Develop Reference

How do I animate my characters' movement in a LibGDX isometric RPG?

I want my characters move once to nearby tiles with one key press, and be rendered within the movements, so their movements would be animated. But when I tried this, they just teleport to the target tiles with some weird shakings. I think the problem is the ptime/delta variable didn't work as I thought, but I can't tell why. Even when I set the condition to "if(ptime >= 200f)", those movements are the same.
Here are my codes:
public class Player{
private Texture img;
public Vector2 worldPos;
public Vector2 tileMapPos;
private float time;
private float ptime;
private boolean isArrived;
private float nowx, nowy;
public Player() {
img = new Texture("filepath")
worldPos = new Vector2(1, 164);
tileMapPos = new Vector2(9, 9);
time = 0.5f;
ptime = 0f;
isArrived = false;
}
public void render(SpriteBatch batch) {
batch.draw(img, worldPos.x, worldPos.y, 32, 32);
}
public void update(SpriteBatch batch, float delta) {
time += delta;
if (time >= 0.5f) {
move(batch, delta);
time = 0f;
}
private void move(SpriteBatch batch, float delta) {
if (Gdx.input.isKeyJustPressed(Input.Keys.W)) {
ptime += delta;
isArrived = false;
nowx = worldPos.x;
nowy = worldPos.y;
if (ptime >= 0.02f) {
worldPos.x -= 2;
worldPos.y += 1;
ptime = 0f;
}
if ((nowx - worldPos.x) == 16 && (worldPos.y - nowy) == 8) {
isArrived = true;
}
tileMapPos.x += 1;
} else if (Gdx.input.isKeyJustPressed(Input.Keys.A)) {
///
} else if (Gdx.input.isKeyJustPressed(Input.Keys.S)) {
///
} else if (Gdx.input.isKeyJustPressed(Input.Keys.D)) {
///
}
}
}
And this is in the game screen class:
batch.begin();
map.render(batch, delta);
player.update(batch, delta);
player.render(batch);
batch.end();

