Force applied - Libgdx - java

Hi guys so i was trying to make this simple game in libgdx and everything was fine until i noticed that i need to apply a big force just to make the player move a little is there any way to make it need less force?
This is my PlayScreen where I render the player.
`
private Logang game;
//basic playscreen variables
private OrthographicCamera gamecam;
private Viewport gamePort;
//Box2d variables
private World world;
private Box2DDebugRenderer b2dr;
boolean drawn = true;
private Player p;
private int pX = 100, pY = 300;
public GameScreen(Logang game) {
this.game = game;
//create cam used to follow mario through cam world
gamecam = new OrthographicCamera();
gamecam.update();
Box2D.init();
//create our Box2D world, setting no gravity in X, -10 gravity in Y, and allow bodies to sleep
world = new World(new Vector2(0, Logang.GRAVITY), true);
//allows for debug lines of our box2d world.
b2dr = new Box2DDebugRenderer();
//create a FitViewport to maintain virtual aspect ratio despite screen size
gamePort = new ScalingViewport(Scaling.fill, Logang.GWIDTH, Logang.GHEIGHT, gamecam);
p = new Player(new Sprite(new Texture("hud_p3.png")), world, pX, pY, 1);
//initially set our gamcam to be centered correctly at the start of of map
gamecam.position.set(gamePort.getWorldWidth() / 2 , gamePort.getWorldHeight() / 2, 0);
line();
}
#Override
public void show() {
}
public void update(float dt) {
//handle user input first
p.update(dt);
//update our gamecam with correct coordinates after changes
}
#Override
public void render(float delta) {
//separate our update logic from render
update(delta);
//Clear the game screen with Black
Gdx.gl.glClearColor(0, 0, 0, 1);
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
world.step(1f / 60f, 6, 2);
gamecam.position.set(p.getSprite().getX(),Logang.GHEIGHT / 2, 0); // x and y could be changed by Keyboard input for example
gamecam.update();
game.getBatch().setProjectionMatrix(gamecam.combined);
//renderer our Box2DDebugLines
b2dr.render(world, gamecam.combined);
System.out.println("Player x: " + p.getSprite().getX() + " Camera X: " + gamecam.position.x + " Body X: " + p.getBody().getPosition().x);
//System.out.println("Player y: " + p.getSprite().getY() + " Camera Y: " + gamecam.position.y + " Body Y: " + p.getBody().getPosition().y);
game.getBatch().begin();
if (p.getBody() != null)
p.render(game.getBatch());
EntityManager.renderTerra(game.getBatch(), delta);
game.getBatch().end();
}
public void line() {
Texture tmp = new Texture("hud_p3.png");
tmp.setWrap(Texture.TextureWrap.MirroredRepeat, Texture.TextureWrap.MirroredRepeat);
for (int i = 0; i < 50; i++) {
EntityManager.add(new Ground(new Sprite(tmp), world, (int)(i * Logang.TILE), 1, 2));
}
// EntityManager.changeSize(((Logang.TILE) * 5),Logang.TILE);
}
#Override
public void resize(int width, int height) {
//updated our game viewport
gamePort.update(width, height);
}
public World getWorld() {
return world;
}
#Override
public void pause() {
}
#Override
public void resume() {
}
#Override
public void hide() {
}
#Override
public void dispose() {
world.dispose();
b2dr.dispose();
}`
And this is my Entity class which is extended by the player
private World world;
private Sprite sprite;
private Body body;
private int tipo;
public Entity(Sprite sprite, World world, int x, int y, int tipo){
this.sprite = sprite;
this.world = world;
getSprite().setPosition(x, y);
getSprite().setSize(Logang.TILE , Logang.TILE);
