gistfile1.java

import static org.lwjgl.opengl.GL11.*;

import java.util.ArrayList;
import java.util.Random;
import org.lwjgl.opengl.*;
import org.lwjgl.*;
import org.lwjgl.input.Keyboard;
 
public class Map {

	static int displayHeight = 480;
	static int displayWidth = 640;
	static int currHeight = 300;
	ArrayList<Integer> map = new ArrayList<Integer>();
	Random randomHeight = new Random();
	static int b = 0;
	static int offset = 0;
	static int direction = 1;

	public Map() {
		try {
			Display.setDisplayMode(new DisplayMode(displayWidth, displayHeight));
			Display.setTitle("Input");
			Display.create();
		} catch (LWJGLException e) {
			e.printStackTrace();
		}


		glMatrixMode(GL_PROJECTION);
		glLoadIdentity();
		glOrtho(0, displayWidth, displayHeight, 0, 1, -1);
		glMatrixMode(GL_MODELVIEW);
		for(int i=1; i<=displayWidth; i+=10){
			int height = randomHeight.nextInt(60);
			if (height > 0 && height < 20) {
				currHeight += 10;
			}
			if (height > 40 && height < 60) {
				currHeight -= 10;
			}
			if (currHeight < 200) {
				currHeight = 300;
			}
			if (currHeight > displayHeight) {
				currHeight = 300;
			}
			map.add(currHeight);	
		}

		while (!Display.isCloseRequested() && !Keyboard.isKeyDown(Keyboard.KEY_ESCAPE)) {
			glClear(GL_COLOR_BUFFER_BIT);

			// Draw
			for (int i=1; i<=map.size(); i+= 1){
				//System.out.println("Height: "+Integer.valueOf(map.get(i-1).toString()));
				Box.draw(map.get(i-1));
			}
			
			offset += direction * Box.boxWidth;
			
			if(offset >= displayWidth)
				offset = 0;
			if(offset < 0)
				offset = displayWidth-Box.boxWidth;
			
			if (Keyboard.next()) {
				if (Keyboard.isKeyDown(Keyboard.KEY_LEFT)) {
					direction = 1;
				}
				if (Keyboard.isKeyDown(Keyboard.KEY_DOWN)) {
					direction = 0;
				}
				if (Keyboard.isKeyDown(Keyboard.KEY_RIGHT)) {
					direction = -1;
				}
			}

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

		Display.destroy();

	}

	private static class Box {

		public static int boxWidth = 10;

		public static void draw(int h) {

			h = displayHeight - h;
			int x = (b+offset)%displayWidth;
			glBegin(GL_QUADS);
				glVertex2f(x, h); // Upper Left
				glVertex2f(x, displayHeight); // Bottom Left
				glVertex2f(x + boxWidth, displayHeight); // Bottom Right
				glVertex2f(x + boxWidth, h); // Upper Right
			glEnd();
			b += 10;
			
			if(b == displayWidth)
				b = 0;
		}
	}
	
    public static void main(String[] args) {
    	new Map();
    }
}