refactor: remember emulation window resizes (fixes #1568)

When using Windowed mode, if the emulation window is manually resized, that position will be remembered and restored, if the GUI is opened and closed again.

src/osdep/amiberry.cpp

@@ -443,10 +443,8 @@ static void setcursor(struct AmigaMonitor* mon, int oldx, int oldy)
 
 	mon->windowmouse_max_w = mon->amigawinclip_rect.w / 2 - 50;
 	mon->windowmouse_max_h = mon->amigawinclip_rect.h / 2 - 50;
-	if (mon->windowmouse_max_w < 10)
-		mon->windowmouse_max_w = 10;
-	if (mon->windowmouse_max_h < 10)
-		mon->windowmouse_max_h = 10;
+	mon->windowmouse_max_w = std::max(mon->windowmouse_max_w, 10);
+	mon->windowmouse_max_h = std::max(mon->windowmouse_max_h, 10);
 
 	if ((currprefs.input_mouse_untrap & MOUSEUNTRAP_MAGIC) && currprefs.input_tablet > 0 && mousehack_alive() && isfullscreen() <= 0) {
 		mon->mouseposx = mon->mouseposy = 0;

src/osdep/amiberry_gfx.cpp

@@ -2522,7 +2522,14 @@ bool target_graphics_buffer_update(int monid, bool force)
 
 		if (mon->amiga_window && isfullscreen() == 0)
 		{
-			SDL_SetWindowSize(mon->amiga_window, scaled_width, scaled_height);
+			if (mon->amigawin_rect.w != 800 && mon->amigawin_rect.h != 600)
+			{
+				SDL_SetWindowSize(mon->amiga_window, mon->amigawin_rect.w, mon->amigawin_rect.h);
+			}
+			else
+			{
+				SDL_SetWindowSize(mon->amiga_window, scaled_width, scaled_height);
+			}
 		}
 #ifdef USE_OPENGL
 		if (!currprefs.gfx_auto_crop && !currprefs.gfx_manual_crop) {
@@ -2561,7 +2568,9 @@ bool target_graphics_buffer_update(int monid, bool force)
 			set_scaling_option(&currprefs, scaled_width, scaled_height);
 		}
 		else
+		{
 			return false;
+		}
 #endif
 	}