package main;

import java.awt.Graphics;

import javax.swing.JFrame;
import javax.swing.JPanel;

public class Program extends JPanel{

	private static final long serialVersionUID = 1L;
	
	private static final float FOV = 70;
	private static final float NEAR_PLANE = 0.1f;
	private static final float FAR_PLANE = 1000;
	
	double angle_x = Math.toRadians(3);
    double angle_y = Math.toRadians(3);
    double angle_z = Math.toRadians(3);
	
	private static Point3D[] p = new Point3D[8];
	private static Vector3D[] zielVector = new Vector3D[8];
	
	private static Matrix transformationmatrix = null;
	private static Matrix projectionMatrix = null;
	
	public Program() {
		addKeyListener(new KeyInput());
		setFocusable(true);
		requestFocus();
		initPoints();
	}
	
	public void initPoints() {
		p[0] = new Point3D(-100,-100,100);
		p[1] = new Point3D(100,-100,100);
		p[2] = new Point3D(100,100,100);
		p[3] = new Point3D(-100,100,100);
		p[4] = new Point3D(-100,-100,-100);
		p[5] = new Point3D(+100,-100,-100);
		p[6] = new Point3D(+100,+100,-100);
		p[7] = new Point3D(-100,+100,-100);
		
		projectionMatrix = createProjectionMatrix();
		
		transformationmatrix = Tools.transformationMatrix(30,0,0,1,angle_x,angle_y,angle_z,1.0f);
		
		for(int i = 0;i<zielVector.length;i++) {
			zielVector[i] = new Vector3D(4,p[i].x,p[i].y,p[i].z,1.0f);
		}
	}
	
	public void paintComponent(Graphics g) {
		super.paintComponents(g);
		
		g.clearRect(0,0,getWidth(),getHeight());
		
		g.translate(getWidth()/2,getHeight()/2);
		
		for(int i = 0;i<zielVector.length;i++) {
			zielVector[i] = Vector3D.multipliziereMatrixmitVector(transformationmatrix,zielVector[i]);
		}
		
		for(int i = 0;i<p.length;i++) {
			p[i].x=zielVector[i].vector[0];
			p[i].y=zielVector[i].vector[1];
			p[i].z=zielVector[i].vector[2];
			
		}

		renderCube(g,p);
		
    	try {
			Thread.sleep(100);
		} catch (InterruptedException e) {e.printStackTrace();}
    	
		repaint();
	}
	
	

	private Matrix createProjectionMatrix() {
		Matrix projectionMatrix = null;
		
		float aspectratio = 1024 / 768;
		float y_scale =(float) ((1f / Math.tan(Math.toRadians(FOV/2f)))*aspectratio);
		float x_scale = (float) (y_scale/aspectratio);
		float frustumlength = FAR_PLANE - NEAR_PLANE;
		
		projectionMatrix = new Matrix(4,4);
		projectionMatrix.set(0, 0, x_scale);
		projectionMatrix.set(1, 1, y_scale);
		projectionMatrix.set(2, 2, -((FAR_PLANE + NEAR_PLANE) / frustumlength));
		projectionMatrix.set(2, 3, -1);
		projectionMatrix.set(3, 2, -((2 * NEAR_PLANE * FAR_PLANE) / frustumlength));
		projectionMatrix.set(2, 3, 0);
		
		return projectionMatrix;
		
	}
	
	public static void main(String[] args) {
		JFrame window = new JFrame();
    	window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		window.setSize(1024,768);
		window.add(new Program());
		window.setLocationRelativeTo(null);
		window.setVisible(true);
	}
	
	public void renderCube(Graphics g,Point3D[] p) {
		g.drawLine((int)(p[0].x),(int)(p[0].y),(int)(p[1].x),(int)(p[1].y));
    	g.drawLine((int)(p[1].x),(int)(p[1].y),(int)(p[2].x),(int)(p[2].y));
    	g.drawLine((int)(p[2].x),(int)(p[2].y),(int)(p[3].x),(int)(p[3].y));
    	g.drawLine((int)(p[3].x),(int)(p[3].y),(int)(p[0].x),(int)(p[0].y));
    	
    	g.drawLine((int)(p[4].x),(int)(p[4].y),(int)(p[5].x),(int)(p[5].y));
    	g.drawLine((int)(p[5].x),(int)(p[5].y),(int)(p[6].x),(int)(p[6].y));
    	g.drawLine((int)(p[6].x),(int)(p[6].y),(int)(p[7].x),(int)(p[7].y));
    	g.drawLine((int)(p[7].x),(int)(p[7].y),(int)(p[4].x),(int)(p[4].y));
    	
    	g.drawLine((int)(p[0].x),(int)(p[0].y),(int)(p[4].x),(int)(p[4].y));
    	g.drawLine((int)(p[1].x),(int)(p[1].y),(int)(p[5].x),(int)(p[5].y));
    	g.drawLine((int)(p[2].x),(int)(p[2].y),(int)(p[6].x),(int)(p[6].y));
    	g.drawLine((int)(p[3].x),(int)(p[3].y),(int)(p[7].x),(int)(p[7].y));
	}
	
	public void renderGrid(Graphics g,Point3D[] p) {
		g.drawLine((int)(p[1].x),(int)(p[1].y),(int)(p[2].x),(int)(p[2].y));
    	g.drawLine((int)(p[2].x),(int)(p[2].y),(int)(p[3].x),(int)(p[3].y));
    	g.drawLine((int)(p[3].x),(int)(p[3].y),(int)(p[4].x),(int)(p[4].y));
    	g.drawLine((int)(p[4].x),(int)(p[4].y),(int)(p[1].x),(int)(p[1].y));
	}
}