计算机图形学实验报告

计算机图形学实验报告 This manuscript was revised on November 28, 2020

实验一直线的DDA算法

一、【实验目的】

1.掌握DDA算法的基本原理。

2.掌握DDA直线扫描转换算法。

3.深入了解直线扫描转换的编程思想。

二、【实验内容】

1.利用DDA的算法原理，编程实现对直线的扫描转换。

2.加强对DDA算法的理解和掌握。

三、【测试数据及其结果】

四、【实验源代码】

#include<>

#include

#include<>

GLsizei winWidth=500;

GLsizei winHeight=500;

void Initial(void)

{

glClearColor,,,;

glMatrixMode(GL_PROJECTION);

gluOrtho2D,,,;

}

void DDALine(int x0,int y0,int x1,int y1)

{

glColor3f,,;

int dx,dy,epsl,k;

float x,y,xIncre,yIncre;

dx=x1-x0; dy=y1-y0;

x=x0; y=y0;

if(abs(dx)>abs(dy)) epsl=abs(dx);

else epsl=abs(dy);

xIncre=(float)dx/(float)epsl;

yIncre=(float)dy/(float)epsl;

for(k=0;k<=epsl;k++)

{

glPointSize(3);

glBegin(GL_POINTS);

glVertex2i(int(x+,(int)(y+);

glEnd();

x+=xIncre;

y+=yIncre;

}

void Display(void)

{

glClear(GL_COLOR_BUFFER_BIT);

DDALine(100,100,200,180);

glFlush();

}

void winReshapeFcn(GLint newWidth, GLint newHeight)

{

glMatrixMode(GL_PROJECTION);

glLoadIdentity();

gluOrtho2D, GLdouble(newWidth), , GLdouble(newHeight)); glClear(GL_COLOR_BUFFER_BIT);

winWidth=newWidth;

winHeight=newHeight;

}

int main(int argc,char*argv[])

{

glutInit(&argc,argv);

glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB);

glutInitWindowSize(400,300);

glutInitWindowPosition(100,120);

glutCreateWindow("line");

Initial();

glutDisplayFunc(Display);

glutReshapeFunc(winReshapeFcn);

glutMainLoop();

return 0;

}

实验二 Bresenham绘制直线和圆

一、【实验目的】

1.掌握Bresenham算法扫描转换圆和直线的基本原理。

二、【实验内容】

1.利用Bresenham算法扫描转换圆和直线的基本原理编程实现对圆和直线的扫描转换。

三、【测试数据及其结果】

四、【实验源代码】

绘制直线：

#include<>

#include

#include<>

GLsizei winWidth=500;

GLsizei winHeight=500;

void lineBres(int x0, int y0, int xEnd, int yEnd)

{

glColor3f, , ;

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 (x0>xEnd)

{

x=xEnd;

y=yEnd;

xEnd=x0;

}

else{

x=x0;

y=y0;

}

glPointSize(6);

glBegin(GL_POINTS);

glVertex2i(x, y);

glEnd();

while (x

{

x++;

if (p<0)

p+=twoDy;

else{

y++;

p+=twoDyMinusDx;

}

glPointSize(2);

glBegin(GL_POINTS);

glVertex2i(x, y);

glEnd();

}

void init (void)

{

glClearColor, , , ;

glShadeModel(GL_FLAT);

}

void display (void)

{

glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);

lineBres(10, 10, 400, 300);

glFlush();

}

void winReshapeFcn(GLint newWidth, GLint newHeight)

{

glMatrixMode(GL_PROJECTION);

glLoadIdentity();

gluOrtho2D, GLdouble(newWidth), , GLdouble(newHeight)); glClear(GL_COLOR_BUFFER_BIT);

winWidth=newWidth;

winHeight=newHeight;

}

void main(int argc, char** argv)

