计算机图形学裁剪

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1、《计算机图形学》实验报告学院：理学院专业：信息与计算科学班级：姓名学号指导教师实验时间4.实验地点计算机实验室成绩实验项目名称裁剪实验环境VC++6.0实验内容（1） 理解直线裁剪的原理（Cohen-Surtherland算法、梁友栋算法） （2） 利用VC+OpenGL实现直线的编码裁剪算法，在屏幕上用一个封闭矩形裁剪任意一条直线。 （3） 调试、编译、修改程序。 实验原理编码裁剪算法的主要思想是：对于每条线段，分为三种情况处理。（1）若线段完全在窗口之内，则显示该线段，称为“取”；（2）若线段明显在窗口之外，则丢弃该线段，称为“弃”；（3）若线段既不满足“取

2、”的条件，也不满足“舍”的条件，则把线段分割为两段。其中一段完全在窗口之外，可弃之；对另一段则重复上述处理实验过程#include#include#include#defineLEFT_EDGE1#defineRIGHT_EDGE2#defineBOTTOM_EDGE4#defineTOP_EDGE8voidLineGL(intx0,inty0,intx1,inty1){glBegin(GL_LINES);glColor3f(1.0f,0.0f,0.0f);glVertex2f(x0,y0);glCol

3、or3f(0.0f,1.0f,0.0f);glVertex2f(x1,y1);glEnd();}structRectangle{floatxmin,xmax,ymin,ymax;};Rectanglerect;intx0,y0,x1,y1;intCompCode(intx,inty,Rectanglerect){intcode=0x00;if(yrect.ymax)code=code8;if(x>rect.xmax)code=code2;if(x

4、;}intcohensutherlandlineclip(Rectanglerect,int&x0,int&y0,int&x1,int&y1){intaccept,done;floatx,y;accept=0;done=0;intcode0,code1,codeout;code0=CompCode(x0,y0,rect);code1=CompCode(x1,y1,rect);do{if(!(code0code1)){accept=1;done=1;}elseif(code0&code1)done=1;else{if(code0!=0)codeout=code0;

5、elsecodeout=code1;if(codeout&LEFT_EDGE){y=y0+(y1-y0)(rect.xmin-x0)/(x1-x0);x=(float)rect.xmin;}elseif(codeout&RIGHT_EDGE){y=y0+(y1-y0)(rect.xmax)/(x1-x0);x=(float)rect.xmax;}elseif(codeout&BOTTOM_EDGE){x=x0+(x1-x0)(rect.ymin-y0)/(y1-y0);y=(float)rect.ymin;}elseif(codeout&TOP_EDGE){x=

6、x0+(x1-x0)(rect.ymax-y0)/(y1-y0);y=(float)rect.ymax;}if(codeout==code0){x0=x;y0=y;code0=CompCode(x0,y0,rect);}else{x1=x;y1=y;code1=CompCode(x1,y1,rect);}}}while(!done);if(accept)LineGL(x0,y0,x1,y1);returnaccept;}voidmyDisplay(){glClear(GL_COLOR_BUFFER_BIT);glColor3f(1.0f,0.0f,0.0f);g

7、lRectf(rect.xmin,rect.ymin,rect.xmax,rect.ymax);LineGL(x0,y0,x1,y1);glFlush();}voidInit(){glClearColor(0.0,0.0,0.0,0.0);glShadeModel(GL_FLAT);rect.xmin=100;rect.xmax=300;rect.ymin=100;rect.ymax=300;x0=450,y0=0,x1=0,y1=450;printf("Presskey'c'toClip!Presskey'r'toRrstore!");}voidRes

8、hape(intw,in