图形学实验图形剪裁.doc

实 验 报 告课 程计算机图形学实验项目图形剪裁成 绩专业班级软件工程08级学 号0805020337批阅日期姓 名实验日期2011.12.29指导教师一【实验目的】1.编程实现用鼠标绘制线段和矩形，并实现剪裁的功能2.实现计算机系统的交互功能，掌握基本的图形剪裁的思路4.掌握开发环境，及相关类库和工具的使用二【实验内容】根据已提供的程序框架及思路，完成系统的开发，要求运用图形剪裁算法实现功能，系统健壮，实现人机交互。三【实验过程】本次实验我采用了glut的框架,源代码如下：#include #include #include class wcPt2D public: float x,y;int w=1024,h=768,flag=1;inthh=h;wcPt2D point1512;wcPt2D point2512;wcPt2D temporary;wcPt2D glRectf1;wcPt2D glRectf2;int i=0;bool first=true;bool second=true;void Reshape(int w, int h)glMatrixMode(GL_PROJECTION);glLoadIdentity(); glViewport(0, 0, w, h);gluOrtho2D(0, w, 0, h); void Display() glClearColor(1.0,1.0,1.0,1.0);glClear(GL_COLOR_BUFFER_BIT);glLineWidth(2.0);if(flag=1) if(first)Drawtemporaryline();elseDrawtrueline();first=!first;else if(flag=2)if(second)DrawtemporaryglRectf();elseDrawtrueglRectf();flag=1;first=true;second=true;for(int j=0;j=i;j+)point1j.x=point1j.y=0;point2j.x=point2j.y=0;i=0;glutSwapBuffers();void Keyboard(unsigned char key,int x, int y)switch(key)case 1:flag=1; break;case 2:flag=2;break;default:return;voidmymouse(intbutton,int state, int x, int y) if(button=GLUT_LEFT_BUTTON)if(state=GLUT_DOWN&flag=1)point1i.x=x;point1i.y=hh-y;else if(state=GLUT_UP&flag=1)point2i.x=x;point2i.y=hh-y;i+;first=!first;glutPostRedisplay();if(state=GLUT_DOWN&flag=2)glRectf1.x=x;glRectf1.y=hh-y;else if(state=GLUT_UP&flag=2)glRectf2.x=x;glRectf2.y=hh-y;second=!second;glutPostRedisplay();voidmymotion(intx,int y)temporary.x=x;temporary.y=hh-y;glutPostRedisplay();voidDrawtemporaryline()for(int j=0;ji;j+)glBegin(GL_LINES);glColor3f(0.0,0.0,0.0);glVertex3f(point1j.x,point1j.y,0.0);glVertex3f(point2j.x,point2j.y,0.0);glEnd();glBegin(GL_LINES);glColor3f(0.0,0.0,0.0);glVertex3f(point1i.x,point1i.y,0.0);glVertex3f(temporary.x,temporary.y,0.0);glEnd();voidDrawtrueline()for(int j=0;j=i;j+)glBegin(GL_LINES);glColor3f(0.0,0.0,0.0);glVertex3f(point1j.x,point1j.y,0.0);glVertex3f(point2j.x,point2j.y,0.0);glEnd();voidDrawtemporaryglRectf()for(int j=0;jglRectf2.x)a=glRectf1.x;glRectf1.x=glRectf2.x;glRectf2.x=a;if(glRectf1.yglRectf2.y)a=glRectf1.y;glRectf1.y=glRectf2.y;glRectf2.y=a;for(int j=0;j=i;j+)clipLine(glRectf1,glRectf2,point1j,point2j);glRectf(glRectf1.x,glRectf1.y,glRectf2.x,glRectf2.y);intclipTest(float p,floatq,float *u1,float *u2)float r; boolretVal=true;if(p*u2) retVal=false; elseif(r*u1)*u1 = r;else if(p 0.0) r=q/p;if(r*u1) retVal=false;else if(r*u2) *u2 = r;else if(q0.0) retVal=false;return (retVal) ;voidclipLine(wcPt2D winMin,wcPt2D winMax,wcPt2D p1,wcPt2D p2)float u1=0.0,u2=1.0,dx=p2.x-p1.x,dy;if(clipTest(-dx,p1.x-winMin.x,&u1,&u2)if(clipTest(dx,winMax.x-p1.x,&u1,&u2) dy=p2.y-p1.y;if(clipTest(-dy,p1.y-winMin.y,&u1,&u2)if(clipTest(dy,winMax.y-p1.y,&u1,&u2) if(u20.0) p1.x+=u1*dx;p1.y+=u1*dy;glBegin(GL_LINES);glColor3f(0.0,0.0,0.0);glVertex3f(p1.x,p1.y,0.0);glVertex3f(p2.x,p2.y,0.0);glEnd();int main(intargc, char* argv)glutInit(&argc, argv);glutInitWindowPosition(0, 0);glutInitWindowSize(w,h);glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB);glutCreateWindow(liangbarskey);glPolygonMode(GL_FRONT_AND_BACK,GL_