Libgdx - Rotate an object using its movement

I'm trying to implement an autorotation method for a SpriteAnimation class (trying to port SpriteAnimation).
Everything is working, the sprite draws correctly (it uses the correct animations) it just doesn't rotate properly if at all, normally it seems to point to the origin (0, 0) only after its target matches its position while I want its rotation to update as it moves, i've tried both degrees and radians, neither of which work. It should be rotating to match the current direction it's going. I've been struggling with this for about a week now, but still have not gotten the desired result.
Full Code Here
Relevant code:
From SpriteAnimation
// The x position of the sprite's upper left corner pixel.
public int getX() { return (int)position.x; }
public void setX(int value)
{
prevPosition.x = position.x;
position.x = value;
updateRotation();
}
// The y position of the sprite's upper left corner pixel.
public int getY() { return (int)position.y; }
public void setY(int value)
{
prevPosition.y = position.y;
position.y = value;
updateRotation();
}
void updateRotation()
{
if (rotateByPosition)
{
Vector2 rotationVector = new Vector2(position.x - prevPosition.x, position.y - prevPosition.y);
rotationRad = rotationVector.angle();
rotationDeg = rotationRad * MathUtils.radiansToDegrees;
}
}
public void MoveBy(int x, int y)
{
prevPosition = new Vector2(position);
position.x += x;
position.y += y;
updateRotation();
}
public void Update(float deltaTime)
{
// Don't do anything if the sprite is not animating
if (animating)
{
// If there is not a currently active animation
if (getCurrentFrameAnimation() == null)
{
// Make sure we have an animation associated with this sprite
if (animations.size() > 0)
{
// Set the active animation to the first animation
// associated with this sprite
String[] sKeys = new String[animations.size()];
int index = 0;
for (Entry<String, FrameAnimation> mapEntry : animations.entrySet()) {
sKeys[index] = mapEntry.getKey();
index++;
}
setCurrentAnimation(sKeys[0]);
}
else
{
return;
}
}
// Run the Animation's update method
getCurrentFrameAnimation().Update(deltaTime);
// Check to see if there is a "follow-up" animation named for this animation
if (getCurrentFrameAnimation().getNextAnimation() != null && !getCurrentFrameAnimation().getNextAnimation().isEmpty())
{
// If there is, see if the currently playing animation has
// completed a full animation loop
if (getCurrentFrameAnimation().getPlayCount() > 0)
{
// If it has, set up the next animation
setCurrentAnimation(getCurrentFrameAnimation().getNextAnimation());
}
}
}
}
public void Draw(SpriteBatch spriteBatch, int xOffset, int yOffset)
{
updateRotation(); // Calling this while testing to make sure that it is being called
spriteBatch.draw(getCurrentTextureRegion(), getPosition().x + xOffset - center.x, getPosition().y + yOffset - center.y, center.x, center.y, getCurrentFrameAnimation().getFrameWidth(), getCurrentFrameAnimation().getFrameHeight(), 1.0f, 1.0f, rotationRad);
}
TestScreen class
package com.darkstudio.darkisle.screens;
import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.Screen;
import com.badlogic.gdx.graphics.GL20;
import com.badlogic.gdx.graphics.OrthographicCamera;
import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.math.Vector2;
import com.badlogic.gdx.math.Vector3;
import com.darkstudio.darkisle.DarkIsle;
import com.delib.engine.sprite.MobileSprite;
/**
* Created by DarkEnder on 2017/06/27.
*/
public class TestScreen implements Screen {
final DarkIsle game;
OrthographicCamera camera;
Texture tankTexture;
MobileSprite mouseTank;
public TestScreen(final DarkIsle game)
{
this.game = game;
camera = new OrthographicCamera();
configureCamera();
tankTexture = new Texture(Gdx.files.internal("MulticolorTanks.png"));
mouseTank = new MobileSprite(tankTexture, 32, 32);
mouseTank.getSprite().AddAnimation("red", 0, 32, 32, 32, 8, 0.1f);
mouseTank.getSprite().AddAnimation("purple", 0, 128, 32, 32, 8, 0.1f, "red");
mouseTank.getSprite().AddAnimation("yellow", 0, 64, 32, 32, 8, 0.1f);
mouseTank.getSprite().setAutoRotate(true);
mouseTank.setPosition(new Vector2(100, 100));
mouseTank.setTarget(new Vector2(mouseTank.getPosition()));
mouseTank.setIsPathing(true);
mouseTank.setEndPathAnimation("yellow");
mouseTank.setLoopPath(false);
mouseTank.setSpeed(2);
}
#Override
public void show() {
}
#Override
public void render(float delta) {
Gdx.gl.glClearColor(0, 0, 0, 1);
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT | GL20.GL_DEPTH_BUFFER_BIT);
update();
game.batch.begin();
mouseTank.draw(game.batch);
game.batch.end();
}
#Override
public void resize(int width, int height) {
}
#Override
public void pause() {
}
#Override
public void resume() {
}
#Override
public void hide() {
}
#Override
public void dispose() {
}
private void configureCamera()
{
Vector3 camPos = new Vector3(camera.position);
float size = 800;
float cameraWidth = 0;
float cameraHeight = 0;
if (Gdx.graphics.getHeight() < Gdx.graphics.getWidth())
{
cameraWidth = size;
cameraHeight = size * Gdx.graphics.getHeight() / Gdx.graphics.getWidth();
}
else
{
cameraWidth = size * Gdx.graphics.getWidth() / Gdx.graphics.getHeight();
cameraHeight = size;
}
camera.setToOrtho(true, cameraWidth, cameraHeight);
camera.position.set(camPos.x + camera.viewportWidth / 2f, camPos.y + camera.viewportHeight / 2f, 0);
}
private void update() {
int xTouch = Gdx.input.getX(0);
int yTouch = Gdx.input.getY(0);
mouseTank.setTarget(xTouch, yTouch);
mouseTank.update(Gdx.graphics.getDeltaTime());
}
}
Edit: Just saying now that I've already tried using atan2 in MathUtils and it gave the same results.
The MobileSprite update method
public void update(float deltaTime)
{
if (active && movingTowardsTarget)
{
if ((target != null))
{
// Get a vector pointing from the current location of the sprite
// to the destination.
Vector2 Delta = new Vector2(target.x - sprite.getX(), target.y - sprite.getY());
if (Delta.len() > getSpeed())
{
Delta.nor();
Delta.scl(getSpeed());
getPosition().add(Delta);
}
else
{
if (target == sprite.getPosition())
{
if (pathing)
{
if (queuePath.size() > 0)
{
target = queuePath.remove();
if (loopPath)
{
queuePath.remove(target);
}
}
else
{
if (!(endPathAnimation == null))
{
if (!(getSprite().getCurrentAnimation() == endPathAnimation))
{
getSprite().setCurrentAnimation(endPathAnimation);
}
}
if (deactivateAtEndOfPath)
{
setIsActive(false);
}
if (hideAtEndOfPath)
{
setIsVisible(false);
}
}
}
}
else
{
sprite.setPosition(target);
}
}
}
}
if (active)
sprite.Update(deltaTime);
}

