New command line option to start emu with mouse captured (#190)

README.md

@@ -101,6 +101,7 @@ When starting `x16emu` without arguments, it will pick up the system ROM (`rom.b
 * `-nvram` lets you specify a 64 byte file for the system's non-volatile RAM. If it does not exist, it will be created once the NVRAM is modified.
 * `-keymap` tells the KERNAL to switch to a specific keyboard layout. Use it without an argument to view the supported layouts.
 * `-noemucmdkeys`  Disable emulator command keys.
+* `-capture` starts the emulator with the mouse/keyboard captured
 * `-sdcard` lets you specify an SD card image (partition table + FAT32). Without this option, drive 8 will interface to the current directory on the host.
 * `-fsroot <dir>` specifies a file system root for the HostFS interface. This lets you save and load files without an SD card image. (As of R42, this is the preferred method.) Default is the current working directory.
 * `-startin <dir>` specify the host filesystem directory path that the emulated filesystem starts in. Default is the current working directory if it lies within the hierarchy of fsroot, otherwise it defaults to fsroot itself.

src/glue.h

@@ -71,6 +71,7 @@ extern uint8_t *fsroot_path;
 extern uint8_t *startin_path;
 extern uint8_t keymap;
 extern bool warp_mode;
+extern bool grab_mouse;
 extern bool testbench;
 extern bool has_via2;
 extern uint32_t host_sample_rate;

src/main.c

@@ -103,6 +103,7 @@ bool dump_ram = true;
 bool dump_bank = true;
 bool dump_vram = false;
 bool warp_mode = false;
+bool grab_mouse = false;
 echo_mode_t echo_mode;
 bool save_on_exit = true;
 bool disable_emu_cmd_keys = false;
@@ -381,6 +382,8 @@ usage()
 	printf("\totherwise it defaults to fsroot itself.\n");
 	printf("-noemucmdkeys\n");
 	printf("\tDisable emulator command keys.\n");
+	printf("-capture\n");
+	printf("\tStart emulator with mouse/keyboard captured.\n");
 	printf("-prg <app.prg>[,<load_addr>]\n");
 	printf("\tLoad application from the *host filesystem* into RAM,\n");
 	printf("\teven if an SD card is attached.\n");
@@ -896,6 +899,10 @@ main(int argc, char **argv)
 			argc--;
 			argv++;
 			disable_emu_cmd_keys = true;
+		} else if (!strcmp(argv[0], "-capture")) {
+			argc--;
+			argv++;
+			grab_mouse = true;
 		} else if (!strcmp(argv[0], "-via2")) {
 			argc--;
 			argv++;

src/video.c

@@ -201,6 +201,16 @@ static void video_space_read_range(uint8_t* dest, uint32_t address, uint32_t siz
 
 static void refresh_palette();
 
+void
+mousegrab_toggle() {
+	mouse_grabbed = !mouse_grabbed;
+	SDL_SetWindowGrab(window, mouse_grabbed);
+	SDL_SetRelativeMouseMode(mouse_grabbed);
+	SDL_ShowCursor((mouse_grabbed || kernal_mouse_enabled) ? SDL_DISABLE : SDL_ENABLE);
+	sprintf(window_title, WINDOW_TITLE "%s", mouse_grabbed ? MOUSE_GRAB_MSG : "");
+	video_update_title(window_title);
+}
+
 void
 video_reset()
 {
@@ -358,6 +368,9 @@ video_init(int window_scale, float screen_x_scale, char *quality, bool fullscree
 		DEBUGInitUI(renderer);
 	}
 
+	if (grab_mouse && !mouse_grabbed)
+		mousegrab_toggle();
+
 	return true;
 }
 
@@ -531,16 +544,6 @@ struct video_sprite_properties
 	uint16_t palette_offset;
 };
 
-void
-mousegrab_toggle() {
-	mouse_grabbed = !mouse_grabbed;
-	SDL_SetWindowGrab(window, mouse_grabbed);
-	SDL_SetRelativeMouseMode(mouse_grabbed);
-	SDL_ShowCursor((mouse_grabbed || kernal_mouse_enabled) ? SDL_DISABLE : SDL_ENABLE);
-	sprintf(window_title, WINDOW_TITLE "%s", mouse_grabbed ? MOUSE_GRAB_MSG : "");
-	video_update_title(window_title);
-}
-
 #ifndef __EMSCRIPTEN__
 static void
 screenshot(void)