define(tipo);
this.tipo = tipo;
}
public void update(float dt){
if(Gdx.input.isKeyPressed(Input.Keys.LEFT)){
getBody().applyLinearImpulse(new Vector2(-Logang.PPM,0f), getBody().getWorldCenter(), true);
}
if(Gdx.input.isKeyPressed(Input.Keys.RIGHT)){
getBody().applyLinearImpulse(new Vector2(Logang.PPM,0f), getBody().getWorldCenter(), true);
}
if(Gdx.input.isKeyPressed(Input.Keys.SPACE)){
getBody().applyLinearImpulse(0f,-Logang.GRAVITY * Logang.PPM, getBody().getPosition().x, getBody().getPosition().y, true);
}
}
}
public void define(int tipo){
BodyDef bdef = new BodyDef();
bdef.position.set((getSprite().getX() + getSprite().getWidth() / 2), (getSprite().getY() + getSprite().getHeight() / 2));
switch(tipo){
case 1: {
bdef.type = BodyDef.BodyType.DynamicBody;
break;
}
case 2:{
bdef.type = BodyDef.BodyType.StaticBody;
break;
}
case 3:{
bdef.type = BodyDef.BodyType.DynamicBody;
break;
}
}
body = world.createBody(bdef);
FixtureDef fdef = new FixtureDef();
PolygonShape shape = new PolygonShape();
shape.setAsBox(getSprite().getWidth() / 2, getSprite().getHeight() / 2);
fdef.shape = shape;
body.createFixture(fdef);
body.setUserData(this);
shape.dispose();
}
public void render(SpriteBatch batch){
if(tipo != 2) {
float posX = getBody().getPosition().x;
float posY = getBody().getPosition().y;
getSprite().setPosition(posX - getSprite().getWidth() / 2, posY - getSprite().getHeight() / 2);
}
getSprite().draw(batch);
}
public Sprite getSprite() {
return sprite;
}
public void setSprite(Sprite sprite) {
this.sprite = sprite;
}
public Body getBody() {
return body;
}
public void setBody(Body body) {
this.body = body;
}
}
Thank everybody for any answer

Box2D is a physics engine so tries to imitate real life physics in game. So if your object is large and heavy it will require a large amount of force to move it.
To make it so your objects can move with less force you can either make them smaller or change the density of them to make them lighter which will allow them to be moved with less force.
To change the density you set it in the fixtureDefinition
FixtureDef fdef = new FixtureDef();
fdef.density=0.1f; // (weight: range 0.01 to 1 is good)
fdef.friction = 0.7f; // (how slippery it is: 0=like ice 1 = like rubber)
fdef.restitution = 0.3f; //(how bouncy is it 0= not bouncy 1 = 100% bouncy)
Another thing I noticed is you are using what seems to be a PixelPerMeter ratio for your forces in this line:
getBody().applyLinearImpulse(new Vector2(-Logang.PPM,0f), getBody().getWorldCenter(), true);
You shouldn't use this value for your forces as this is for converting box2d world to render coordinates and you can use the following code to apply the force to the center.
getBody().applyLinearImpulse(new Vector2((10f*getBody().getMass()),0f), getBody().getWorldCenter(), true);
As a side note the impulse is used to create a single application of force whereas body.applyForceToCenter(force,wake); is used to apply a constant force over time. Try with the apply force method and see if this helps.

Related

Extreme Zoom with gamecam - Libgdx

Hi guys i'm quite new to libgdx I tried to make the camera follow the player.
Trying to do so i read online that i had to add this line of code.
game.getBatch().setProjectionMatrix(gamecam.combined);
By doing so i noticed that my game was really zoomed i tried to dezoom it but i was not able to make it work. Do you guys have any suggestion?
This is my GameScreen where i render the player.
