package pv112;

import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import javax.media.opengl.GL2;
import javax.media.opengl.GLAutoDrawable;
import javax.media.opengl.GLEventListener;
import javax.media.opengl.awt.GLJPanel;
import static javax.media.opengl.GL2.*; // GL2 konstanty

public class OpenGlListener implements GLEventListener, KeyListener {

    private final GLJPanel glPanel;
    private boolean wireframeEnabled = true;
    private float angleTriangle = 0.0f;
    private float speedTriangle = 1.0f;

    OpenGlListener(GLJPanel glPanel) {
        this.glPanel = glPanel;
    }

    @Override
    // metoda volana pri vytvoreni okna OpenGL
    public void init(GLAutoDrawable glad) {
        GL2 gl = glad.getGL().getGL2();
        gl.glClearColor(1.0f, 1.0f, 1.0f, 0);
    }

    @Override
    // metoda volana pri zatvoreni okna OpenGL
    public void dispose(GLAutoDrawable glad) {
    }

    @Override
    // metoda volana pri kazdom prekresleni obrazovky
    public void display(GLAutoDrawable glad) {

        GL2 gl = glad.getGL().getGL2();
        gl.glClear(GL_COLOR_BUFFER_BIT);
        gl.glClearDepth(1.0);
        gl.glClear(GL_DEPTH_BUFFER_BIT);
        if( wireframeEnabled ) {
            gl.glPolygonMode(GL_FRONT, GL_LINE);
        }

        gl.glColor3f(0.0f,0.0f,0.0f);

        gl.glRotatef(45f, 1.0f, 1.0f, 1.0f);

        //front
        gl.glBegin(GL_QUADS);
            gl.glColor3f(1.0f, 0.0f, 0.0f);
            gl.glVertex3f(0.0f, 0.0f, 0.0f);
            gl.glVertex3f(0.5f, 0.0f, 0.0f);
            gl.glVertex3f(0.5f, 0.5f, 0.0f);
            gl.glVertex3f(0.0f, 0.5f, 0.0f);
        gl.glEnd();

        //back
        gl.glBegin(GL_QUADS);
            gl.glColor3f(0.0f,1.0f,0.0f);
            gl.glVertex3f(0.0f,0.0f,0.5f);
            gl.glVertex3f(0.5f,0.0f,0.5f);
            gl.glVertex3f(0.5f,0.5f,0.5f);
            gl.glVertex3f(0.0f,0.5f,0.5f);
        gl.glEnd();

        //top
        gl.glBegin(GL_QUADS);
            gl.glColor3f(0.0f,0.0f,1.0f);
            gl.glVertex3f(0.0f,0.5f,0.0f);
            gl.glVertex3f(0.5f,0.5f,0.0f);
            gl.glVertex3f(0.5f,0.5f,0.5f);
            gl.glVertex3f(0.0f,0.5f,0.5f);
        gl.glEnd();

        //down
        gl.glBegin(GL_QUADS);
            gl.glColor3f(1.0f,1.0f,0.0f);
            gl.glVertex3f(0.0f,0.0f,0.0f);
            gl.glVertex3f(0.5f,0.0f,0.0f);
            gl.glVertex3f(0.5f,0.0f,0.5f);
            gl.glVertex3f(0.0f,0.0f,0.5f);
        gl.glEnd();

        //right
        gl.glBegin(GL_QUADS);
            gl.glColor3f(1.0f,0.0f,1.0f);
            gl.glVertex3f(0.5f,0.0f,0.0f);
            gl.glVertex3f(0.5f,0.0f,0.5f);
            gl.glVertex3f(0.5f,0.5f,0.5f);
            gl.glVertex3f(0.5f,0.5f,0.0f);
        gl.glEnd();

        //left
        gl.glBegin(GL_QUADS);
            gl.glColor3f(0.0f,1.0f,1.0f);
            gl.glVertex3f(0.0f,0.0f,0.0f);
            gl.glVertex3f(0.0f,0.0f,0.5f);
            gl.glVertex3f(0.0f,0.5f,0.5f);
            gl.glVertex3f(0.0f,0.5f,0.0f);
        gl.glEnd();

        gl.glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);


    }

    @Override
    // metoda volana pri zmene velkosti okna
    public void reshape(GLAutoDrawable glad, int x, int y, int width, int height) {
        GL2 gl = glad.getGL().getGL2();
//        gl.glViewport(x, y, width, height); // volano automaticky

    }

    @Override
    public void keyTyped(KeyEvent evt) {
    }

    @Override
    public void keyPressed(KeyEvent evt) {

        switch (evt.getKeyCode()) {
            case KeyEvent.VK_ESCAPE:
                System.exit(0);
                break;

            case KeyEvent.VK_E:
                glPanel.display();
                break;


            case KeyEvent.VK_F:
                wireframeEnabled = !wireframeEnabled;
                glPanel.display();
                break;

            default:

        }
    }

    @Override
    public void keyReleased(KeyEvent evt) {
    }
}