I am new to Slick2D and I am trying movements with my character. I can make it move smoothly while holding movement key, but I also want the character to finish its movement so it stops exactly on the next tile (I have simple map with tiles 32x32). And that is a problem for me, because it moves to the next tiles, but it teleports there - the movement is instant and I want my character to just continue with its movement with the same speed.
I tried for example something like this in my update() method:
else if (input.isKeyPressed(Input.KEY_D))
{
characterAnimation = characterAnimationRight;
characterAnimation.update(delta);
xCoord = (int) xCoord;
while (xCoord%32 != 0)
{
xCoord += 1;
characterAnimation.update(delta);
if (xCoord > Window.WIDTH - 32)
{
xCoord = Window.WIDTH - 32;
}
}
}
but I can´t make it work.
Why don't you try to have a "xSpeed" and "ySpeed" and set those values according to where the 'characterAnimation' is set to and to whether you are on an exact tile or not?
Something like:
else if (input.isKeyPressed(Input.KEY_D)) {
characterAnimation = characterAnimationRight;
}
// ...
if (characterAnimation == characterAnimationRight){
xSpeed = 1;
}
else if (characterAnimation == characterAnimationLeft){
xSpeed = -1;
}
xCoord += xSpeed;
characterAnimation.update(delta);
if(xCoord % 32 == 0) {
xSpeed = 0;
}
// ...
I do not actually know how your code (or slick2d) works, so I assumed the xCoord value is magically taken into account when characterAnimation.update(delta) is called. Otherwise do whatever you need to update your character's position according to xCoord.
The solution is not to calculate xCoord in while() in the update() method. The reason is that it is calculated in single run of update() method and after that the render() method is called to render the character. That means character is rendered after that while() and it teleports.
Here is my solution:
#Override
public void update(GameContainer gc, StateBasedGame s, int delta)
throws SlickException {
// .......
if (moving)
{
if (movingDirection == DIR_RIGHT)
{
if (xCoord >= targetCoord)
{
xCoord = targetCoord;
moving = false;
}
else
{
xCoord += delta * 0.1f;
characterAnimation.update(delta);
if (xCoord > Window.WIDTH - 32)
{
xCoord = Window.WIDTH - 32;
}
}
}
else if (movingDirection == DIR_LEFT)
{
if (xCoord <= targetCoord)
{
xCoord = targetCoord;
moving = false;
}
else
{
xCoord -= delta * 0.1f;
characterAnimation.update(delta);
if (xCoord < 0)
{
xCoord = 0;
}
}
}
else if (movingDirection == DIR_UP)
{
if (yCoord <= targetCoord)
{
yCoord = targetCoord;
moving = false;
}
else
{
yCoord -= delta * 0.1f;
characterAnimation.update(delta);
if (yCoord < 0)
{
yCoord = 0;
}
}
}
else if (movingDirection == DIR_DOWN)
{
if (yCoord >= targetCoord)
{
yCoord = targetCoord;
moving = false;
}
else
{
yCoord += delta * 0.1f;
characterAnimation.update(delta);
if (yCoord > Window.WIDTH - 32)
{
yCoord = Window.WIDTH - 32;
}
}
}
}
}
Variable moving is set true after pressing movement key. Now after every call of render() the character is moved a little bit in the update() and rendered at this new position until it is exactly on the tile.
Related
I am currently working on a 2D side scroller and have implemented the techniques use in this article for a grapple hook, and it works really well. My problem is I want my player to be able to swing around the rope a little bit to gain a bit of momentum, but currently I can't stop the player from moving all the way up to 90 degrees either side. What techniques can be applied to force this limit?
I have tried using a separate player speed for swinging but this only slows the process down I can still swing up to 90 deg each side.
