1 files changed, 138 insertions, 0 deletions
diff --git a/Assets/AmplifyShaderEditor/Plugins/Editor/Nodes/Operators/InverseOpNode.cs b/Assets/AmplifyShaderEditor/Plugins/Editor/Nodes/Operators/InverseOpNode.cs
new file mode 100644
index 00000000..178fc545
--- /dev/null
+++ b/Assets/AmplifyShaderEditor/Plugins/Editor/Nodes/Operators/InverseOpNode.cs
@@ -0,0 +1,138 @@
+// Amplify Shader Editor - Visual Shader Editing Tool
+// Copyright (c) Amplify Creations, Lda <info@amplify.pt>
+// 4x4 Invert by DBN in 
+// http://answers.unity3d.com/questions/218333/shader-inversefloat4x4-function.html?childToView=641391#answer-641391 
+
+using System;
+
+namespace AmplifyShaderEditor
+{
+	[Serializable]
+	[NodeAttributes( "Inverse", "Matrix Operators", "Inverse matrix of a matrix" )]
+	public sealed class InverseOpNode : SingleInputOp
+	{
+		private string Inverse4x4Header = "Inverse4x4( {0} )";
+
+		//4x4
+		private string[] Inverse4x4Function =
+		{
+			"{0}4x4 Inverse4x4({0}4x4 input)\n",
+			"{\n",
+			"\t#define minor(a,b,c) determinant({0}3x3(input.a, input.b, input.c))\n",
+			"\t{0}4x4 cofactors = {0}4x4(\n",
+			"\tminor( _22_23_24, _32_33_34, _42_43_44 ),\n",
+			"\t-minor( _21_23_24, _31_33_34, _41_43_44 ),\n",
+			"\tminor( _21_22_24, _31_32_34, _41_42_44 ),\n",
+			"\t-minor( _21_22_23, _31_32_33, _41_42_43 ),\n",
+			"\n",
+			"\t-minor( _12_13_14, _32_33_34, _42_43_44 ),\n",
+			"\tminor( _11_13_14, _31_33_34, _41_43_44 ),\n",
+			"\t-minor( _11_12_14, _31_32_34, _41_42_44 ),\n",
+			"\tminor( _11_12_13, _31_32_33, _41_42_43 ),\n",
+			"\n",
+			"\tminor( _12_13_14, _22_23_24, _42_43_44 ),\n",
+			"\t-minor( _11_13_14, _21_23_24, _41_43_44 ),\n",
+			"\tminor( _11_12_14, _21_22_24, _41_42_44 ),\n",
+			"\t-minor( _11_12_13, _21_22_23, _41_42_43 ),\n",
+			"\n",
+			"\t-minor( _12_13_14, _22_23_24, _32_33_34 ),\n",
+			"\tminor( _11_13_14, _21_23_24, _31_33_34 ),\n",
+			"\t-minor( _11_12_14, _21_22_24, _31_32_34 ),\n",
+			"\tminor( _11_12_13, _21_22_23, _31_32_33 ));\n",
+			"\t#undef minor\n",
+			"\treturn transpose( cofactors ) / determinant( input );\n",
+			"}\n"
+		};
+
+		private bool[] Inverse4x4FunctionFlags =
+		{
+			true,
+			false,
+			true,
+			true,
+			false,
+			false,
+			false,
+			false,
+			false,
+			false,
+			false,
+			false,
+			false,
+			false,
+			false,
+			false,
+			false,
+			false,
+			false,
+			false,
+			false,
+			false,
+			false,
+			false,
+			false,
+			false,
+			false
+		};
+
+		protected override void CommonInit( int uniqueId )
+		{
+			base.CommonInit( uniqueId );
+			m_opName = "inverse";
+			m_drawPreview = false;
+
+			m_inputPorts[ 0 ].CreatePortRestrictions( WirePortDataType.FLOAT3x3,
+													  WirePortDataType.FLOAT4x4 );
+			m_inputPorts[ 0 ].ChangeType( WirePortDataType.FLOAT4x4, false );
+			m_outputPorts[ 0 ].ChangeType( WirePortDataType.FLOAT4x4, false );
+		}
+
+		public override string GenerateShaderForOutput( int outputId, ref MasterNodeDataCollector dataCollector, bool ignoreLocalvar )
+		{
+			if ( m_outputPorts[ 0 ].IsLocalValue( dataCollector.PortCategory ) )
+				return m_outputPorts[ 0 ].LocalValue( dataCollector.PortCategory );
+
+			string precisionString = UIUtils.PrecisionWirePortToCgType( CurrentPrecisionType, WirePortDataType.FLOAT );
+			string value = m_inputPorts[ 0 ].GeneratePortInstructions( ref dataCollector );
+
+			if ( m_outputPorts[ 0 ].DataType == WirePortDataType.FLOAT3x3 )
+			{
+				GeneratorUtils.Add3x3InverseFunction( ref dataCollector, precisionString );
+				RegisterLocalVariable( 0, string.Format( GeneratorUtils.Inverse3x3Header, value ), ref dataCollector, "invertVal" + OutputId );
+			}
+			else
+			{
+				if ( !dataCollector.HasFunction( Inverse4x4Header ) )
+				{
+					//Hack to be used util indent is properly used
+					int currIndent = UIUtils.ShaderIndentLevel;
+
+					if ( dataCollector.IsTemplate )
+					{
+						UIUtils.ShaderIndentLevel = 0;
+					}
+					else
+					{
+						UIUtils.ShaderIndentLevel = 1;
+						UIUtils.ShaderIndentLevel++;
+					}
+
+					string finalFunction = string.Empty;
+					for ( int i = 0; i < Inverse4x4Function.Length; i++ )
+					{
+						finalFunction += UIUtils.ShaderIndentTabs + ( Inverse4x4FunctionFlags[ i ] ? string.Format( Inverse4x4Function[ i ], precisionString ) : Inverse4x4Function[ i ] );
+					}
+
+					
+					UIUtils.ShaderIndentLevel = currIndent;
+
+					dataCollector.AddFunction( Inverse4x4Header, finalFunction );
+				}
+				
+				RegisterLocalVariable( 0, string.Format( Inverse4x4Header, value ), ref dataCollector, "invertVal" + OutputId );
+			}
+
+			return m_outputPorts[ 0 ].LocalValue( dataCollector.PortCategory );
+		}
+	}
+}