Bresenham改进算法结合wu反走样算法画直线

来源：互联网发布：乐器软件模拟器编辑：程序博客网时间：2024/06/06 18:14

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 <math.h>#define   Round(a) int(a+0.5) //四舍五入#ifdef _DEBUG#undef THIS_FILEstatic 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;i<dx;i++){pDC->SetPixelV(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;elsep.x+=s1;e-=dx+dx;}if(!interchange)p.x+=s1;elsep.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;elsee=s3;for(int i=1;i<dx;i++){a=p.x;b=p.y;CRGB c0=CRGB(e,e,e)*255;CRGB c1=CRGB(1.0-e,1.0-e,1.0-e)*255;pDC->SetPixelV(Round(p.x),Round(p.y),RGB(c0.r,c0.g,c0.b));if(!interchange)b=p.y+s2;elsea=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;elsep.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);}

做了CP2 CRGB CLine类，将bresenham算法和wu反走样算法都写进了CLine类，利用对称性对算法实现进行了些改进，可以通过参数控制绘制直线时是否需要反走样

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