#include<windows.h>
#include<GL/glut.h>
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);
//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
//Line drawing algorithm
glPointSize(2.0);
GLint x,y, x1=50, x2=100, y1=100, y2=200;
GLint dx, dy, inc1, inc2, d;
x = x1;
y = y1;
dx = x2-x1;
dy = y2-y1;
inc1 = 2 * dy;
inc2 = 2 * (dy-dx);
d = inc1 – dx;
while(x <= x2)
{
glBegin(GL_POINTS);
{
glVertex2i(x,y);
}
glEnd();
x++;
if(d < 0)
d = d + inc1;
else {
d = d + inc2;
y++;
}
}
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”);
glutDisplayFunc(myDisplay);
myInit();
glutMainLoop(); //go into a perpetual loop
//fprintf(stderr, “Hello!\n”);
return 1;
}