`public class GameScreen implements Screen {
private Logang game;
//basic playscreen variables
private OrthographicCamera gamecam;
private Viewport gamePort;
//Box2d variables
private World world;
private Box2DDebugRenderer b2dr;
boolean drawn = true;
private Player p;
private int pX = 100, pY = 300;
public GameScreen(Logang game) {
this.game = game;
//create cam used to follow mario through cam world
gamecam = new OrthographicCamera(Logang.GWIDTH, Logang.GHEIGHT);
gamecam.update();
//create our Box2D world, setting no gravity in X, -10 gravity in Y, and allow bodies to sleep
world = new World(new Vector2(0, Logang.GRAVITY), true);
//allows for debug lines of our box2d world.
b2dr = new Box2DDebugRenderer();
//create a FitViewport to maintain virtual aspect ratio despite screen size
gamePort = new ScalingViewport(Scaling.fill, Logang.GWIDTH / Logang.PPM, Logang.GHEIGHT / Logang.PPM, gamecam);
p = new Player(new Sprite(new Texture("badlogic.jpg")), world, pX, pY, 1);
//initially set our gamcam to be centered correctly at the start of of map
//gamecam.position.set(gamePort.getWorldWidth() / 2, gamePort.getWorldHeight() / 2, 0);
line();
}
#Override
public void show() {
}
public void update(float dt) {
//handle user input first
p.update(dt);
//update our gamecam with correct coordinates after changes
/*gamecam.position.set(p.getSprite().getX(),0,0);
gamecam.update();*/
}
#Override
public void render(float delta) {
//separate our update logic from render
update(delta);
//Clear the game screen with Black
Gdx.gl.glClearColor(0, 0, 0, 1);
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
world.step(1f / 60f, 6, 2);
gamecam.position.set(p.getSprite().getX(), p.getSprite().getY(), 0); // x and y could be changed by Keyboard input for example
//gamecam.position.set(p.getSprite().getX(), p.getSprite().getY(), 0);
gamecam.update();
game.getBatch().setProjectionMatrix(gamecam.combined);
//renderer our Box2DDebugLines
b2dr.render(world, gamecam.combined);
System.out.println("Player x: " + p.getSprite().getX() + " Camera X: " + gamecam.position.x + " Body X: " + p.getBody().getPosition().x);
//System.out.println("Player y: " + p.getSprite().getY() + " Camera Y: " + gamecam.position.y + " Body Y: " + p.getBody().getPosition().y);
game.getBatch().begin();
if (p.getBody() != null)
p.render(game.getBatch());
EntityManager.renderTerra(game.getBatch(), delta);
game.getBatch().end();
}
public void line() {
Texture tmp = new Texture("dirt.png");
tmp.setWrap(Texture.TextureWrap.MirroredRepeat, Texture.TextureWrap.MirroredRepeat);
for (int i = 0; i < 10; i++) {
EntityManager.add(new Ground(new Sprite(tmp), world, i * Logang.TILE, 0, 2));
}
//EntityManager.changeSize(Logang.TILE * 5,Logang.TILE);
}
#Override
public void resize(int width, int height) {
//updated our game viewport
gamePort.update(width, height);
}
public World getWorld() {
return world;
}
#Override
public void pause() {
}
#Override
public void resume() {
}
#Override
public void hide() {
}
#Override
public void dispose() {
world.dispose();
b2dr.dispose();
}`
And this is my Entity class which is extended by the Player which i empty for now`
public abstract class Entity {
private World world;
private Sprite sprite;
private Body body;
private int tipo;
public Entity(Sprite sprite, World world, int x, int y, int tipo){
this.sprite = sprite;
this.world = world;
getSprite().setPosition(x, y);
getSprite().setSize(Logang.TILE, Logang.TILE);
define(tipo);
this.tipo = tipo;
}
public abstract void update(float dt);
public void define(int tipo){
BodyDef bdef = new BodyDef();
bdef.position.set((getSprite().getX() + getSprite().getWidth() / 2) / Logang.PPM, (getSprite().getY() + getSprite().getHeight() / 2) / Logang.PPM);
switch(tipo){
case 1: {
bdef.type = BodyDef.BodyType.DynamicBody;
break;
}
case 2:{
bdef.type = BodyDef.BodyType.StaticBody;
break;
}
case 3:{
bdef.type = BodyDef.BodyType.DynamicBody;
break;
}
}
body = world.createBody(bdef);
FixtureDef fdef = new FixtureDef();
PolygonShape shape = new PolygonShape();
shape.setAsBox(getSprite().getWidth() / Logang.PPM / 2, getSprite().getHeight() / Logang.PPM / 2);
fdef.shape = shape;
body.createFixture(fdef);
body.setUserData(this);
shape.dispose();
}
public void render(SpriteBatch batch){
if(tipo != 2) {
float posX = getBody().getPosition().x * Logang.PPM;
float posY = getBody().getPosition().y * Logang.PPM;
getSprite().setPosition(posX - getSprite().getWidth() / 2, posY - getSprite().getHeight() / 2);
}
getSprite().draw(batch);
}
public Sprite getSprite() {
return sprite;
}
public void setSprite(Sprite sprite) {
this.sprite = sprite;
}
public Body getBody() {
return body;
}
public void setBody(Body body) {
this.body = body;
}`
If I remove that line at the start the game sizes are good but my camera doesn't follow my player.
