static Color[] GenerateColors(AdaptiveGradient gradient, uint numSamples)
{
double leftAnchor = gradient.First().Anchor.AnchorValue;
double rightAnchor = gradient.Last().Anchor.AnchorValue;
//we need to make sure it spreads out across the whole range, so we set the
//increment such that we include the end two colors.
double increment = (rightAnchor - leftAnchor) / (numSamples - 1);
Color[] colors = new Color[numSamples];
double targetValue;
for (int i = 0; i < numSamples; i++)
{
targetValue = leftAnchor + increment * i;
//consider stops in pairs, and if we're in the right pair
// interpolate between the stops.
for (int j = 0; j < gradient.Count - 1; j++)
{
//because of the way we're counting, if this condition
// is true, we're between a pair of gradient stops
// with the left one smaller and the right one larger.
if (targetValue >= gradient[j].Anchor.AnchorValue)
{
colors[i] = InterpolateBetweenStops(targetValue, gradient[j], gradient[j + 1]);
continue;
}
}
}
return(colors);
}
/// <summary>
/// Generates <see cref="AdaptiveGradientMap{T}"/>s based upon the specified
/// <see cref="AdaptiveGradient"/> and a number of samples.
/// </summary>
/// <param name="gradient">The gradient to generate a map with.</param>
/// <param name="numSamples">The number of samples to interpolate on the
/// gradient.</param>
public AdaptiveGradientMapBuilder(AdaptiveGradient gradient, uint numSamples = 10)
{
NumSamples = numSamples;
targetValues = GenerateTargetValues(gradient, numSamples);
colorValues = GenerateColors(gradient, numSamples);
}
/// <summary>
/// Generate a default gradient, with <see cref="Colors.Blue"/> at the
/// minimum value of the dataset and <see cref="Colors.Red"/> at the
/// maximum.
/// </summary>
/// <returns>A default gradient, auto scaled from blue to red.</returns>
public static AdaptiveGradient BlueRedGradient()
{
AdaptiveGradient ag = new AdaptiveGradient();
//default blue = low, red = high.
ag.Add(new AdaptiveGradientStop(Colors.Blue, new MinValue()));
ag.Add(new AdaptiveGradientStop(Colors.Red, new MaxValue()));
return(ag);
}
static double[] GenerateTargetValues(AdaptiveGradient gradient, uint numSamples)
{
double leftAnchor = gradient.First().Anchor.AnchorValue;
double rightAnchor = gradient.Last().Anchor.AnchorValue;
double increment = (rightAnchor - leftAnchor) / numSamples;
double[] targetValues = new double[numSamples];
//generate sample sets. Note that each block is represented by the max value in the block.
for (int i = 1; i <= numSamples; i++)
{
targetValues[i - 1] = leftAnchor + increment * i;
}
return(targetValues);
}
