Bresenham改进算法结合wu反走样算法画直线
自己打造了CLine画直线类
1.CP2类 定义了点类
class CP2
{
public:
CRGB clr;
double y;
double x;
CP2();
CP2(double,double,CRGB clr=CRGB());
virtual ~CP2();
};2.CRGB类 定义了颜色类
class CRGB
{
public:
double r;
double g;
double b;
public:
CRGB();
CRGB(double,double,double);
virtual ~CRGB();
CRGB& operator= (const CRGB& c1)
{
r=c1.r;
g=c1.g;
b=c1.b;
return *this;
}
friend CRGB operator+ (const CRGB&, const CRGB&);
friend CRGB operator- (const CRGB&, const CRGB&);
friend CRGB operator* (const CRGB&, const CRGB&);
friend CRGB operator* (const CRGB&, double);
friend CRGB operator* (double, const CRGB&);
friend CRGB operator/ (const CRGB&, double);
friend CRGB operator+= (CRGB&, CRGB&);
friend CRGB operator-= (CRGB&, CRGB&);
friend CRGB operator*= (CRGB&, CRGB&);
friend CRGB operator/= (CRGB&, double);
void Normalize();
};3.定义了CLine类
class CLine
{
public:
CP2 P1;
CP2 P0;
public:
void LineTo(CDC*,double,double,CRGB,BOOL anti=FALSE);
void LineTo(CDC*,double,double,BOOL anti=FALSE);
void LineTo(CDC*,CP2,BOOL anti=FALSE);
void MoveTo(CDC*,double,double,CRGB);
void MoveTo(CDC*,double,double);
void MoveTo(CDC*,CP2);
CLine();
virtual ~CLine();
};4.CLine类的实现
// Line.cpp: implementation of the CLine class.
//
//
#include "stdafx.h"
#include "Class.h"
#include "Line.h"
#include
#define Round(a) int(a+0.5) //四舍五入
#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[]=__FILE__;
#define new DEBUG_NEW
#endif
//
// Construction/Destruction
//
CLine::CLine()
{
}
CLine::~CLine()
{
}
void CLine::MoveTo(CDC* pDC, CP2 p0)
{
P0=p0;
}
void CLine::MoveTo(CDC* pDC, double x, double y)
{
MoveTo(pDC,CP2(x,y));
}
void CLine::MoveTo(CDC* pDC, double x, double y, CRGB c)
{
MoveTo(pDC,CP2(x,y,c));
}
void CLine::LineTo(CDC* pDC, CP2 p1, BOOL anti) //anti控制直线是否进行反走样
{
P1=p1;
CP2 p = P0;
int dx = abs ( P1.x - P0.x );
int dy = abs ( P1.y - P0.y );
int s1 = P1.x > P0.x ? 1 : -1;
int s2 = P1.y > P0.y ? 1 : -1;
BOOL interchange = FALSE;
if(dy>dx)
{
int temp=dx;
dx=dy;
dy=temp;
interchange=TRUE;
}
if(anti==FALSE) //用Bresenham算法绘制走样直线 利用对称性并且对其去小数和去除法运算改进了代码
{
int e=dy+dy-dx;
for(int i=1;iSetPixelV(p.x,p.y,RGB(p.clr.r*255,p.clr.g*255,p.clr.b*255));
if(e>0)
{
if(!interchange)
p.y+=s2;
else
p.x+=s1;
e-=dx+dx;
}
if(!interchange)
p.x+=s1;
else
p.y+=s2;
e+=dy+dy;
}
}
else //绘制反走样直线 利用了Wu反走样算法
{
double s3 = P1.x > P0.x ? 1/((P1.y-P0.y)/(P1.x-P0.x)) : -1/((P1.y-P0.y)/(P1.x-P0.x));
double s4 = P1.y > P0.y ? (P1.y-P0.y)/(P1.x-P0.x) : -(P1.y-P0.y)/(P1.x-P0.x);
double e,a,b;
double k=(P1.y-P0.y)/(P1.x-P0.x);
if(!interchange)
e=s4;
else
e=s3;
for(int i=1;iSetPixelV(Round(p.x),Round(p.y),RGB(c0.r,c0.g,c0.b));
if(!interchange)
b=p.y+s2;
else
a=p.x+s1;
pDC->SetPixelV(Round(a),Round(b),RGB(c1.r,c1.g,c1.b));
if(!interchange)
{
p.x+=s1;
e+=s4*s1;
}
else
{
p.y+=s2;
e+=s3*s2;
}
if(e>=1.0)
{
if(!interchange)
p.y+=s2;
else
p.x+=s1;
e--;
}
}
}
}
void CLine::LineTo(CDC* pDC, double x, double y, BOOL anti)
{
LineTo(pDC,CP2(x,y),anti);
}
void CLine::LineTo(CDC* pDC, double x, double y, CRGB c, BOOL anti)
{
LineTo(pDC,CP2(x,y,c),anti);
}