Terraria.Lighting.BrightnessAverage C# (CSharp) Method

        public static float BrightnessAverage(int x, int y, int width, int height)
        {
            int num1 = x - Lighting.firstTileX + Lighting.offScreenTiles;
            int num2 = y - Lighting.firstTileY + Lighting.offScreenTiles;
            int num3 = num1 + width;
            int num4 = num2 + height;
            if (num1 < 0)
                num1 = 0;
            if (num2 < 0)
                num2 = 0;
            if (num3 >= Main.screenWidth / 16 + Lighting.offScreenTiles * 2 + 10)
                num3 = Main.screenWidth / 16 + Lighting.offScreenTiles * 2 + 10;
            if (num4 >= Main.screenHeight / 16 + Lighting.offScreenTiles * 2 + 10)
                num4 = Main.screenHeight / 16 + Lighting.offScreenTiles * 2 + 10;
            float num5 = 0.0f;
            float num6 = 0.0f;
            for (int index1 = num1; index1 < num3; ++index1)
            {
                for (int index2 = num2; index2 < num4; ++index2)
                {
                    ++num5;
                    Lighting.LightingState lightingState = Lighting.states[index1][index2];
                    num6 += (float)(((double)lightingState.r + (double)lightingState.g + (double)lightingState.b) / 3.0);
                }
            }
            if ((double)num5 == 0.0)
                return 0.0f;
            return num6 / num5;
        }