计算机图形学实验内容

计算机图形学实验内容PAGEPAGE21计算机图形学实验肖加清实验一图形学实验基础实验目的掌握VC++绘图的一般步骤；掌握OpenGL软件包的安装方法；掌握OpenGL绘图的一般步骤；掌握OpenGL的主要功能与基本语法。二、实验内容1、VC++绘图实验（1）实验内容：以下是绘制金刚石图案。已给出VC++参考程序，但里面有部分错误，请改正，实现以下图案。N=3//视图类的一个成员函数，这个成员函数可以放在OnDraw函数里调用。//在视图类的头文件（.h）里定义此函数voidDiamond();//在视图类的实现文件（.cpp）里实现此函数voidCTestView::Diamond(){ CP2*P; intN; doubleR;R=300;N=10;P=newCP2[N]; CClientDCdc(this); CRectRect; GetClientRect(&Rect); doubletheta; theta=2*PI/N; for(inti=0;i<N;i++) { P[i].x=R*cos(i*theta); P[i].y=R*sin(i*theta); } for(i=0;i<=N-2;i++) { for(intj=i+1;j<=N-1;j++) {//其中ROUND函数需要自己实现，实现四舍五入的功能。 dc.MoveTo(ROUND(P[i].x+Rect.right/2),ROUND(P[i].y+Rect.bottom/2)); dc.LineTo(ROUND(P[j].x+Rect.right/2),ROUND(P[j].y+Rect.bottom/2)); } } delete[]P; }2、OpenGL绘图（1）以下是用OpenGL绘制茶壶的代码，请在OpenGL环境下运行，分析OpenGL程序的结构#include<windows.h>#include<GL/gl.h>#include<GL/glu.h>#include<GL/glaux.h>//定义输出窗口的大小#defineWINDOW_HEIGHT300#defineWINDOW_WIDTH500//用户初始化函数voidmyninit(void);//窗口大小变化时的回调函数voidCALLBACKmyReshape(GLsizeiw,GLsizeih);//每帧OpenGL都会调用这个函数，应该把显示代码放在这个函数中voidCALLBACKdisplay(void);intwindow_width=WINDOW_WIDTH;intwindow_height=WINDOW_HEIGHT;//视点离物体的距离floatdistance=3.6f;//初始化，此时为空，可以在这里进行初始化操作voidmyinit(void){}voidCALLBACKdisplay(void){ //设置清屏的颜色，并清屏和深度缓冲 glClearColor(0.0f,0.0f,0.0f,0.0f); glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT); //设置成模型矩阵模式 glMatrixMode(GL_MODELVIEW); //载入单位化矩阵 glLoadIdentity(); //坐标中心向Z轴平移-distance，这样使坐标中心位于视点前方 glTranslatef(0.0,0.0,-distance); //在坐标中心显示一个茶壶 auxWireTeapot(1.0); //等待现有的OpenGL命令执行完成 glFlush(); //交换前后缓冲区 auxSwapBuffers();}voidCALLBACKmyReshape(GLsizeiw,GLsizeih){ if(!h)return; //这定视区 glViewport(0,0,w,h); //设定透视方式 glMatrixMode(GL_PROJECTION); glLoadIdentity(); gluPerspective(60.0,1.0*(GLfloat)w/(GLfloat)h,1.0,30.0); window_width=w; window_height=h;}//移近移远的回调函数voidCALLBACKMoveNear(void){ distance-=0.3f;}voidCALLBACKMoveFar(void){ distance+=0.3f;}//主函数intmain(intargc,char**argv){ //初始化OpenGL的显示方式 auxInitDisplayMode(AUX_DOUBLE|AUX_RGB|AUX_DEPTH16); //设定OpenGL窗口位置和大小 auxInitPosition(0,0,WINDOW_WIDTH,WINDOW_HEIGHT); //打开窗口 auxInitWindow("OpenGL的一个简单的例子！"); //调用初始化函数 myinit(); //设定窗口大小变化的回调函数 auxReshapeFunc(myReshape); //设定移动视点的回调函数 auxKeyFunc('A',MoveNear);//按A键变大 auxKeyFunc('a',MoveFar);//按a键变小 //使display函数一直被调用 auxIdleFunc(display); //开始OpenGL的循环 auxMainLoop(display); //结束程序 return(0);}其运行结果如图所示：（2）OPENGL绘制矩形的简单例子参考程序：#include<gl/glut.h>voidInitial(void){ glClearColor(1.0f,1.0f,1.0f,1.0f);//设置窗口背景颜色为白色 glMatrixMode(GL_PROJECTION);//设置投影参数 gluOrtho2D(0.0,200.0,0.0,150.0);}voidDisplay(void){ glClear(GL_COLOR_BUFFER_BIT);//用当前背景色填充窗口 glColor3f(1.0f,0.0f,0.0f);//设置当前的绘图颜色为红色 glRectf(50.0f,100.0f,150.0f,50.0f);//绘制一个矩形glFlush();//处理所有的OpenGL程序}intmain(intargc,char*argv[]){ glutInit(&argc,argv); glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB);//初始化窗口的显示模式 glutInitWindowSize(400,300);//设置窗口的尺寸 glutInitWindowPosition(100,120);//设置窗口的位置 glutCreateWindow("矩形");//创建一个名为矩形的窗口 glutDisplayFunc(Display);//设置当前窗口的显示回调函数 Initial();//完成窗口初始化 glutMainLoop();//启动主GLUT事件处理循环 return0;}三、实验结果分析实验二直线生成算法与用户接口与交互式技术一、实验目的1、掌握直线生成算法（1）DDA算法（2）Bresenham算法掌握交互式技术（1）鼠标（2）键盘数字键、字母键、功能键和特殊键3、实现拾取操作二、实验内容1、以下给出了DDA算法的C++代码，请参考用VisualC++实现Bresenham算法。