Thanks for the answer and sorry if the question was not well asked.
1) If your viewport dimensions divided by Logang.PPM then all Textures size should be also divided by Logang.PPM.
Logang.TILE should be float and divided by Logang.PPM
Player sprite also should be resized**.
2) To follow player try dividing gamecam resolution by Logang.PPM.
Initialize it like this:
gamecam = new OrthographicCamera(Logang.GWIDTH / Logang.PPM, Logang.GHEIGHT / Logang.PPM);
UPD: I found issue, it was in player render method:
float posX = getBody().getPosition().x; // delete * Logang.PPM
float posY = getBody().getPosition().y; // delete * Logang.PPM
The camera takes in two variables: the width and height of the world. That's an important keyword here, as it defines the rendered size of the world. If the width and height of the camera is 300x300, that means there's 300x300 units visible on the screen, even if the screen is 1920x1080.
When you do:
gamecam = new OrthographicCamera(Logang.GWIDTH, Logang.GHEIGHT);
You set the width and height of the camera to a given value.
The second you apply it:
game.getBatch().setProjectionMatrix(gamecam.combined);
the batch you use to render uses the projection matrix of the camera, meaning it converts screen coordinates to world coordinates based on the width and height of what's visible at once. For an instance 300x300.
If you think the world is too small (meaning what you render shows up as too big) you can of course zoom out by adding a scale factor, but you can also increase the width and height of the camera. I have no clue what you set the width and height to, but if you increase the width and height it'll probably work.
And as I already mentioned, the world coordinates can be different from the screen coordinates.

Java libGDX Game - Animation doesn't flip

I have a animation which i want to flip to the left if key LEFT is pressed, but it doesnt stay flipped. It only flips like 1 frame then turns back again.
Here is my GameScreen where i draw everything:
public class GameScreen extends ScreenManager{
//For the view of the game and the rendering
private SpriteBatch batch;
private OrthographicCamera cam;
//DEBUG
private Box2DDebugRenderer b2dr;
//World, Player and so on
private GameWorld world;
private Player player;
private Ground ground;
//player animations
private TextureRegion currFrame;
public static float w, h;
public GameScreen(Game game) {
super(game);
//vars
w = Gdx.graphics.getWidth();
h = Gdx.graphics.getHeight();
//view and rendering
batch = new SpriteBatch();
cam = new OrthographicCamera();
cam.setToOrtho(false, w/2, h/2);
//debug
b2dr = new Box2DDebugRenderer();
//world, bodies ...
