计算机图形学Bresenham完整算法 画直线、椭圆和圆

1、#include <>#include <gl/>#include ""int m_PointNumber = 0; /动画时绘制点的数目int m_DrawMode = 1; /绘制模式 1 DDA算法画直线 / 2 中点Bresenham算法画直线 / 3 改进Bresenham算法画直线 / 4 八分法绘制圆 / 5 四分法绘制椭圆/绘制坐标线void DrawCordinateLine(void)int i = -250 ;/坐标线为黑色glColor3f(0.0f, 0.0f ,0.0f);glBegin(GL_LINES); for (i

2、=-250;i<=250;i=i+10)glVertex2f(float)(i), -250.0f);glVertex2f(float)(i), 250.0f);glVertex2f(-250.0f, (float)(i);glVertex2f(250.0f, (float)(i);glEnd();/绘制一个点，这里用一个正方形表示一个点void putpixel(GLsizei x, GLsizei y)glRectf(10*x,10*y,10*x+10,10*y+10);/DDA画线算法 / / / / / / void DDACreateLine(GLsizei x0, GLsiz

3、ei y0, GLsizei x1, GLsizei y1, GLsizei num)/设置颜色glColor3f(1.0f,0.0f,0.0f);/对画线动画进行控制if(num = 1)printf("DDA画线算法：各点坐标n");else if(num=0)return;/画线算法的实现 GLsizei dx,dy,epsl,k;GLfloat x,y,xIncre,yIncre;dx = x1-x0;dy = y1-y0;x = x0;y = y0;if(abs(dx) > abs(dy) epsl = abs(dx);else epsl = abs(dy)

4、;xIncre = (float)dx / epsl ;yIncre = (float)dy / epsl ;for(k = 0; k<=epsl; k+)putpixel(int)(x+0.5), (int)(y+0.5);if (k>=num-1) printf("x=%f , y=%f,取整后 x=%d,y=%dn", x, y, (int)(x+0.5),(int)(y+0.5);break;x += xIncre;y += yIncre;if(x >= 25 | y >= 25) break;/中点Bresenham算法画直线(0<=

5、k<=1) / / / / / / void BresenhamLine(GLsizei x0, GLsizei y0, GLsizei x1, GLsizei y1, GLsizei num)glColor3f(1.0f,0.0f,0.0f);if(num = 1)printf("中点Bresenham算法画直线各点坐标及判别式的值n");else if(num=0)return;/画线算法的实现GLsizei p=0;GLfloatUpIncre,DownIncre,x,y,d,k,dx,dy;if(x0>x1)x=x1;x1=x0;x0=x;y=y1;y1

6、=y0;y0=y;x=x0;y=y0;dx=x1-x0;dy=y1-y0;k=dy/dx;if(k>=0&&k<=1) d=dx-2*dy; UpIncre=2*dx-2*dy; DownIncre=-2*dy; while(x<=x1) putpixel(x,y); if (p>=num-1) printf("x=%d,y=%dn", x, y);break; p+; x+; if(d<0) y+; d+=UpIncre; else d+=DownIncre; if(k>1) d=dy-2*dx; UpIncre=2*d

7、y-2*dx; DownIncre=-2*dx; while(y<=y1) putpixel(x,y);if (p>=num-1) printf("x=%d,y=%dn", x, y); break; p+;y+; if(d<0) x+; d+=UpIncre; else d+=DownIncre; if(k<0&&k>=-1) d=dx-2*dy; UpIncre=-2*dy; DownIncre=-2*dx-2*dy; while(x<=x1) putpixel(x,y); if (p>=num-1) print

8、f("x=%d,y=%dn", x, y);break; p+; x+; if(d>0) y-; d+=DownIncre; else d+=UpIncre; if(k<-1) d=-dy-2*dx; UpIncre=-2*dx-2*dy; DownIncre=-2*dx; while(y>=y1) putpixel(x,y);if (p>=num-1) printf("x=%d,y=%dn", x, y); break; p+;y-; if(d<0) x+; d+=UpIncre;else d+=DownIncre; /改

9、进的Bresenham算法画直线(0<=k<=1) / / / x1,y1 终点坐标 / / / void Bresenham2Line(GLsizei x0, GLsizei y0, GLsizei x1, GLsizei y1, GLsizei num)glColor3f(1.0f,0.0f,0.0f);GLsizei x,y,dx,dy,e,k;if(num = 1)printf("改进的Bresenham算法画直线各点坐标及判别式的值n");else if(num=0)return;/画线算法的实现GLsizei p=0;if(x0>x1)x=x1

