Rooms

package de.numpad.demo;

import de.numpad.framework.Frapp;
import de.numpad.framework.gui.Display;
import de.numpad.framework.gui.Fonts;
import de.numpad.framework.gui.elements.Button;

public class LevelNoStates extends Frapp {
    private static final long serialVersionUID = 10L;

    public Level level; // Very important: Instance of the abstract class
                        // Since TestLevel1 and TestLevel2 both extend Level, they are in _general_ the same.

    public void start() {
        Display.size(20 * (Level.TILESIZE+1), 10 * (Level.TILESIZE +1) + 100);

        level = new TestLevel1(); // Instantiate level as TestLevel1

        GUI.add(new Button(10, Display.height - 90, 210, 60, "Change World", 2) {
            public void onCreate() {
                this.font = Fonts.thin_dark;
            }
            public void onClick(int button) {
                if (level.id == 1) { // If the current level is 1
                    level = new TestLevel2(); // change it to 2
                } else if (level.id == 2) { // If the current level is 2
                    level = new TestLevel1(); // change it to 1
                }
            }
        });
    }

    public void render() {
        Display.background(51);
        Display.smooth();

        level.display(); // render the level, both levels could be rendered totally different, if you want to do so.

        Display.GUI();
    }

    public static void main(String[] args) {
        Frapp.build(new LevelNoStates(), "Levels");
    }
}

abstract class Level { // An abstract class is important, it is the base frame of the level
    public int[][] block; // hold a 2 dimensional array of ints representing blocks
    public int width, height; // how wide and high the level is

    public int id = -1; // the current id of the level, used to differentiate the levels

    public static final int TILESIZE = 32; // the normal size per tile, change it if you want to ;)
    public static final int BLOCK_AIR = 0, BLOCK_SOLID = 1; // the block types


    public Level(int width, int height) { // a basic constructor
        this.width = width;
        this.height = height;

        block = new int[width][height]; // initialize the array
    }

    public void display() {
        for (int x = 0; x < width; x++) { // for every row...
            for (int y = 0; y < height; y++) { // ...check each part in the column...
                Display.color(45 + 200 * block[x][y]); // ...and set the color depending on the tile id.
                Display.fill();

                Display.rect(x * (TILESIZE +1), y * (TILESIZE +1), TILESIZE, TILESIZE); // draw a rect for each block.
            }
        }
    }
}
class TestLevel1 extends Level { // important! the Level needs to extend the base frame, or "use its form"

    public TestLevel1() {
        super(20, 10); // call the constructor -> set width and height and initialize the blocks

        this.id = 1; // id for each level: TestLevel1 has the id 1, and I think you can guess about TestLevel2. Right, 2!

        for (int x = 0; x < width; x++) {
            block[x][4] = BLOCK_SOLID; // Set every block in the 4th row solid.
        }
    }
}

class TestLevel2 extends Level { // extend again, same form, you know

    public TestLevel2() {
        super(20, 10); // constructor again

        this.id = 2; // id = 2 to differentiate them

        for (int x = 0; x < width; x++) {
            block[x][1] = BLOCK_SOLID; // every block in the first(actually second, because we start counting at 0) row shall be solid!
        }
        for (int y = 0; y < height; y++) {
            block[1][y] = BLOCK_SOLID; // every block in the first...
            block[5][y] = BLOCK_SOLID; // and fifth column shall be solid.
        }
    }
}