2D平台游戏中的碰撞错误

Question

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!

Answer 1

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;
            }
        }
    }
}