{

glutInit(&argc, argv);

glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);

glutInitWindowPosition(10, 10);

glutInitWindowSize(winWidth, winHeight); glutCreateWindow("lineBres");

init();

glutDisplayFunc(display);

glutReshapeFunc(winReshapeFcn);

glutMainLoop();

}

绘制圆：

#include

void init()

{

glClearColor(0,0,0,0);

}

void MidBresenhamCircle(int r)

{

int x,y,d;

x=0;

y=r;

d=1-r;

glBegin(GL_LINE_STRIP);

while(x<=y){

glVertex2f(x,y);

if(d<0) d+=2*x+3;

else{

d+=2*(x-y)+5;

y--;

}

x++;

}

glEnd();

}

void display()

{

glClearColor(1,1,1,1);

glClear(GL_COLOR_BUFFER_BIT);

glColor3f(1,0,0);

MidBresenhamCircle(8);

glRotated(45,0,0,1);

MidBresenhamCircle(8);

glRotated(45,0,0,1);

MidBresenhamCircle(8);

glRotated(45,0,0,1);

MidBresenhamCircle(8);

glRotated(45,0,0,1);

MidBresenhamCircle(8);

glRotated(45,0,0,1);

MidBresenhamCircle(8);

glRotated(45,0,0,1);

MidBresenhamCircle(8);

glRotated(45,0,0,1);

MidBresenhamCircle(8);

glutSwapBuffers();

}

void reshape(int w,int h)

{

glViewport(0,0,w,h);

glMatrixMode(GL_PROJECTION);

glLoadIdentity();

gluOrtho2D(-10,10,-10,10);

}

int main(int argc,char**argv)

{

glutInit(&argc,argv);

glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGB);

glutInitWindowSize(400,400);

glutInitWindowPosition(100,100);

glutCreateWindow("扫描转换圆");

glutDisplayFunc(display);

glutReshapeFunc(reshape);

glutMainLoop();

return 0;

}

实验三反走样及五环的绘制

一、【实验目的】

1.了解走样和反走样的内容，熟练掌握用opengl实现图形的反走样。

2.学会用反走样消除走样现象。

3.学会五环的绘制方法。

二、【实验内容】

1.通过学习反走样相关课程，用opengl实现光栅图形的反走样。

2.绘制五环。

三、【测试数据及其结果】

四、【实验源代码】

反走样：

#include

#pragma comment(linker,"/subsystem:\"windows\" /entry:\"mainCRTStartup\"")

GLuint lineList;

1.0f1.0f1.0f0.0f1

2.0f4f2f1.0f1.0f2f4.0f2.0f2f2.0f5.0f3f3f3f3f3f3f练掌握各种裁剪算法和二维观察变换。

2.学会在屏幕坐标系下创建多个视区、指定视区的宽度和高度，了解二维观察变换中包含窗口到视区的映射。

二、【实验内容】

1.在一个显示窗口内指定多个视区，分别显示具有相同坐标、不同颜色和不同显示模式的各种图形面。

2.在书本给定程序基础上，对程序做一些改变并在视区中绘制各种图形。

三、【测试数据及其结果】

四、【实验源代码】

#include

#include<>

const float PI=;

void initial(void)

{

glClearColor,,,;

glMatrixMode(GL_PROJECTION);

glLoadIdentity();

gluOrtho2D,,,;

}

void triangle(GLsizei mode)

{

if(mode==1)

glPolygonMode(GL_FRONT_AND_BACK,GL_LINE);

else

glPolygonMode(GL_FRONT_AND_BACK,GL_FILL);

glBegin(GL_TRIANGLES);

glVertex2f,;

glEnd();

}

void polygon(GLsizei mode)

{

if(mode==1)

glPolygonMode(GL_FRONT_AND_BACK,GL_LINE);

else

glPolygonMode(GL_FRONT_AND_BACK,GL_FILL);

glBegin(GL_POLYGON);

glVertex2f,;

glEnd();

