What the title says. Is it possible?
As far as I know, there is no getKeyPressed or anything of the sort. I want to use a switch case for organization (and practice) as well as speed (or so I was informed).
Basically, the switch case clause(?) is just a boolean return. But how can I check if a key is pressed based on a value passed into it without a pasta bowl of if / else statements?
Obviously this code doesn't work, but I'm looking for something like it.
public void moveCamera() {
switch (Keyboard.isKeyDown(!!!CASE CHECKING HERE!!!)) {
case Keyboard.KEY_W:
position.z -= MOVE_SPEED;
break;
case Keyboard.KEY_A:
position.x += MOVE_SPEED;
break;
case Keyboard.KEY_S:
position.z -= MOVE_SPEED;
break;
case Keyboard.KEY_D:
position.x += MOVE_SPEED;
break;
}
}
Here is a solution that I liked (but did not try) from #KysonTyner.
You can switch on getEventKey(). This will hit your current cases and then you can wrap the whole switch statement with if (getEventKeyState()) {switch/case}. There is no need to use an event listener. – Kylon Tyner
As for what I used, I abandoned the idea of a switch entirely, as I realized that the movement speed would multiply if there were more than one direction of input.
I wanted to support multiple directions of motion for diagonal movement, so it wouldn't be "ghosting" as keys were pressed.
What I did is separate the functions, one to test keyboard input, and one to move the camera. There doesn't have to be any special logic for the key input, as it simply passes an LWJGL Vector3f to the camera move function.
Then, in camera move, I normalized that vector and altered the positions accordingly.
This is a simplified version of my Camera class for demonstration. I removed everything except translation.
package spikespaz.engine.main;
import org.lwjgl.input.Keyboard;
import org.lwjgl.util.vector.Vector3f;
// Created by spike on 7/3/2017.
public final class Camera {
private Camera() {}
private float moveSpeed = 0.2f;
private Vector3f position = new Vector3f(0, 0, 0);
public Camera(Vector3f position, Vector3f rotation) {
this.position = position;
}
public void updateKeyInput() {
Vector3f direction = new Vector3f(0, 0, 0);
if (Keyboard.isKeyDown(Keyboard.KEY_W)) {
direction.x = 1;
} else if (Keyboard.isKeyDown(Keyboard.KEY_S)) {
direction.x = -1;
}
if (Keyboard.isKeyDown(Keyboard.KEY_SPACE)) {
direction.y = -1;
} else if (Keyboard.isKeyDown(Keyboard.KEY_LSHIFT)) {
direction.y = 1;
}
if (Keyboard.isKeyDown(Keyboard.KEY_A)) {
direction.z = 1;
} else if (Keyboard.isKeyDown(Keyboard.KEY_D)) {
direction.z = -1;
}
translate(direction);
}
private void translate(Vector3f direction) {
Vector3f normalized = direction.normalise(null);
Vector3f.add(position, (Vector3f) normalized.scale(moveSpeed), position);
}
public float getMoveSpeed() {
return moveSpeed;
}
public void setMoveSpeed(float moveSpeed) {
this.moveSpeed = moveSpeed;
}
}
Translate is relative. In the full class I have another function to set absolute position, without the move speed.
In the above example, the input vector for translate is simply a direction. The function should coordinate that based on the movement speed for each frame.
Related
The following code I wrote does what I want, a touch on the left or right side of the screen to move the sprite left or right and stop at the edge of the phone screen. The issue I'm having is when you do a fast motion of touching the right side of the screen, letting go while using another finger to touch the left side of the screen to change direction will yield a result of the sprite still moving to the right side of the screen despite you wanting to move left. In order to fix this, you need to let go completely for at least 0.5sec then press the other direction to start moving in that direction, which I don't want to have to live with. If anyone has any tips/help for this, please let me know!
