/// <summary>
/// Generates a heat color by using the two colors defining high and low.
/// Hence, if the given value is 1 the function will return the color for high and if the value is 0 the function will return the color for low.
/// If the value is fractional, a color matching the fraction between high and low colors will be chosen.
/// </summary>
/// <param name="low">The color for a value of 0.</param>
/// <param name="high">The color for a value of 1.</param>
/// <param name="value">The value that determines the color.</param>
/// <returns>The color matching the given value.</returns>
public static Color GenerateBiChromaticHeatColor(Color low, Color high, double value)
{
if (value < 0 || value > 1)
{
throw new ArgumentException("Value has to be of the interval [0,1]");
}
// ----> If full transparency is given, ignore the color information of that color
// --> Handle the degree of transparency of the other color
if (low.A == 0 || high.A == 0)
{
if (low.A == 0)
{
byte A = value == 1 ? (byte)255 : (byte)(value * 256);
return(Color.FromArgb(A, high.R, high.G, high.B));
}
else
{
byte A = value == 0 ? (byte)255 : (byte)((1 - value) * 256);
return(Color.FromArgb(A, low.R, low.G, low.B));
}
}
// --> Handle two solid colors
else
{
// Get HSV representation of given color first
double hLow, sLow, vLow;
ColorManager.ConvertColorToHSV(low, out hLow, out sLow, out vLow);
double hHigh, sHigh, vHigh;
ColorManager.ConvertColorToHSV(high, out hHigh, out sHigh, out vHigh);
// Determine fractions based on value
double hOffsetFromLow = Math.Abs(hHigh - hLow) * value;
double sOffsetFromLow = Math.Abs(sHigh - sLow) * value;
double vOffsetFromLow = Math.Abs(vHigh - vLow) * value;
// Determine HSV based resulting color
double h = hLow <= hHigh ? hLow + hOffsetFromLow : hLow - hOffsetFromLow;
double s = sLow <= sHigh ? sLow + sOffsetFromLow : sLow - sOffsetFromLow;
double v = vLow <= vHigh ? vLow + vOffsetFromLow : vLow - vOffsetFromLow;
// Convert it to RGB
double r, g, b;
ColorManager.ConvertHSVtoRGB(h, s, v, out r, out g, out b);
byte R = r == 1 ? (byte)255 : (byte)(r * 256);
byte G = g == 1 ? (byte)255 : (byte)(g * 256);
byte B = b == 1 ? (byte)255 : (byte)(b * 256);
// Create and return the color
Color color = Color.FromRgb(R, G, B);
return(color);
}
}
/// <summary>
/// Generates a heat color from the given value.
/// </summary>
/// <param name="value">The value to generate a heat color for. This has to be a value in the range of [0,1].</param>
/// <returns>A color depicting the heat.</returns>
public static Color GenerateHeatColor(double value)
{
if (value < 0 || value > 1)
{
throw new ArgumentException();
}
// Invert value to fit HSV mode
value = 1 - value;
double h = value * 240;
double s = 0.8;
double v = 0.97;
double r, g, b;
ColorManager.ConvertHSVtoRGB(h, s, v, out r, out g, out b);
byte R = r == 1 ? (byte)255 : (byte)(r * 256);
byte G = b == 1 ? (byte)255 : (byte)(g * 256);
byte B = g == 1 ? (byte)255 : (byte)(b * 256);
Color color = Color.FromRgb(R, G, B);
return(color);
}
