/* Left Click Spins the square and Right Click Stops it
   Build with:
   gcc -Wall glutspin.c -lglut -o glutspin
 */
#include <GL/freeglut.h>
#include <GL/glut.h>
#include <stdlib.h>
#include <stdio.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+=2.0;
    if(spin>360.0)
	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)
		printf("left button spinin\n");
	    glutIdleFunc(spinDisplay);
	    break;
	case GLUT_RIGHT_BUTTON:
	    if(state==GLUT_DOWN)
		printf("right button paused\n");
	    glutIdleFunc(NULL);
	    break;
	default:
	    break;
	}
}

int main(int argc, char** argv)
{
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGB);
    glutInitWindowPosition(200,200);
    glutInitWindowSize(200,200);
    glutCreateWindow(argv[0]);
    init();
    glutDisplayFunc(display); //most impt callback
    glutReshapeFunc(reshape);
    glutMouseFunc(mouse);
    glutMainLoop();
    return 0;
}