MAIN ACTIVITY CLASS METHOD:
public boolean onTouchEvent(MotionEvent event){
int x = (int)event.getX();
switch(event.getAction()) {
case (MotionEvent.ACTION_DOWN):
CharacterSprite.touchedX = x;
break;
case (MotionEvent.ACTION_UP):
CharacterSprite.touchedX = 0;
break;
}
return super.onTouchEvent(event);
}
CHARACTERSPRITE CLASS METHOD:
public void update() {
if (touchedX != 0) {
if (touchedX < screenWidth / 2) {
if (!(xVelocity < 0)) {
xVelocity = xVelocity * -1;
}
if (!(x > 0)) {
touchedX = 0;
return;
}
x += xVelocity;
}
if (touchedX > screenWidth / 2) {
if (!(xVelocity > 0)) {
xVelocity = xVelocity * -1;
}
if (!(x < screenWidth - image.getWidth())) {
touchedX = 0;
return;
}
x += xVelocity;
}
}
}
The way you handling MotionEvent will not work for multitouch events. Each finger (action pointer) data stored as an array and you need to handle each entry separately. Here is the lesson on handling multitouch events:
https://developer.android.com/training/gestures/multi
I am having a rectangle which should represent a car. It should rotate when you tuch the display. How to make this with box2d. I already setted all up: Press W to accelerate and touch display for right turn and dont touch it for left turn. Problem is that the car is drifting when you rotate it and not immediately goes only to the direction its facing to. So far this is my code, how to remove this drifting, its like it drives on ice. :/
EDIT: (copied from C++ code: http://www.iforce2d.net/b2dtut/top-down-car I tried to copy everything until the Torque so now It should drive. But when I do accelerate. It does not move. The currentSpeed Variable is 0 and the currentForwardNormal is 0.0 ,0.0. What did I wrong?)
//Main upate
public void update(float delta) {
updateFriction();
}
//Movements and Subclasses of them
public void accelerate() {
//find current speed in forward direction
Vector2 currentForwardNormal = ship.getWorldVector(new Vector2(0,1));
float currentSpeed = getForwardVelocity().dot(currentForwardNormal);
//apply necessary force
float force = 0;
if(maxSpeed > currentSpeed) {
force = maxDriveForce;
} else {
force = -maxDriveForce;
}
System.out.println("Current Speed: "+currentSpeed);
System.out.println("Current Forward Normal: "+currentForwardNormal);
ship.applyForceToCenter(currentForwardNormal.scl(force),true);
}
public void rotate(boolean direction) { //true for Up and false for Down
if(direction) {
//torques
}
}
private void updateFriction() {
Vector2 impulse = getLateralVelocity().scl(-ship.getMass());
ship.applyLinearImpulse(impulse, ship.getWorldCenter(), true);
ship.applyAngularImpulse(0.1f * ship.getInertia() * -ship.getAngularVelocity(),true);
}
private Vector2 getLateralVelocity() {
Vector2 currentRightNormal = ship.getWorldVector(new Vector2(1,0));
return currentRightNormal.scl(currentRightNormal.dot(ship.getLinearVelocity()));
}
private Vector2 getForwardVelocity() {
Vector2 currentRightNormal = ship.getWorldVector(new Vector2(0,1));
return currentRightNormal.scl(currentRightNormal.dot(ship.getLinearVelocity()));
}
Synopsis
Well, I'm making a little top-down JRPG and today I was like 'Yeah, I'm gonna bust out this whole map collision thing!'. I failed.
Problem
So I went on the internet and looked up 'LibGDX Tiled Map Collision Detection' and found a really neat post about Map Objects so I added in a map object layer and did all that biz and came out with this little method to ensure the player can move freely around the map but at the same time can't exit it but each time I've tried it ends up with a horrible result such as the player moving off the screen. The latest error is that the player gets stuck doing a walk animation and can't move anywhere else!
