UnityXNA/Assets/Scripts/XNAEmulator/Graphics/States/BlendState.cs

// #region License
// /*
// Microsoft Public License (Ms-PL)
// MonoGame - Copyright © 2009 The MonoGame Team
// 
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// This license governs use of the accompanying software. If you use the software, you accept this license. If you do not
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// #endregion License
// 
using System;
using System.Diagnostics;

namespace Microsoft.Xna.Framework.Graphics
{
	public class BlendState : GraphicsResource
	{
        // TODO: We should be asserting if the state has
        // been changed after it has been bound to the device!

		public BlendFunction AlphaBlendFunction { get; set; }
		public Blend AlphaDestinationBlend { get; set; }
		public Blend AlphaSourceBlend { get; set; }
		public Color BlendFactor { get; set; }
		public BlendFunction ColorBlendFunction { get; set; }
		public Blend ColorDestinationBlend { get; set; }
		public Blend ColorSourceBlend { get; set; }
		public ColorWriteChannels ColorWriteChannels { get; set; }
		public ColorWriteChannels ColorWriteChannels1 { get; set; }
		public ColorWriteChannels ColorWriteChannels2 { get; set; }
		public ColorWriteChannels ColorWriteChannels3 { get; set; }
		public int MultiSampleMask { get; set; }

		public static readonly BlendState Additive;
		public static readonly BlendState AlphaBlend;
		public static readonly BlendState NonPremultiplied;
		public static readonly BlendState Opaque;
		
		public BlendState() 
        {
			AlphaBlendFunction = BlendFunction.Add;
			AlphaDestinationBlend = Blend.Zero;
			AlphaSourceBlend = Blend.One;
			BlendFactor = Color.White;
			ColorBlendFunction = BlendFunction.Add;
			ColorDestinationBlend = Blend.Zero;
			ColorSourceBlend = Blend.One;
			ColorWriteChannels = ColorWriteChannels.All;
			ColorWriteChannels1 = ColorWriteChannels.All;
			ColorWriteChannels2 = ColorWriteChannels.All;
			ColorWriteChannels3 = ColorWriteChannels.All;
			MultiSampleMask = Int32.MaxValue;
		}
		
		static BlendState() 
        {
			Additive = new BlendState() 
            {
				ColorSourceBlend = Blend.SourceAlpha,
				AlphaSourceBlend = Blend.SourceAlpha,
    			ColorDestinationBlend = Blend.One,	
				AlphaDestinationBlend = Blend.One
			};
			
			AlphaBlend = new BlendState()
            {
				ColorSourceBlend = Blend.One,
				AlphaSourceBlend = Blend.One,
				ColorDestinationBlend = Blend.InverseSourceAlpha,
				AlphaDestinationBlend = Blend.InverseSourceAlpha
			};
			
			NonPremultiplied = new BlendState() 
            {
				ColorSourceBlend = Blend.SourceAlpha,
				AlphaSourceBlend = Blend.SourceAlpha,
				ColorDestinationBlend = Blend.InverseSourceAlpha,
				AlphaDestinationBlend = Blend.InverseSourceAlpha
			};
			
			Opaque = new BlendState()
            {
				ColorSourceBlend = Blend.One,
				AlphaSourceBlend = Blend.One,			    
				ColorDestinationBlend = Blend.Zero,
				AlphaDestinationBlend = Blend.Zero
			};
		}

        public override string ToString ()
        {
            string blendStateName;

            if(this == BlendState.Additive)
                blendStateName = "Additive";
            else if (this == BlendState.AlphaBlend)
                blendStateName = "AlphaBlend";
            else if (this == BlendState.NonPremultiplied)
                blendStateName = "NonPremultiplied";
            else
                blendStateName = "Opaque";


            return string.Format("{0}.{1}", base.ToString(), blendStateName);
        }
	}
}