#include<windows.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;
const int screenHeight = 480;
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 myMouse(int button, int state, int x ,int y)
{
if(button == GLUT_LEFT_BUTTON && state == GLUT_DOWN)
{
glColor4f(0.0,1.0,0.0,1.0);
glRecti(200,150,500,330); // create a rectangle
glFlush();
}
else if(button == GLUT_RIGHT_BUTTON && state == GLUT_DOWN)
{
//glPointSize(2.0);
glColor3f(1.0,0.0,0.0);
GLint h = 350,k = 240, x, y, r, d;
y = r = 60;
d = 3 – 2*r;
for(x=0; x<=y; x++)
{
glBegin(GL_POINTS);
{
glVertex2i(x+h,y+k);
glVertex2i(x+h,k-y);
glVertex2i(y+h,x+k);
glVertex2i(y+h,k-x);
glVertex2i(-y+h,x+k);
glVertex2i(-y+h,k-x);
glVertex2i(-x+h,y+k);
glVertex2i(-x+h,k-y);
}
glEnd();
if(d<0)
d = d + 4*x + 6;
else{
d = d + 4*(x-y) + 10;
y–;
}
}
glFlush();
} //elseif
}
void myDisplay(void)
{
glClear(GL_COLOR_BUFFER_BIT);
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);
glutMouseFunc(myMouse);
myInit();
glutMainLoop(); //go into a perpetual loop
//fprintf(stderr, “Hello!\n”);
return 1;
}