To get the radians angle:
void updateRotation()
{
if (rotateByPosition)
{
Vector2 rotationVector = new Vector2(position.x - prevPosition.x, position.y - prevPosition.y);
rotationRad = rotationVector.angleRad();
rotationDeg = rotationRad * MathUtils.radiansToDegrees;
}
}
and the draw method needs a degrees angle:
spriteBatch.draw(
getCurrentTextureRegion(),
getPosition().x + xOffset - center.x,
getPosition().y + yOffset - center.y,
center.x, center.y,
getCurrentFrameAnimation().getFrameWidth(), getCurrentFrameAnimation().getFrameHeight(),
1.0f, 1.0f,
rotationDeg
);
The screen mouse position is from the upper left corner the renderer needs from the bottom left corner:
int xTouch = Gdx.input.getX(0);
int yTouch = Gdx.graphics.getHeight() - Gdx.input.getY(0);

Issue with OpenGL textures facing wrong direction

I've got a test texture in a new game that I'm creating, and for some reason, when I implement it into the game, the texture is flipped horizontally, instead of vertically. Why does this happen?
Here's a photo of the app.
As you can see, the little guy is flipped horizontally, almost as if he is sleeping. He should be facing vertically. Why is this happening, and how do I prevent it? I'll post both classes involved.
Player class:
import java.io.IOException;
import org.newdawn.slick.opengl.Texture;
import org.newdawn.slick.opengl.TextureLoader;
import org.newdawn.slick.util.ResourceLoader;
public class Player {
public Texture playerTexture;
// Positions & speed
public float xPos = 20.0f; // This is initial
public float yPos = 450.0f; // Same as above.
private float velocity = 20;
public float gravityForce = 6;
public float jumpVelocity = 25;
private static int moveSpeed = 30 / 2;
public boolean isSupported = false; // Once again, initial value.
boolean canJump = true;
// movement methods
public Texture grabTexture() {
try {
playerTexture = TextureLoader.
getTexture("PNG", ResourceLoader
.getResourceAsStream
("resources/test_char.png"));
} catch (IOException e) {
e.printStackTrace();
}
return playerTexture;
}
public void applyGravity() {
}
private void printPos(String moveMethod) {
System.out.println(moveMethod + " X: "
+ xPos + " Y: " + yPos);
}
public void moveRight() {
xPos += moveSpeed;
printPos("Moving right!");
}
public void moveLeft() {
xPos -= moveSpeed;
printPos("Moving left!");
}
public void jump() {
if (!isSupported) {
}
}
public void shoot() {
// do shooty stuff here
}
}
Main (Launcher) class:
import org.lwjgl.LWJGLException;
import org.lwjgl.input.Keyboard;
import org.lwjgl.opengl.Display;
import org.lwjgl.opengl.DisplayMode;
import org.lwjgl.opengl.GL11;
public class Main {
private void display() {
try {
Display.setDisplayMode(new DisplayMode(1000, 550));
Display.setTitle("Unnamed Platformer Game");
Display.create();
} catch (LWJGLException e) {
e.printStackTrace();
System.exit(0);
}
// OpenGL
while (!Display.isCloseRequested()) {
initGL();
player.applyGravity();
Display.update();
Display.sync(60); // sync to 60 fps
if (Keyboard.isKeyDown(Keyboard.KEY_D)) {
player.moveRight();
} else if (Keyboard.isKeyDown(Keyboard.KEY_A)) {
player.moveLeft();
} else if (Keyboard.isKeyDown(Keyboard.KEY_SPACE)) {
player.jump();
}
}
Display.destroy();
}
private void initGL() {
// initial OpenGL items for 2D rendering
GL11.glClear(GL11.GL_COLOR_BUFFER_BIT);
GL11.glEnable(GL11.GL_TEXTURE_2D);
GL11.glMatrixMode(GL11.GL_PROJECTION);
GL11.glLoadIdentity();
GL11.glOrtho(0, 1000, 550, 0, 1, -1);
// start rendering player image
player.grabTexture().bind();
GL11.glBegin(GL11.GL_QUADS);
GL11.glVertex2f(player.xPos, player.yPos);
GL11.glTexCoord2f(0, 0);
GL11.glVertex2f(player.xPos + 100, player.yPos);
GL11.glTexCoord2f(1, 0);
GL11.glVertex2f(player.xPos + 100, player.yPos + 100);
GL11.glTexCoord2f(1, 1);
GL11.glVertex2f(player.xPos, player.yPos + 100);
GL11.glTexCoord2f(0, 1);
GL11.glEnd(); // stop rendering this image
}
Player player = new Player();
public static void main(String[] args) {
Main main = new Main();
main.display();
}
}

