找出所有点：
根据斜率按照一个方向递增，求出对应的另一个方向的整数值。
Point pStart = new Point(0, 2);
Point pEnd = new Point(8, 2);
//定义线上的点
List<Point> linePoint = new List<Point>();
//定义x坐标的大小
Point pointMaxX = new Point();
Point pointMinX = new Point();
//给x坐标大的点和小的点赋值
if (Math.Max(pStart.X, pEnd.X) == pStart.X)
{
pointMaxX = pStart;
pointMinX = pEnd;
}
else
{
pointMaxX = pEnd;
pointMinX = pStart;
}
// 循环x坐标(循环满足x坐标为整数的y坐标)或者y坐标均可
for (int i = pointMinX.X + 1; i < pointMaxX.X; i++)
{
// 计算斜率
double k = ((double)(pointMinX.Y - pointMaxX.Y)) / (pointMinX.X - pointMaxX.X);
// 根据斜率,计算y坐标
double y = k * (i - pointMinX.X) + pointMinX.Y;
// 简单判断一下y是不是整数
double d = y - (int)y;
if (0.001 > d && d > -0.001)
{
linePoint.Add(new Point(i,(int)d));
}
}
//打印点
foreach (var item in linePoint)
{
Console.WriteLine(item.X + @"," + item.Y);
}
画线
依据某个端点，找出这个端点方向的下一个三个周围点，找出最符合斜率的点。
public bool DrawLineOnPicture(Color c, Point start, Point end)
{
if (MyBitmapData == null) { return false; }
int x, y;
int dstStride = MyBitmapData.Stride;
//Object thisLock = new Object();
//lock (thisLock){
System.IntPtr dstScan0 = MyBitmapData.Scan0;
try
{
if (start.X > end.X)
{
Point temp = start;
start = end;
end = temp;
}
int step;
if (start.Y < end.Y)
step = 1;
else
step = -1;
x = start.X;
y = start.Y;
unsafe
{
byte* pDst = (byte*)(void*)dstScan0; while ((x != end.X) || (y != end.Y))
{ pDst[x * 3 + y * dstStride] = c.R;
pDst[x * 3 + y * dstStride + 1] = c.G;
pDst[x * 3 + y * dstStride + 2] = c.B; Point p1 = new Point(x + 1, y);
Point p2 = new Point(x, y + step);
Point p3 = new Point(x + 1, y + step); double distance1 = DistanceToLine(p1, start, end);
double distance2 = DistanceToLine(p2, start, end);
double distance3 = DistanceToLine(p3, start, end); double distance = Math.Min(Math.Min(distance1, distance3), distance2);
if (distance == distance1)
{
x = p1.X;
y = p1.Y;
}
else if (distance == distance2)
{
x = p2.X;
y = p2.Y;
}
else
{
x = p3.X;
y = p3.Y;
}
}
}
}
catch (Exception )
{
//DBConnection.LevelTrace(TraceLevel.Error, "MyImage-->DrawLineOnPicture failed with:" + e);
return false;
}
//}
return true;
}
private double DistanceToLine(Point p, Point lineStart, Point lineEnd)
{
if (lineStart.X == lineEnd.X)
return (Math.Abs(p.X - lineEnd.X));
else if (lineStart.Y == lineEnd.Y)
return (Math.Abs(p.Y - lineEnd.Y));
else
{
double a = 1.0 * (lineEnd.Y - lineStart.Y) / (lineEnd.X - lineStart.X);
double b = lineStart.Y - a * lineStart.X;
double b2 = p.Y - a * p.X;
return (Math.Abs(b2 - b));
}
}