Code
package com.darkbyte.games.tfa.game.entity.entities;
import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.Input.Keys;
import com.badlogic.gdx.graphics.g2d.Animation;
import com.badlogic.gdx.graphics.g2d.TextureRegion;
import com.badlogic.gdx.maps.objects.RectangleMapObject;
import com.badlogic.gdx.math.Rectangle;
import com.darkbyte.games.tfa.game.entity.Entity;
import com.darkbyte.games.tfa.game.entity.SpriteSheet;
import com.darkbyte.games.tfa.game.world.map.MapManager;
import com.darkbyte.games.tfa.render.Batch;
import com.darkbyte.games.tfa.render.Camera;
public class Player extends Entity {
// The constructor for the player class
public Player(String name, SpriteSheet spriteSheet) {
super(name, spriteSheet);
direction = Direction.DOWN;
collisionBox = new Rectangle(x, y, 64, 64);
}
// A flag to see if the player is moving
private boolean isMoving;
// The variable that holds the state time
private float stateTime;
// The player's walking animations
private Animation[] walkAnimations = {
spriteSheet.getAnimation(8, 8, 1 / 16f),
spriteSheet.getAnimation(9, 8, 1 / 16f),
spriteSheet.getAnimation(10, 8, 1 / 16f),
spriteSheet.getAnimation(11, 8, 1 / 16f) };
// The player's static frames
private TextureRegion[] staticFrames = {
spriteSheet.getTexture(8, 0),
spriteSheet.getTexture(9, 0),
spriteSheet.getTexture(10, 0),
spriteSheet.getTexture(11, 0) };
// The render code for the player
#Override
public void render() {
// Makes the camera follow the player
Camera.setCameraPosition(x, y);
Batch.getGameBatch().setProjectionMatrix(Camera.getCamera().combined);
// Updates the state time
stateTime += Gdx.graphics.getDeltaTime();
// Gets the player's direction, if the player's moving, it sets the
// current frame to the frame that would be played at the current moment
// based on the state time
// If the player isn't moving, it sets the current frame to the static
// frame associated to the direction
switch (direction) {
case UP:
if(isMoving) {
currentFrame = walkAnimations[0].getKeyFrame(stateTime, true);
} else
currentFrame = staticFrames[0];
break;
case LEFT:
if(isMoving) {
currentFrame = walkAnimations[1].getKeyFrame(stateTime, true);
} else
currentFrame = staticFrames[1];
break;
case DOWN:
if(isMoving) {
currentFrame = walkAnimations[2].getKeyFrame(stateTime, true);
} else
currentFrame = staticFrames[2];
break;
case RIGHT:
if(isMoving) {
currentFrame = walkAnimations[3].getKeyFrame(stateTime, true);
} else
currentFrame = staticFrames[3];
break;
}
}
// The tick code for the player
#Override
public void tick() {
// The object to represent the bounds of the land on the map
RectangleMapObject land = (RectangleMapObject) MapManager.getCurrentMap().getMap().getLayers().get("collision").getObjects().get("land");
// Checks if the player is within the bounds of the map
if(land.getRectangle().contains(collisionBox)) {
// If the player is moving but the arrow keys aren't pressed, sets isMoving to false
isMoving = (isMoving && (Gdx.input.isKeyPressed(Keys.W) || Gdx.input.isKeyPressed(Keys.UP)
|| Gdx.input.isKeyPressed(Keys.A) || Gdx.input.isKeyPressed(Keys.LEFT)
|| Gdx.input.isKeyPressed(Keys.S) || Gdx.input.isKeyPressed(Keys.DOWN)
|| Gdx.input.isKeyPressed(Keys.D) || Gdx.input.isKeyPressed(Keys.RIGHT)));
// Checks to see if the arrow / WASD keys are pressed and moves the
// player in the correct direction at the speed of 1.5 pixels/tick
// (45/second)
// It also sets the players state to moving and corresponds it's
// direction to the key pressed
// Doesn't move if opposing keys are pressed
if(Gdx.input.isKeyPressed(Keys.W) || Gdx.input.isKeyPressed(Keys.UP)) {
if(!(Gdx.input.isKeyPressed(Keys.S) || Gdx.input.isKeyPressed(Keys.DOWN))) {
direction = Direction.UP;
y += 1.5f;
isMoving = true;
}
}
if(Gdx.input.isKeyPressed(Keys.A) || Gdx.input.isKeyPressed(Keys.LEFT)) {
if(!(Gdx.input.isKeyPressed(Keys.D) || Gdx.input.isKeyPressed(Keys.RIGHT))) {
direction = Direction.LEFT;
isMoving = true;
x -= 1.5f;
}
}
if(Gdx.input.isKeyPressed(Keys.S) || Gdx.input.isKeyPressed(Keys.DOWN)) {
if(!(Gdx.input.isKeyPressed(Keys.W) || Gdx.input.isKeyPressed(Keys.UP))) {
direction = Direction.DOWN;
y -= 1.5f;
isMoving = true;
}
}
if(Gdx.input.isKeyPressed(Keys.D) || Gdx.input.isKeyPressed(Keys.RIGHT)) {
if(!(Gdx.input.isKeyPressed(Keys.A) || Gdx.input.isKeyPressed(Keys.LEFT))) {
direction = Direction.RIGHT;
x += 1.5f;
isMoving = true;
}
}
} else {
if(!isMoving) {
// If the player's just spawned puts the player to the map's spawn point
x = MapManager.getCurrentMap().getPlayerSpawnX();
y = MapManager.getCurrentMap().getPlayerSpawnY();
} else { // If not, it just moves them back till they're no longer out of the map
if(x > (land.getRectangle().getX() + land.getRectangle().getWidth())) x -= 1.5;
if(y > (land.getRectangle().getY() + land.getRectangle().getHeight())) y -= 1.5;
}
}
// Synchronises the collision box with the player's x and y position
collisionBox.x = x;
collisionBox.y = y;
}
// Returns if the player is moving
public boolean isMoving() {
return isMoving;
}
}
Can you guys make it so that when he reaches the border that he stops but he can still keep moving in other directions instead of staying static!
Thanks for reading!
At the moment it sounds you just copy/pasted it and you need to familiarize yourself with it first. If you don't know what it does then you should learn or stop the project imho.
Anyway, from what I can tell it's just a player class that handles the animation frames based on which direction it is moving. Nothing to do with collision detection at all. It does update some kind of collisionBox but functionality for this is handled elsewhere, perhaps in the parent class Entity?
My guess is that this is a tile map and units are restricted to the grid. It's pretty easy to detect if A tile exists or not.
private boolean tileExists(int tileX, int tileY, tile[][] map)
{
return tileX >= 0 && tileY >= 0 &&
tileX < map.length && tileY < map[0].length;
}
Now whenever a entity requests a move you should check if the destination is within the map bounds.
private void moveRequest(int destinationX, int destinationY, Tile[][] map)
{
//Just return if the tile is outside of the map
if (!tileExists(destinationX, destinationY, map) return;
//Same goes for your other checks...
//Return if the tile is not walkable
if (!tileIsWalkable(destinationX, destinationY, map) return;
//Return if the tile is already occupied
if (tileIsOccupied(destinationX, destinationY, otherEntities) return;
//etc..
//Now the move is valid and you can set it's state to moving in that direction.
}
Tile maps are not very hard to understand. I will make an attempt to give you some better insight into tile maps. You have a 2D array where you store your tiles in. Tiles have a width and a height and from that you can make your own tile engine:
//Find out which tiles to draw based on the camera position and viewport size.
int startX = (int)(camera.position.x - camera.viewportWidth / 2) / tileWidth;
int startY = (int)(camera.position.y - camera.viewportHeight / 2) / tileHeight;
int endX = (int)(startX + camera.viewportWidth / tileWidth) + 1;
int endY = (int)(startY + camera.viewportHeight / tileHeight) + 1;
//Loop using this data as boundaries
for (int y = startY; y < endY; y++)
{
for (int x = startX; x < endX; x++)
{
//If out of bounds continue to next tile.
if (!tileExists(x, y, map) continue;
//Now all we need to draw the on screen tiles properly:
//x == tile position x in array
//y == tile position y in array
//World position of this tile:
//worldX = x * tileWidth;
//worldY = y * tileHeight;
//Let's draw:
batch.draw(map[x][y].getTexture, worldX, worldY,
tileWidth, tileHeight)
}
}
There really is no magic involved here at all. Drawing only what is on screen like in the above example is very important for larger maps. Other then that you should draw thing in the back first. You have several options to do this, the easiest but least versatile is just a separate the ground from the objects that can obscure things and draw this later.
Characters, creatures or other entities can just use a world position and be easily converted back to tile position.
tileX = worldX / tileWidth;
tileY = worldY / tileHeight;
So if you want to move something with the world position calculate it's tile position first using the aforementioned method. Then lookup if this tile is valid to move to. Then block that tile for other and move to it.
I am trying to rotate a custom shape around its center, but can not get the result as expected.
what i want is
*shape should be rotated around its center without moving itself.*
what my solution is currently doing is
rotating a whole shape around its center , by every rotation its changing its position.
I have multiple shapes so i have created a class to encapsulate a shape with its transform in following class
public abstract class Shoe implements Shape, ShoeShape {
// variable declaration
/**
*
*/
public Shoe() {
position = new Point();
lastPosition = new Point();
}
public void draw(Graphics2D g2, AffineTransform transform, boolean firstTime) {
AffineTransform af = firstTime ? getInitTransform()
: getCompositeTransform();
if (af != null) {
Shape s = af.createTransformedShape(this);
if (getFillColor() != null) {
g2.setColor(getFillColor());
g2.fill(s);
} else {
g2.draw(s);
}
}
}
}
public AffineTransform getCompositeTransform() {
AffineTransform af = new AffineTransform();
af.setToIdentity();
af.translate(position.getX(), position.getY());
Point2D centerP = calculateShapeCenter();
af.rotate(orientation, centerP.getX(), centerP.getY());
return af;
}
public void onMouseDrag(MouseEvent me, Rectangle2D canvasBoundary,
int selectionOperation) {
// shape operation can be either resize , rotate , translate ,
switch (selectionOperation) {
case MmgShoeViewer.SHAPE_OPERATION_MOVE:
// MOVEMENT
break;
case MmgShoeViewer.SHAPE_OPERATION_ROTATE:
Point2D origin = calculateShapeCenter();
Point2D.Double starting = new Point2D.Double(me.getX(), me.getY());
currentAngle = RotationHelper.getAngle(origin, starting);
rotationAngle = currentAngle - startingAngle;
rotate(rotationAngle);
break;
case MmgShoeViewer.SHAPE_OPERATION_RESIZE:
break;
default:
System.out.println(" invalid select operation");
}
}
public void onMousePress(MouseEvent me, Rectangle2D canvasBoundary,
int selectionOperation) {
// shape operation can be either resize , rotate , translate ,
switch (selectionOperation) {
case MmgShoeViewer.SHAPE_OPERATION_MOVE:
break;
case MmgShoeViewer.SHAPE_OPERATION_ROTATE:
Point2D origin = calculateShapeCenter();
Point2D.Double starting = new Point2D.Double(me.getX(), me.getY());
startingAngle = RotationHelper.getAngle(origin, starting);
setShapeOperation(selectionOperation);
break;
case MmgShoeViewer.SHAPE_OPERATION_RESIZE:
break;
default:
System.out.println(" invalid select operation");
}
}
public void onMouseRelease(MouseEvent me, Rectangle2D canvasBoundary,
int selectionOperation) {
// shape operation can be either resize , rotate , translate ,
switch (selectionOperation) {
case MmgShoeViewer.SHAPE_OPERATION_MOVE:
break;
case MmgShoeViewer.SHAPE_OPERATION_ROTATE:
// FIXME rotation angle computation
setShapeOperation(-1);
break;
case MmgShoeViewer.SHAPE_OPERATION_RESIZE:
break;
default:
System.out.println(" invalid select operation");
}
}
public void rotate(double angle) {
orientation = (float) angle;
}
public void translate(double deltaX, double deltaY) {
position.setLocation(deltaX, deltaY);
lastPosition.setLocation(deltaX, deltaY);
}
// another getter and setter
I am calculating angle of rotation using following method
public static double getAngle(Point2D origin, Point2D other) {
double dy = other.getY() - origin.getY();
double dx = other.getX() - origin.getX();
double angle;
if (dx == 0) {// special case
angle = dy >= 0 ? Math.PI / 2 : -Math.PI / 2;
} else {
angle = Math.atan(dy / dx);
if (dx < 0) // hemisphere correction
angle += Math.PI;
}
// all between 0 and 2PI
if (angle < 0) // between -PI/2 and 0
angle += 2 * Math.PI;
return angle;
}
in mouse press event of the canvas mouse listener
selectedShape.onMousePress(me, canvasBoundary, shoeViewer
.getShapeOperation());
i am just calling selected shape's onMousePress method
and in my mouse drag method of the canvas mouse listener , i am just calling the selected shape's onMouseDrag method which updates the rotation angle as you can see from the very first class
selectedShape.onMouseDrag(me, canvasBoundary, shoeViewer
.getShapeOperation());
and you can see the draw method of the individual shape , to draw the shape according to current transform , i am calling from paintComponent like
Iterator<Shoe> shoeIter = shoeShapeMap.values().iterator();
while (shoeIter.hasNext()) {
Shoe shoe = shoeIter.next();
shoe.draw(g2, firstTime);
}
where shoeShapeMap contains all of the custom shapes currently on the canvas.
is i am doing mistake in calculating angle or determining anchor point ? my current solution rotates shape 360 degree by checking all the conditions[90 degree etc.] as you can see in the above mentioned method.
i want the shape should be rotated around its center without resizing its positions ?
in the word it is difficult to explain , so please suggest me any better way to show here what i want to accomplish ?
i think i have mentioned all the things related to this issue. if you have any doubts please feel free to ask me.
i found 2 related posts here but i could not find much information from them.
I think that the solution may be to (either/and):
invert the order of operations on your AffineTransform, put translate after rotate
use -x and -y for your translation values
Hello as a starting Java programmer I am busy creating a simple Pacman game in Java just to exercise and I have created a method for the ghost to move randomly horizontal of vertical but I have a few problems with it I don't know how to force it to go left-right or up-down (so not at the same time) my code for the ghost right now is as follows:
public void moveUp() {
}
public void moveLeft() {
if (g1x >= 500) { g1x = 500; g1r = false; }
else if (g1x <= 0) { g1x = 0; g1r = true; }
}
public void moveRight() {
if (g1x >= 500) { g1x = 500; g1r = false; }
else if (g1x <= 0) { g1x = 0; g1r = true; }
}
public void moveDown() {
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
// pacman movement
diameter = 25;
pacman.drawPacMan(g, getHorPlaats(), getVerPlaats(), diameter, getView(), Color.yellow);
// ghosts movement
g1x += ghostSpeed * (Math.random() > 0.5? 1 : -1); // random direction
Random randomGen = new Random();
// generate a random number, between 0 - 3
int randomize = randomGen.nextInt(4);
switch(randomize) {
case 0:
moveUp();
System.out.println("up");
break;
case 1:
moveLeft();
System.out.println("Left");
break;
case 2:
moveRight();
System.out.println("Right");
break;
case 3:
moveDown();
System.out.println("down");
break;
}
ghost.drawGhost(g, randomize, 40, diameter, Color.red);
}
I have used the randomize variable for the direction as you can see and the horizontal position is hardcoded but the horizontal position is also stated by randomize but if I use it for both it makes some weird diagonal movements
the next problem is that i use a timer in my construction like this
public PacMan() {
// create timer and start timer
javax.swing.Timer autoKlik = new javax.swing.Timer(WACHTTIJD, this);
autoKlik.start();
}
so the random values for the directions is changing to fast ( 500ms ) but the speed also configures the gameplay speed so I think I made a logical mistake but Im not sure how to solve this.. do I have to seperate the actions maybe? or is there a easier way to achieve this please share your skills with me I am motivated to learn :) and if you might need more code I could post it here or give a link to my github account so you can check it out :)
Thanks in advance!
link to the full source: pacman game source
I suggest to separate the concerns:
a set of classes to model the simulation contains only the entities and the logic
a set of graphic classes which draw the pacman
a controller to handle actions and delegate them to the model, fired by the swing classes
In paint() method, for performance reason, do only the painting, NEVER 'new' nor call complex methods. Paint are called very often by the framework.