GL11.glVertex2f(player.xPos, player.yPos);
GL11.glTexCoord2f(0, 0);
The issue is you're calling these functions out of order. Whenever you call glVertex2f, OpenGL will grab whatever attributes are currently set and use that for the vertex. In this case, you're setting up the texture coordinate after setting the vertex, so the coords are "delayed" by one vertex. If you swap every pair of these calls, it should work.
Also, your call to glOrtho has the top and bottom parameters swapped. The bottom value is what the y value is supposed to be at the bottom of the screen (in this case, 0). Likewise for the top value.

Need help on breakout game ball speed

This is a grade 12 object oriented programming project.
I have a class called Ball to construct my ball object.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;
public class Ball{
private double xPos;
private double yPos;
private int direction;
public Ball(int ixPos, int iyPos, int idirection){
xPos = ixPos;
yPos = iyPos;
direction = idirection;
}
public int returnX(){
return (int)xPos;
}
public int returnY(){
return (int)yPos;
}
public int returnDirection(){
return direction;
}
public void move(){
xPos += 1*Math.cos(Math.toRadians(direction));
yPos -= 1*Math.sin(Math.toRadians(direction));
}
public void collide(int collideWith){
if(collideWith==1){//collide with left wall
if(90<direction && direction<180){
direction = 180-direction;
}
if(180<direction && direction<270){
direction = 540-direction;
}
}
if(collideWith==2){//collide with right wall
if(0<direction && direction<90){
direction = 180-direction;
}
if(270<direction && direction<360){
direction = 540-direction;
}
}
if(collideWith==3){//collide with up wall
if(0<direction && direction<90){
direction = 360-direction;
}
if(90<direction && direction<180){
direction = 360-direction;
}
}
if(collideWith==4){//collide with down wall
direction = 360-direction;
}
}
public void collidePaddle(int collidePos){
if(collidePos!=50 && collidePos!=0){
direction = (50-collidePos)*180/50;
}
}
}
As you can see in the "move" function, right now the ball is going at a very low speed. But i need the ball to go faster. If I change the 1 into something like, 5, there would be a problem. In my main class where it checks if the ball is hitting the wall or blocks to change direction, the ball would go into the wall or the blocks if the amount of pixels the ball can move each time is greater than 1.
To me it seems like there's no way to solve this problem, no idea where I would start thinking, is there a better way of checking collide or something?
Thank you.

