发布时间 : 星期三 文章计算机图形学实验C++代码更新完毕开始阅读
一、 bresenham算法画直线
#include
void draw_pixel(int ix,int iy) { glBegin(GL_POINTS); glVertex2i(ix,iy); glEnd();
}
void Bresenham(int x1,int y1,int xEnd,int yEnd) { int dx=abs(xEnd-x1),dy=abs(yEnd-y1); int p=2*dy-dx;
int twoDy=2*dy,twoDyMinusDx=2*dy-2*dx; int x,y; if (x1>xEnd) { x=xEnd;y=yEnd; xEnd=x1; } else { x=x1; y=y1;
}
draw_pixel(x,y); while(x p+=twoDy; else { y++; p+=twoDyMinusDx; draw_pixel(x,y); } } } void display() { glClear(GL_COLOR_BUFFER_BIT); Bresenham(0,0,400,400); glFlush(); 1 } void myinit() { } void main(int argc,char **argv ) { } glutInit(&argc,argv); glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB); glutInitWindowSize(500,500); glutInitWindowPosition(200.0,200.0); glutCreateWindow(\); glutDisplayFunc(display); myinit(); glutMainLoop(); glClearColor(0.8,1.0,1.0,1.0); glColor3f(0.0,0.0,1.0); glPointSize(1.0); glMatrixMode(GL_PROJECTION); glLoadIdentity(); gluOrtho2D(0.0,500.0,0.0,500.0); 二、 中点法绘制椭圆 #include inline int round(const float a){return int (a+0.5);} void setPixel(GLint xCoord,GLint yCoord) { } void ellipseMidpoint(int xCenter,int yCenter,int Rx,int Ry) { int Rx2=Rx*Rx; int Ry2=Ry*Ry; int twoRx2=2*Rx2; int twoRy2=2*Ry2; int p; int x=0; int y=Ry; int px=0; int py=twoRx2*y; void ellipsePlotPoints(int,int,int,int); 2 glBegin(GL_POINTS); glVertex2i(xCoord,yCoord); glEnd(); } ellipsePlotPoints(xCenter,yCenter,x,y); p=round(Ry2-(Rx2*Ry)+(0.25*Rx2)); while(px p=round(Ry2*(x+0.5)*(x+0.5)+Rx2*(y-1)*(y-1)-Rx2*Ry2); while(y>0){ } y--; py-=twoRx2; if(p>0) } ellipsePlotPoints(xCenter,yCenter,x,y); p+=Rx2-py; x++; px+=twoRy2; p+=Rx2-py+px; x++; px+=twoRy2; if(p<0) p+=Ry2+px; else{ } ellipsePlotPoints(xCenter,yCenter,x,y); y--; py-=twoRx2; p+=Ry2+px-py; else{ void ellipsePlotPoints(int xCenter,int yCenter,int x,int y) { } void display() { } void myinit() { glClearColor(0.8,1.0,1.0,1.0); glColor3f(0.0,0.0,1.0); glPointSize(1.0); 3 glClear(GL_COLOR_BUFFER_BIT); ellipseMidpoint(200,200,50,30); glFlush(); setPixel(xCenter+x,yCenter+y); setPixel(xCenter-x,yCenter+y); setPixel(xCenter+x,yCenter-y); setPixel(xCenter-x,yCenter-y); } glMatrixMode(GL_PROJECTION); glLoadIdentity(); gluOrtho2D(0.0,300.0,0.0,300.0); void main(int argc,char **argv ) { } glutInit(&argc,argv); glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB); glutInitWindowSize(300,300); glutInitWindowPosition(200.0,200.0); glutCreateWindow(\); glutDisplayFunc(display); myinit(); glutMainLoop(); 三、 抛物线 #include inline int round(const float a){return int (a+0.5);} void setPixel(GLint xCoord,GLint yCoord) { } void ellipseMidpoint(int xCenter,int yCenter,int a,int b) { int p; int x=xCenter; int y=yCenter; int px=0,py=0; void ellipsePlotPoints(int,int,int,int); ellipsePlotPoints(xCenter,yCenter,px,py); p=yCenter+a*(x+1-xCenter)*(x+1-xCenter)+b*(x+1-xCenter)-y-0.5; do{ if(p<0) { } else{ x=x+1; y=y-1; 4 x=x+1; y=y; p=yCenter+a*(x+1-xCenter)*(x+1-xCenter)+b*(x+1-xCenter)-y-0.5; glBegin(GL_POINTS); glVertex2i(xCoord,yCoord); glEnd();