}

void DrawCircle(GLfloat r)

{

GLfloat x,y,z;

glBegin(GL_LINE_LOOP);

for (int alpha=0;alpha<360;alpha++)

{

x=r*cos(alpha*PI/180);

y=r*sin(alpha*PI/180);

z=0;

glVertex3f(x,y,z);

}

glEnd();

}

void Display()

{

glClear(GL_COLOR_BUFFER_BIT);

glColor3f,,;

glViewport(0,0,100,100);

triangle(1);

glColor3f,,;

glViewport(100,0,100,100);

triangle(2);

glColor3f,,;

glViewport(0,100,100,100);

polygon(2);

glViewport(100,100,100,100);

DrawCircle(5);

glFlush();

}

void main(void)

{

glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB);

glutInitWindowPosition(10,10);

glutInitWindowSize(400,200);

glutCreateWindow("多视区");

initial();

glutDisplayFunc(Display);

glutMainLoop();

}

实验五分子模型

一、【实验目的】

1.熟练掌握二维、三维几何变换矩阵和透视投影的相关知识从而用opengl实现分子模型的运动。

2.熟练掌握opengl中相关函数的调用和实现。

二、【实验内容】

1.显示分子模型：红色大球表示原子，三个黄色小球表示电子，分别绕原子旋转，采用透视投影变换显示电子旋转过程。

2.启用深度测试和模型视图矩阵完成分子动画。

三、【测试数据及其结果】

四、【实验源代码】

#include

GLint angleSelf=0;

void Initial()

{

glEnable(GL_DEPTH_TEST);

glClearColor(1.0f,1.0f,1.0f,1.0f);

}

void ChangeSize(int w,int h)

{

if(h==0) h=1;

glViewport(0,0,w,h);

glMatrixMode(GL_PROJECTION);

glLoadIdentity();

GLfloat fAspect;

fAspect=(float)w/(float)h;

gluPerspective,fAspect,1,;

glMatrixMode(GL_MODELVIEW);

glLoadIdentity();

}

void Display(void){

static float fElect1=0.0f;

glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);

glMatrixMode(GL_MODELVIEW);

glLoadIdentity();

glTranslatef(0.0f,0.0f,-250.0f);

glColor3f(1.0f,0.0f,0.0f);

glutWireSphere(12.0f,15,15);

glColor3f(0.0f,1.0f,0.0f);

glPushMatrix();

glRotatef(fElect1,0.0f,1.0f,0.0f);

glTranslatef(90.0f,0.0f,0.0f);

glRotatef(angleSelf,0,1,0);

glutWireSphere(6.0f,15,15);

glPopMatrix();

glPushMatrix();

glRotatef(45.0f,0.0f,0.0f,1.0f);

glRotatef(fElect1,0.0f,1.0f,0.0f);

glTranslatef(-70.0f,0.0f,0.0f);

glRotatef(angleSelf,0,1,0);

glutWireSphere(6.0f,15,15);

glPopMatrix();

glPushMatrix();

glRotatef(-45.0f,0.0f,0.0f,1.0f);

glRotatef(fElect1,0.0f,1.0f,;

glTranslatef(0.0f,0.0f,60.0f);

glRotatef(angleSelf,0,1,0);

glutWireSphere(6.0f,15,15);

glPopMatrix();

fElect1 +=5.0f;

if(fElect1>360.0f) fElect1=10.0f;

glutSwapBuffers();

}

void RotateSelf(int value)

{

if(value==1)

{

angleSelf+=5;

angleSelf%=360;

glutPostRedisplay();

glutTimerFunc(100,RotateSelf,1);

}

void TimerFunc(int value)

{

glutPostRedisplay();

glutTimerFunc(100,TimerFunc,1);

}

int main(int argc,char*argv[])