world = new GameWorld();
player = new Player(world);
ground = new Ground(world);
}
#Override
public void pause() {
}
#Override
public void show() {
}
#Override
public void render(float delta) {
//clearing the screen
Gdx.gl.glClearColor(0, 0, 0, 1);
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
//updating
update(Gdx.graphics.getDeltaTime());
player.stateTime += Gdx.graphics.getDeltaTime();
//render
batch.setProjectionMatrix(cam.combined);
currFrame = Player.anim.getKeyFrame(Player.stateTime, true);
batch.begin();
batch.draw(currFrame, Player.body.getPosition().x * PPM - 64, Player.getBody().getPosition().y * PPM- 72);
batch.end();
//debug
b2dr.render(GameWorld.getWorld(), cam.combined.scl(PPM));
}
#Override
public void resize(int width, int height) {
}
#Override
public void hide() {
}
#Override
public void dispose() {
}
#Override
public void onKlick(float delta) {
}
public void update(float delta){
world.update(delta);
updateCam(delta);
Player.keyInput(delta);
System.out.println("X-POS" + Player.getBody().getPosition().x);
System.out.println("Y-POS" + Player.getBody().getPosition().y);
}
public void updateCam(float delta){
Vector3 pos = cam.position;
pos.x = Player.getBody().getPosition().x * PPM;
pos.y = Player.getBody().getPosition().y * PPM;
cam.position.set(pos);
cam.update();
}
}
and this is the Player class where the animation is:
public class Player {
public static Body body;
public static BodyDef def;
private FixtureDef fd;
//textures
public static Texture texture;
public static Sprite sprite;
public static TextureRegion[][] region;
public static TextureRegion[] idle;
public static Animation<TextureRegion> anim;
public static float stateTime;
//set form
private PolygonShape shape;
private GameScreen gs;
public Player(GameWorld world){
texture = new Texture(Gdx.files.internal("player/char_animation_standing.png"));
region = TextureRegion.split(texture, texture.getWidth() / 3, texture.getHeight() / 2);
idle = new TextureRegion[6];
int index = 0;
for(int i = 0; i < 2; i++){
for(int j = 0; j < 3; j++){
sprite = new Sprite(region[i][j]);
idle[index++] = sprite;
}
}
anim = new Animation<TextureRegion>(1 / 8f, idle);
stateTime = 0f;
def = new BodyDef();
def.fixedRotation = true;
def.position.set(gs.w / 4, gs.h / 4);
def.type = BodyType.DynamicBody;
body = world.getWorld().createBody(def);
shape = new PolygonShape();
shape.setAsBox(32 / 2 / PPM, 64/ 2 / PPM);
fd = new FixtureDef();
fd.shape = shape;
fd.density = 30;
body.createFixture(fd);
shape.dispose();
}
public static Body getBody() {
return body;
}
public static BodyDef getDef() {
return def;
}
public static Texture getTexture() {
return texture;
}
public static void keyInput(float delta){
int horizonForce = 0;
if(Gdx.input.isKeyJustPressed(Input.Keys.UP)){
body.applyLinearImpulse(0, 300f, body.getWorldCenter().x, body.getWorldCenter().y, true);
//body.applyForceToCenter(0, 1200f, true);
System.out.println("PRESSED");
}
if(Gdx.input.isKeyPressed(Input.Keys.LEFT)){
horizonForce -= 1;
sprite.flip(!sprite.isFlipX(), sprite.isFlipY());
}
if(Gdx.input.isKeyPressed(Input.Keys.RIGHT)){
horizonForce += 1;
}
body.setLinearVelocity(horizonForce * 20, body.getLinearVelocity().y);
}
}
thank you in advance and any answer is appreciated :D
Your sprite variable contain only one frame at the time of pressing left key. So, it flip that current sprite of your animation frame.
To solve the Problem you have to flip all the animation frame on pressing the left key.
You're only flipping last frame of Animation by sprite reference, You need to flip all frames of your Animation anim. You can flip in this way :
if(keycode== Input.Keys.RIGHT) {
for (TextureRegion textureRegion:anim.getKeyFrames())
if(!textureRegion.isFlipX()) textureRegion.flip(true,false);
}
else if(keycode==Input.Keys.LEFT) {
for (TextureRegion textureRegion:anim.getKeyFrames())
if(textureRegion.isFlipX()) textureRegion.flip(true,false);
}

Libgdx: how to detect if an enemy was touched?

I want to add to the score of my game +1 when an enemy was touched, I tried two methods addListener and touchDown but not worked for me or I didn't use them right.
