/*
 * File: Renderer.java
 * Author: Joe Phillips
 * Date: 2/6/08
 */
package edu.msoe.phillijw.main;

import javax.media.opengl.*;
import javax.media.opengl.glu.*;
import java.util.*;
import java.io.*;
import edu.msoe.phillijw.helper.*;
import edu.msoe.phillijw.entity.*;

public class Renderer implements GLEventListener
{
	private GLU glu = new GLU();
	private LinkedList<Entity> entities = new LinkedList<Entity>();
	private int texture;
	
	public Renderer()
	{
		entities.add(new FloorEntity());
		entities.add(new BlockEntity());
	}
	
	/**
	 * Called by the drawable to initiate OpenGL rendering by the client.
	 * After all GLEventListeners have been notified of a display event, the
	 * drawable will swap its buffers if necessary.
	 * @author Joe Phillips
	 * @param gLDrawable The GLAutoDrawable object.
	 */
	public void display(GLAutoDrawable gLDrawable)
	{
		final GL gl = gLDrawable.getGL();
		gl.glClear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT);
		gl.glLoadIdentity();
		glu.gluLookAt(5.0, 6.0, 25.0, //eye position
				  	  0.0, 5.0, 0.0,  //look at
				  	  0.0, 1.0, 0.0); //y-axis is up
		
		for (Entity e : entities)
		{
			gl.glColor3f(0.0f, 0.8f, 0.0f);
			e.render(gl);
		}

		//render hud
		gl.glBindTexture(GL.GL_TEXTURE_2D, texture);
		gl.glDisable(GL.GL_DEPTH_TEST);
		gl.glPushMatrix();
		gl.glLoadIdentity();
		glu.gluOrtho2D(-1, 1, -1, 1);
		gl.glBindTexture(GL.GL_TEXTURE_2D, texture);
		gl.glBegin(GL.GL_QUADS);
			gl.glTexCoord2f(0.0f, 0.0f); gl.glVertex3f(-1.0f, -1.0f, 1.0f);
			gl.glTexCoord2f(1.0f, 0.0f); gl.glVertex3f( 1.0f, -1.0f,  1.0f);
	        gl.glTexCoord2f(1.0f, 1.0f); gl.glVertex3f( 1.0f,  1.0f,  1.0f);
	        gl.glTexCoord2f(0.0f, 1.0f); gl.glVertex3f(-1.0f,  1.0f,  1.0f);
		gl.glEnd();
		
		gl.glEnable(GL.GL_BLEND);
		gl.glPopMatrix();
		gl.glEnable(GL.GL_DEPTH_TEST);
		gl.glDisable(GL.GL_BLEND);

	}

	/** 
	 * Called by the drawable immediately after the OpenGL context is
	 * initialized for the first time. Can be used to perform one-time OpenGL
	 * initialization such as setup of lights and display lists.
	 * @param gLDrawable The GLAutoDrawable object.
	 */
	public void init(GLAutoDrawable gLDrawable)
	{
		GL gl = gLDrawable.getGL();
		gl.glEnable(GL.GL_DEPTH_TEST);
		gl.glShadeModel(GL.GL_SMOOTH);              // Enable Smooth Shading
		gl.glClearColor(0.0f, 0.0f, 0.0f, 1.0f);    // Black Background
		
		gl.glEnable(GL.GL_LIGHTING);
		gl.glEnable(GL.GL_LIGHT1);
		
		float[] diffuse = new float[] {1.0f, 1.0f, 1.0f, 0.5f};
		float[] position = new float[] {2.0f, 2.0f, 10.0f, 1.0f};
		gl.glLightfv(GL.GL_LIGHT1, GL.GL_DIFFUSE, diffuse, 0);
		gl.glLightfv(GL.GL_LIGHT1, GL.GL_POSITION, position, 0);
		
		gl.glEnable(GL.GL_TEXTURE_2D);
		texture = genTexture(gl);
        gl.glBindTexture(GL.GL_TEXTURE_2D, texture);
        TextureReader.Texture texture = null;
        try {
            texture = TextureReader.readTexture("OMSBerry.png");
        } catch (IOException e) {
            e.printStackTrace();
            throw new RuntimeException(e);
        }
        makeRGBTexture(gl, glu, texture, GL.GL_TEXTURE_2D, false);
        gl.glTexParameteri(GL.GL_TEXTURE_2D, GL.GL_TEXTURE_MIN_FILTER, GL.GL_LINEAR);
        gl.glTexParameteri(GL.GL_TEXTURE_2D, GL.GL_TEXTURE_MAG_FILTER, GL.GL_LINEAR);
		
	}


	/**
	 * Called by the drawable during the first repaint after the component has
	 * been resized. The client can update the viewport and view volume of the
	 * window appropriately, for example by a call to
	 * GL.glViewport(int, int, int, int); note that for convenience the component
	 * has already called GL.glViewport(int, int, int, int)(x, y, width, height)
	 * when this method is called, so the client may not have to do anything in
	 * this method.
	 * @param gLDrawable The GLAutoDrawable object.
	 * @param x The X Coordinate of the viewport rectangle.
	 * @param y The Y coordinate of the viewport rectangle.
	 * @param width The new width of the window.
	 * @param height The new height of the window.
	 */
	public void reshape(GLAutoDrawable gLDrawable, int x, int y, int width, int height)
	{
		final GL gl = gLDrawable.getGL();

		if (height <= 0) { height = 1; } // avoid a divide by zero error!
		final float h = (float) width / (float) height;
		gl.glViewport(0, 0, width, height);
		
		gl.glMatrixMode(GL.GL_PROJECTION);
		gl.glLoadIdentity();
		glu.gluPerspective(30.0, h, 1.0, 100.0);
		
        gl.glMatrixMode(GL.GL_MODELVIEW);
        gl.glLoadIdentity();
	}

    private void makeRGBTexture(GL gl, GLU glu, TextureReader.Texture img, 
            int target, boolean mipmapped) {
        
        if (mipmapped) {
            glu.gluBuild2DMipmaps(target, GL.GL_RGB8, img.getWidth(), 
                    img.getHeight(), GL.GL_RGB, GL.GL_UNSIGNED_BYTE, img.getPixels());
        } else {
            gl.glTexImage2D(target, 0, GL.GL_RGB, img.getWidth(), 
                    img.getHeight(), 0, GL.GL_RGB, GL.GL_UNSIGNED_BYTE, img.getPixels());
        }
    }

    private int genTexture(GL gl) {
        final int[] tmp = new int[1];
        gl.glGenTextures(1, tmp, 0);
        return tmp[0];
    }
	
	/**
	 * Called when the display mode has been changed.
	 * <B>!! CURRENTLY UNIMPLEMENTED IN JOGL!</B>
	 * @param gLDrawable The GLAutoDrawable object.
	 * @param modeChanged Indicates if the video mode has changed.
	 * @param deviceChanged Indicates if the video device has changed.
	 */
	public void displayChanged(GLAutoDrawable gLDrawable, boolean modeChanged, boolean deviceChanged)
	{
		//unavailable
	}
}