package com.starshock;

import java.io.File;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.IntBuffer;

import org.lwjgl.LWJGLException;
import org.lwjgl.LWJGLUtil;
import org.lwjgl.Sys;
import org.lwjgl.opengl.Display;
import org.lwjgl.opengl.DisplayMode;
import static org.lwjgl.opengl.GL11.*;
import static org.lwjgl.opengl.GL30.*;
import static org.lwjgl.util.glu.GLU.*;

public class Main {

	static {
		System.setProperty("org.lwjgl.librarypath",
				new File(new File(System.getProperty("user.dir"), "native"),
						LWJGLUtil.getPlatformName()).getAbsolutePath());
	}

	public static final int S_WIDTH = 320, S_HEIGHT = 200, S_SCALE = 2;

	public long lastFrame, lastFPS;
	public int fps;
	public int defaultFBO = 0, drawFBO, drawFBOTexture;

	public void start() {
		try {
			Display.setDisplayMode(new DisplayMode(S_WIDTH * S_SCALE, S_HEIGHT
					* S_SCALE));
			Display.setTitle("Starhack - FPS: " + fps);
			Display.create();
		} catch (LWJGLException e) {
			e.printStackTrace();
			System.exit(0);
		}

		initFBO();

		getDelta();
		lastFPS = getTime();

		while (!Display.isCloseRequested()) {
			int delta = getDelta();

			update(delta);
			renderGL();

			Display.update();
			Display.sync(60);
		}

		Display.destroy();
	}

	public void update(int delta) {
		updateFPS();
	}

	public int getDelta() {
		long time = getTime();
		int delta = (int) (time - lastFrame);
		lastFrame = time;

		return delta;
	}

	public long getTime() {
		return (Sys.getTime() * 1000) / Sys.getTimerResolution();
	}

	public void updateFPS() {
		if (getTime() - lastFPS > 1000) {
			Display.setTitle("Starhack - FPS: " + fps);
			fps = 0;
			lastFPS += 1000;
		}
		fps++;
	}

	public void initFBO() {
		IntBuffer buffer = ByteBuffer.allocateDirect(4)
				.order(ByteOrder.nativeOrder()).asIntBuffer();
		glGenFramebuffers(buffer);
		drawFBO = buffer.get();
		buffer = ByteBuffer.allocateDirect(4).order(ByteOrder.nativeOrder())
				.asIntBuffer();
		glGenTextures(buffer);
		drawFBOTexture = buffer.get();
		glBindFramebuffer(GL_FRAMEBUFFER, drawFBO);
		glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
				GL_TEXTURE_2D, drawFBOTexture, 0);
	}

	public void renderGL() {
		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
		glBindFramebuffer(GL_FRAMEBUFFER, drawFBO);
		ready3D();
		render3D();
		ready2D();
		render2D();
		renderScaledFBO();
	}

	public void ready3D() {
		glViewport(0, 0, S_WIDTH, S_HEIGHT);
		glMatrixMode(GL_PROJECTION);

		glLoadIdentity();
		gluPerspective(45f, (float) S_WIDTH / S_HEIGHT, 0.0f, 5000.0f);

		glMatrixMode(GL_MODELVIEW);
		glLoadIdentity();

		glDepthFunc(GL_LEQUAL);
		glEnable(GL_DEPTH_TEST);
	}

	public void render3D() {
		glTranslatef(0, 0, -6f);
		glBegin(GL_QUADS);
		glVertex3f(0, 0, 0);
		glVertex3f(2, 0, 0);
		glVertex3f(2, 2, 0);
		glVertex3f(0, 2, 0);
		glEnd();
	}

	public void ready2D() {
		glMatrixMode(GL_PROJECTION);
		glLoadIdentity();

		gluOrtho2D(0.0f, S_WIDTH, S_HEIGHT, 0.0f);

		glMatrixMode(GL_MODELVIEW);
		glLoadIdentity();
		glTranslatef(0.375f, 0.375f, 0.0f);

		glDisable(GL_DEPTH_TEST);
	}

	public void render2D() {
	}

	public void renderScaledFBO() {
		glViewport(0, 0, S_WIDTH * S_SCALE, S_HEIGHT * S_SCALE);
		glBindFramebuffer(GL_FRAMEBUFFER, defaultFBO);
		glBlitFramebuffer(0, 0, S_WIDTH, S_HEIGHT, 0, 0, S_WIDTH * S_SCALE,
				S_HEIGHT * S_SCALE, GL_COLOR_BUFFER_BIT, GL_NEAREST);
	}

	public static void main(String[] argv) {
		Main main = new Main();
		main.start();
	}
}