add theming support, fix ui issues, add ui scaling option

Scripts/GraphicsOptions.gd

@@ -0,0 +1,37 @@
+extends Panel
+
+@export var thisTab = 0
+
+func _ready() -> void:
+	$AAOption.select(get_viewport().msaa_3d)
+	$SSAAOption.select(get_viewport().screen_space_aa)
+	$FOVSlider.value = Globalvariables.FOV
+	$FOVSlider/CurrentLabel.text = str(int(Globalvariables.FOV))
+
+func _on_tab_bar_tab_changed(tab: int) -> void:
+	if (thisTab == tab):
+		visible = true
+	else:
+		visible = false
+
+func _on_fov_slider_value_changed(value: float) -> void:
+	Globalvariables.FOV = value
+	$FOVSlider/CurrentLabel.text = str(int(value))
+	Globalvariables.updateConfig()
+
+
+func _on_option_aa_ss_item_selected(index: int) -> void:
+	get_viewport().screen_space_aa = int(index == 1) as Viewport.ScreenSpaceAA
+	Globalvariables.updateConfig()
+
+
+func _on_option_aa_msaa_item_selected(index: int) -> void:
+	if index == 0: # Disabled
+		get_viewport().msaa_3d = Viewport.MSAA_DISABLED
+	elif index == 1: # 2×
+		get_viewport().msaa_3d = Viewport.MSAA_2X
+	elif index == 2: # 4×
+		get_viewport().msaa_3d = Viewport.MSAA_4X
+	elif index == 3: # 8×
+		get_viewport().msaa_3d = Viewport.MSAA_8X
+	Globalvariables.updateConfig()