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| using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;
namespace Null.FuncDraw
{
public static class FuncDraw
{
/// <summary>
/// 根据数字坐标获取像素位置
/// </summary>
/// <param name="xCoord">x坐标</param>
/// <param name="yCoord">y坐标</param>
/// <param name="xOffset">原点位置</param>
/// <param name="yOffset">原点位置</param>
/// <param name="scale">缩放</param>
/// <returns>像素位置</returns>
public static Point GetPointFromCoords(double xCoord, double yCoord, int xOffset, int yOffset, double scale)
{
return new Point((int)(xCoord * scale + xOffset), (int)(-yCoord * scale + yOffset));
}
/// <summary>
///
/// </summary>
/// <param name="coords">数字坐标</param>
/// <param name="offset">原点位置</param>
/// <param name="scale">缩放</param>
/// <returns>像素位置</returns>
public static Point GetPointFromCoords(PointF coords, Point offset, double scale)
{
return new Point((int)(coords.X * scale + offset.X), (int)(-coords.Y * scale + offset.Y));
}
/// <summary>
/// 根据像素位置获取数字坐标
/// </summary>
/// <param name="x">水平位置</param>
/// <param name="y">竖直位置</param>
/// <param name="xOffset">原点位置</param>
/// <param name="yOffset">原点位置</param>
/// <param name="scale">缩放</param>
/// <param name="xCoord">输出: 数字X坐标</param>
/// <param name="yCoord">输出: 数字Y坐标</param>
public static void GetCoordsFromPoint(int x, int y, int xOffset, int yOffset, double scale, out double xCoord, out double yCoord)
{
xCoord = (x - xOffset) / scale;
yCoord = -((y - yOffset) / scale);
return;
}
/// <summary>
/// 根据像素长度返回数字
/// </summary>
/// <param name="length">像素长度</param>
/// <param name="scale">缩放</param>
/// <returns>数字</returns>
public static double GetNumberFromPixel(int length, double scale)
{
return length / scale;
}
/// <summary>
/// 根据数字来获取它距离原点的像素长度
/// </summary>
/// <param name="number">数字</param>
/// <param name="scale">缩放</param>
/// <returns>像素长度</returns>
public static double GetPixelFromNumber(int number, double scale)
{
return number * scale;
}
/// <summary>
/// 画函数图像
/// </summary>
/// <param name="func">要画的函数</param>
/// <param name="inputs">X的取值</param>
/// <param name="graphics">绘图Graphics</param>
/// <param name="pen">画线所用的Pen</param>
/// <param name="drawArea">画函数的区域</param>
/// <param name="xOffset">原点的位置</param>
/// <param name="yOffset">原点的位置</param>
/// <param name="scale">缩放参数</param>
public static void DrawFunc(Func<double, double> func, IEnumerable<double> inputs, Graphics graphics, Pen pen, Rectangle drawArea, int xOffset, int yOffset, double scale)
{
double[] nums = inputs.ToArray();
Point[] coords = new Point[nums.Length];
int drawAreaLeft = drawArea.X,
drawAreaRight = drawAreaLeft + drawArea.Width,
drawAreaTop = drawArea.Y,
drawAreaBottom = drawAreaTop + drawArea.Height;
double y;
for (int i = 0, len = nums.Length; i < len; i++) // 最近刚知道要少用属性, 毕竟属性的实质是函数, 函数调用需要分配栈空间, 而且似乎还涉及到装箱拆箱, 所以这样效率高一些
{
y = func.Invoke(nums[i]);
coords[i] = GetPointFromCoords(nums[i], y, xOffset, yOffset, scale);
}
bool point1xIn1,
point1xIn2,
point1yIn1,
point1yIn2,
point2xIn1,
point2xIn2,
point2yIn1,
point2yIn2;
for (int i = 1, len = nums.Length; i < len; i++)
{
Point point1 = coords[i - 1];
Point point2 = coords[i];
point1xIn1 = point1.X >= drawAreaLeft;
point1xIn2 = point1.X <= drawAreaRight;
point1yIn1 = point1.Y >= drawAreaTop;
point1yIn2 = point1.Y <= drawAreaBottom;
point2xIn1 = point2.X >= drawAreaLeft;
point2xIn2 = point2.X <= drawAreaRight;
point2yIn1 = point2.Y >= drawAreaTop;
point2yIn2 = point2.Y <= drawAreaBottom;
if ((!(point1xIn1 && point2xIn1)) || (!(point1xIn2 && point2xIn2)) || (!(point1yIn1 && point2yIn1)) || (!(point1yIn2 && point2yIn2)))
continue;
if (!point1xIn1)
point1 = new Point(drawAreaLeft, (int)(point1.Y + (point2.Y - point1.Y) * ((double)drawAreaLeft - point1.X) / (point2.X - point1.X))); // 这里是有一些奇妙优化的, 不要删去. 否则将导致某些函数无法绘制.