10、;x1=x0;x0=x;y=y1;y1=y0;y0=y;dx=x1-x0;dy=y1-y0;k=dy/dx;if(k>=0&&k<=1) e=-dx;x=x0;y=y0; while(x<=x1) putpixel(x,y); if (p>=num-1) printf("x=%d,y=%dn", x, y); break; p+; x+; e=e+2*dy; if(e>0) y+; e=e-2*dx; if(k>1) e=-dy;x=x0;y=y0; while(y<=y1) putpixel(x,y); if (p

11、>=num-1) printf("x=%d,y=%dn", x, y); break; p+; y+; e=e+2*dx; if(e>0) x+; e=e-2*dy; if(k<0&&k>=-1) e=-dx;x=x0;y=y0; while(x<=x1) putpixel(x,y); if (p>=num-1) printf("x=%d,y=%dn", x, y); break; p+; x+; e=e+2*dy; if(e<0) y-; e=e+2*dx; if(k<-1) e=-dy;

12、x=x0;y=y0; while(y>=y1) putpixel(x,y); if (p>=num-1) printf("x=%d,y=%dn", x, y); break; p+; y-; e=e-2*dx; if(e<0) x+; e=e-2*dy; /Bresenham算法画圆 / / / / / /void CirclePoint(GLsizei x,GLsizei y) putpixel(x,y); putpixel(x,-y); putpixel(y,-x); putpixel(-y,-x); putpixel(-x,-y); putpixel

13、(-x,y); putpixel(-y,x); putpixel(y,x);void BresenhamCircle(GLsizei x, GLsizei y, GLsizei R, GLsizei num)glColor3f(1.0f,0.0f,0.0f);GLsizei d;x=0;y=R;d=1-R;if(num = 1)printf("Bresenham算法画圆：各点坐标及判别式的值n");else if(num=0)return;while(x<=y)CirclePoint(x,y); if (x>=num-1) printf("x=%d,y

14、=%d,d=%dn", x, y,d); break; if(d<0)d+=2*x+3;else d+=2*(x-y)+5; y-;x+;void Bresenham2Circle(GLsizei a,GLsizei b,GLsizei num)glColor3f(1.0f,0.0f,0.0f);if(num=1)printf("Bresenham算法画椭圆：各点坐标及判别式的值n");else if(num=0)return;GLsizei x,y;float d1,d2;x=0;y=b;d1=b*b+a*a*(-b+0.5);putpixel(x,y);

15、 putpixel(-x,-y);putpixel(-x,y);putpixel(x,-y);while(b*b*(x+1)<a*a*(y-0.5)if (x>=num-1) printf("x=%d,y=%d,d1=%dn", x, y,d1); break; if(d1<=0)d1+=b*b*(2*x+3);x+;elsed1+=b*b*(2*x+3)+a*a*(-2*y+2);x+;y-;putpixel(x,y); putpixel(-x,-y);putpixel(-x,y);putpixel(x,-y);/while上半部分)+a*a*(y-1)

16、*(y-1)-a*a*b*b;while(y>0)if (x>=num-1) printf("x=%d,y=%d,d2=%dn", x, y,d2); break; if(d2<=0)d2+=b*b*(2*x+2)+a*a*(-2*y+3);x+;y-;elsed2+=a*a*(-2*y+3);y-;putpixel(x,y); putpixel(-x,-y);putpixel(-x,y);putpixel(x,-y);/初始化窗口void Initial(void) / 设置窗口颜色为蓝色 glClearColor(0.0f, 0.0f, 1.0f, 1

17、.0f);/ 窗口大小改变时调用的登记函数void ChangeSize(GLsizei w, GLsizei h)if(h = 0)h = 1;/ 设置视区尺寸 glViewport(0,0, w, h);/ 重置坐标系统glMatrixMode(GL_PROJECTION);glLoadIdentity();/ 建立修剪空间的范围 if (w <= h) glOrtho (-250.0f, 250.0f, -250.0f, 250.0f*h/w, 1.0, -1.0); else glOrtho (-250.0f, 250.0f*w/h, -250.0f, 250.0f, 1.0,

18、-1.0);/ 在窗口中绘制图形void ReDraw(void)/用当前背景色填充窗口glClear(GL_COLOR_BUFFER_BIT);/画出坐标线DrawCordinateLine();switch(m_DrawMode)case 1:DDACreateLine(0,0,20,15,m_PointNumber);break;case 2:BresenhamLine(0,0,-20,15,m_PointNumber);break;case 3:Bresenham2Line(1,1,8,6,m_PointNumber);break;case 4:BresenhamCircle(0,0,20,m_PointNumber);break;case 5:Bresenham2Circle(10,8,m_PointNumber);default:break; glFlush();/设置时间回调函数void TimerFunc(int value)if(m_PointNumber = 0)value = 1;m_PointNumber = value;glutPostRedisplay();glutTimerFunc(500, TimerFunc, value+1);/设置键盘回调函数void Keyboard(unsigned char key, int x, int y) if (