#include<windows.h>
#include<iostream.h>
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<math.h>
#include<GL/gl.h>
#include<GL/glu.h>
#include<GL/glut.h>
const int screenWidth = 640*2;
const int screenHeight = 480*2;
GLdouble A,B,C,D; // values for scaling and shifting
void myInit(void)
{
glClearColor(1.0, 1.0, 1.0, 0.0); //background color is white
glColor3f(0.0f, 0.0f, 0.0f); //drawing color is black
glPointSize(4.0); //a dot is 2 by 2 pixels
//glLineWidth(4.0); //a line is 4 times thicker
//initialize view (simple orthographic projection)
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(-1.0,1.0,-1.0, 1.0, -1.0, 1.0);
A = screenWidth/4.0; //Set values for scaling and shifting
B= 0.0;
C=D=screenHeight/2.0;
//set the viewing coordinates
gluOrtho2D(0.0, 640.0, 0.0, 480.0);
}
void myDisplay(void)
{
glClear(GL_COLOR_BUFFER_BIT); //clear the screen
// glRecti(10,10,150,60); //draw a rectangle with background color
glPointSize(2.0);
GLint h = 300, k = 300, x, x2, y, a = 150, b = 25;
x2 = a;
for(x=1;x<=x2;x++)
{
y = b * sqrt(1 – (pow(x,2)/pow(a,2)));
glBegin(GL_POINTS);
{
glVertex2i(x+h,y+k);
glVertex2i(-x+h,-y+k);
glVertex2i(-x+h,y+k);
glVertex2i(x+h,-y+k);
}
glEnd();
}
glFlush(); //send all output to display
}
int main(int argc, char** argv)
{
glutInit(&argc, argv); //initialize the toolkit
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB); //set the display mode
glutInitWindowSize(640,480); //set window size
//set window position on screen
glutInitWindowPosition(100,150);
//open the screen window and set the name
glutCreateWindow(“My First Window”);
//register the callback functions
glutDisplayFunc(myDisplay);
myInit();
glutMainLoop(); //go into a perpetual loop
return 1;
}