实现DDA画线程序实验步骤：1．建立一个DDALine的工程文件；2．添加ddaline()成员函数方法：在工作区中选择CLASSVIEW类窗口，右击CDDAlineView类，选择“addmemberfunction…”，定义如下的成员函数：voidddaline(CDC*pDC,intx0,inty0,intx1,inty1,COLORREFcolor);3．编写自定义的成员函数ddaline()程序voidCDDALineView::ddaline(CDC*pDC,intx0,inty0,intx1,inty1,COLORREFcolor){intlength,i;floatx,y,dx,dy;length=abs(x1-x0);if(abs(y1-y0)>length)length=abs(y1-y0);dx=(x1-x0)/length;dy=(y1-y0)/length;x=x0+0.5;y=y0+0.5;for(i=1;i<=length;i++){pDC->SetPixel((int)x,(int)y,color);x=x+dx;y=y+dy;}}4．编写OnDraw()函数voidCDDALineView::OnDraw(CDC*pDC){CDDALineDoc*pDoc=GetDocument();ASSERT_VALID(pDoc);//TODO:adddrawcodefornativedatahereddaline(pDC,100,100,400,100,RGB(255,0,0));ddaline(pDC,400,100,400,400,RGB(0,255,0));ddaline(pDC,400,400,100,400,RGB(0,0,255));ddaline(pDC,100,400,100,100,RGB(255,255,0));ddaline(pDC,100,100,400,400,RGB(255,0,255));ddaline(pDC,100,400,400,100,RGB(0,255,255));}}5．编译、调试和运行程序，查看程序结果。2、以下是利于鼠标和字母键实现用户接口与交互式技术，请参照利用特殊键实现，写出其代码。（1）OPENGL中利用鼠标实现橡皮筋技术的例子#include<gl/glut.h>intiPointNum=0;//已确定点的数目intx1=0,x2=0,y1=0,y2=0;//确定的点坐标intwinWidth=400,winHeight=300;//窗口的宽度和高度voidInitial(void){ glClearColor(1.0f,1.0f,1.0f,1.0f);}voidChangeSize(intw,inth){ winWidth=w; winHeight=h; glViewport(0,0,w,h);//指定窗口显示区域 glMatrixMode(GL_PROJECTION);//设置投影参数 glLoadIdentity(); gluOrtho2D(0.0,winWidth,0.0,winHeight);}voidDisplay(void){ glClear(GL_COLOR_BUFFER_BIT); glColor3f(1.0f,0.0f,0.0f); if(iPointNum>=1) { glBegin(GL_LINES);//绘制直线段 glVertex2i(x1,y1); glVertex2i(x2,y2); glEnd(); } glutSwapBuffers();//交换缓冲区}voidMousePlot(GLintbutton,GLintaction,GLintxMouse,GLintyMouse){ if(button==GLUT_LEFT_BUTTON&&action==GLUT_DOWN) { if(iPointNum==0||iPointNum==2){ iPointNum=1; x1=xMouse; y1=winHeight-yMouse; } else{ iPointNum=2; x2=xMouse; y2=winHeight-yMouse; glutPostRedisplay();//指定窗口重新绘制 } } if(button==GLUT_RIGHT_BUTTON&&action==GLUT_DOWN){ iPointNum=0; glutPostRedisplay(); }}voidPassiveMouseMove(GLintxMouse,GLintyMouse){ if(iPointNum==1) { x2=xMouse; y2=winHeight-yMouse; glutPostRedisplay(); } }intmain(intargc,char*argv[]){ glutInit(&argc,argv); glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGB);//使用双缓存及RGB模型 glutInitWindowSize(400,300); glutInitWindowPosition(100,100); glutCreateWindow("橡皮筋技术"); glutDisplayFunc(Display); glutReshapeFunc(ChangeSize);//指定窗口在整形回调函数 glutMouseFunc(MousePlot);//指定鼠标响应函数 glutPassiveMotionFunc(PassiveMouseMove);//指定鼠标移动响应函数 Initial(); glutMainLoop(); return0;}（2）OPENGL中利用键盘实现橡皮筋技术的例子#include<gl/glut.h>intiPointNum=0;//已确定点的数目intx1=0,x2=0,y1=0,y2=0;//确定的点坐标intwinWidth=400,winHeight=300;//窗口的宽度和高度voidInitial(void){ glClearColor(1.0f,1.0f,1.0f,1.0f);}voidChangeSize(intw,inth){ winWidth=w; winHeight=h; glViewport(0,0,w,h);//指定窗口显示区域 