c++ 画贝塞尔曲线代码

#pragma once

#include <stdio.h>
#include <iostream>
#include <vector>


using namespace std;

//Point的数据结构
typedef struct
{
	float X;
	float Y;
} PointF;

class Bezier {
public:
	Bezier() = default;
	
	PointF InterpolationFunc(float t, PointF* points, PointF* tmpPoint, int count);
	void DrawBezierCurves(PointF* points, int count, PointF* out_points, int out_count);
};

#include "Curve.h"

PointF Bezier::InterpolationFunc(float t, PointF* points, PointF* tmpPoint, int count)
{
	
	for (int i = 1; i < count; ++i)
	{
		for (int j = 0; j < count - i; ++j)
		{
			if (i == 1)
			{
				tmpPoint[j].X = (float)(points[j].X * (1 - t) + points[j + 1].X * t);
				tmpPoint[j].Y = (float)(points[j].Y * (1 - t) + points[j + 1].Y * t);
				continue;
			}
			tmpPoint[j].X = (float)(tmpPoint[j].X * (1 - t) + tmpPoint[j + 1].X * t);
			tmpPoint[j].Y = (float)(tmpPoint[j].Y * (1 - t) + tmpPoint[j + 1].Y * t);
		}
	}
	
	return tmpPoint[0];
}

void Bezier::DrawBezierCurves(PointF* points, int count, PointF* out_points, int out_count)
{
	float step = 1.0 / out_count;
	float t = 0;
	PointF *tmpPoints = new PointF[count];
	for (int i = 0; i < out_count; i++)
	{
		PointF temp_point = InterpolationFunc(t, points, tmpPoints, count);    // 计算插值点
		t += step;
		out_points[i] = temp_point;
	}
	delete[] tmpPoints;
}

调用

Bezier calBz;
	PointF in[3] = { {100,0},{200,200},{300,100} }; // 输入点

	int num = 100;     // 输出点数
	PointF out[100];    // 输出点数组

	calBz.DrawBezierCurves(in, 3, out, num);// 二阶贝塞尔曲线