How can I do that my (enemy object is linked to an userData and Actor classes, I regroup many different sizes for my enemy in an enum class also those enemies move from the top of the screen to bot. How to detect if an enemy was touched?
public class GameStage extends Stage {
// This will be our viewport measurements while working with the debug renderer
private static final int VIEWPORT_WIDTH = 13;
private static final int VIEWPORT_HEIGHT = 20;
private World world;
private Ground ground;
private Enemy enemy;
private final float TIME_STEP = 1 / 300f;
private float accumulator = 0f;
private Rectangle bounds;
private Vector3 touchPoint = new Vector3();;
private int score;
private String yourScoreName;
BitmapFont yourBitmapFontName;
private SpriteBatch batch;
private OrthographicCamera camera;
private Box2DDebugRenderer renderer;
public GameStage() {
world = WorldUtils.createWorld();
renderer = new Box2DDebugRenderer();
Gdx.input.setInputProcessor(this);
batch = new SpriteBatch();
score = 0;
yourScoreName = "score: 0";
yourBitmapFontName = new BitmapFont();
setUpWorld();
setUpCamera();
}
public void setUpWorld(){
world = WorldUtils.createWorld();
setUpGround();
createEnemy();
}
private void setUpGround(){
ground = new Ground (WorldUtils.createGround(world));
addActor(ground);
}
private void createEnemy() {
enemy = new Enemy(WorldUtils.createEnemy(world));
// (1) *****using addListener method
enemy.addListener(new InputListener()
{
#Override
public boolean touchDown(InputEvent event, float x, float y,
int pointer, int button)
{
score++;
yourScoreName = "score: " + score;
return true;
}
});
/*enemy.addListener(new ClickListener() {
public void clicked() {
world.destroyBody(enemy.getBody());
}});*/
//bounds = new Rectangle(enemy.getX(), enemy.getY(), enemy.getWidth(), enemy.getHeight());
addActor(enemy);
}
private void setUpCamera() {
camera = new OrthographicCamera(VIEWPORT_WIDTH, VIEWPORT_HEIGHT);
camera.position.set(camera.viewportWidth / 2, camera.viewportHeight / 2, 0f);
camera.update();
}
#Override
public void act(float delta) {
super.act(delta);
checkEnemy();
// Fixed timestep
accumulator += delta;
while (accumulator >= delta) {
world.step(TIME_STEP, 6, 2);
accumulator -= TIME_STEP;
}
//TODO: Implement interpolation
}
private void checkEnemy(){
final Body body = enemy.getBody();
UserData userData = enemy.getUserData();
bounds = new Rectangle(enemy.getBody().getPosition().x, enemy.getBody().getPosition().y, enemy.getUserData().getWidth(), enemy.getUserData().getHeight());
// bounds = new Rectangle(body.getPosition().x, body.getPosition().y,userData.getWidth() ,userData.getHeight());
if (!BodyUtils.enemyInBounds(body,userData)){
world.destroyBody(body);
createEnemy();}
}
public World getWorld(){
return world;
}
// (2) ****using TouchDown method
#Override
public boolean touchDown(int x, int y, int pointer, int button) {
// Need to get the actual coordinates
translateScreenToWorldCoordinates(x, y);
// score++;
// yourScoreName = "score: " + score;
if(enemyTouched(touchPoint.x,touchPoint.y)){
// world.destroyBody(enemy.getBody());
score++;
yourScoreName = "score: " + score;
}
return super.touchDown(x, y, pointer, button);
}
private boolean enemyTouched(float x, float y) {
return bounds.contains(x, y);
}
private void translateScreenToWorldCoordinates(int x, int y) {
getCamera().unproject(touchPoint.set(x, y, 0));
}
#Override
public void draw() {
super.draw();
batch.begin();
yourBitmapFontName.setColor(1.0f, 1.0f, 1.0f, 1.0f);
yourBitmapFontName.draw(batch, yourScoreName, 25, 100);
batch.end();
enemy.setBounds(enemy.getBody().getPosition().x,enemy.getBody().getPosition().y,enemy.getUserData().getWidth(),enemy.getUserData().getHeight());
renderer.render(world, camera.combined);
}
}
A screen from my game:
It should work the way you did it (with the addListener() method). But you have to set the correct bounds of the actor (width, height, position): actor.setBounds(x, y, width, height). I would use the body to get these values. You can also use a ClickListener instead of the InputListener.