glMatrixMode(GL_PROJECTION);//设置投影参数 glLoadIdentity(); gluOrtho2D(0.0,winWidth,0.0,winHeight);}voidDisplay(void){ glClear(GL_COLOR_BUFFER_BIT); glColor3f(1.0f,0.0f,0.0f); if(iPointNum>=1) { glBegin(GL_LINES);//绘制直线段 glVertex2i(x1,y1); glVertex2i(x2,y2); glEnd(); } glutSwapBuffers();//交换缓冲区}voidPassiveMouseMove(GLintxMouse,GLintyMouse){ if(iPointNum==1) { x2=xMouse; y2=winHeight-yMouse; glutPostRedisplay(); } }voidKey(unsignedcharkey,intx,inty){ switch(key){ case'p': if(iPointNum==0||iPointNum==2) { iPointNum=1; x1=x; y1=winHeight-y; } else { iPointNum=2; x2=x; y2=winHeight-y; glutPostRedisplay(); } break; default:break; } }intmain(intargc,char*argv[]){ glutInit(&argc,argv); glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGB);//使用双缓存及RGB模型 glutInitWindowSize(400,300); glutInitWindowPosition(100,100); glutCreateWindow("橡皮筋技术"); glutDisplayFunc(Display); glutReshapeFunc(ChangeSize);//指定窗口在整形回调函数 glutKeyboardFunc(Key);//指定键盘响应函数 glutPassiveMotionFunc(PassiveMouseMove);//指定鼠标移动响应函数 Initial(); glutMainLoop(); return0;}3、以下OPENGL实现拾取操作的例子，请掌握实现拾取操作的方法。#include<gl/glut.h>#include"stdio.h"constGLintpickSize=32;intwinWidth=400,winHeight=300;voidInitial(void){ glClearColor(1.0f,1.0f,1.0f,1.0f);}voidDrawRect(GLenummode){ if(mode==GL_SELECT)glPushName(1);//压入堆栈 glColor3f(1.0f,0.0f,0.0f); glRectf(60.0f,50.0f,150.0f,150.0f); if(mode==GL_SELECT)glPushName(2);//压入堆栈glColor3f(0.0f,1.0f,0.0f);glRectf(230.0f,50.0f,330.0f,150.0f);if(mode==GL_SELECT)glPushName(3);//压入堆栈glColor3f(0.0f,0.0f,1.0f);glRectf(140.0f,140.0f,240.0f,240.0f);}voidProcessPicks(GLintnPicks,GLuintpickBuffer[]){ GLinti; GLuintname,*ptr;printf("选中的数目为%d个\n",nPicks);ptr=pickBuffer;for(i=0;i<nPicks;i++){ name=*ptr;//选中图元在堆栈中的位置 ptr+=3;//跳过名字和深度信息 ptr+=name-1;//根据位置信息获得选中的图元名字 if(*ptr==1)printf("你选择了红色图元\n"); if(*ptr==2)printf("你选择了绿色图元\n"); if(*ptr==3)printf("你选择了蓝色图元\n"); ptr++;} printf("\n\n");}voidChangeSize(intw,inth){winWidth=w;winHeight=h;glViewport(0,0,w,h);glMatrixMode(GL_PROJECTION);glLoadIdentity();gluOrtho2D(0.0,winWidth,0.0,winHeight);}voidDisplay(void){glClear(GL_COLOR_BUFFER_BIT);DrawRect(GL_RENDER);glFlush();}voidMousePlot(GLintbutton,GLintaction,GLintxMouse,GLintyMouse){GLuintpickBuffer[pickSize];GLintnPicks,vp[4];if(button==GLUT_LEFT_BUTTON&&action==GLUT_DOWN){ glSelectBuffer(pickSize,pickBuffer);//设置选择缓冲区glRenderMode(GL_SELECT);//激活选择模式glInitNames();//初始化名字堆栈glMatrixMode(GL_PROJECTION);glPushMatrix();glLoadIdentity();glGetIntegerv(GL_VIEWPORT,vp);//定义一个10×10的选择区域gluPickMatrix(GLdouble(xMouse),GLdouble(vp[3]-yMouse),10.0,10.0,vp);gluOrtho2D(0.0,winWidth,0.0,winHeight);DrawRect(GL_SELECT);//恢复投影变换glMatrixMode(GL_PROJECTION);glPopMatrix();glFlush();//获得选择集并输出nPicks=glRenderMode(GL_RENDER);ProcessPicks(nPicks,pickBuffer);glutPostRedisplay();}}intmain(intargc,char*argv[]){glutInit(&argc,argv);glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB);glutInitWindowSize(400,300);glutInitWindowPosition(100,100);glutCreateWindow("拾取操作");glutDisplayFunc(Display);glutReshapeFunc(ChangeSize);glutMouseFunc(MousePlot);Initial();glutMainLoop();return0;}三、实验结果分析实验三圆和椭圆及其它基本图形的生成算法一、实验目的（1）掌握和利用VC++实现Bresenham算法；（2）掌握利用OPENGL绘制简单多面体、二次及三次曲线的方法；（3）掌握利用OPENGL层次建模的方法。