Added BlackBodySpectrum

Author: castarco

ColorSharp/ColorSharp.csproj

@@ -85,6 +85,7 @@
     <Compile Include="src\Illuminants\CIE_C.cs" />
     <Compile Include="src\Illuminants\CIE_D50.cs" />
     <Compile Include="src\Illuminants\CIE_D55.cs" />
+    <Compile Include="src\LightSpectrums\BlackBodySpectrum.cs" />
   </ItemGroup>
   <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" />
   <ItemGroup>

ColorSharp/src/LightSpectrums/ALightSpectrum.cs

@@ -78,7 +78,7 @@ protected ALightSpectrum(AConvertibleColor dataSource=null) : base(dataSource) {
 			 * If the method returns -1.0 , then we suppose we have an "analytic" spectrum, so we don't have samples.
 			 * </summary>
 			 */
-			public abstract double GetNextAmplitudeSample (double waveLength);
+			//public abstract double GetNextAmplitudeSample (double waveLength);
 
 			#endregion
 
@@ -98,27 +98,49 @@ public CIEXYZ ToCIEXYZ (SpectrumStrategy strategy=SpectrumStrategy.Default)
 			{
 				AMatchingFunction[] MFs;
 
+				int step;
 				if (strategy == SpectrumStrategy.Nm1Deg2) {
+					step = 1;
 					MFs = new AMatchingFunction[] {
 						CIE1931XYZ1Nm2DegX.Instance, CIE1931XYZ1Nm2DegY.Instance, CIE1931XYZ1Nm2DegZ.Instance
 					};
 				} else if (strategy == SpectrumStrategy.Nm1Deg10) {
+					step = 1;
 					MFs = new AMatchingFunction[] {
 						CIE1964XYZ1Nm10DegX.Instance, CIE1964XYZ1Nm10DegY.Instance, CIE1964XYZ1Nm10DegZ.Instance
 					};
 				} else if (strategy == SpectrumStrategy.Nm5Deg10) {
+					step = 5;
 					MFs = new AMatchingFunction[] {
 						CIE1964XYZ5Nm10DegX.Instance, CIE1964XYZ5Nm10DegY.Instance, CIE1964XYZ5Nm10DegZ.Instance
 					};
 				} else { // if (strategy == SpectrumStrategy.Nm5Deg2) {
+					step = 5;
 					MFs = new AMatchingFunction[] {
 						CIE1931XYZ5Nm2DegX.Instance, CIE1931XYZ5Nm2DegY.Instance, CIE1931XYZ5Nm2DegZ.Instance
 					};
 				}
 
-				return new CIEXYZ (
-					MFs [0].DoConvolution (this), MFs [1].DoConvolution (this), MFs [2].DoConvolution (this), DataSource ?? this
-				);
+				double X = 0.0, Y = 0.0, Z = 0.0;
+				int n = MFs [0].GetNumberOfDataPoints ();
+				double minV = MFs [0].GetSupportMinValue ();
+
+				for (int i = 0; i < n; i++) {
+					if (i * step + minV < GetSupportMinValue ()) {
+						continue;
+					}
+					if (i * step + minV > GetSupportMaxValue ()) {
+						break;
+					}
+
+					double v = EvaluateAt (i * step + minV);
+
+					X += MFs [0].EvaluateAt (i * step + minV) * v * step;
+					Y += MFs [1].EvaluateAt (i * step + minV) * v * step;
+					Z += MFs [2].EvaluateAt (i * step + minV) * v * step;
+				}
+
+				return new CIEXYZ (X, Y, Z);
 			}
 
