closes #755

you'll have to do your own testing btw, I'm too tired (and lazy) :P
but it looks fine to me, so it should work in theory (and yeah, it works the same as setSpriteShader, you must initialize the shader first before you can use it)

source/FunkinLua.hx

@@ -34,6 +34,7 @@ import flixel.util.FlxSave;
 import flixel.addons.transition.FlxTransitionableState;
 import flixel.system.FlxAssets.FlxShader;
 import Shaders;
+import openfl.filters.ShaderFilter;
 
 #if (!flash && sys)
 import flixel.addons.display.FlxRuntimeShader;
@@ -65,6 +66,10 @@ class FunkinLua {
 	public static var Function_Continue:Dynamic = "##PSYCHLUA_FUNCTIONCONTINUE";
 	public static var Function_StopLua:Dynamic = "##PSYCHLUA_FUNCTIONSTOPLUA";
 
+	#if (!flash && MODS_ALLOWED && sys)
+	private static var storedFilters:Map<String, ShaderFilter> = []; // for a few shader functions
+	#end
+
 	//public var errorHandler:String->Void;
 	#if LUA_ALLOWED
 	public var lua:State = null;
@@ -276,7 +281,7 @@ class FunkinLua {
 			#if (!flash && MODS_ALLOWED && sys)
 			if(!PlayState.instance.runtimeShaders.exists(shader) && !initLuaShader(shader))
 			{
-				luaTrace('setSpriteShader: Shader $shader is missing!', false, false, FlxColor.RED);
+				luaTrace('setSpriteShader: Shader $shader is missing! Make sure you\'ve initalized your shader first!', false, false, FlxColor.RED);
 				return false;
 			}
 
@@ -310,6 +315,61 @@ class FunkinLua {
 			return false;
 		});
 
+		// camera shaders
+		Lua_helper.add_callback(lua, "setCameraShader", function(cam:String, shader:String, ?index:String) {
+			final funk = PlayState.instance;
+			if (!ClientPrefs.shaders) return false;
+
+			if (index == null || index.length < 1)
+			    index = shader;
+
+			#if (!flash && MODS_ALLOWED && sys)
+			if (!funk.runtimeShaders.exists(shader) && !funk.initLuaShader(shader)) {
+			    luaTrace('addShaderToCam: Shader $shader is missing! Make sure you\'ve initalized your shader first!', false, false, FlxColor.RED);
+			    return false;
+			}
+
+            var arr:Array<String> = funk.runtimeShaders.get(shader);
+			// Both FlxGame and FlxCamera has a _filters array and a setFilters function
+			// We should maybe make an interface for that?
+            var camera = getCam(cam);
+            @:privateAccess {
+            if (camera._filters == null)
+                camera._filters = [];
+				final filter = new ShaderFilter(new FlxRuntimeShader(arr[0], arr[1]));
+				storedFilters.set(index, filter);
+				camera._filters.push(filter);
+            }
+            return true;
+			#else
+            luaTrace("addShaderToCam: Platform unsupported for Runtime Shaders!", false, false, FlxColor.RED);
+			#end
+			return false;
+		});
+
+		Lua_helper.add_callback(lua, "removeCameraShader", function(cam:String, shader:String) {
+			#if (!flash && MODS_ALLOWED && sys)
+			final camera = getCam(cam);
+			@:privateAccess {
+			if(!storedFilters.exists(shader)) {
+				luaTrace('removeCamShader: $shader does not exist!', false, false, FlxColor.YELLOW);
+				return false;
+			}
+
+			if (camera.filters == null) {
+				luaTrace('removeCamShader: camera $cam does not have any shaders!', false, false, FlxColor.YELLOW);
+				return false;
+			}
+
+			camera.filters.remove(storedFilters.get(shader));
+			storedFilters.remove(shader);
+			return true;
+			}
+			#else
+			luaTrace('removeCamShader: Platform unsupported for Runtime Shaders!', false, false, FlxColor.RED);
+			#end
+			return false;
+		});
 
 		Lua_helper.add_callback(lua, "getShaderBool", function(obj:String, prop:String) {
 			#if (!flash && MODS_ALLOWED && sys)
@@ -3227,14 +3287,21 @@ class FunkinLua {
 		return NORMAL;
 	}
 
-	function cameraFromString(cam:String):FlxCamera {
+	static function cameraFromString(cam:String):FlxCamera {
 		switch(cam.toLowerCase()) {
 			case 'camhud' | 'hud': return PlayState.instance.camHUD;
 			case 'camother' | 'other': return PlayState.instance.camOther;
 		}
 		return PlayState.instance.camGame;
 	}
 
+	// alias for above, helper function basically
+	public static function getCam(obj:String):Dynamic {
+        if (obj.toLowerCase().trim() == "global")
+		    return FlxG.game;
+	    return cameraFromString(obj);
+    }
+
 	public static function luaTrace(text:String, ignoreCheck:Bool = false, deprecated:Bool = false, color:FlxColor = FlxColor.WHITE) {
 		#if LUA_ALLOWED
 		if(ignoreCheck || getBool('luaDebugMode')) {
@@ -3524,7 +3591,7 @@ class HScript
 		#if (!flash && sys)
 		interp.variables.set('FlxRuntimeShader', FlxRuntimeShader);
 		#end
-		interp.variables.set('ShaderFilter', openfl.filters.ShaderFilter);
+		interp.variables.set('ShaderFilter', ShaderFilter);
 		interp.variables.set('StringTools', StringTools);
 
 		interp.variables.set('setVar', function(name:String, value:Dynamic)