二、实验内容（1）用VisualC++实现圆和椭圆的Bresenham算法；（2）利用OPENGL绘制简单多面体、二次及三次曲线；（3）利用OPENGL层次建模1、VisualC++实现圆的Bresenham生成算法的参考程序如下，请在MFC环境下实现程序实现步骤：（1）建立MidPointCircle工程文件；（2）右击CMidPointCircleView类，建立成员函数voidMidpointCircle(CDC*pDC,intx0,inty0,intr,COLORREFcolor)intCirPot(CDC*pDC,intx0,inty0,intx,inty,COLORREFcolor)(3)编写成员函数代码，程序如下：voidCMidPointCircleView::MidpointCircle(CDC*pDC,intx0,inty0,intr,COLORREFcolor){intx,y;floatd;x=0;y=r;d=1.25-r;CirPot(pDC,x0,y0,x,y,color);while(x<=y){if(d<0){d+=2*x+3;x++;}else{d+=2*(x-y)+5;x++;y--;}CirPot(pDC,x0,y0,x,y,color);}/*while*/}intCMidPointCircleView::CirPot(CDC*pDC,intx0,inty0,intx,inty,COLORREFcolor){pDC->SetPixel((x0+x),(y0+y),color);pDC->SetPixel((x0+y),(y0+x),color);pDC->SetPixel((x0+y),(y0-x),color);pDC->SetPixel((x0+x),(y0-y),color);pDC->SetPixel((x0-x),(y0-y),color);pDC->SetPixel((x0-y),(y0-x),color);pDC->SetPixel((x0-y),(y0+x),color);pDC->SetPixel((x0-x),(y0+y),color);return0;}（4）编写OnDraw(CDC*pDC)函数，程序如下：voidCMidPointCircleView::OnDraw(CDC*pDC){CMidPointCircleDoc*pDoc=GetDocument();ASSERT_VALID(pDoc);//TODO:adddrawcodefornativedatahereMidpointCircle(pDC,100,100,10,RGB(255,0,0));MidpointCircle(pDC,500,300,60,RGB(255,255,0));}（6）编译、运行程序，查看结果。2、编写画椭圆法的扫描转换程序，请在MFC环境下实现程序实现步骤：(1)建立MidPointEllise工程文件；(2)右击CMidPointElliseView类，建立成员函数voidMidpointEllise(CDC*pDC,intx0,inty0,inta,intb,COLORREFcolor)(3)编写成员函数代码，程序如下：voidCMidPointEllipseView::MidpointEllise(CDC*pDC,intx0,inty0,inta,intb,COLORREFcolor){intx,y;floatd1,d2;x=0;y=b;d1=b*b+a*a*(-b+0.25);pDC->SetPixel(x+x0,y+y0,color);while(b*b*(x+1)<a*a*(y-0.5)){if(d1<0){d1+=b*b*(2*x+3);x++;}else{d1+=(b*b*(2*x+3)+a*a*(-2*y+2));x++;y--;}pDC->SetPixel(x0+x,y0+y,color);pDC->SetPixel(x0+x,y0-y,color);pDC->SetPixel(x0-x,y0+y,color);pDC->SetPixel(x0-x,y0-y,color);}//上半部分d2=(b*(x+0.5))*(b*(x+0.5))+(a*(y-1))*(a*(y-1))-(a*b)*(a*b);while(y>0){if(d2<0){d2+=b*b*(2*x+2)+a*a*(-2*y+3);x++;y--;}else{d2+=a*a*(-2*y+3);y--;}pDC->SetPixel(x0+x,y0+y,color);pDC->SetPixel(x0+x,y0-y,color);pDC->SetPixel(x0-x,y0+y,color);pDC->SetPixel(x0-x,y0-y,color);}//下半部分}(4)编写OnDraw()函数voidCMidPointEllipseView::OnDraw(CDC*pDC){CMidPointEllipseDoc*pDoc=GetDocument();ASSERT_VALID(pDoc);//TODO:adddrawcodefornativedatahereMidpointEllise(pDC,300,200,50,20,RGB(255,0,0));}编译、运行程序。3、用OPENGL绘制简单多面体、二次及三次曲线的例子#include<gl/glut.h>staticGLsizeiiMode=1;staticGLfloatxRot=0.0f;//x方向旋转参数staticGLfloatyRot=0.0f;//y方向旋转参数GLUquadricObj*obj;//二次曲面对象voidInitial(void){ glClearColor(1.0f,1.0f,1.0f,1.0f); glColor3f(0.0f,0.0f,0.0f); obj=gluNewQuadric(); gluQuadricDrawStyle(obj,GLU_LINE);//以线框方式绘制二次曲面对象}voidChangeSize(intw,inth){glViewport(0,0,w,h); glMatrixMode(GL_PROJECTION); glLoadIdentity(); gluOrtho2D(-1.5f,1.5f,-1.5f,1.5f);}voidDisplay(void){ glClear(GL_COLOR_BUFFER_BIT); glMatrixMode(GL_MODELVIEW); glLoadIdentity(); glRotatef(xRot,1.0f,0.0f,0.0f);//旋转图形 glRotatef(yRot,0.0f,1.0f,0.0f);//旋转图形 //指定需要绘制的图元 switch(iMode) { case1: glutWireTetrahedron(); break; case2: glutSolidTetrahedron(); break; case3: glutWireOctahedron(); break; case4: glutSolidOctahedron(); break; case5: glutWireSphere(1.0f,15,15); break; case6: glutSolidSphere(1.0f,15,15);break; case7: glutWireTeapot(1.0f);break; case8: glutSolidTeapot(1.0f);break; case9: gluSphere(obj,1.0f,15,15); break; case10: gluCylinder(obj,1.0f,0.0f,1.0f,15,15); break; case11: gluPartialDisk(obj,0.3f,0.8f,15,15,30.0f,260.0f); break; default:break; } glFlush();}voidProcessMenu(intvalue){ iMode=value; glutPostRedisplay();}voidSpecialKeys(intkey,intx,inty){ if(key==GLUT_KEY_UP) xRot-=5.0f; if(key==GLUT_KEY_DOWN) xRot+=5.0f; if(key==GLUT_KEY_LEFT) yRot-=5.0f; if(key==GLUT_KEY_RIGHT) yRot+=5.0f; if(xRot>356.0f) xRot=0.0f; if(xRot<-1.0f) xRot=355.0f; if(yRot>356.0f) yRot=0.0f; if(yRot<-1.0f) yRot=355.0f; glutPostRedisplay();}intmain(intargc,char*argv[]){ glutInit(&argc,argv); glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB); glutInitWindowSize(400,400); glutInitWindowPosition(100,100); glutCreateWindow("OpenGL模型绘制函数示例"); //创建菜单并定义菜单回调函数 intnGlutPolyMenu=glutCreateMenu(ProcessMenu); glutAddMenuEntry("线框正四面体",1);//创建GLUT多面体绘制菜单 glutAddMenuEntry("实体正四面体",2); glutAddMenuEntry("线框正八面体",3); glutAddMenuEntry("实体正八面体",4); intnGlutCurveMenu=glutCreateMenu(ProcessMenu);//创建GLUT曲面绘制菜单 glutAddMenuEntry("线框球面",5); glutAddMenuEntry("实体球面",6); glutAddMenuEntry("线框茶壶",7); glutAddMenuEntry("实体茶壶",8); intnGluCurveMenu=glutCreateMenu(ProcessMenu);//创建GLU曲面绘制菜单 glutAddMenuEntry("线框球面",9); glutAddMenuEntry("线框圆锥面",10); glutAddMenuEntry("线框圆环面",11); intnMainMenu=glutCreateMenu(ProcessMenu);//创建主菜单 glutAddSubMenu("GLUT多面体",nGlutPolyMenu); glutAddSubMenu("GLUT曲面",nGlutCurveMenu); glutAddSubMenu("GLU曲面",nGluCurveMenu); glutAttachMenu(GLUT_RIGHT_BUTTON); glutDisplayFunc(Display); glutReshapeFunc(ChangeSize); glutSpecialFunc(SpecialKeys); Initial(); glutMainLoop(); return0;}4、用OPENGL实现绘制奥运五环标志#include<gl/glut.h>GLuintOlympicRings;voidInitial(void){ glClearColor(1.0f,1.0f,1.0f,1.0f); OlympicRings=glGenLists(1); glNewList(OlympicRings,GL_COMPILE); glColor3f(1.0,1.0,0.0); glTranslatef(-22.0,0.0,0.0); glutSolidTorus(0.5,20.0,15,50);//绘制黄色环 glColor3f(0.0,1.0,0.0); glTranslatef(44.0,0.0,0.0); glutSolidTorus(0.5,20.0,15,50);//绘制绿色环 glColor3f(0.0,0.0,0.0); glTranslatef(-22.0,30.0,0.0); glutSolidTorus(0.5,20.0,15,50);//绘制黑色环 glColor3f(0.0,0.0,1.0); glTranslatef(-42.0,0.0,0.0); glutSolidTorus(0.5,20.0,15,50);//绘制蓝色环 glColor3f(1.0,0.0,0.0); glTranslatef(84.0,0.0,0.0); glutSolidTorus(0.5,20.0,15,50);//绘制红色环 glEndList();}voidChangeSize(intw,inth){ glViewport(0,0,w,h); glMatrixMode(GL_PROJECTION); glLoadIdentity(); gluOrtho2D(-70.0f,70.0f,-70.0f,70.0f);}voidDisplay(void){ glClear(GL_COLOR_BUFFER_BIT); glMatrixMode(GL_MODELVIEW); glLoadIdentity(); glCallList(OlympicRings);//调用显示列表 glFlush();}intmain(intargc,char*argv[]){ glutInit(&argc,argv); glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB); glutInitWindowSize(400,400); glutInitWindowPosition(100,100); glutCreateWindow("OpenGL模型绘制函数示例"); glutDisplayFunc(Display); glutReshapeFunc(ChangeSize); Initial(); glutMainLoop(); return0;}实验结果分析实验四裁剪算法一、实验目的（1）掌握Cohen－Sutherland线段裁剪算法，中点分割线段裁剪算法，Liang-Barsky裁剪算法。