Getting the computer to know when a sprite walks over a specific tile in a tmx map

I have a Circle shape that is going to represent the character I will play and control. I have a tmx map, and in the map there are red squares that are meant to represent "fences". The fences are in each corner of the map, inside the fences I have the ground that looks the same as the rest of the ground in the map, but I want to make it so that the game knows when the character is standing on those tiles in the map. can anyone help me? I don't know if it will help but here is the code:
public class PlayScreen implements Screen{
private Game game;
private OrthographicCamera gamecam;
private Viewport gamePort;
private TmxMapLoader mapLoader;
private TiledMap map;
OrthogonalTiledMapRenderer renderer;
//Box#d variables
private World world;
private Box2DDebugRenderer b2dr;
private Hero hero;
private ArrayList<Rectangle> specGroundList;
private boolean heroOnGround;
public PlayScreen(BasicGame game){
this.game = game;
gamecam = new OrthographicCamera();
gamePort = new FitViewport(BasicGame.V_WIDTH, BasicGame.V_HEIGHT, gamecam);
mapLoader = new TmxMapLoader();
map = mapLoader.load("Basic Map.tmx");
renderer = new OrthogonalTiledMapRenderer(map);
gamecam.position.set(gamePort.getWorldWidth() / 2, gamePort.getWorldHeight() / 2, 0);
world = new World(new Vector2(0, 0), true);
b2dr = new Box2DDebugRenderer();
hero = new Hero(world, this);
specGroundList = new ArrayList<Rectangle>();
world.setContactListener(new WorldContactListener());
BodyDef bdef = new BodyDef();
PolygonShape shape = new PolygonShape();
FixtureDef fdef = new FixtureDef();
Body body;
//create fence bodies/fixtures
for(MapObject object: map.getLayers().get(3).getObjects().getByType(RectangleMapObject.class)){
Rectangle rect = ((RectangleMapObject) object).getRectangle();
bdef.type = BodyDef.BodyType.StaticBody;
bdef.position.set(rect.getX() + rect.getWidth() / 2, rect.getY() + rect.getHeight() / 2);
body = world.createBody(bdef);
shape.setAsBox(rect.getWidth() / 2, rect.getHeight() / 2);
fdef.shape = shape;
body.createFixture(fdef);
}
//create special ground bodies/fixtures
for(MapObject object: map.getLayers().get(2).getObjects().getByType(RectangleMapObject.class)) {
Rectangle rect = ((RectangleMapObject) object).getRectangle();
bdef.type = BodyDef.BodyType.StaticBody;
bdef.position.set(rect.getX() + rect.getWidth() / 2, rect.getY() + rect.getHeight() / 2);
body = world.createBody(bdef);
shape.setAsBox(rect.getWidth() / 2, rect.getHeight() / 2);
fdef.shape = shape;
body.createFixture(fdef);
}
}
#Override
public void render(float delta) {
update(delta);
// Clear the game screen with Black
Gdx.gl.glClearColor(0, 0, 0, 1);
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
renderer.render();
b2dr.render(world, gamecam.combined);
}
#Override
public void show() {
}
public void handleInput(float dt){
if(Gdx.input.isTouched()) {
// gamecam.position.x += 100 * dt;
gamecam.position.y -= 100 * dt;
}
}
public void update(float dt){
handleInput(dt);
world.step(1/60f, 6, 0);
hero.update(dt);
for(Rectangle rect: specGroundList){
}
gamecam.update();
renderer.setView(gamecam);
}
#Override
public void resize(int width, int height) {
gamePort.update(width, height);
}
#Override
public void pause() {
}
#Override
public void resume() {
}
#Override
public void hide() {
}
#Override
public void dispose() {
}
public Viewport getGamePort() {
return gamePort;
}
}
Assuming your hero has a known position, and your regions of special ground are oriented rectangles then can't you just use a boolean function that returns something along the lines of:
Hero.x > rectangle.left & Hero.x < rectangle.right & hero.y > rectangle.bottom & hero.y < rectangle.top

JBox2D + Slick2D - Doesn't collide

UPDATE
I have a hint. That is because the center of the screen in JBox2D is (0, 0). This is so weird because x and y are not from -1 to 1, it depends of the screen size.