Instead of using absolute checks in your collidePaddle check, you should allow for ranges.
For example...
public void collidePaddle(int collidePos){
if (collidePos >= 50) {
direction = (50-collidePos)*180/50;
// Correct the position of the ball to meet the minimum requirements
// of the collision...
} else if (collidePos <= 0) {
direction = (50-collidePos)*180/50;
// Correct the position of the ball to meet the minimum requirements
// of the collision...
}
}
(Sorry, I'm having fun working out your code ;))
This will allow the ball the "pass" beyond the these points within a virtual context, but if you correct the position to componsate, it should make no difference...when it's rendered...
Updated
Here's a REALLY SIMPLE example of what I'm talking about...
public class SimpleBouncyBall {
public static void main(String[] args) {
new SimpleBouncyBall();
}
public SimpleBouncyBall() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (Exception ex) {
}
JFrame frame = new JFrame("Test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new CourtPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class CourtPane extends JPanel {
private Ball ball;
private int speed = 5;
public CourtPane() {
Timer timer = new Timer(40, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
Rectangle bounds = new Rectangle(new Point(0, 0), getSize());
if (ball == null) {
ball = new Ball(bounds);
}
speed = ball.move(speed, bounds);
repaint();
}
});
timer.setRepeats(true);
timer.setCoalesce(true);
timer.start();
}
#Override
public Dimension getPreferredSize() {
return new Dimension(100, 100);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (ball != null) {
Graphics2D g2d = (Graphics2D) g.create();
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
Point p = ball.getPoint();
g2d.translate(p.x, p.y);
ball.paint(g2d);
g2d.dispose();
}
}
}
public class Ball {
private Point p;
private int radius = 12;
public Ball(Rectangle bounds) {
p = new Point();
p.x = 0;
p.y = bounds.y + (bounds.height - radius) / 2;
}
public Point getPoint() {
return p;
}
public int move(int speed, Rectangle bounds) {
p.x += speed;
if (p.x + radius >= (bounds.x + bounds.width)) {
speed *= -1;
p.x = ((bounds.x + bounds.width) - radius) + speed;
} else if (p.x <= bounds.x) {
speed *= -1;
p.x = bounds.x + speed;
}
p.y = bounds.y + (bounds.height - radius) / 2;
return speed;
}
public void paint(Graphics2D g) {
g.setColor(Color.RED);
g.fillOval(0, 0, radius, radius);
}
}
}
My move method doesn't care if you've past the boundaries as it will reposition the ball back to sit within side those boundaries
public int move(int speed, Rectangle bounds) {
// Apply the delta
p.x += speed;
// Have we passed beyond the right side??
if (p.x + radius >= (bounds.x + bounds.width)) {
speed *= -1;
p.x = ((bounds.x + bounds.width) - radius) + speed;
// Have we past beyond the left side??
} else if (p.x <= bounds.x) {
speed *= -1;
p.x = bounds.x + speed;
}
p.y = bounds.y + (bounds.height - radius) / 2;
return speed;
}
Play around with the speed and see what you get ;)

