glClear(GL_COLOR_BUFFER_BIT);
winWidth=newWidth;
winHeight=newHeight;
}
void main(int argc, char** argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
{
glColor3f(0.0, 0.0, 1.0);
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;
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。
glClear(GL_COLOR_BUFFER_BIT);
winWidth=newWidth;
winHeight=newHeight;
}
int main(int argc,char*argv[])
{
glutInit(&argc,argv);
glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB);
glBegin(GL_POINTS);
glVertex2i(x, y);
glEnd();
}
}
void init (void)
{
glClearColor(1.0, 1.0, 1.0, 1.0);
glShadeModel(GL_FLAT);
}
void display (void)
{
glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
glutDisplayFunc(Displayt);
glutReshapeFunc(ChangeSize);
Initial();
glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB);
glFlush();
}
void winReshapeFcn(GLint newWidth, GLint newHeight)
{
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluOrtho2D(0.0, GLdouble(newWidth), 0.0, GLdouble(newHeight));
glutInitWindowPosition(10, 10);
glutInitWindowSize(winWidth, winHeight);
glutCreateWindow("lineBres");
init();
glutDisplayFunc(display);
glutReshapeFunc(winReshapeFcn);
MidBresenhamCircle(8);
glRotated(45,0,0,1);
MidBresenhamCircle(8);
glRotated(45,0,0,1);
MidBresenhamCircle(8);
glRotated(45,0,0,1);
MidBresenhamCircle(8);
glutSwapBuffers();
glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGB);
glutInitWindowSize(400,400);
glutInitWindowPosition(100,100);
glutCreateWindow("扫描转换圆");
glutDisplayFunc(display);
glBegin(GL_LINE_LOOP);
glVertex2f(1.0f,1.0f);
glVertex2f(4.0f,2.0f);
glVertex2f(2.0f,5.0f);
glEnd();
glEndList();
}
void ChangeSize(GLsizei w,GLsizei h)
{
if(h==0) h=1;
xEnd=x0;
}
else{
x=x0;
y=y0;
}
glPointSize(6);
glBegin(GL_POINTS);
glVertex2i(x, y);
glEnd();
while (x<xEnd)
{
x++;
if (p<0)
p+=twoDy;
else{
y++;
p+=twoDyMinusDx;
}
glPointSize(2);
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);
void Displayw(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
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+0.5),(int)(y+0.5));
glEnd();
x+=xIncre;
y+=yIncre;
}
}
void Display(void)
{
glClear(GL_COLOR_BUFFER_BIT);
DDALine(100,100,200,180);
glViewport(0,0,w,h);
glMatrixMode(GL_PROJECTION); //指定设置投影参数
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);
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
绘制直线：
2.绘制五环。
三、【测试数据及其结果】
四
反走样：
#include<gl/glut.h>
#pragma comment(linker,"/subsystem:\"windows\" /entry:\"mainCRTStartup\"")
GLuint lineList; //指定显示列表
void Initial()
}
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);
{
glClearColor(1.0f,1.0f,1.0f,0.0f);
glLineWidth(12.0f);
glColor4f(0.0,0.6,1.0,1.0);
lineList=glGenLists(1); //获得一个显示列表标识
glNewList(lineList,GL_COMPILE); //定义显示列表
#include<math.h>
#include<GL/glut.h>
#include<stdio.h>
GLsizei winWidth=500;
GLsizei winHeight=500;