Here's my update function in the player
public void update(float dt){
//handle friction and air resistance
if(dx !=0){
if(touchingGround) {
// apply friction
if (dx > 0) {
dx -= retardation;
} else {
dx += retardation;
}
} else {
//applied air resistance
if (dx > 0) {
dx -= airResistance;
} else {
dx += airResistance;
}
}
}
// handle gravity
dy -= Constants.GRAVITY * dt;
if(dy < -terminalVelocity){
dy = -terminalVelocity;
}
/*
Handle Player movement
*/
if(right){
if(dx <= maxSpeed){
dx += acceleration;
}
dx = maxSpeed;
}
if(left){
if(dx <= -maxSpeed){
dx -= acceleration;
}
dx = -maxSpeed;
}
if(isGrappling){
//If we collide with something we need to stop grappling
if(hasCollided){
isGrappling = false;
} else {
// This algorithm from here:
// http://gamedev.stackexchange.com/questions/61596/player-rope-swing
float currentD = (float) Math.sqrt(((grappleX - x) * (grappleX - x)) + ((grappleY - y) * (grappleY - y)));
float prevX = getX(), prevY = getY();
if (currentD > grappleRadius) {
Vector2 hookPos = new Vector2(grappleX, grappleY);
Vector2 testPos = (new Vector2(x, y).sub(hookPos)).nor();
y = (hookPos.y + testPos.y * grappleRadius);
x = (hookPos.x + testPos.x * grappleRadius);
// s = d / t
dx += (x - prevX) / dt;
dy += (y - prevY) / dt;
}
}
}
/*
Collision Detection, handle last always!
*/
float oldX = getX(), oldY = getY();
boolean collisionX = false, collisionY = false;
// move on x
x += dx * dt;
// calculate the increment for step in #collidesLeft() and #collidesRight()
increment = collisionLayer.getTileWidth();
increment = getWidth() < increment ? getWidth() / 2 : increment / 2;
if(dx < 0) // going left
collisionX = collidesLeft();
else if(dx > 0) // going right
collisionX = collidesRight();
// react to x collision
if(collisionX) {
setX(oldX);
dx = 0;
}
// move on y
y += dy * dt;
// calculate the increment for step in #collidesBottom() and #collidesTop()
increment = collisionLayer.getTileHeight();
increment = getHeight() < increment ? getHeight() / 2 : increment / 2;
if(dy < 0) {
touchingGround = collisionY = collidesBottom();
// we can only jump 2 times before we have to touch the floor again
if(collisionY){
numberOfJumps = 2;
}
} else if(dy > 0) {
collisionY = collidesTop();
}
// react to y collision
if(collisionY) {
setY(oldY);
dy = 0;
}
hasCollided = collisionX || collisionY;
}
As I am not using any physics engine I chose to just emulate the physics by limiting the angle at which the player can apply force to the swing.
// check if angle permits movement
if(grappleAngle < Math.PI/9 && grappleAngle > -Math.PI/9) {
// handle momentum gaining on rope
if (right) {
dx += swingAcceleration * dt;
}
if (left) {
dx -= swingAcceleration * dt;
}
}
I have been trying to do player intersection with a small project i'm doing, and I can't seem to make it work. I got the Intersection to work with the player and the wall, but it's very buggy, by buggy I mean, it draws the player in the wall then moves him back instantly. (Check Gyazo for gif of this). I'm pretty sure the problem is that it only checks if the player is in the wall, and not WILL be in the wall, but I can't seem to figure out how to check this. This is what I have so far:
public void intersectsBox2(Rectangle r, Rectangle r2) {
P1 = new Point((int) r.getMinX(), (int) r.getMinY());
P2 = new Point((int) r.getMaxX(), (int) r.getMaxY());
P3 = new Point((int) r2.getMinX(), (int) r2.getMinY());
P4 = new Point((int) r2.getMaxX(), (int) r2.getMaxY());
if ((P2.y < P3.y || P1.y > P4.y || P2.x < P3.x || P1.x > P4.x)
&& !intersectsBox(playerRectangle(), noWalls[0])) {
isInsideWalls = true;
}
}
// Gets the players rectangle
public Rectangle playerRectangle() {
return new Rectangle(9 + dx, 23 + dy, 54, 90);
}
This is to make the player Move:
public void playerMovement() {
if (isInsideWalls) {
System.out.println("YOU ARE IN THE BOX!");
if (animation == down) {
dy -= moveSpeed;
isInsideWalls = false;
} else if (animation == up) {
dy += moveSpeed;
isInsideWalls = false;
} else if (animation == left) {
dx += moveSpeed;
isInsideWalls = false;
} else if (animation == right) {
dx -= moveSpeed;
isInsideWalls = false;
}
} else {
// Moves the player
if (moving == downMove) {
dy += moveSpeed;
moving = 0;
} else if (moving == upMove) {
dy -= moveSpeed;
moving = 0;
} else if (moving == leftMove) {
dx -= moveSpeed;
moving = 0;
} else if (moving == rightMove) {
dx += moveSpeed;
moving = 0;
}
}
This is to check for the intersection:
//Checks for intersection
for (int i = 0; i < 9; i++) {
for (int j = 0; j < 9; j++) {
intersectsBox2(walls[i][j], playerRectangle());
}
}
Not really sure if this is needed but heres the full Game.java if you need to see this: http://pastebin.com/GrDy689d
Also here is the Gif of the problem: http://i.gyazo.com/1f31f739897af78f81e61cf22ac772db.mp4
P.S: It's on purpose I can only go into 1 box at the moment for testing purposes.
