Version (%s), OpenGL 2.0 is required", version );
 		}
@@ -636,57 +662,91 @@ static int GLimp_SetMode(int mode, qboolean fullscreen, qboolean noborder, qbool
 
 		if (!fixedFunction)
 		{
-			int profileMask, majorVersion, minorVersion;
-			SDL_GL_GetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, &profileMask);
-			SDL_GL_GetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, &majorVersion);
-			SDL_GL_GetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, &minorVersion);
+			int profileMask;
 
-			ri.Printf(PRINT_ALL, "Trying to get an OpenGL 3.2 core context\n");
-			SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
-			SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
-			SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 2);
-			if ((SDL_glContext = SDL_GL_CreateContext(SDL_window)) == NULL)
+			SDL_GL_GetAttribute( SDL_GL_CONTEXT_PROFILE_MASK, &profileMask );
+
+			if ( r_useOpenGLES->integer == 1 || ( r_useOpenGLES->integer == -1 && profileMask == SDL_GL_CONTEXT_PROFILE_ES ) )
 			{
-				ri.Printf(PRINT_ALL, "SDL_GL_CreateContext failed: %s\n", SDL_GetError());
-				ri.Printf(PRINT_ALL, "Reverting to default context\n");
+				ri.Printf( PRINT_ALL, "Trying to get an OpenGL ES 2.0 context\n" );
+				SDL_GL_SetAttribute( SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_ES );
+				SDL_GL_SetAttribute( SDL_GL_CONTEXT_MAJOR_VERSION, 2 );
+				SDL_GL_SetAttribute( SDL_GL_CONTEXT_MINOR_VERSION, 0 );
 
-				SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, profileMask);
-				SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, majorVersion);
-				SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, minorVersion);
-			}
-			else
-			{
-				const char *renderer;
-
-				ri.Printf(PRINT_ALL, "SDL_GL_CreateContext succeeded.\n");
-
-				if ( GLimp_GetProcAddresses( fixedFunction ) )
+				SDL_glContext = SDL_GL_CreateContext( SDL_window );
+				if ( !SDL_glContext )
 				{
-					renderer = (const char *)qglGetString(GL_RENDERER);
+					ri.Printf( PRINT_ALL, "SDL_GL_CreateContext failed: %s\n", SDL_GetError() );
 				}
 				else
 				{
-					ri.Printf( PRINT_ALL, "GLimp_GetProcAddresses() failed for OpenGL 3.2 core context\n" );
-					renderer = NULL;
-				}
+					ri.Printf( PRINT_ALL, "SDL_GL_CreateContext succeeded.\n" );
 
-				if (!renderer || (strstr(renderer, "Software Renderer") || strstr(renderer, "Software Rasterizer")))
+					if ( !GLimp_GetProcAddresses( fixedFunction ) )
+					{
+						ri.Printf( PRINT_ALL, "GLimp_GetProcAddresses() failed for OpenGL ES 2.0 context\n" );
+						GLimp_ClearProcAddresses();
+						SDL_GL_DeleteContext( SDL_glContext );
+						SDL_glContext = NULL;
+					}
+				}
+			}
+
+			if ( !SDL_glContext )
+			{
+				ri.Printf( PRINT_ALL, "Trying to get an OpenGL 3.2 core context\n" );
+				SDL_GL_SetAttribute( SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE );
+				SDL_GL_SetAttribute( SDL_GL_CONTEXT_MAJOR_VERSION, 3 );
+				SDL_GL_SetAttribute( SDL_GL_CONTEXT_MINOR_VERSION, 2 );
+
+				SDL_glContext = SDL_GL_CreateContext( SDL_window );
+				if ( !SDL_glContext )
 				{
-					if ( renderer )
-						ri.Printf(PRINT_ALL, "GL_RENDERER is %s, rejecting context\n", renderer);
-
-					GLimp_ClearProcAddresses();
-					SDL_GL_DeleteContext(SDL_glContext);
-					SDL_glContext = NULL;
-
-					SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, profileMask);
-					SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, majorVersion);
-					SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, minorVersion);
+					ri.Printf( PRINT_ALL, "SDL_GL_CreateContext failed: %s\n", SDL_GetError() );
 				}
+				else
+				{
+					const char *renderer;
+
+					ri.Printf( PRINT_ALL, "SDL_GL_CreateContext succeeded.\n" );
+
+					if ( GLimp_GetProcAddresses( fixedFunction ) )
+					{
+						renderer = (const char *)qglGetString( GL_RENDERER );
+					}
+					else
+					{
+						ri.Printf( PRINT_ALL, "GLimp_GetProcAddresses() failed for OpenGL 3.2 core context\n" );
+						renderer = NULL;
+					}
+
+					if ( !renderer || strstr( renderer, "Software Renderer" ) || strstr( renderer, "Software Rasterizer" ) )
+					{
+						if ( renderer )
+							ri.Printf(PRINT_ALL, "GL_RENDERER is %s, rejecting context\n", renderer);
+
+						GLimp_ClearProcAddresses();
+						SDL_GL_DeleteContext( SDL_glContext );
+						SDL_glContext = NULL;
+					}
+				}
+			}
+
+			if ( !SDL_glContext )
+			{
+				ri.Printf( PRINT_ALL, "Trying to get an OpenGL 2.0 context\n" );
+
+				SDL_GL_SetAttribute( SDL_GL_CONTEXT_PROFILE_MASK, 0 );
+				SDL_GL_SetAttribute( SDL_GL_CONTEXT_MAJOR_VERSION, 2 );
+				SDL_GL_SetAttribute( SDL_GL_CONTEXT_MINOR_VERSION, 0 );
 			}
 		}
 		else
 		{
+			SDL_GL_SetAttribute( SDL_GL_CONTEXT_PROFILE_MASK, 0 );
+			SDL_GL_SetAttribute( SDL_GL_CONTEXT_MAJOR_VERSION, 1 );
+			SDL_GL_SetAttribute( SDL_GL_CONTEXT_MINOR_VERSION, 1 );
+
 			SDL_glContext = NULL;
 		}
 
