OpenGL计算机图形学梁友栋裁剪算法实验代码及运行结果.doc

计算机图形学实验报告任课教师：钱文华2016年春季学期实验:梁友栋裁剪实验时间：2016年11月17日实验地点：信息学院2204实验目的：掌握梁友栋裁剪程序代码：#include #include #include #include class wcPt2Dpublic:GLfloat x,y;void setCoords(GLfloat xCoord,GLfloat yCoord)x=xCoord;y=yCoord;GLfloat getx() constreturn x;GLfloat gety() constreturn y;inline GLint round(const GLfloat a)return GLint(a+0.5);void setPixel(int x,int y)glBegin(GL_POINTS);glVertex2i(x,y);glEnd();void init()glClearColor(1.0,1.0,1.0,0.0);glMatrixMode (GL_PROJECTION);gluOrtho2D(-200.0,200.0,-200.0,200.0);void lineBres(GLfloat x0,GLfloat y0,GLfloat xEnd,GLfloat yEnd)int dx = fabs(xEnd - x0),dy = fabs(yEnd - y0);int p = 2*dy - dx;int twoDy = 2*dy,twoDyMinusDx = 2*(dy - dx);int x,y;if(x0xEnd)x = xEnd;y = yEnd;xEnd = x0;elsex = x0;y = y0;setPixel(x,y);while(xxEnd)x+;if(p0)p+=twoDy;elsey+;p+=twoDyMinusDx;setPixel(x,y);GLint clipTest(GLfloat p,GLfloat q,GLfloat *u1,GLfloat *u2)GLfloat r;GLint returnValue = true;if(p*u2)returnValue = false;elseif(r*u1)*u1 = r;elseif(p0.0)r = q/p;if(r*u1)returnValue = false;else if(r*u2)*u2 = r;elseif(q0.0)returnValue = false;return(returnValue);void lineClipLiangBarsk(wcPt2D winMin,wcPt2D winMax,wcPt2D p1,wcPt2D p2)GLfloat u1 = 0.0,u2 = 1.0,dx = p2.getx()-p1.getx(),dy;GLfloat x1 = p1.getx(),y1 = p1.gety();GLfloat x2 = p2.getx(),y2 = p2.gety();if(clipTest(-dx,p1.getx()-winMin.getx(),&u1,&u2)if(clipTest(dx,winMax.getx()-p1.getx(),&u1,&u2)dy = p2.gety()-p1.gety();if(clipTest(-dy,p1.gety()-winMin.gety(),&u1,&u2)if(clipTest(dy,winMax.gety()-p1.gety(),&u1,&u2)if(u20.0)p1.setCoords(p1.getx()+u1*dx,p1.gety()+u1*dy);glColor3f(0.0,0.0,0.0);lineBres(x1,y1,p1.getx(),p1.gety();lineBres(p2.getx(),p2.gety(),x2,y2);glColor3f(1.0,0.0,0.0);lineBres(p1.getx(),p1.gety(),p2.getx(),p2.gety();elseglColor3f(0.0,0.0,0.0);lineBres(x1,y1,x2,y2);void displayliangyoudongcaijian()glClear(GL_COLOR_BUFFER_BIT);glLineWidth(5.0);glColor3f(0.0,0.0,0.0);glBegin(GL_LINE_LOOP);glVertex2i(100,100);glVertex2i(100,-100);glVertex2i(-100,-100);glVertex2i(-100,100);glEnd();glPointSize(4);wcPt2D test14 = -100.0,-100.0,100.0,100.0,-150.0,-200.0,200.0,120.0;wcPt2D test24 = -100.0,-100.0,100.0,100.0,-150.0,-120.0,0.0,0.0;wcPt2D test34 = -100.0,-100.0,100.0,100.0,-50.0,50.0,150.0,150.0;wcPt2D test44 = -100.0,-100.0,100.0,100.0,-50.0,0.0,60.0,50.0;wcPt2D test54 = -100.0,-100.0,100.0,100.0,-170.0,-200.0,200.0,-120.0;lineClipLiangBarsk(test10,test11,test12,test13);lineClipLiangBarsk(test20,test21,test22,test23);lineClipLiangBarsk(test30,test31,test32,test33);lineClipLiangBarsk(test40,test41,test42,test43);lineClipLiangBarsk(test50,test51,test52,test53);glFlush();void main(int argc, char* argv)glutInit(&argc,argv);glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);glutInitWindowP