public Color Lookup(double value)
{
int startId = LookupSegment(0, colorMap_.Count - 1, value);
int endId = startId + 1;
if (startId == -1)
{
return(colorMap_[0].Color);
}
if (endId == colorMap_.Count)
{
return(colorMap_[endId - 1].Color);
}
//线性插值一下
ColorValuePair startCV = colorMap_[startId];
ColorValuePair endCV = colorMap_[endId];
double t = 0.5;
if (Math.Abs(startCV.Value - endCV.Value) > float.Epsilon)
{
t = (endCV.Value - value) / (endCV.Value - startCV.Value);
}
double one_t = 1.0 - t;
return(Color.FromArgb(
(int)(startCV.Color.R * t + endCV.Color.R * one_t),
(int)(startCV.Color.G * t + endCV.Color.G * one_t),
(int)(startCV.Color.B * t + endCV.Color.B * one_t)
));
}
public ColorMap GenerateLinearColorMap(Color fromColor, Color toColor, double min, double max)
{
List <ColorValuePair> cMap = new List <ColorValuePair>(
new ColorValuePair[] { ColorValuePair.Create(fromColor, min), ColorValuePair.Create(toColor, max) }
);
return(new LinearColorMap(cMap));
}