3D图形学实验.doc

数字图像处理实验指导书3D游戏图形学实验指导书指导老师：马文娟姓名：戎洪洋 学号：E09700223浙江理工大学二一一 年 11 月实验三 几何图形变换实验实验项目性质：设计性实验所属课程名称：3D游戏图形学实验计划学时：3学时一、 实验目的和要求1. 进一步掌握二维、三维变换的数学知识、变换原理、变换种类、变换方法；2. 利用OpenGL实现二维、三维图形变换，在屏幕上显示变换过程或变换结果；3. 掌握OpenGL常用的变换函数。二、 实验内容1、下面的代码采用GLUT库，使用了双缓存，在按下鼠标左键后，程序在空闲时一直不停地调用spinDisplay函数，实现了一个矩形在窗口中匀速转动（单击鼠标右键停止转动）。请修改代码，实现矩形在窗口内沿着水平线移动。#include #include static GLfloat spin = 0.0;void display(void) glClear(GL_COLOR_BUFFER_BIT); glPushMatrix(); glTranslatef(spin,0.0f,0.0f); glColor3f(1.0, 1.0, 1.0); glRectf(-10.0, -10.0, 10.0, 10.0); glPopMatrix(); glutSwapBuffers(); /交换双缓存void spinDisplay(void) spin = spin + 0.02; if (spin 360.0) spin = spin - 360.0; glutPostRedisplay();void init(void) glClearColor (0.0, 0.0, 0.0, 0.0); glShadeModel (GL_FLAT);void reshape(int w, int h) glViewport (0, 0, (GLsizei) w, (GLsizei) h); glMatrixMode(GL_PROJECTION); glLoadIdentity(); glOrtho(-50.0, 50.0, -50.0, 50.0, -1.0, 1.0); glMatrixMode(GL_MODELVIEW); glLoadIdentity();void mouse(int button, int state, int x, int y) switch (button) case GLUT_LEFT_BUTTON: if (state = GLUT_DOWN) glutIdleFunc(spinDisplay); /设备空闲时调用的函数 break; case GLUT_MIDDLE_BUTTON: case GLUT_RIGHT_BUTTON: if (state = GLUT_DOWN) glutIdleFunc(NULL); break; default: break; int main(int argc, char* argv) glutInit(&argc, argv); glutInitDisplayMode (GLUT_DOUBLE | GLUT_RGB); /使用双缓存模式 glutInitWindowSize (500, 500); glutInitWindowPosition (100, 100); glutCreateWindow (argv0); init (); glutDisplayFunc(display); glutReshapeFunc(reshape); glutMouseFunc(mouse); glutMainLoop(); return 0; 2. 已知某三角形的三顶点坐标50.0,25.0,150.0,25.0,100.0,100.0。要求：（1）创建一个长宽分别为600、600的窗口，窗口的左上角位于屏幕坐标（100，100）处。（提示：请试着修改gluOrtho2D函数参数，使得绘制的三角形尽可能居中显示）（2）绘制一个由上述顶点所描绘的三角形，实现该三角形进行下列的几何变化：首先使三角形沿着其中心的x轴，y轴方向缩小50%;然后沿着初始中心旋转90度；最后沿着y轴平移100个单位。参考代码：#include #include void init(void) glClearColor (0.0, 0.0, 0.0, 0.0); glShadeModel (GL_FLAT);void draw_triangle(void) glBegin (GL_LINE_LOOP); glVertex2f(50.0, 25.0); glVertex2f(150.0, 25.0); glVertex2f(100.0, 100.0); glEnd();void display(void)glClear(GL_COLOR_BUFFER_BIT); glColor3f (1.0, 1.0, 1.0); glViewport(0,0,600,600); glClear (GL_COLOR_BUFFER_BIT); glColor3f (1.0, 1.0, 1.0); draw_triangle (); glLineStipple (1, 0xF00F); glTranslatef (0.0, 100.0, 0.0); glTranslatef (100.0, 62.5, 0.0); glScalef (0.5, 0.5, 1.0); glRotatef (90.0, 0.0, 0.0, 1.0);glTranslatef (-100.0, -62.5, 0.0); draw_triangle (); glFlush ();void reshape (int w, int h) glViewport (0, 0, (GLsizei) w, (GLsizei) h); glMatrixMode (GL_PROJECTION); glLoadIdentity (); if (w = h) gluOrtho2D (-300.0, 500.0, -300.0*(GLfloat)h/(GLfloat)w, 500.0*(GLfloat)h/(GLfloat)w); else gluOrtho2D (-50.0*(GLfloat)w/(GLfloat)h, 50.0*(GLfloat)w/(GLfloat)h, -50.0, 50.0); glMatrixMode(GL_MODELVIEW);int main(int argc, char* argv) glutInit(&argc, argv); glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB); glutInitWindowSize (500, 500); glutInitWindowPosition (100, 100); glutCreateWindow (argv0); init (); glutDisplayFunc(display); glutReshapeFunc(reshape); glutMainLoop(); return 0;3. 绘制一个三棱椎的透视投影图，要求：实现匀速旋转（提示：参考题目1，使用双缓存模式）；改变变换方式，达到不同的效果。