This means the Util class I copied from the internet (everybody shared this code) is not up to date. I still need help because I can't find any 'algorithm' to have aspect ratio + screen size dependency.
BASE QUESTION
Since I have added the "slick2D to jbox2D position" and vice versa (it's like position in screen = position in screen / 100 for JBox), I don't get a good result. Screenshots below
I'm explaining with code:
public class Util {
private static final float SCALE = 0.01f; // 1/100 pixels
public static float toPosX(float posX) { return (posX * SCALE); }
public static float toPosY(float posY) { return (-posY * SCALE); }
public static float toScreenX(float posX) { return (posX / SCALE); }
public static float toScreenY(float posY) { return (-posY / SCALE); }
}
Square.java :
public class Square {
private Body body;
private Rectangle rectangle;
Square(World world, BodyType type, Vec2 pos, Vec2 size) {
float x = Util.toPosX(pos.x);
float y = Util.toPosY(pos.y);
float sx = Util.toPosX(size.x);
float sy = Util.toPosY(size.y);
//body definition
BodyDef bd = new BodyDef();
bd.position.set(x, y);
bd.type = type;
//define shape of the body.
PolygonShape cs = new PolygonShape();
cs.setAsBox(sx, sy);
//define fixture of the body.
FixtureDef fd = new FixtureDef();
fd.shape = cs;
fd.density = 1f;
fd.friction = 0.3f;
fd.restitution = 1.0f;
//create the body and add fixture to it
body = world.createBody(bd);
body.createFixture(fd);
rectangle = new Rectangle(0, 0, size.x, size.y);
rectangle.setLocation(pos.x, pos.y);
}
public Body getBody() { return this.body; }
public Rectangle getRectangle() { return this.rectangle; }
}
And finally my display class:
public class DisplayManager extends BasicGame {
private GameManager gameManager;
private Body b1, b2;
private Rectangle r1, r2;
private World world;
public DisplayManager(GameManager game) {
super("Title");
this.gameManager = game;
}
#Override
public void init(GameContainer container) throws SlickException {
this.gameManager.initPlayersSprites();
world = new World(new Vec2(0, -10));
Square s1, s2;
s1 = new Square(world, BodyType.STATIC, new Vec2(10, 800), new Vec2(1900, 30));
b1 = s1.getBody();
r1 = s1.getRectangle();
s2 = new Square(world, BodyType.DYNAMIC, new Vec2(945, 200), new Vec2(30, 30));
b2 = s2.getBody();
r2 = s2.getRectangle();
}
public void render(GameContainer container, Graphics g) throws SlickException {
float step = 1.0f / 600.0f;
world.step(step, 6, 2);
r1.setLocation(Util.toScreenX(b1.getPosition().x), Util.toScreenY(b1.getPosition().y));
r2.setLocation(Util.toScreenX(b2.getPosition().x), Util.toScreenY(b2.getPosition().y));
g.draw(r1);
g.draw(r2);
}
}
Here is the result :
first frame :
http://i.stack.imgur.com/WgQPK.png
some frames later :
http://i.stack.imgur.com/a1XyL.png
(the ground didn't move, it's just another screenshot took from my hand)
In other words, the cube falls down like for ever. I debugged the position of the cube and it doesn't stop to go down.
With Slick2D DebugDraw it doesn't help because the cube goes through the ground anyway.
Please note that in JBox2D, it worked with pixels measurements (that was not accurate at all but collisions worked well)
That was because of the negative size. (toPoxY reverse the y pos)

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