Allow pixelnuke to be fullscreened on startup by commandline argument

README.md

@@ -67,6 +67,11 @@ Server written in C, based on libevent2, OpenGL, GLFW and pthreads. It won't get
     make
     ./pixelnuke
 
+Commandline Arguments:
+
+* `H`: Show help for commandline arguments
+* `F[screen_id]`: Start fullscreened. You can additionally specify the fullscreen monitor by adding a screen id from 0 to 9 after the F
+
 Keyboard controls:
 
 * `F11`: Toggle between fullscreen and windowed mode

pixelnuke/pixelnuke.c

@@ -183,13 +183,37 @@ void px_on_window_close() {
 	net_stop();
 }
 
+uint8_t args_parse_and_act(int argc, char **argv) {
+	for (int arg = 1; arg < argc; ++arg) {
+		switch (argv[arg][0]) { //compare first char of argument
+			case 'H':
+				printf("==pixelnuke commandline arguments==\nH\t\tshows this help\nF[screen_id]\tStart fullscreened. You can additionally specify the fullscreen monitor\n\t\tby adding a screen id from 0 to 9 after the F, the default is 0.\n");
+				return 1; //1 means please quit
+			case 'F':
+				; //funny C quirk not allowing lables before declarations
+				int target_fs_disp = 0;
+				if (argv[arg][1] != 0) { //if not null
+					int possible_num = argv[arg][1] - '0'; //convert to number if in range 0-9
+					if (possible_num >= 0 && possible_num <= 9) { //check if range fits
+						target_fs_disp = possible_num;
+					}
+				}
+				printf("Fullscreening on display %d due to cmdline arg\n", target_fs_disp);
+				canvas_fullscreen(target_fs_disp); //fullscreen pxnuke on the target screen
+				return 0;
+		}
+	}
+	return 0;
+}
+
 int main(int argc, char **argv) {
 	canvas_setcb_key(&px_on_key);
 	canvas_setcb_resize(&px_on_resize);
 
 	canvas_start(1024, &px_on_window_close);
 
+	if (args_parse_and_act(argc, argv)) return 0; //handle args and quit if needed
+
 	net_start(1337, &px_on_connect, &px_on_read, &px_on_close);
 	return 0;
 }
-