参考代码：#include#includestatic GLfloat spin = 0.0;void init(void)glClearColor(0.0f,0.0f,0.0f,0.0f);glShadeModel(GL_SMOOTH); /设为smooth处理方式glEnable(GL_DEPTH_TEST); /激活深度测试（可以去掉，看看效果）void display(void)glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);glPushMatrix();/清除颜色缓存和深度缓存glLoadIdentity(); glTranslatef(-1.5f,0.0f,-6.0f); /试尝试修改此函数，掌握其用法与参数含义 glRotatef(spin, 0.0, 5.0, 0.0); /试尝试修改此函数，掌握其用法与参数含义glBegin(GL_TRIANGLES);glColor3f(1.0f,0.0f,0.0f);glVertex3f(0.0f,1.0f,0.0f);glColor3f(0.0f,1.0f,0.0f);glVertex3f(-1.0f,-1.0f,1.0f);glColor3f(0.0f,0.0f,1.0f);glVertex3f(1.0f,-1.0f,1.0f);glColor3f(1.0f,0.0f,0.0f);glVertex3f(0.0f,1.0f,0.0f);glColor3f(0.0f,0.0f,1.0f);glVertex3f(1.0f,-1.0f,1.0f);glColor3f(0.0f,1.0f,0.0f);glVertex3f(1.0f,-1.0f,-1.0f);glColor3f(1.0f,0.0f,0.0f);glVertex3f(0.0f,1.0f,0.0f);glColor3f(0.0f,1.0f,0.0f);glVertex3f(1.0f,-1.0f,-1.0f);glColor3f(0.0f,0.0f,1.0f);glVertex3f(-1.0f,-1.0f,-1.0f);glColor3f(1.0f,0.0f,0.0f);glVertex3f(0.0f,1.0f,0.0f);glColor3f(0.0f,0.0f,1.0f);glVertex3f(-1.0f,-1.0f,-1.0f);glColor3f(0.0f,1.0f,0.0f);glVertex3f(-1.0f,-1.0f,1.0f);glEnd(); glPopMatrix(); glutSwapBuffers(); /交换双缓存glFlush();void reshape(int width, int height)glViewport(0,0,width,height);glMatrixMode(GL_PROJECTION);glLoadIdentity();gluPerspective(45.0f, (GLfloat)width/(GLfloat)height,0.1f,100.0f);glMatrixMode(GL_MODELVIEW);glLoadIdentity();void keyboard(unsigned char key, int x, int y)switch(key)case x:exit(0);break;default:break;void spinDisplay(void) spin = spin + 0.02; if (spin 360.0) spin = spin - 360.0; glutPostRedisplay();void mouse(int button, int state, int x, int y) switch (button) case GLUT_LEFT_BUTTON: if (state = GLUT_DOWN) glutIdleFunc(spinDisplay); /设备空闲时调用的函数 break; case GLUT_MIDDLE_BUTTON: case GLUT_RIGHT_BUTTON: if (state = GLUT_DOWN) glutIdleFunc(NULL); break; default: break;int main(int argc, char * *argv)glutInit(&argc, argv);glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGB|GLUT_DEPTH);glutInitWindowSize(640,480);glutInitWindowPosition(100,100);glutCreateWindow(Transform2);init();glutDisplayFunc(display);glutReshapeFunc(reshape);glutMouseFunc(mouse);glutKeyboardFunc(keyboard);glutMainLoop();return 0;附加：实现直线的编码裁剪算法（Cohen-Surtherland算法）。参考代码：#include #include #include #define LEFT_EDGE 1#define RIGHT_EDGE 2#define BOTTOM_EDGE 4#define TOP_EDGE 8void LineGL(int x0, int y0, int x1, int y1)glBegin(GL_LINES);glColor3f(1.0f,0.0f,0.0f); glVertex2f(x0,y0);glColor3f(0.0f,1.0f,0.0f); glVertex2f(x1,y1);glEnd();struct Rectanglefloat xmin, xmax, ymin, ymax;Rectangle rect;int x0,y0,x1,y1;int CompCode(int x, int y, Rectangle rect)int code=0x00;if(yrect.ymax)code=code|8;if(xrect.xmax)code=code|2;if(xrect.xmin)code=code|1;return code;int cohensutherlandlineclip(Rectangle rect, int &x0, int &y0, int &x1, int &y1)int accept, done;float x,y;accept=0;done=0;int code0, code1, codeout;code0=CompCode(x0,y0,rect);code1=CompCode(x1,y1,rect);doif(!(code0|code1)accept=1;done=1;else if(code0&code1)done=1;elseif(code0!=0)codeout=code0;elsecodeout=code1;if(codeout&LEFT_EDGE)y=y0+(y0-y1)*(rect.xmin-x0)/(x1-x0);x=(float)rect.xmin;else if(codeout&RIGHT_EDGE)y=y0+(y0-y1)*(rect.xmax-x0)/(x1-x0);x=(float)rect.xmax;else if(codeout&BOTTOM_EDGE)x=x0+(x1-x0)*(rect.ymin-y0)/(y1-y0);y=(float)rect.ymin;else if(codeout&TOP_EDGE)x=x0+(x1-x0)*(rect.ymax-y0)/(y1-y0);y=(float)rect.ymax;if(codeout=code0)x0=x;y0=y;code0=CompCode(x0,y0,rect);elsex1=x;y1=y;code1=CompCode(x1,y1,rect);while(!done);if(accept)LineGL(x0,y0,x1,y1);return accept;void myDisplay()glClear(GL_COLOR_BUFFER_BIT);glColor3f(1.0f,0.0f,0.0f);glRectf(rect.xmin, rect.ymin, rect.xmax, rect.ymax);LineGL(x0,y0,x1,y1);glFlush();void Init()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(Press key c to Clip! nPress key r to Restore!n);void Reshape(int w, int h)glViewport(0,0,(GLsizei)w, (GLsizei)h);glMatrixMode(GL_PROJECTION);glLoadIdentity();gluOrtho2D(0.0, (GLdouble)w, 0.0, (GLdouble)h);void keyboard(