public void Invert()
{
float fDet = Determinant();
if ( (float) System.Math.Abs(fDet) < float.Epsilon )
throw new Exception( "Matrix is not invertible!" ); // The matrix is not invertible! Singular case!
float fIDet = 1.0f / fDet;
float4x4 Temp = new float4x4();
Temp[0, 0] = CoFactor( 0, 0 ) * fIDet;
Temp[1, 0] = CoFactor( 0, 1 ) * fIDet;
Temp[2, 0] = CoFactor( 0, 2 ) * fIDet;
Temp[3, 0] = CoFactor( 0, 3 ) * fIDet;
Temp[0, 1] = CoFactor( 1, 0 ) * fIDet;
Temp[1, 1] = CoFactor( 1, 1 ) * fIDet;
Temp[2, 1] = CoFactor( 1, 2 ) * fIDet;
Temp[3, 1] = CoFactor( 1, 3 ) * fIDet;
Temp[0, 2] = CoFactor( 2, 0 ) * fIDet;
Temp[1, 2] = CoFactor( 2, 1 ) * fIDet;
Temp[2, 2] = CoFactor( 2, 2 ) * fIDet;
Temp[3, 2] = CoFactor( 2, 3 ) * fIDet;
Temp[0, 3] = CoFactor( 3, 0 ) * fIDet;
Temp[1, 3] = CoFactor( 3, 1 ) * fIDet;
Temp[2, 3] = CoFactor( 3, 2 ) * fIDet;
Temp[3, 3] = CoFactor( 3, 3 ) * fIDet;
row0 = Temp.row0;
row1 = Temp.row1;
row2 = Temp.row2;
row3 = Temp.row3;
}
/// <summary>
/// Builds the RGB<->XYZ transforms from chromaticities
/// (refer to http://wiki.nuaj.net/index.php/Color_Transforms#XYZ_Matrices for explanations)
/// </summary>
protected void BuildTransformFromChroma( bool _bCheckGammaCurveOverride )
{
float3 xyz_R = new float3( m_Chromaticities.R.x, m_Chromaticities.R.y, 1.0f - m_Chromaticities.R.x - m_Chromaticities.R.y );
float3 xyz_G = new float3( m_Chromaticities.G.x, m_Chromaticities.G.y, 1.0f - m_Chromaticities.G.x - m_Chromaticities.G.y );
float3 xyz_B = new float3( m_Chromaticities.B.x, m_Chromaticities.B.y, 1.0f - m_Chromaticities.B.x - m_Chromaticities.B.y );
float3 XYZ_W = xyY2XYZ( new float3( m_Chromaticities.W.x, m_Chromaticities.W.y, 1.0f ) );
float4x4 M_xyz = new float4x4() {
row0 = new float4( xyz_R, 0.0f ),
row1 = new float4( xyz_G, 0.0f ),
row2 = new float4( xyz_B, 0.0f ),
row3 = new float4( 0.0f, 0.0f, 0.0f, 1.0f )
};
M_xyz.Invert();
float4 Sum_RGB = new float4( XYZ_W, 1.0f ) * M_xyz;
// Finally, we can retrieve the RGB->XYZ transform
m_RGB2XYZ.row0 = new float4( Sum_RGB.x * xyz_R, 0.0f );
m_RGB2XYZ.row1 = new float4( Sum_RGB.y * xyz_G, 0.0f );
m_RGB2XYZ.row2 = new float4( Sum_RGB.z * xyz_B, 0.0f );
// And the XYZ->RGB transform
m_XYZ2RGB = m_RGB2XYZ;
m_XYZ2RGB.Invert();
// ============= Attempt to recognize a standard profile =============
STANDARD_PROFILE RecognizedChromaticity = m_Chromaticities.RecognizedChromaticity;
if ( _bCheckGammaCurveOverride )
{ // Also ensure the gamma ramp is correct before assigning a standard profile
bool bIsGammaCorrect = true;
switch ( RecognizedChromaticity )
{
case STANDARD_PROFILE.sRGB: bIsGammaCorrect = EnsureGamma( GAMMA_CURVE.sRGB, GAMMA_EXPONENT_sRGB ); break;
case STANDARD_PROFILE.ADOBE_RGB_D50: bIsGammaCorrect = EnsureGamma( GAMMA_CURVE.STANDARD, GAMMA_EXPONENT_ADOBE ); break;
case STANDARD_PROFILE.ADOBE_RGB_D65: bIsGammaCorrect = EnsureGamma( GAMMA_CURVE.STANDARD, GAMMA_EXPONENT_ADOBE ); break;
case STANDARD_PROFILE.PRO_PHOTO: bIsGammaCorrect = EnsureGamma( GAMMA_CURVE.PRO_PHOTO, GAMMA_EXPONENT_PRO_PHOTO ); break;
case STANDARD_PROFILE.RADIANCE: bIsGammaCorrect = EnsureGamma( GAMMA_CURVE.STANDARD, 1.0f ); break;
}
if ( !bIsGammaCorrect )
RecognizedChromaticity = STANDARD_PROFILE.CUSTOM; // A non-standard gamma curves fails our pre-defined design...