@@ -818,7 +878,7 @@ static void GLimp_InitExtensions( qboolean fixedFunction )
 	glConfig.textureCompression = TC_NONE;
 
 	// GL_EXT_texture_compression_s3tc
-	if ( SDL_GL_ExtensionSupported( "GL_ARB_texture_compression" ) &&
+	if ( ( QGLES_VERSION_ATLEAST( 2, 0 ) || SDL_GL_ExtensionSupported( "GL_ARB_texture_compression" ) ) &&
 	     SDL_GL_ExtensionSupported( "GL_EXT_texture_compression_s3tc" ) )
 	{
 		if ( r_ext_compressed_textures->value )
@@ -999,6 +1059,7 @@ void GLimp_Init( qboolean fixedFunction )
 	r_sdlDriver = ri.Cvar_Get( "r_sdlDriver", "", CVAR_ROM );
 	r_allowResize = ri.Cvar_Get( "r_allowResize", "0", CVAR_ARCHIVE | CVAR_LATCH );
 	r_centerWindow = ri.Cvar_Get( "r_centerWindow", "0", CVAR_ARCHIVE | CVAR_LATCH );
+	r_useOpenGLES = ri.Cvar_Get( "r_useOpenGLES", "-1", CVAR_ARCHIVE | CVAR_LATCH );
 
