#include <GL/gl.h>
#include <GL/glu.h>

#include <freeglut.h>


static GLfloat spin = 0.0;

void init(void)
{
    glClearColor(0.0, 0.0, 0.0, 0.0);
    glShadeModel(GL_FLAT);
}

void display(void)
{
    glClear(GL_COLOR_BUFFER_BIT);
    glPushMatrix();
    glRotatef(spin, 0.0, 0.0, 1.0);
    glColor3f(1.0, 1.0, 1.0);
    glRectf(-25.0, -25.0, 25.0, 25.0);
    glPopMatrix();
    glutSwapBuffers();
}

void spinDisplay(void)
{
    spin = spin + 2.0;
    if (spin > 360.0)
        spin = spin - 360.0;
    glutPostRedisplay();
}

void reshape(int w, int h)
{
    glViewport(0, 0, (GLsizei) w, (GLsizei) h);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glOrtho(-50.0, 50.0, -50.0, 50.0, -1.0, 1.0);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
}

void mouse(int button, int state, int x, int y)
{
    switch (button) {
        case GLUT_LEFT_BUTTON:
            if (state == GLUT_DOWN)
            glutIdleFunc(spinDisplay);
        break;
            case GLUT_MIDDLE_BUTTON:
            if (state == GLUT_DOWN)
                glutIdleFunc(NULL);
            break;
        default:
            break;
    }
}

/*
* Request double buffer display mode.
* Register mouse input callback functions
*/
int main(int argc, char** argv)
{
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB);
    glutInitWindowSize(250, 250);
    glutInitWindowPosition(100, 100);
    glutCreateWindow(argv[0]);
    init();

    glutDisplayFunc(display);
    glutReshapeFunc(reshape);
    glutMouseFunc(mouse);

    glutMainLoop();

    return 0;
}