PacMan game movement

I am creating a pacman game in Java and I have 1 problem I can't get rid of.. The problem is as follows:
I have 4 buttons in the game screen for each way: up, down, left, right. The problem is that I can not use the buttons in the same time in x position as in the y position because I always get a value of 0 ( you understand this if you see my code below )
Below you can find my class for the pacman that i think is related to the problem ( see setBesturing(int besturing) method )
package h04PacMan;
/*
* PacMan laten bewegen
*/
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class PacMan extends JPanel implements ActionListener {
private int horizontalePlaats = 250; // x location
private int verticalePlaats = 150; // y location
private int richtingEnSnelheid = +10; // speed
private final int WACHTTIJD = 500; // DELAY
int diameter;
int waarde;
public PacMan() {
// create timer and start timer
javax.swing.Timer autoKlik = new javax.swing.Timer(WACHTTIJD, this);
autoKlik.start();
}
public int getHorPlaats() {
return horizontalePlaats;
}
// current y positie
public int getVerPlaats() {
return verticalePlaats;
}
// speed and way;
public int getRichtingEnSnelheid() {
return richtingEnSnelheid;
}
// new x position
public void setHorPlaats(int nieuweHorPlaats) {
if(nieuweHorPlaats > getWidth()) {
nieuweHorPlaats = 0;
}
else if(nieuweHorPlaats < 0) {
nieuweHorPlaats = getWidth();
}
horizontalePlaats = nieuweHorPlaats;
}
// new y position
public void setVerPlaats(int nieuweVerPlaats) {
if(nieuweVerPlaats > getHeight()) {
nieuweVerPlaats = 0;
}
else if(nieuweVerPlaats < 0) {
nieuweVerPlaats = getHeight();
}
verticalePlaats = nieuweVerPlaats;
}
public void setRichtingEnSnelheid(int nieuweRichtingEnSnelheid) {
richtingEnSnelheid = nieuweRichtingEnSnelheid;
}
//movement
public void setBesturing(int besturing) {
besturing = waarde;
if(waarde == 0) {
setVerPlaats( getVerPlaats() + richtingEnSnelheid);
}
else if(waarde == 1){
setHorPlaats( getHorPlaats() + richtingEnSnelheid);
}
}
#Override
public void actionPerformed(ActionEvent e) {
setBesturing(waarde);
System.out.println(waarde);
repaint();
}
DrawPacMan pacman = new DrawPacMan();
DrawPacMan ghost1 = new DrawPacMan();
DrawPacMan ghost2 = new DrawPacMan();
public void paintComponent(Graphics g) {
super.paintComponent(g);
// pacman movement
diameter = 75;
pacman.drawPacMan(g, getHorPlaats(), getVerPlaats(), diameter, Color.yellow);
// ghosts movement
int g1x;
for(g1x = 0; g1x < 10; g1x++) {
pacman.drawGhost(g, g1x, 40, diameter, Color.red);
}
pacman.drawGhost(g, 170, 70, diameter, Color.blue);
}
}
and this is the actionListener in my gamecontrol class
#Override
public void actionPerformed(ActionEvent e) {
if(e.getSource() == links) {
pacman.setRichtingEnSnelheid( -10 );
pacman.setBesturing(1);
System.out.println("links");
}
else if(e.getSource() == rechts) {
pacman.setRichtingEnSnelheid( +10 );
pacman.setBesturing(1);
System.out.println("rechts");
}
else if(e.getSource() == boven) {
pacman.setRichtingEnSnelheid( -10);
pacman.setBesturing(0);
System.out.println("boven");
}
else {
pacman.setRichtingEnSnelheid( +10);
pacman.setBesturing(0);
System.out.println("beneden");
}
}

Here is your problem:
//movement
public void setBesturing(int besturing) {
besturing = waarde; <-- THIS LINE
if(waarde == 0) {
setVerPlaats( getVerPlaats() + richtingEnSnelheid);
}
else if(waarde == 1){
setHorPlaats( getHorPlaats() + richtingEnSnelheid);
}
}
You are overwriting the value of besturing with the old value waarde. It should be the other way around.
//movement
public void setBesturing(int besturing) {
waarde = besturing; <-- THIS LINE
if(waarde == 0) {
setVerPlaats( getVerPlaats() + richtingEnSnelheid);
}
else if(waarde == 1){
setHorPlaats( getHorPlaats() + richtingEnSnelheid);
}
}

I think inside the method setBesturing(int besturing) should be:
waarde = besturing;

In your setBesturing method: -
besturing = waarde;
This line never changes the value of your waarde.. It is always zero.
You should do the assignment the other way : -
this.waarde = besturing;

You'll need to keep track of whether the button is pressed or not indepentently. Also, you're model doesn't support a diagonal movement at all (I'm not sure what your nederlands names exactly mean, i can interprete snelheid=Schnelligkeit=speed and some more).
You'll need to put diagonal movement into the model (e.g. give him an x and y velocity indepent from each other)