Add minimal emscripten support

code/qcommon/q_platform.h

@@ -290,6 +290,22 @@ 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

code/sdl/sdl_glimp.c

@@ -398,7 +398,7 @@ static int GLimp_SetMode(int mode, qboolean fullscreen, qboolean noborder, qbool
 		int profileMask;
 		int majorVersion;
 		int minorVersion;
-	} contexts[3];
+	} contexts[4];
 	int numContexts, type;
 	const char *glstring;
 	int perChannelColorBits;
@@ -543,6 +543,14 @@ static int GLimp_SetMode(int mode, qboolean fullscreen, qboolean noborder, qbool
 		                 ( r_preferOpenGLES->integer == -1 && profileMask == SDL_GL_CONTEXT_PROFILE_ES ) );
 
 		if ( preferOpenGLES ) {
+#ifdef __EMSCRIPTEN__
+			// WebGL 2.0 isn't fully backward compatible so you have to ask for it specifically
+			contexts[numContexts].profileMask = SDL_GL_CONTEXT_PROFILE_ES;
+			contexts[numContexts].majorVersion = 3;
+			contexts[numContexts].minorVersion = 0;
+			numContexts++;
+#endif
+
 			contexts[numContexts].profileMask = SDL_GL_CONTEXT_PROFILE_ES;
 			contexts[numContexts].majorVersion = 2;
 			contexts[numContexts].minorVersion = 0;
@@ -560,6 +568,13 @@ static int GLimp_SetMode(int mode, qboolean fullscreen, qboolean noborder, qbool
 		numContexts++;
 
 		if ( !preferOpenGLES ) {
+#ifdef __EMSCRIPTEN__
+			contexts[numContexts].profileMask = SDL_GL_CONTEXT_PROFILE_ES;
+			contexts[numContexts].majorVersion = 3;
+			contexts[numContexts].minorVersion = 0;
+			numContexts++;
+#endif
+
 			contexts[numContexts].profileMask = SDL_GL_CONTEXT_PROFILE_ES;
 			contexts[numContexts].majorVersion = 2;
 			contexts[numContexts].minorVersion = 0;

code/sys/sys_main.c

@@ -31,6 +31,10 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 #include <ctype.h>
 #include <errno.h>
 
+#ifdef __EMSCRIPTEN__
+#include <emscripten/emscripten.h>
+#endif
+
 #ifndef DEDICATED
 #ifdef USE_LOCAL_HEADERS
 #	include "SDL.h"
@@ -863,10 +867,14 @@ int main( int argc, char **argv )
 	signal( SIGTERM, Sys_SigHandler );
 	signal( SIGINT, Sys_SigHandler );
 
+#ifdef __EMSCRIPTEN__
+	emscripten_set_main_loop( Com_Frame, 0, 1 );
+#else
 	while( 1 )
 	{
 		Com_Frame( );
 	}
+#endif
 
 	return 0;
 }