public override void UpdateParameters(ColorTransformContext context)
{
// TODO This could be put as part
double b = BlackPoint;
double c = CrossOver;
double w = WhitePoint;
double t = Toe;
double s = Shoulder;
double k = ((1 - t) * (c - b)) / ((1 - s) * (w - c) + (1 - t) * (c - b));
var toe = new Vector4(
(float)((k * (1 - t))),
(float)(-t),
(float)(k * (1 - t) * (-b)),
(float)(c - (1 - t) * b));
var shoulder = new Vector4(
(float)(((1 - k) + k * s)),
(float)(s),
(float)((1 - k) * (-c) + k * ((1 - s) * w - c)),
(float)((1 - s) * w - c));
// Don't call base, as we are rewriting all parameters for the shader
Parameters.Set(ToneMapMikeDayOperatorShaderKeys.ToeCoeffs, toe);
Parameters.Set(ToneMapMikeDayOperatorShaderKeys.ShoulderCoeffs, shoulder);
Parameters.Set(ToneMapMikeDayOperatorShaderKeys.MiddleCrossOver, CrossOver);
}
public override void UpdateParameters(ColorTransformContext context)
{
base.UpdateParameters(context);
// Update the luminance
var elapsedTime = timer.Elapsed;
timer.Restart();
var luminanceResult = context.SharedParameters.Get(LuminanceEffect.LuminanceResult);
var avgLuminanceLog = 0.18f; // TODO: Add a parmetrized average luminance
if (luminanceResult.LocalTexture != null)
{
// Adapt the luminance using Pattanaik's technique
var currentAvgLuminance = (float)Math.Max(luminanceResult.AverageLuminance, 0.0001);
weightedLuminances[currentWeightedLuminanceIndex] = currentAvgLuminance;
currentWeightedLuminanceIndex = (currentWeightedLuminanceIndex + 1) % weightedLuminances.Length;
float avgLuminannce = 0.0f;
for (int i = 0; i < weightedLuminances.Length; i++)
{
avgLuminannce += weightedLuminances[i];
}
avgLuminannce /= weightedLuminances.Length;
// Get current avg luminance
// Get adapted luminance
var adaptedLum = (float)(previousLuminance + (avgLuminannce - previousLuminance) * (1.0 - Math.Exp(-elapsedTime.TotalSeconds * AdaptationRate)));
avgLuminanceLog = (float)Math.Log(adaptedLum, 2);
previousLuminance = adaptedLum;
//Trace.WriteLine(string.Format("Adapted: {0} Luminance: {1}", adaptedLum, currentAvgLuminance));
if (AutoKeyValue)
{
KeyValue = 1.03f - (2.0f / (2.0f + (float)Math.Log10(adaptedLum + 1)));
}
}
// Setup parameters
Parameters.Set(ToneMapShaderKeys.LuminanceTexture, luminanceResult.LocalTexture);
Parameters.Set(ToneMapShaderKeys.LuminanceAverageGlobal, avgLuminanceLog);
// Update operator parameters
var currentOperator = Operator ?? defaultOperator;
currentOperator.UpdateParameters(context);
// Copy sub parameters from composition to this transform
foreach (var parameterValue in currentOperator.Parameters)
{
var key = parameterValue.Key.ComposeWith("ToneMapOperator");
currentOperator.Parameters.CopySharedTo(parameterValue.Key, key, Parameters);
}
}
/// <summary>
/// Initializes a new instance of the <see cref="ColorTransformGroup"/> class.
/// </summary>
/// <param name="context">The context.</param>
/// <param name="colorTransformGroupEffect">The color transform group effect.</param>
public ColorTransformGroup(ImageEffectContext context, string colorTransformGroupEffect = "ColorTransformGroupEffect")
: base(context, colorTransformGroupEffect)
{
compositeKeys = new Dictionary <ParameterCompositeKey, ParameterKey>();
transforms = new ColorTransformCollection();
enabledTransforms = new List <ColorTransform>();
collectTransforms = new List <ColorTransform>();
transformsParameters = new ParameterCollection();
gammaTransform = new GammaTransform();
transformGroupEffect = new ImageEffectShader(context, colorTransformGroupEffect, Parameters);
// we are adding parameter collections after as transform parameters should override previous parameters
transformGroupEffect.ParameterCollections.Add(transformsParameters);
this.context = new ColorTransformContext(this);
}
/// <summary>
/// Updates the parameters for this transformation.
/// </summary>
/// <param name="context">The context.</param>
/// <remarks>This method is called just before rendering the ColorTransformGroup that is holding this ColorTransform</remarks>
public virtual void UpdateParameters(ColorTransformContext context)
{
}