{

glutInit(&argc,argv);

glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGB|GLUT_DEPTH);

glutCreateWindow("分子动画示例");

glutReshapeFunc(ChangeSize);

glutDisplayFunc(Display);

glutTimerFunc(500,TimerFunc,1);

glutTimerFunc(100,RotateSelf,1);

Initial();

glutMainLoop();

return 0;

}

实验六 Bezier曲线

一、【实验目的】

1.掌握Bezire曲线定义。

2.掌握设计绘制一次、二次和三次Bezier曲线算法。

二、【实验内容】

1.绘制NURBS曲面。

2.基于Bezier定义根据控制多边形的阶次绘制Bezier曲线。

三、【测试数据及其结果】

四、【实验源代码】

原实验代码：

#include

#include<>

class Pt3D{

public:

GLfloat x,y,z;

};

void GetCnk(GLint n,GLint *c)

{

GLint i,k;

for(k=0;k<=n;k++){

c[k]=1;

for(i=n;i>=k+1;i--)c[k]=c[k]*i;

for(i=n-k;i>=2;i--)c[k]=c[k]/i;

}

void GetPointPr(GLint *c,GLfloat t,Pt3D*Pt,int ControlN,Pt3D*ControlP) {

GLint k,n=ControlN-1;

GLfloat Bernstein;

Pt->x=; Pt->y=; Pt->z=;

for(k=0;k

Bernstein=c[k]*pow(t,k)*pow(1-t,n-k);

Pt->x+=ControlP[k].x*Bernstein;

Pt->y+=ControlP[k].y*Bernstein;

Pt->z+=ControlP[k].z*Bernstein;

}

void BezierCurve(GLint m,GLint ControlN,Pt3D *ControlP)

{

GLint *C,i;

Pt3D CurvePt;

C=new GLint[ControlN];

GetCnk(ControlN-1,C);

glBegin(GL_POINTS);

for(i=0;i<=m;i++){

GetPointPr(C,(GLfloat)i/(GLfloat)m,&CurvePt,ControlN,ControlP);

glVertex2f,;

}

glEnd();

delete [] C;

}

void initial(void)

{

glClearColor,,,;

}

void Display(void){

glClear(GL_COLOR_BUFFER_BIT);

GLint ControlN=4,m=500;

Pt3D ControlP[4]={{,,},{,,},{,,},{,,}};

glPointSize(2);

glColor3f,,;

BezierCurve(m,ControlN,ControlP);

glBegin(GL_LINE_STRIP);

for(GLint i=0;i<4;i++)glVertex3f(ControlP[i].x,ControlP[i].y,ControlP[i].z);

glEnd();

glFlush();

}

void reshape(GLint newWidth,GLint newHeight)

{

glViewport(0,0,newWidth,newHeight);

glMatrixMode(GL_PROJECTION);

glLoadIdentity();

gluOrtho2D,,,;

}

void main(void)

{

glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB);

glutInitWindowPosition(100,100);

glutInitWindowSize(400,400);

glutCreateWindow("Bezier曲线");

initial();

glutDisplayFunc(Display);

glutReshapeFunc(reshape);

glutMainLoop();

}

加改后的：

#include

void initial(void)

{

glClearColor,,,;

glLineWidth;

GLfloat ControlP[4][3]={{,,},{,,},

{,,},{,,}};

glMap1f(GL_MAP1_VERTEX_3,,,3,4,*ControlP);

glEnable(GL_MAP1_VERTEX_3);

}

void Display(void)

{

glClear(GL_COLOR_BUFFER_BIT);

glColor3f,,;

glMapGrid1f(100,,;

glEvalMesh1(GL_LINE,0,100);

glFlush();

}

void Reshape(GLint newWidth,GLint newHeight) {

glViewport(0,0,newWidth,newHeight);

glMatrixMode(GL_PROJECTION);

glLoadIdentity();

gluOrtho2D,,,;

}

void main(void)

{

glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB);

glutInitWindowPosition(100,100);

glutInitWindowSize(400,400);