（2）掌握反走样技术二、实验内容1）实现Cohen-Sutherland线段裁剪算法；2）实现中点分割线段裁剪算法；3）实现Liang-Barsky裁剪算法；4）实现反走样技术。1、Cohen-Sutherland编码裁剪算法的程序设计，请在MFC环境下实现，并理解代码。实验环境：VisualC++步骤1：创建Code_Clip工程文件；步骤2：在主程序的程序头部定义符号常量#defineLEFT1#defineRIGHT2#defineBOTTOM4#defineTOP8步骤3：定义成员变量和成员函数intWT;intWB;intWR;intWL;intC_S_Line(CDC*pDC,intx1,inty1,intx2,inty2);voidencode(intx,inty,int*code);步骤4：在构造函数中为窗口边界变量赋初值CCode_ClipView::CCode_ClipView(){//TODO:addconstructioncodehereWL=100;WR=400;WB=100;WT=300;}步骤5：编写成员函数程序voidCCode_ClipView::encode(intx,inty,int*code){intc=0;if(x<WL)c=c|LEFT;elseif(x>WR)c=c|RIGHT;if(y<WB)c=c|BOTTOM;elseif(y>WT)c=c|TOP;*code=c;}intCCode_ClipView::C_S_Line(CDC*pDC,intx1,inty1,intx2,inty2){//CDC*pDC=GetDC();intcode1,code2,code,x,y;encode(x1,y1,&code1);//(x1,y1)处的编码encode(x2,y2,&code2);//(x1,y1)处的编码while(code1!=0||code2!=0)//当code1不等于0或code2不等于0{if((code1&code2)!=0)return0;//当code1与code2不等于0，在同侧；code=code1;if(code1==0)code=code2;if((LEFT&code)!=0)//求交点{x=WL;y=y1+(y2-y1)*(WL-x1)/(x2-x1);}elseif((RIGHT&code)!=0){x=WR;y=y1+(y2-y1)*(WR-x1)/(x2-x1);}elseif((BOTTOM&code)!=0){y=WB;x=x1+(x2-x1)*(WB-y1)/(y2-y1);}elseif((TOP&code)!=0){y=WT;x=x1+(x2-x1)*(WT-y1)/(y2-y1);}if(code==code1){x1=x;y1=y;encode(x,y,&code1);}else{x2=x;y2=y;encode(x,y,&code2);}}//endwhile,表示code1，code2都为0，其中的线段为可视部分pDC->MoveTo(x1,y1);pDC->LineTo(x2,y2);}步骤6：编写OnDraw()程序voidCCode_ClipView::OnDraw(CDC*pDC){CCode_ClipDoc*pDoc=GetDocument();ASSERT_VALID(pDoc);//TODO:adddrawcodefornativedatahere//定义三条直线的坐标intx11,y11,x21,y21,x12,y12,x22,y22,x13,y13,x23,y23;x11=50;y11=150;x21=450;y21=250;x12=150;y12=150;x22=350;y22=240;x13=50;y13=400;x23=500;y23=350;//定义画笔CPenPenRed(PS_SOLID,1,RGB(255,0,0));//定义红色笔CPenPenBlue(PS_SOLID,1,RGB(0,0,255));//定义蓝色笔//先画出窗口，用蓝色pDC->SelectObject(&PenBlue);pDC->Rectangle(WL,WB,WR,WT);//先画出三条直线,用红线pDC->SelectObject(&PenRed);pDC->MoveTo(x11,y11);pDC->LineTo(x21,y21);pDC->MoveTo(x12,y12);pDC->LineTo(x22,y22);pDC->MoveTo(x13,y13);pDC->LineTo(x23,y23);//用蓝线，画出裁剪三条线pDC->SelectObject(&PenBlue);C_S_Line(pDC,x11,y11,x21,y21);C_S_Line(pDC,x12,y12,x22,y22);C_S_Line(pDC,x13,y13,x23,y23);}步骤7：编译、调试，查看运行结果。