c# - 如何将 IList 映射到位图？

Question

IList 包含 xy 平面上的一组 z 样本(均为 double )。GetColor() 将任何 z 值转换为像素颜色。我计划缩放 IList x 和 y 限制以对应于位图宽度和高度，因为样本数通常不等于像素数。样本是作为光栅扫描收集的，因此顺序不同。在扫描完成之前，我不知道有多少样本。是否有使用 LINQ 和/或 Lambda 表达式为每个位图像素找到最接近的 IList x 和 y 的巧妙方法？

PictureBox pb;
Bitmap bmp = new Bitmap(pb.Width, pb.Height);
IList<Sample> samples = new List<Sample>();
// ... collect samples ...
// Find closest sample
Sample GetSample(int w, int h)
{
    // how to find closest x and y for each w and h?
}
// Map samples to bitmap
for (var w = 0; w < pb.Width; w++) 
{
    for (var h = 0; h < pb.Height; h++)
    {
        var sample = GetSample(w, h);
        var color = GetColor(sample.z, samples.Min().z, samples.Max().z);
        bmp.SetPixel(w, h, color);
    }
}
pb.Image = bmp;
Color GetColor(double z, double minZ, double maxZ)
{
    var red = (int) (255*(z - minZ)/(maxZ - minZ));
    var blue = 255 - red;
    var green = red*blue/65;
    return Color.FromArgb(red, green, blue);
}
// class Sample
public class Sample : IComparable<Sample>
{
    public double z { get; set; }
    public double x { get; set; }
    public double y { get; set; }
    int IComparable<Sample>.CompareTo(Sample s)
    {
        return z < s.z ? -1 : 1;
    }
}

Answer 1

也许我提供的方法可以帮助您，它可以找到最接近的数字。

找到最接近样本的问题是处理以下情况:

w == 1
h == 1

Sample(x = 1, y = 8)
Sample(x = 8, x = 1)

Which one should be considered as closest?

用法:

int closestX = this.FindClosest(samples.Select(p => p.x).ToList(), w);
int closestY = this.FindClosest(samples.Select(p => p.y).ToList(), h);

方法:

public int FindClosest(IList<int> points, int desiredNumber)
{
    int nearest = -1;
    int latestDistance = int.MaxValue;

    foreach (int t in points)
    {
        if (t == desiredNumber)
        {
            return t;
        }

        int currentDistance = Math.Abs(desiredNumber - t);
        if (currentDistance < latestDistance) 
        {                    
            nearest = t;
            latestDistance = currentDistance;
        }
    }

    return nearest;
}