import org.lwjgl.opengl.GL11;
import org.lwjgl.opengl.Display;
import org.lwjgl.opengl.DisplayMode;
import org.lwjgl.LWJGLException;

/** No documentation for teh win! */
class Quads {

    float angle = 0.0f;

    private void initGL() {
        // Initialisering
	GL11.glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
	GL11.glShadeModel(GL11.GL_SMOOTH);

	GL11.glMatrixMode(GL11.GL_PROJECTION);
	GL11.glLoadIdentity();
	GL11.glOrtho(0.0f, 1.0f, 0.0f, 1.0f, -1.0f, 1.0f);

	GL11.glMatrixMode(GL11.GL_MODELVIEW);
	GL11.glLoadIdentity();

	GL11.glEnable(GL11.GL_BLEND);
	GL11.glBlendFunc(GL11.GL_SRC_COLOR, GL11.GL_ONE);
    }

    private void display() {
        // Tegne trekant
	GL11.glClear(GL11.GL_COLOR_BUFFER_BIT);

	GL11.glPushMatrix();
	GL11.glTranslatef(0.5f, 0.5f, 0.0f);

	float red = 0.5f;
	float green = 0.25f;
	float blue = 0.1f;

	for(int i = 0; i < 25; i++) {
	    GL11.glRotatef(angle, 0.0f, 0.0f, 1.0f);

	    GL11.glBegin(GL11.GL_QUADS);
	    GL11.glColor3f(red, green, blue);
	    GL11.glVertex2f(0.1f, 0.3f);

	    red = switchColor(red);
	    green = switchColor(green);
	    blue = switchColor(blue);

	    GL11.glColor3f(red, green, blue);
	    GL11.glVertex2f(0.1f, -0.3f);

	    red = switchColor(red);
	    green = switchColor(green);
	    blue = switchColor(blue);

	    GL11.glColor3f(red, green, blue);
	    GL11.glVertex2f(-0.1f, -0.3f);

	    red = switchColor(red);
	    green = switchColor(green);
	    blue = switchColor(blue);

	    GL11.glColor3f(red, green, blue);
	    GL11.glVertex2f(-0.1f, 0.3f);



	    GL11.glEnd();
	}

	GL11.glPopMatrix();
	GL11.glFlush();
	angle += 0.005f;
    }

    private float switchColor(float color) {
	if (color == 0.5f)
	    return 0.25f;
	if (color == 0.25f)
	    return 0.1f;
	return 0.5f;
    }

    private void run() {
        init();

        while (!Display.isCloseRequested()) {
            display();
            Display.update();
        }

        Display.destroy();
    }

    private void init() {
        try {
            Display.setTitle("Spinning Quads!");
            Display.setDisplayMode(new DisplayMode(512, 512));
            Display.create();
        } catch (LWJGLException e) {
            System.err.println("Could't create display. Exiting");
            System.exit(0);
        }
        initGL();
    }

    public static void main(String[] args) {
        new Quads().run();
    }
}