You could move the player, then check to see if it is in a wall and, if it is, undo the move (or better, calculate a new location as the result of a move, check it, and if it is good, only then move the player there). Note that this assumes a single move can't put you all the way on the other side of a wall, but then it looks like your code does, too.
I'm trying to implement rope swinging in my platformer, following this tutorial. Instead of swing on the rope, the player looks like he's sliding down a slope: he moves very slowly towards the bottom.
This is what it looks like now:
Instead, I want the player to have more natural movement, like he's really swinging on the rope.
This is the update method from my player class:
#Override
public final void update() {
setPosition(getNextPosition());
if (direction == Direction.LEFT && moving) {
getVelocity().x = -WALK_SPEED;
} else if (getVelocity().x < 0) {
getVelocity().x *= COEF_FRIC;
}
if (direction == Direction.RIGHT && moving) {
getVelocity().x = WALK_SPEED;
} else if (getVelocity().x > 0) {
getVelocity().x *= COEF_FRIC;
}
checkAsleep();
animations.update();
if (ropePoint != null) {
//getCenter() returns the center position of the player
if (getCenter().toPoint().distanceSq(ropePoint) > ROPE_LENGTH * ROPE_LENGTH) {
final Vec2D oldPosition = getCenter();
final Vec2D oldVelocity = getVelocity();
final Vec2D ropePosition = new Vec2D(ropePoint);
setCenter((oldPosition.subtract(ropePosition).unit().multiply(ROPE_LENGTH).add(ropePosition)));
setVelocity(oldPosition.subtract(getCenter()).unit().multiply(oldVelocity));
}
}
}
This is my implementation of getNextPosition(), if it is needed.
public final Vec2D getNextPosition() {
final int currCol = (int) (getX() / Tile.SIZE);
final int currRow = (int) (getY() / Tile.SIZE);
final double destX = getX() + moveData.velocity.x;
final double destY = getY() + moveData.velocity.y;
double tempX = getX();
double tempY = getY();
Corners solidCorners = getCornersAreSolid(getX(), destY);
boolean topLeft = solidCorners.topLeft;
boolean topRight = solidCorners.topRight;
boolean bottomLeft = solidCorners.bottomLeft;
boolean bottomRight = solidCorners.bottomRight;
framesSinceLastTopCollision += 1;
framesSinceLastBottomCollision += 1;
framesSinceLastLeftCollision += 1;
framesSinceLastRightCollision += 1;
if (moveData.velocity.y < 0) {
if (topLeft || topRight) {
moveData.velocity.y = 0;
tempY = currRow * Tile.SIZE;
framesSinceLastTopCollision = 0;
} else {
tempY += moveData.velocity.y;
}
} else if (moveData.velocity.y > 0) {
if (bottomLeft || bottomRight) {
moveData.velocity.y = 0;
tempY = (currRow + 1) * Tile.SIZE - moveData.collisionBox.getHeight() % Tile.SIZE - 1;
framesSinceLastBottomCollision = 0;
} else {
tempY += moveData.velocity.y;
}
}
solidCorners = getCornersAreSolid(destX, getY());
topLeft = solidCorners.topLeft;
topRight = solidCorners.topRight;
bottomLeft = solidCorners.bottomLeft;
bottomRight = solidCorners.bottomRight;
if (moveData.velocity.x < 0) {
if (topLeft || bottomLeft) {
moveData.velocity.x = 0;
tempX = currCol * Tile.SIZE;
framesSinceLastLeftCollision = 0;
} else {
tempX += moveData.velocity.x;
}
}
if (moveData.velocity.x > 0) {
if (topRight || bottomRight) {
moveData.velocity.x = 0;
tempX = (currCol + 1) * Tile.SIZE - moveData.collisionBox.getWidth() % Tile.SIZE - 1;
framesSinceLastRightCollision = 0;
} else {
tempX += moveData.velocity.x;
}
}
return new Vec2D(tempX, tempY);
}
What should I change in this code to get natural movement?