 	if( ri.Cvar_VariableIntegerValue( "com_abnormalExit" ) )
 	{
diff --git a/code/web/client-config.json b/code/web/client-config.json
new file mode 100644
index 00000000..eddf35db
--- /dev/null
+++ b/code/web/client-config.json
@@ -0,0 +1,47 @@
+{
+    "baseq3": {
+        "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"},
+            {"src": "baseq3/vm/cgame.qvm", "dst": "/baseq3/vm"},
+            {"src": "baseq3/vm/qagame.qvm", "dst": "/baseq3/vm"},
+            {"src": "baseq3/vm/ui.qvm", "dst": "/baseq3/vm"}
+        ]
+    },
+    "missionpack": {
+        "files": [
+            {"src": "missionpack/pak0.pk3", "dst": "/missionpack"},
+            {"src": "missionpack/pak1.pk3", "dst": "/missionpack"},
+            {"src": "missionpack/pak2.pk3", "dst": "/missionpack"},
+            {"src": "missionpack/pak3.pk3", "dst": "/missionpack"},
+            {"src": "missionpack/vm/cgame.qvm", "dst": "/missionpack/vm"},
+            {"src": "missionpack/vm/qagame.qvm", "dst": "/missionpack/vm"},
+            {"src": "missionpack/vm/ui.qvm", "dst": "/missionpack/vm"}
+        ]
+    },
+    "demoq3": {
+        "_comment": "Copy baseq3/vm/*.qvm to demoq3/vm/ as the Quake 3 demo QVMs are not compatible. However the botfiles are not fully compatible with newer QVMs.",
+        "files": [
+            {"src": "demoq3/pak0.pk3", "dst": "/demoq3"},
+            {"src": "demoq3/vm/cgame.qvm", "dst": "/demoq3/vm"},
+            {"src": "demoq3/vm/qagame.qvm", "dst": "/demoq3/vm"},
+            {"src": "demoq3/vm/ui.qvm", "dst": "/demoq3/vm"}
+        ]
+    },
+    "tademo": {
+        "_comment": "Copy missionpack/vm/*.qvm to tademo/vm/ as the Team Arena demo QVMs are not compatible.",
+        "files": [
+            {"src": "tademo/pak0.pk3", "dst": "/tademo"},
+            {"src": "tademo/vm/cgame.qvm", "dst": "/tademo/vm"},
+            {"src": "tademo/vm/qagame.qvm", "dst": "/tademo/vm"},
+            {"src": "tademo/vm/ui.qvm", "dst": "/tademo/vm"}
+        ]
+    }
+}
diff --git a/code/web/client.html b/code/web/client.html
new file mode 100644
index 00000000..3a23ab92
--- /dev/null
+++ b/code/web/client.html
@@ -0,0 +1,116 @@
+<!DOCTYPE html><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1">
+<title>__CLIENTBIN__ 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>
+// These strings are set in the generated HTML file in the build directory.
+let CLIENTBIN = '__CLIENTBIN__';
+let BASEGAME = '__BASEGAME__';
+let EMSCRIPTEN_PRELOAD_FILE = Number('__EMSCRIPTEN_PRELOAD_FILE__');
+// Detect if it's not the generated HTML file.
+let clientHtmlFallback = (CLIENTBIN === '\_\_CLIENTBIN\_\_');
+
+// Path or URL containing the client engine .js, .wasm, and possibly .data.
+let enginePath = './';
+// Path or URL containing fs_game directories.
+let dataPath = './';
+// Path or URL for config file that specifies the files to load for each fs_game.
+let configFilename = `./${CLIENTBIN}-config.json`;
+
+// If displaying the unmodified HTML file, fallback to defaults.
+if (clientHtmlFallback) {
+    CLIENTBIN='ioquake3';
+    BASEGAME='baseq3';
+    EMSCRIPTEN_PRELOAD_FILE=0;
+    configFilename='./client-config.json';
+}
+
+if (window.location.protocol === 'file:') throw new Error(`Unfortunately browser security restrictions prevent loading wasm from a file: URL. This file must be loaded from a web server. The easiest way to do this is probably to use Python\'s built-in web server by running \`python3 -m http.server\` in the top level source directory and then navigate to http://localhost:8000/build/debug-emscripten-wasm32/${CLIENTBIN}.html`);
+
+// First set up the command line arguments and the Emscripten filesystem.
+const urlParams = new URLSearchParams(window.location.search);
+const com_basegame = urlParams.get('com_basegame') || BASEGAME;
+const fs_basegame = urlParams.get('fs_basegame') || '';
+const fs_game = urlParams.get('fs_game') || '';
+let generatedArguments = `
+    +set sv_pure 0
+    +set net_enabled 0
+    +set r_mode -2
+    +set com_basegame "${com_basegame}"
+    +set fs_basegame "${fs_basegame}"
+    +set fs_game "${fs_game}"
+`;
+// 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 += ` ${queryArgs} `;
+
+// If displaying the unmodified HTML file, the engine and data are probably located in a different directory.
+if (clientHtmlFallback) {
+    // If buildPath is not specified, try to find a build in one of a few default paths.
+    let buildPath = urlParams.get('buildPath');
+    if (buildPath && !buildPath.endsWith('/')) buildPath += '/';
+    const buildPaths = buildPath ? [buildPath] : ['../../build/debug-emscripten-wasm32/', '../../build/release-emscripten-wasm32/', './'];
+    const scriptPaths = buildPaths.map(buildPath => buildPath + `${CLIENTBIN}_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 ${CLIENTBIN}_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. ${goodURL(buildPaths.filter((path, i)=>scriptResponses[i].ok)[0])}`);
+    const buildIndex = scriptResponses.findIndex(r => r.ok);
+
+    enginePath = buildPaths[buildIndex];
+    dataPath = buildPaths[buildIndex];
+}
+
+const dataURL = new URL(dataPath, location.origin + location.pathname);
+
+const configPromise = ( EMSCRIPTEN_PRELOAD_FILE === 1 ) ? Promise.resolve({[BASEGAME]: {files: []}})
+  : fetch(configFilename).then(r => r.ok ? r.json() : { /* empty config */ });
+
+const ioquake3 = (await import(enginePath + `${CLIENTBIN}_opengl2.wasm32.js`)).default;
+ioquake3({
+    canvas: canvas,
+    arguments: generatedArguments.trim().split(/\s+/),
+    locateFile: (file) => enginePath + file,
+    preRun: [async (module) => {
+        module.addRunDependency('setup-ioq3-filesystem');
+        try {
+            const config = await configPromise;
+            const gamedirs = [com_basegame,fs_basegame,fs_game];
+            for (let g = 0; g < gamedirs.length; g++) {
+                const gamedir = gamedirs[g];
+                if (gamedir === '') {
+                    continue;
+                }
+                if (config[gamedir] === null
+                 || config[gamedir].files === null) {
+                    console.warn(`Game directory '${gamedir}' cannot be used. It must have files listed in ${configFilename}.`);
+                    continue;
+                }
+                const files = config[gamedir].files;
+                const fetches = files.map(file => fetch(new URL(file.src, dataURL)));
+                for (let i = 0; i < files.length; i++) {
+                    const response = await fetches[i];
+                    if (!response.ok) continue;
+                    const data = await response.arrayBuffer();
+                    let name = files[i].src.match(/[^/]+$/)[0];
+                    let dir = files[i].dst;
+                    module.FS.mkdirTree(dir);
+                    module.FS.writeFile(`${dir}/${name}`, new Uint8Array(data));
+                }
+            }
+        } finally {
+            module.removeRunDependency('setup-ioq3-filesystem');
+        }
+    }],
+});
+</script>