else if (!point2xIn1)
point2 = new Point(drawAreaLeft, (int)(point2.Y + (point1.Y - point2.Y) * ((double)drawAreaLeft - point2.X) / (point1.X - point2.X)));
if (!point1xIn2)
point1 = new Point(drawAreaRight, (int)(point2.Y + (point1.Y - point2.Y) * ((double)drawAreaRight - point2.X) / (point1.X - point2.X)));
else if (!point2xIn2)
point2 = new Point(drawAreaRight, (int)(point1.Y + (point2.Y - point1.Y) * ((double)drawAreaRight - point1.X) / (point2.X - point1.X)));
if (!point1yIn1)
point1 = new Point((int)(point1.X + (point2.X - point1.X) * ((double)drawAreaTop - point1.Y) / (point2.Y - point1.Y)), drawAreaTop);
else if (!point2yIn1)
point2 = new Point((int)(point2.X + (point1.X - point2.X) * ((double)drawAreaTop - point2.Y) / (point1.Y - point2.Y)), drawAreaTop);
if (!point1yIn2)
point1 = new Point((int)(point2.X + (point1.X - point2.X) * ((double)drawAreaBottom - point2.Y) / (point1.Y - point2.Y)), drawAreaBottom);
else if (!point2yIn2)
point2 = new Point((int)(point1.X + (point2.X - point1.X) * ((double)drawAreaBottom - point1.Y) / (point2.Y - point1.Y)), drawAreaBottom);
graphics.DrawLine(pen, point1, point2);
}
}
/// <summary>
/// 画一个坐标轴
/// </summary>
/// <param name="xNumbers">x轴要画的数</param>
/// <param name="yNumbers">y轴要画的数</param>
/// <param name="graphics">绘图Graphics</param>
/// <param name="brush">填充坐标轴三角所使用的Brush</param>
/// <param name="pen">画坐标轴所使用的Pen</param>
/// <param name="font">画坐标数字所使用的Font</param>
/// <param name="drawArea">画坐标轴的区域</param>
/// <param name="xOffset">原点的位置</param>
/// <param name="yOffset">远点的位置</param>
/// <param name="barLength">坐标轴上小竖线的长度</param>
/// <param name="scale">缩放参数</param>
/// <param name="text">是否绘出数字</param>
public static void DrawShaft(IEnumerable<double> xNumbers, IEnumerable<double> yNumbers, Graphics graphics, Brush brush, Pen pen, Font font, Rectangle drawArea, int xOffset, int yOffset, int barLength, double scale, bool text)
{
Action<Point, double> drawText;
if (text)
drawText = (point, num) => graphics.DrawString(num.ToString("F2"), font, brush, point); // 使用委托, 那么接下来就不需要进行多余的对text的判断, 而直接Invoke就彳亍
else
drawText = (point, num) => { };
Point
yTop = new Point(xOffset, drawArea.Y),
yBottom = new Point(xOffset, drawArea.Y + drawArea.Height), // 确认轴的位置
xLeft = new Point(drawArea.X, yOffset),
xRight = new Point(drawArea.X + drawArea.Width, yOffset);
graphics.DrawLine(pen, yTop, yBottom); // 画轴
graphics.DrawLine(pen, xLeft, xRight);
int triangleHeight = (int)(Math.Tan(Math.PI / 3) * barLength); // 坐标轴末端小三角的高度
Point[]
triangle1 = new Point[] { yTop, new Point(yTop.X - barLength, yTop.Y + triangleHeight), new Point(yTop.X + barLength, yTop.Y + triangleHeight) },
triangle2 = new Point[] { xRight, new Point(xRight.X - triangleHeight, xRight.Y + barLength), new Point(xRight.X - triangleHeight, xRight.Y - barLength) };
graphics.FillPolygon(brush, triangle1); // 画三角
graphics.FillPolygon(brush, triangle2);
foreach (double x in xNumbers)
{
Point numBase = GetPointFromCoords(x, 0, xOffset, yOffset, scale);
Point numEnd = new Point(numBase.X, numBase.Y - barLength);
graphics.DrawLine(pen, numBase, numEnd); // 画x轴数
drawText(numBase, x);
}
foreach (double y in yNumbers)
{
Point numBase = GetPointFromCoords(0, y, xOffset, yOffset, scale);
Point numEnd = new Point(numBase.X + barLength, numBase.Y);
graphics.DrawLine(pen, numBase, numEnd); // 画y轴数
drawText(numBase, y);
}
}
}
}
|
欸嘿, 这就是程序图了, 通过鼠标拖拽可以移动, 鼠标滚轮可以缩放, 右下角还可以选择要绘制的函数. 项目仓库链接在文章末尾
然后, 标尺, 也是一个个线呗, 那个数字的话, 就是这个:
填充小三角的话, 就是这个:
