chase board

#include <GL/glut.h>

void shapes(void) {
    float y1 = 0.0;
    float y2 = 0.0;
    float y3 = 0.1;
    float y4 = 0.1;
    for (int j = 0; j < 8; j++) {
        float x1 = 0.0;
        float x2 = 0.1;
        float x3 = 0.1;
        float x4 = 0.0;
        for (int i = 0; i < 8; i++) {
            glBegin(GL_QUADS);
            if ((j % 2) != 0) {
                if ((i % 2) != 0) {
                    glColor3f(1.0, 1.0, 1.0);
                }
                else {
                    glColor3f(0.2, 0.2, 0.2);
                }
            }
            if ((j % 2) == 0) {
                if ((i % 2) != 0) {
                    glColor3f(0.2, 0.2, 0.2);
                }
                else {
                    glColor3f(1.0, 1.0, 1.0);
                }
            }
            glVertex3f(x1, y1, 0.0);
            glVertex3f(x2, y2, 0.0);
            glVertex3f(x3, y3, 0.0);
            glVertex3f(x4, y4, 0.0);
            glEnd();
            x1 += 0.1;
            x2 += 0.1;
            x3 += 0.1;
            x4 += 0.1;
        }
        y1 += 0.1;
        y2 += 0.1;
        y3 += 0.1;
        y4 += 0.1;
    }
}

void display(void) {
    // clearing the window with black color, 1st 3 parameter are for R,G,B. last one for opacity
    glClearColor(0.0, 0.0, 0.0, 1.0);
    glClear(GL_COLOR_BUFFER_BIT);
    glLoadIdentity();

    //viewing transformation
    //glulookat() positions the camera towards the object
    //camera position, camera target, up vector
    gluLookAt(0.0, 0.0, 5.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0);
    shapes();
    glFlush();
}

void reshape(int w, int h) {
    // 1st 2 parameters for lower left corner of the viewport rectangle. the default is 0,0
    // the next coordinates are width and height of the viewport
    //Set the viewport to be the entire window
    glViewport(0, 0, (GLsizei)w, (GLsizei)h);

    // setting the camera
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();

    //perspective transform
    //gluPerspective (30, (GLfloat)w / (GLfloat)h, 1.0, 100.0);
    gluPerspective(30, 1, 1.0, 100.0);
    glMatrixMode(GL_MODELVIEW); //switch back the the model editing mode.

}

int main(int argc, char **argv) {
    glutInit(&argc, argv);
    // single buffering.. (double buffering for animation)
    glutInitDisplayMode(GLUT_SINGLE);
    // full screen is 1000,1000
    // this 0,0 or 1000,1000 are world coordinates
    glutInitWindowSize(700, 700);
    glutInitWindowPosition(100, 100);
    glutCreateWindow("A basic OpenGL Window");
    // registering callback functions
    glutDisplayFunc(display);
    glutReshapeFunc(reshape);

    glutMainLoop();
    return 0;
}