graphics 101

1. #include <gl//glut.h>
//#include<math.h>
void init ()
{
glClearColor(0.0, 0.0, 0.0, 0.0);
glPointSize(5.0);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
//setting the resolution for the 2D object
gluOrtho2D(0.0,300.0, 0.0, 300.0); //void gluOrtho2D(left,r,bot,top);
//gluOrtho2D sets up a two-dimensional orthographic viewing region.
//equivalent to calling glOrtho with near = -1 and far = 1 .
//void glOrtho(left,right,bottom,top,nearVal,farVal);
}
void CheckerBoard()
{
glPointSize(5.0);
//
int x1,y1;
x1=0;
y1=500;
for(int i=1;i<=8;i++)
{
x1=x1+50;
y1=500;
for(int j=1;j<=8;j++)
{
y1=y1-50;
glBegin(GL_QUADS);
if(i%2 != 0 )
{
if( j%2 != 0 )
{
//glColor3f(1.0,1.0,1.0); //white
glColor3f(202.0/255.00, 169.0/255.0,
106.0/255.0);//orange
glVertex3f(x1,y1,0);
glVertex3f(x1+50,y1,0);
glVertex3f(x1+50,y1-50,0);
glVertex3f(x1,y1-50,0);
}
else
{
glColor3f(146.0/255.0, 140.0/255.0,
168.0/255.0);//brown
//glColor3f(0.0,0.0,0.0); //black
glVertex3f(x1,y1,0);
glVertex3f(x1+50,y1,0);
glVertex3f(x1+50,y1-50,0);
glVertex3f(x1,y1-50,0);
}
}

2. else{
if(j%2 != 0)
{
glColor3f(146.0/255.0, 140.0/255.0,
168.0/255.0);
//glColor3f(0.0,0.0,0.0);
glVertex3f(x1,y1,0);
glVertex3f(x1+50,y1,0);
glVertex3f(x1+50,y1-50,0);
glVertex3f(x1,y1-50,0);
}
else{
glColor3f(202.0/255.00, 169.0/255.0,
106.0/255.0);
// glColor3f(1.0,1.0,1.0);
glVertex3f(x1,y1,0);
glVertex3f(x1+50,y1,0);
glVertex3f(x1+50,y1-50,0);
glVertex3f(x1,y1-50,0);
}
}
glEnd();
}
}
}
void Display()
{
glClear(GL_COLOR_BUFFER_BIT);
//calling
CheckerBoard();
glFlush ();
}
int main(int argc, char** argv)
{
glutInit(&argc, argv);
glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB);
glutInitWindowSize (900, 450);
glutInitWindowPosition (100, 100);
glutCreateWindow ("Assignment: Lab 2");
init ();
glutDisplayFunc(Display);
glutMainLoop();
}