public SpaceLine(SpacePoint p1, SpacePoint p2)
{
x = p1.x; y = p1.y; z = p1.z;
l = p2.x - p1.x;
m = p2.y - p1.y;
n = p2.z - p1.z;
}
public Color select(double value)
{
if (gradient == null)
{
return(Color.White);
}
if (gradient.Length == 0)
{
return(Color.White);
}
SpacePoint p1 = gradient[0], p2 = null;
if (p1 == null)
{
return(Color.White);
}
if (gradient.Length == 1 || p1.extra >= value)
{
// single color or min >= value
return(Color.FromArgb((int)(p1.x * 255), (int)(p1.y * 255), (int)(p1.z * 255)));
}
SpaceLine line = null;
double percent = 0.0;
for (int i = 1; i < gradient.Length; i++)
{
p2 = gradient[i];
if (p2 == null)
{
return(Color.White);
}
if (value > p1.extra && value <= p2.extra)
{
percent = p2.extra - p1.extra;
// point collision or decrease order
if (percent <= 0.0f)
{
return(Color.FromArgb((int)(p1.x * 255), (int)(p1.y * 255), (int)(p1.z * 255)));
}
percent = (value - p1.extra) / percent;
line = new SpaceLine(p1, p2);
p1 = line.get(percent);
return(Color.FromArgb((int)(p1.x * 255), (int)(p1.y * 255), (int)(p1.z * 255)));
}
p1 = p2;
}
// max < value
if (p2 == null)
{
return(Color.White);
}
return(Color.FromArgb((int)(p2.x * 255), (int)(p2.y * 255), (int)(p2.z * 255)));
}