2、多边形裁剪实验环境：VisualC++和OpenGL/*代码*/#include<windows.h>#include<GL/gl.h>#include<GL/glu.h>#include<GL/glaux.h>voidmyinit(void);voidCALLBACKmyReshape(GLsizeiw,GLsizeih);voidCALLBACKdisplay(void);voidCALLBACKdisplay(void){GLdoubleeqn[4]={1.0,0.0,0.0,0.0};glClear(GL_COLOR_BUFFER_BIT);glColor3f(1.0,0.0,1.0);glPushMatrix();glTranslatef(0.0,0.0,-5.0);/*cliptheleftpartofwire_sphere:x<0*/glClipPlane(GL_CLIP_PLANE0,eqn);glEnable(GL_CLIP_PLANE0);glRotatef(-90.0,1.0,0.0,0.0);auxWireSphere(1.0);glPopMatrix();glFlush();}voidmyinit(void){glShadeModel(GL_FLAT);}voidCALLBACKmyReshape(GLsizeiw,GLsizeih){ glViewport(0,0,w,h);glMatrixMode(GL_PROJECTION);glLoadIdentity();gluPerspective(60.0,(GLfloat)w/(GLfloat)h,1.0,20.0);glMatrixMode(GL_MODELVIEW);}voidmain(void){auxInitDisplayMode(AUX_SINGLE|AUX_RGB);auxInitPosition(0,0,500,500);auxInitWindow("裁剪例子");myinit();auxReshapeFunc(myReshape);auxMainLoop(display);}运行结果：3、OPENGL实现直线段的反走样#include<gl/glut.h>GLuintlineList;//指定显示列表IDvoidInitial(){ glClearColor(1.0f,1.0f,1.0f,0.0f); glLineWidth(12.0f); glColor4f(0.0,0.6,1.0,1.0); lineList=glGenLists(1); glNewList(lineList,GL_COMPILE);//定义显示列表 glBegin(GL_LINE_LOOP); glVertex2f(1.0f,1.0f); glVertex2f(4.0f,2.0f); glVertex2f(2.0f,5.0f); glEnd(); glEndList();}voidChangeSize(GLsizeiw,GLsizeih){ if(h==0) h=1; glViewport(0,0,w,h); glMatrixMode(GL_PROJECTION); glLoadIdentity(); if(w<=h) gluOrtho2D(0.0,5.0,0.0,6.0*(GLfloat)h/(GLfloat)w); else gluOrtho2D(0.0,5.0*(GLfloat)w/(GLfloat)h,0.0,6.0); glMatrixMode(GL_MODELVIEW); glLoadIdentity();}voidDisplayt(void){ glClear(GL_COLOR_BUFFER_BIT); glCallList(lineList);glFlush();}voidDisplayw(void){ glClear(GL_COLOR_BUFFER_BIT); glEnable(GL_LINE_SMOOTH);//使用反走样 glEnable(GL_BLEND);//启用混合函数 glBlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA);//指定混合函数 glCallList(lineList);glFlush();}voidmain(void){ glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB); glutInitWindowSize(300,300); glutCreateWindow("原始图形"); glutDisplayFunc(Displayt);glutReshapeFunc(ChangeSize); Initial(); glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB); glutInitWindowPosition(300,300); glutInitWindowSize(300,300); glutCreateWindow("反走样图形"); glutDisplayFunc(Displayw);glutReshapeFunc(ChangeSize); Initial(); glutMainLoop();}三、实验结果分析实验五二维变换一、实验目的（1）二维平移变换原理（2）二维缩放变换（3）二维对称变换（4）二维旋转变换（5）二维错切变换二、实验内容1、实现一个三角形的基本几何变换。 实验环境：OpenGL和VisualC++。/*代码*/#include<windows.h>#include<GL/gl.h>#include<GL/glu.h>#include<GL/glaux.h>voidmyinit(void);voiddraw_triangle(void);voidCALLBACKdisplay(void);voidCALLBACKmyReshape(GLsizeiw,GLsizeih);voiddraw_triangle(void){glBegin(GL_LINE_LOOP);glVertex2f(0.0,25.0);glVertex2f(25.0,-25.0);glVertex2f(-25.0,-25.0);glEnd();}voidCALLBACKdisplay(void){glClearColor(0.0,0.0,0.0,1.0);glClear(GL_COLOR_BUFFER_BIT);/*drawanoriginaltriangle*/glLoadIdentity();glColor3f(1.0,1.0,1.0);/*white*/draw_triangle(); /*translatingatrianglealongX_axis*/ glLoadIdentity(); glTranslatef(-20.0,0.0,0.0);glColor3f(1.0,0.0,0.0);/*red*/draw_triangle(); /*scalingatrianglealongX_axisby1.5andalongY_axisby0.5*/glLoadIdentity();glScalef(1.5,0.5,1.0);glColor3f(0.0,1.0,0.0);/*green*/draw_triangle(); /*rotatingatriangleinacounterclockwisedirectionaboutZ_axis*/glLoadIdentity();glRotatef(90.0,0.0,0.0,1.0);glColor3f(0.0,0.0,1.0);/*blue*/draw_triangle(); /*scalingatrianglealongY_axisandreflectingitaboutY_axis*/glLoadIdentity();glScalef(1.0,-0.5,1.0);glColor3f(1.0,1.0,0.0);/*yellow*/draw_triangle();glFlush();}voidmyinit(void){ glShadeModel(GL_FLAT);}voidCALLBACKmyReshape(GLsizeiw,GLsizeih){glViewport(0,0,w,h);glMatrixMode(GL_PROJECTION);glLoadIdentity();if(w<=h)glOrtho(-50.0,50.0,-50.0*(GLfloat)h/(GLfloat)w,50.0*(GLfloat)h/(GLfloat)w,-1.0,1.0);elseglOrtho(-50.0*(GLfloat)w/(GLfloat)h,50.0*(GLfloat)w/(GLfloat)h,-50.0,50.0,-1.0,1.0);glMatrixMode(GL_MODELVIEW);}voidmain(void){auxInitDisplayMode(AUX_SINGLE|AUX_RGBA);auxInitPosition(0,0,500,500);auxInitWindow("三角形的基本几何变换"); myinit();auxReshapeFunc(myReshape);auxMainLoop(display);}运行结果：2、参考例子2 #include<gl/glut.h>voidinitial(void){ glClearColor(1.0,1.0,1.0,1.0); glMatrixMode(GL_PROJECTION); glLoadIdentity(); gluOrtho2D(-10.0,10.0,-10.0,10.0);//指定二维裁剪窗口}voidtriangle(GLsizeimode){ if(mode==1) glPolygonMode(GL_FRONT_AND_BACK,GL_LINE);//多边形模式为线框 else glPolygonMode(GL_FRONT_AND_BACK,GL_FILL);//多边形模式为填充多边形 glBegin(GL_TRIANGLES); glVertex2f(0.0,5.0); glVertex2f(5.0,-5.0); glVertex2f(-5.0,-5.0); glEnd();}voidDisplay(void){ glClear(GL_COLOR_BUFFER_BIT); glColor3f(1.0,0.0,0.0); glViewport(0,0,200,200);//指定从0，0开始长宽均为200的 triangle(1); glColor3f(0.0,0.0,1.0); glViewport(200,0,200,200); triangle(2); glFlush();}voidmain(void){ glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB); glutInitWindowPosition(100,100); glutInitWindowSize(400,200); glutCreateWindow("多视区"); initial(); glutDisplayFunc(Display); glutMainLoop();}三、实验结果分析实验六三维变换一、实验目的掌握三维平移变换，三维缩放变换，三维旋转变换，三维平行投影。二、实验内容1）利用三维变换原理实现一个三维长方体物体的平移，旋转和缩放变换。2）利用三维透视原理实现平行投影和透视投影。1、绘制一个三维的正面透视立方体。采用OpenGL进行编程。实验环境：OpenGL和VisualC++。#include<windows.h>#include<GL/gl.h>#include<GL/glu.h>#include<GL/glaux.h>voidmyinit(void);voidCALLBACKmyReshape(GLsizeiw,GLsizeih);voidCALLBACKdisplay(void);voidCALLBACKdisplay(void){glClear(GL_COLOR_BUFFER_BIT);glColor3f(1.0,1.0,1.0);glLoadIdentity();/*clearthematrix*/glTranslatef(0.0,0.0,-5.0);/*viewingtransformation*/glScalef(1.0,2.0,1.0);/*modelingtransformation*/auxWireCube(1.0);/*drawthecube*/glFlush();}voidmyinit(void){glShadeModel(GL_FLAT);}voidCALLBACKmyReshape(GLsizeiw,GLsizeih){ glMatrixMode(GL_PROJECTION);/*prepareforandthen*/glLoadIdentity();/*definetheprojection*/glFrustum(-1.0,1.0,-1.0,1.0,1.5,20.0);/*transformation*/glMatrixMode(GL_MODELVIEW);/*backtomodelviewmatrix*/glViewport(0,0,w,h);/*definetheviewport*/}voidmain(void){auxInitDisplayMode(AUX_SINGLE|AUX_RGBA);auxInitPosition(0,0,500,500);auxInitWindow("三维的正面透视立方体");myinit();auxReshapeFunc(myReshape);auxMainLoop(display);}2、利用OPENGL建立分子模型#include<gl/glut.h>voidInitial(){ glEnable(GL_DEPTH_TEST);//启用深度测试 glClearColor(1.0f,1.0f,1.0f,1.0f); //背景为白色}voidChangeSize(intw,inth){ if(h==0) h=1;glViewport(0,0,w,h);//设置视区尺寸 glMatrixMode(GL_PROJECTION);//指定当前操作投影矩阵堆栈 glLoadIdentity();//重置投影矩阵 GLfloatfAspect; fAspect=(float)w/(float)h;//计算视区的宽高比 gluPerspective(45.0,fAspect,1.0,500.0);//指定透视投影的观察空间 glMatrixMode(GL_MODELVIEW); glLoadIdentity();}voidDisplay(void){ staticflo