My first guess is that the problem lies in that first if statement:
if (direction == Direction.LEFT && moving) {
getVelocity().x = -WALK_SPEED;
} else if (getVelocity().x < 0) {
getVelocity().x *= COEF_FRIC;
}
If the first thing is true, you're going to constantly be setting the velocity to walking pace, which doesn't make sense when your guy is swinging on a rope. He should be speeding up as he goes down and slowing down on the way up.
If the first thing is false, then since he is going left, you're definitely going to go into the else if statement, and he'll be slowed down by friction. I don't see where you set that, but it seems to still be the friction he has on the ground, which would seem to explain why he's all stuttery and looks more like he's sliding than falling.
You might want to add different states instead of just "moving", (perhaps jumping, swinging, walking, running, stopped) and vary how he behaves while doing each of those things.
I'm new to java, and game programming and I'm starting my first big project which is a 2D platform puzzle game.
This is my player movement code
if (speedX > 0 && centerX <= 400){
centerX += speedX;
}
if (speedX < 0 && centerX >= 400){
centerX += speedX;
}
if (speedX > 0 && centerX >= 400){
bg1.setSpeedX(-MOVESPEED);
bg2.setSpeedX(-MOVESPEED);
}
if (speedX < 0 && centerX <= 400){
bg1.setSpeedX(MOVESPEED);
bg2.setSpeedX(MOVESPEED);
}
if (speedX == 0){
bg1.setSpeedX(0);
bg2.setSpeedX(0);
}
if(movingRight == true && movingLeft == true ){
bg1.setSpeedX(0);
bg2.setSpeedX(0);
}
// Handles Jumping
if (jumped == true) {
speedY += 1;
}
// Prevents going beyond X coordinate of 0
if (centerX + speedX <= 60) {
centerX = 61;
}
rect.setRect(centerX - 47, centerY - 65, 32, 87);
centerY += speedY;
}
public void moveRight() {
speedX = MOVESPEED;
}
public void moveLeft() {
speedX = -MOVESPEED;
}
public void stopRight() {
movingRight = false;
stop();
}
public void stopLeft() {
movingLeft = false;
stop();
}
private void stop() {
if (movingRight == false && movingLeft == false) {
speedX = 0;
}
if (movingRight == false && movingLeft == true) {
moveLeft();
}
if (movingRight == true && movingLeft == false) {
moveRight();
}
}
public void jump() {
if (jumped == false) {
speedY = JUMPSPEED;
jumped = true;
}
}
and this is the collision code
public void checkCollision(Rectangle rect){
if (rect.intersects(r)){
if(Player.movingRight){
Player.centerX = tileX + 11;
Player.speedX =0;
}
if(Player.movingLeft){
Player.centerX = tileX + 89;
Player.speedX = 0;
}
if(Player.speedY > 0){
Player.centerY = tileY - 25;
Player.speedY = 0;
Player.jumped = false;
}
}
}
There are two problems.The first one is that if I press one of the movement keys when landing the character "teleports" to the right or left.
