fan.cpp

电子画图板

//正弦曲线fan类 
//fan.cpp

//包含的头文件
#include "stdafx.h"
#include "Coordinate.h"
#include "Shape.h"
#include "fan.h"
#include <math.h>

//类实现
IMPLEMENT_SERIAL(fan,Shape,1)

fan::fan(){
	a=0.0;
	b=0.0;
	c=0.0;
	d=0.0;
	expression.Format("y=%1.2lf/(%1.2lf*x+%1.2lf)+%1.2lf",a,b,c,d);
	//expression.Format("y=%1.2lf*fan(%1.2lf*x+%1.2lf)+%1.2lf",a,b,c,d);
}

fan::fan(double a,double b,double c,double d){
	this->a=a;
	this->b=b;
	this->c=c;
	this->d=d;
	expression.Format("y=%1.2lf/(%1.2lf*x+%1.2lf)+%1.2lf",a,b,c,d);
	//expression.Format("y=%1.2lf*fan(%1.2lf*x+%1.2lf)+%1.2lf",a,b,c,d);
}

fan::~fan(){

}

void fan::drawShape(CDC *pDC,Coordinate co){	//画二次函数
	//利用逐步逼近法画曲线
	double left=-200.0;            //最左边的坐标的横轴坐标（实际坐标）为left
								   //则最右边的坐标的横轴坐标（实际坐标）为-left
	double step=0.1;			   //设置逐步逼近的步长
    int size=(int)(2*(-left)/step)+1;	//计算出从最左边到最右边（以step为步长）的点数
	double x=left,y;
	CPoint * p=new CPoint[size];
	
	//得出一系列点的视图坐标，并放于一CPoing数组里
	for(int i=0;i<size;i++){
		y=c/(a*x+b)+d;
		//y=a*fan(b*x+c)+d;  //y=f(x)	
		p[i]=co.getTrueAxis(x,y);	//坐标转换
		x+=step;
	}
	pDC->Polyline(p,size);		//利用一系列存放在点数组的点画线
	delete [] p;
}

void fan::Serialize(CArchive &ar){	//串行化
	Shape::Serialize(ar);
	if(ar.IsStoring()){
		//storing
		ar <<a<<b<<c<<d;
	}
	else{
		//loading
		ar >>a>>b>>c>>d;
	}
}