 			#endregion

ColorSharp/src/LightSpectrums/BlackBodySpectrum.cs

@@ -0,0 +1,129 @@
+/*
+ * The MIT License (MIT)
+ * Copyright (c) 2014 Andrés Correa Casablanca
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+/*
+* Contributors:
+*  - Andrés Correa Casablanca <castarco@gmail.com , castarco@litipk.com>
+*/
+
+
+using System;
+
+
+namespace Litipk.ColorSharp
+{
+	namespace LightSpectrums
+	{
+		public sealed class BlackBodySpectrum : ALightSpectrum
+		{
+			#region properties
+
+			public readonly double CCT;
+
+			public readonly double MinWaveLength;
+			public readonly double MaxWaveLength;
+
+			#endregion
+
+			#region constructors
+
+			public BlackBodySpectrum (double cct) : this (cct, 380.0, 780.0)
+			{
+				// Nothing to do here
+			}
+
+			public BlackBodySpectrum (double cct, double minWaveLength, double maxWaveLength)
+			{
+				if (minWaveLength <= 0.0) {
+					throw new ArgumentOutOfRangeException ("minWaveLength", "minWaveLength must be greater than 0");
+				}
+
+				if (maxWaveLength <= minWaveLength) {
+					throw new ArgumentException("maxWaveLength must be greater than minWaveLength", "maxWaveLength");
+				}
+
+				if (cct <= 1) {
+					throw new ArgumentOutOfRangeException ("cct", "cct must be greater than 1");
+				}
+
+				CCT = cct;
+				MinWaveLength = minWaveLength;
+				MaxWaveLength = maxWaveLength;
+			}
+
+			#endregion
+
+			#region inherited methods
+
+			public override double EvaluateAt (double waveLength)
+			{
+				// 2*h*c² = 2 * 299792458 * 1.98644568e-25 = 1.1910428661813628e-16
+				double a = (
+					1.1910428661813628e-16 / (
+						Math.Pow(waveLength, 5) * (
+							Math.Exp(1.98644568e-25 / (waveLength * CCT * 1.3806488e-23)) - 1.0
+						)
+					)
+				);
+
+				double b = (
+					(3.7417749e-16 * Math.Pow(waveLength, -5.0) / Math.PI) * Math.Pow(
+						(Math.Exp(1.4388e-2 / (waveLength * CCT)) - 1), -1
+					)
+				);
+
+				Console.WriteLine (a + " <--> " + b);
+
+				return a;
+			}
+
+			public override double GetMaxValueOnSupport ()
+			{
+				double result = Double.NegativeInfinity;
+
+				for (int i = 0; i + MinWaveLength < MaxWaveLength; i++) {
+					result = Math.Max (EvaluateAt (MinWaveLength + i), result);
+				}
+
+				return result;
+			}
+
+			public override double GetSupportMinValue ()
+			{
+				return MinWaveLength;
+			}
+
+			public override double GetSupportMaxValue ()
+			{
+				return MaxWaveLength;
+			}
+
+			public override bool IsInsideColorSpace (bool highPrecision = false)
+			{
+				return true;
+			}
+
+			#endregion
+		}
+	}
+}

ColorSharp/src/LightSpectrums/RegularLightSpectrum.cs

@@ -157,6 +157,7 @@ public override int GetNumberOfDataPoints()
 			/**
 			 * <inheritdoc />
 			 */
+			/*
 			public override double GetNextAmplitudeSample (double waveLength)
 			{
 				if (waveLength < MinWaveLength && waveLength >= MaxWaveLength) {
@@ -165,6 +166,7 @@ public override double GetNextAmplitudeSample (double waveLength)
 
 				return MinWaveLength + ((uint)Math.Floor ((waveLength - MinWaveLength) / NmPerStep) + 1) * NmPerStep;
 			}
+			*/
 
 			#endregion
 

ColorSharp/src/LightSpectrums/TabularLightSpectrum.cs

@@ -131,6 +131,7 @@ public override double EvaluateAt(double waveLength)
 			/**
 			 * <inheritdoc />
 			 */
+			/*
 			public override double GetNextAmplitudeSample (double waveLength)
 			{
 				if (waveLength < RawAmplitudes[0].Key || waveLength >= RawAmplitudes[RawAmplitudes.Count-1].Key) {
@@ -147,6 +148,7 @@ public override double GetNextAmplitudeSample (double waveLength)
 
 				return RawAmplitudes [index + 1].Key;
 			}
+			*/
 
 			#endregion