I know this happens because I programmed it that if the character intersects with the ground while movingRight or movingLeft are true he moves right or left.(I made it this way so the horizonal collision will work) and I cant think of any other way to do it or how to fix it.
The second problem is that if the character moves of a platfrom he does not fall down.
I tryed to fix it by adding to the collision method
else{
speedY += 1;
}
But it made the character disappear for some reason.
Thanks a lot!
This code was originally written in C++ for a 3D platformer. I rewrote it, but there might be some bugs. I can draw a picture later if it's difficult to understand.
public void checkCollision(Rectangle rect){
if(player.intersects(rect)) {
//the rectangles intersect, time to move the player out of the block
if(rect.y+rect.height >= player.y && rect.y+rect.height-0.7f < player.y) { //if the player is at most 0.7 units (you should change this!) below top side
player.y = rect.y+rect.height; //set player to stand on top
speed.y = 0f; //stop the movement
onGround = true;
} else if(rect.y+rect.height > player.y && rect.y < player.y+player.height) { //if the playeer is on the side, but not below
float xEscMinus = (float)Math.abs((rect.x+rect.width)-player.x); //find the distance to the side
float xEscPlus = (float)Math.abs(rect.x-(player.x+player.width));
if(xEscMinus<xEscPlus) {
player.x = rect.x+rect.width;
} else {
player.x = rect.x-player.width;
}
}
}
}
I am currently creating a maze using a pair of boolean array (horizontal and vertical) in order to draw lines for the maze.
The maze only every displays 5 bools from the array at one time. Then, I have an user who is always centered and as he moves through the maze the next set of bools are drawn. This is working as it should.
The issue that I am having is: when the user moves to a certain part of the maze the for loop drawing the lines becomes higher than the bool array and therefore crashes the app. Please find below some code snippets.
The onDraw:
protected void onDraw(Canvas canvas) {
canvas.drawRect(0, 0, width, height, background);
int currentX = maze.getCurrentX(),currentY = maze.getCurrentY();
int drawSizeX = 6 + currentX;
int drawSizeY = 6 + currentY;
currentX = currentX - 2;
currentY = currentY - 2;
for(int i = 0; i < drawSizeX - 1; i++) {
for(int j = 0; j < drawSizeY - 1; j++) {
float x = j * totalCellWidth;
float y = i * totalCellHeight;
if(vLines[i + currentY][j + currentX]) {
canvas.drawLine(x + cellWidth, //start X
y, //start Y
x + cellWidth, //stop X
y + cellHeight, //stop Y
line);
}
if(hLines[i + currentY][j + currentX]) {
canvas.drawLine(x, //startX
y + cellHeight, //startY
x + cellWidth, //stopX
y + cellHeight, //stopY
line);
}
}
//draw the user ball
canvas.drawCircle((2 * totalCellWidth)+(cellWidth/2), //x of center
(2 * totalCellHeight)+(cellWidth/2), //y of center
(cellWidth*0.45f), //radius
ball);
}
EDIT 1 - The Move -
public boolean move(int direction) {
boolean moved = false;
if(direction == UP) {
if(currentY != 0 && !horizontalLines[currentY-1][currentX]) {
currentY--;
moved = true;
}
}
if(direction == DOWN) {
if(currentY != sizeY-1 && !horizontalLines[currentY][currentX]) {
currentY++;
moved = true;
}
}
if(direction == RIGHT) {
if(currentX != sizeX-1 && !verticalLines[currentY][currentX]) {
currentX++;
moved = true;
}
}
if(direction == LEFT) {
if(currentX != 0 && !verticalLines[currentY][currentX-1]) {
currentX--;
moved = true;
}
}
if(moved) {
if(currentX == finalX && currentY == finalY) {
gameComplete = true;
}
}
return moved;
}
If there is anything else that I need to clarify please let me know.
Thanks in advance.
drawSizeX/Y indexes over the array when currentX/Y is high enough (length-6)
So limit the values to Math.min(current + 6, array.length)