}
// ============= Assign the internal converter depending on the profile =============
switch ( RecognizedChromaticity )
{
case STANDARD_PROFILE.sRGB:
m_GammaCurve = GAMMA_CURVE.sRGB;
m_Gamma = GAMMA_EXPONENT_sRGB;
m_InternalConverter = new InternalColorConverter_sRGB();
break;
case STANDARD_PROFILE.ADOBE_RGB_D50:
m_GammaCurve = GAMMA_CURVE.STANDARD;
m_Gamma = GAMMA_EXPONENT_ADOBE;
m_InternalConverter = new InternalColorConverter_AdobeRGB_D50();
break;
case STANDARD_PROFILE.ADOBE_RGB_D65:
m_GammaCurve = GAMMA_CURVE.STANDARD;
m_Gamma = GAMMA_EXPONENT_ADOBE;
m_InternalConverter = new InternalColorConverter_AdobeRGB_D65();
break;
case STANDARD_PROFILE.PRO_PHOTO:
m_GammaCurve = GAMMA_CURVE.PRO_PHOTO;
m_Gamma = GAMMA_EXPONENT_PRO_PHOTO;
m_InternalConverter = new InternalColorConverter_ProPhoto();
break;
case STANDARD_PROFILE.RADIANCE:
m_GammaCurve = GAMMA_CURVE.STANDARD;
m_Gamma = 1.0f;
m_InternalConverter = new InternalColorConverter_Radiance();
break;
default: // Switch to one of our generic converters
switch ( m_GammaCurve )
{
case GAMMA_CURVE.sRGB:
m_InternalConverter = new InternalColorConverter_Generic_sRGBGamma( m_RGB2XYZ, m_XYZ2RGB );
break;
case GAMMA_CURVE.PRO_PHOTO:
m_InternalConverter = new InternalColorConverter_Generic_ProPhoto( m_RGB2XYZ, m_XYZ2RGB );
break;
case GAMMA_CURVE.STANDARD:
if ( Math.Abs( m_Gamma - 1.0f ) < 1e-3f )
m_InternalConverter = new InternalColorConverter_Generic_NoGamma( m_RGB2XYZ, m_XYZ2RGB );
else
m_InternalConverter = new InternalColorConverter_Generic_StandardGamma( m_RGB2XYZ, m_XYZ2RGB, m_Gamma );
break;
}
break;
}
}
public InternalColorConverter_Generic_sRGBGamma( float4x4 _RGB2XYZ, float4x4 _XYZ2RGB )
{
m_RGB2XYZ = _RGB2XYZ;
m_XYZ2RGB = _XYZ2RGB;
}
public InternalColorConverter_Generic_StandardGamma( float4x4 _RGB2XYZ, float4x4 _XYZ2RGB, float _Gamma )
{
m_RGB2XYZ = _RGB2XYZ;
m_XYZ2RGB = _XYZ2RGB;
m_Gamma = _Gamma;
m_InvGamma = 1.0f / _Gamma;
}
public InternalColorConverter_Generic_ProPhoto( float4x4 _RGB2XYZ, float4x4 _XYZ2RGB )
{
m_RGB2XYZ = _RGB2XYZ;
m_XYZ2RGB = _XYZ2RGB;
}
