Java tutorial
/******************************************************************************* * Copyright 2011 See AUTHORS file. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. ******************************************************************************/ import com.badlogic.gdx.ApplicationAdapter; import com.badlogic.gdx.Gdx; import com.badlogic.gdx.Input.Keys; import com.badlogic.gdx.graphics.GL20; import com.badlogic.gdx.graphics.OrthographicCamera; import com.badlogic.gdx.graphics.Texture; import com.badlogic.gdx.graphics.g2d.Animation; import com.badlogic.gdx.graphics.g2d.Batch; import com.badlogic.gdx.graphics.g2d.TextureRegion; import com.badlogic.gdx.maps.tiled.TiledMap; import com.badlogic.gdx.maps.tiled.TiledMapTileLayer; import com.badlogic.gdx.maps.tiled.TiledMapTileLayer.Cell; import com.badlogic.gdx.maps.tiled.TmxMapLoader; import com.badlogic.gdx.maps.tiled.renderers.OrthogonalTiledMapRenderer; import com.badlogic.gdx.math.Rectangle; import com.badlogic.gdx.math.Vector2; import com.badlogic.gdx.utils.Array; import com.badlogic.gdx.utils.Pool; /** Super Mario Brothers like very basic platformer, using a tile map build via <a href="http://www.mapeditor.org/">Tiled</a> and a * tileset and sprites by <a href="http://www.vickiwenderlich.com/">Vicky Wenderlich</a></p> * * Shows simple platformer collision detection as well as on-the-fly map modifications through destructable blocks! * @author mzechner */ public class MyGdxGame extends ApplicationAdapter { /** The player character, has state and state time, */ static class Koala { static float WIDTH; static float HEIGHT; static float MAX_VELOCITY = 10f; static float JUMP_VELOCITY = 40f; static float DAMPING = 0.87f; enum State { Standing, Walking, Jumping } final Vector2 position = new Vector2(); final Vector2 velocity = new Vector2(); State state = State.Walking; float stateTime = 0; boolean facesRight = true; boolean grounded = false; } private TiledMap map; private OrthogonalTiledMapRenderer renderer; private OrthographicCamera camera; private Texture koalaTexture; private Animation stand; private Animation walk; private Animation jump; private Koala koala; private Pool<Rectangle> rectPool = new Pool<Rectangle>() { @Override protected Rectangle newObject() { return new Rectangle(); } }; private Array<Rectangle> tiles = new Array<Rectangle>(); private static final float GRAVITY = -2.5f; @Override public void create() { // load the koala frames, split them, and assign them to Animations koalaTexture = new Texture("koalio.png"); TextureRegion[] regions = TextureRegion.split(koalaTexture, 18, 26)[0]; stand = new Animation(0, regions[0]); jump = new Animation(0, regions[1]); walk = new Animation(0.15f, regions[2], regions[3], regions[4]); walk.setPlayMode(Animation.PlayMode.LOOP_PINGPONG); // figure out the width and height of the koala for collision // detection and rendering by converting a koala frames pixel // size into world units (1 unit == 16 pixels) Koala.WIDTH = 1 / 16f * regions[0].getRegionWidth(); Koala.HEIGHT = 1 / 16f * regions[0].getRegionHeight(); // load the map, set the unit scale to 1/16 (1 unit == 16 pixels) map = new TmxMapLoader().load("level1.tmx"); renderer = new OrthogonalTiledMapRenderer(map, 1 / 16f); // create an orthographic camera, shows us 30x20 units of the world camera = new OrthographicCamera(); camera.setToOrtho(false, 30, 20); camera.update(); // create the Koala we want to move around the world koala = new Koala(); koala.position.set(20, 20); } @Override public void render() { // clear the screen Gdx.gl.glClearColor(0.7f, 0.7f, 1.0f, 1); Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT); // get the delta time float deltaTime = Gdx.graphics.getDeltaTime(); // update the koala (process input, collision detection, position update) updateKoala(deltaTime); // let the camera follow the koala, x-axis only camera.position.x = koala.position.x; camera.update(); // set the tile map rendere view based on what the // camera sees and render the map renderer.setView(camera); renderer.render(); // render the koala renderKoala(deltaTime); } private Vector2 tmp = new Vector2(); private void updateKoala(float deltaTime) { if (deltaTime == 0) return; koala.stateTime += deltaTime; // check input and apply to velocity & state if ((Gdx.input.isKeyPressed(Keys.SPACE) || isTouched(0.5f, 1)) && koala.grounded) { koala.velocity.y += Koala.JUMP_VELOCITY; koala.state = Koala.State.Jumping; koala.grounded = false; } if (Gdx.input.isKeyPressed(Keys.LEFT) || Gdx.input.isKeyPressed(Keys.A) || isTouched(0, 0.25f)) { koala.velocity.x = -Koala.MAX_VELOCITY; if (koala.grounded) koala.state = Koala.State.Walking; koala.facesRight = false; } if (Gdx.input.isKeyPressed(Keys.RIGHT) || Gdx.input.isKeyPressed(Keys.D) || isTouched(0.25f, 0.5f)) { koala.velocity.x = Koala.MAX_VELOCITY; if (koala.grounded) koala.state = Koala.State.Walking; koala.facesRight = true; } // apply gravity if we are falling koala.velocity.add(0, GRAVITY); // clamp the velocity to the maximum, x-axis only if (Math.abs(koala.velocity.x) > Koala.MAX_VELOCITY) { koala.velocity.x = Math.signum(koala.velocity.x) * Koala.MAX_VELOCITY; } // clamp the velocity to 0 if it's < 1, and set the state to standign if (Math.abs(koala.velocity.x) < 1) { koala.velocity.x = 0; if (koala.grounded) koala.state = Koala.State.Standing; } // multiply by delta time so we know how far we go // in this frame koala.velocity.scl(deltaTime); // perform collision detection & response, on each axis, separately // if the koala is moving right, check the tiles to the right of it's // right bounding box edge, otherwise check the ones to the left Rectangle koalaRect = rectPool.obtain(); koalaRect.set(koala.position.x, koala.position.y, Koala.WIDTH, Koala.HEIGHT); int startX, startY, endX, endY; if (koala.velocity.x > 0) { startX = endX = (int) (koala.position.x + Koala.WIDTH + koala.velocity.x); } else { startX = endX = (int) (koala.position.x + koala.velocity.x); } startY = (int) (koala.position.y); endY = (int) (koala.position.y + Koala.HEIGHT); getTiles(startX, startY, endX, endY, tiles); koalaRect.x += koala.velocity.x; for (Rectangle tile : tiles) { if (koalaRect.overlaps(tile)) { koala.velocity.x = 0; break; } } koalaRect.x = koala.position.x; // if the koala is moving upwards, check the tiles to the top of it's // top bounding box edge, otherwise check the ones to the bottom if (koala.velocity.y > 0) { startY = endY = (int) (koala.position.y + Koala.HEIGHT + koala.velocity.y); } else { startY = endY = (int) (koala.position.y + koala.velocity.y); } startX = (int) (koala.position.x); endX = (int) (koala.position.x + Koala.WIDTH); getTiles(startX, startY, endX, endY, tiles); koalaRect.y += koala.velocity.y; for (Rectangle tile : tiles) { if (koalaRect.overlaps(tile)) { // we actually reset the koala y-position here // so it is just below/above the tile we collided with // this removes bouncing :) if (koala.velocity.y > 0) { koala.position.y = tile.y - Koala.HEIGHT; // we hit a block jumping upwards, let's destroy it! TiledMapTileLayer layer = (TiledMapTileLayer) map.getLayers().get("walls"); layer.setCell((int) tile.x, (int) tile.y, null); } else { koala.position.y = tile.y + tile.height; // if we hit the ground, mark us as grounded so we can jump koala.grounded = true; } koala.velocity.y = 0; break; } } rectPool.free(koalaRect); // unscale the velocity by the inverse delta time and set // the latest position koala.position.add(koala.velocity); koala.velocity.scl(1 / deltaTime); // Apply damping to the velocity on the x-axis so we don't // walk infinitely once a key was pressed koala.velocity.x *= Koala.DAMPING; } private boolean isTouched(float startX, float endX) { // check if any finge is touch the area between startX and endX // startX/endX are given between 0 (left edge of the screen) and 1 (right edge of the screen) for (int i = 0; i < 2; i++) { float x = Gdx.input.getX(i) / (float) Gdx.graphics.getWidth(); if (Gdx.input.isTouched(i) && (x >= startX && x <= endX)) { return true; } } return false; } private void getTiles(int startX, int startY, int endX, int endY, Array<Rectangle> tiles) { TiledMapTileLayer layer = (TiledMapTileLayer) map.getLayers().get("walls"); rectPool.freeAll(tiles); tiles.clear(); for (int y = startY; y <= endY; y++) { for (int x = startX; x <= endX; x++) { Cell cell = layer.getCell(x, y); if (cell != null) { Rectangle rect = rectPool.obtain(); rect.set(x, y, 1, 1); tiles.add(rect); } } } } private void renderKoala(float deltaTime) { // based on the koala state, get the animation frame TextureRegion frame = null; switch (koala.state) { case Standing: frame = stand.getKeyFrame(koala.stateTime); break; case Walking: frame = walk.getKeyFrame(koala.stateTime); break; case Jumping: frame = jump.getKeyFrame(koala.stateTime); break; } // draw the koala, depending on the current velocity // on the x-axis, draw the koala facing either right // or left Batch batch = renderer.getBatch(); batch.begin(); if (koala.facesRight) { batch.draw(frame, koala.position.x, koala.position.y, Koala.WIDTH, Koala.HEIGHT); } else { batch.draw(frame, koala.position.x + Koala.WIDTH, koala.position.y, -Koala.WIDTH, Koala.HEIGHT); } batch.end(); } @Override public void dispose() { } }