Sticky Collisions

106 views Asked by At

I'm making a quick tilemap game, with tilemap collisions. The problem is when I run into a wall it sticks. I can get out of it, but I'm aiming to make it so when you hit the wall, you still fall, instead of stay on the wall. I've tried to detect the collisions separately, but it doesn't work. Here's the collision section of the code:

//31 is the amount of blocked tiles.
for(int counter = 0; counter < 31; counter++) {

        if(spriteX + 40 + velX >= collisionX[counter] && collisionX[counter] + 100 >= spriteX + velX &&spriteY + 40 + velY >= collisionY[counter] && collisionY[counter] + 100 >= spriteY + velY) {

            velX = 0;
            velY = 0;

            collisions = counter;

        } else {

            if(counter == collisions && jumping == false) {

                fall();

            }

        }

I know the array is bulky, I'm fixing that. Here's the whole class:

package Main;

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.image.BufferedImage;

import javax.swing.JPanel;

public class Panel extends JPanel implements Runnable, KeyListener {

// dimensions

public static final int width = 800;
public static final int height = 800;
public static final int scale = 1;

// main loop

private Thread thread;
private boolean running = false;
private int FPS = 60;
private int targetTime = 1000 / FPS;

// drawing

private Graphics2D g;
private BufferedImage image;

int x;
int y;

boolean makeCollision = false;

// sprite

int spriteX = 210;
int spriteY = 200;
int velX = 0;
int velY = 10;

public boolean notOnGround = true;

int counter;
int collisionsCounter;
int jumps = 0;

public int row;
public int column;

public boolean collision;
public boolean jumping = false;

public String side = null;

// tilemap

int[][] map = {

        {1, 1, 1, 1, 1, 1, 1, 1},
        {1, 0, 0, 1, 0, 0, 1, 1},
        {1, 0, 0, 0, 0, 1, 1, 1},
        {1, 0, 0, 0, 1, 1, 0, 1},
        {1, 0, 0, 1, 1, 0, 0, 1},
        {1, 0, 0, 1, 0, 0, 0, 1},
        {1, 0, 0, 0, 0, 0, 0, 1},
        {1, 1, 1, 1, 1, 1, 1, 1}

};

int[] collisionX = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, };
int[] collisionY = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, };
int[] jump = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, };
int collisions;

public Panel() {

    setPreferredSize(new Dimension(width * scale, height * scale));
    setFocusable(true);
    requestFocus();

}

public void addNotify() {
    super.addNotify();

    if(thread == null) {

        running = true;
        addKeyListener(this);
        thread = new Thread(this);
        thread.start();

    }

}

public void init() {

    image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
    g = (Graphics2D) image.getGraphics();

}

public void update() {

    if(spriteY < jump[0]) {

        System.out.println(jump[0]);

        jumping = false;

        fall();

    }

}

public void draw() {

    g.clearRect(0, 0, WIDTH, HEIGHT);

    x = 0;
    y = 0;

    for(column = 0; column <= 7; column++) {

        x = 0;

        for(row = 0; row <= 7; row++) {

            changeColor(row, column, g);

            g.fillRect(x, y, 100, 100);

            x = x + 100;

        }

        y = y + 100;

    }

    g.setColor(Color.YELLOW);
    g.fillRect(spriteX, spriteY, 40, 40);

    spriteX += velX;
    spriteY += velY;

    for(int counter = 0; counter < 31; counter++) {

        if(spriteX + 40 + velX >= collisionX[counter] && collisionX[counter] + 100 >= spriteX + velX &&spriteY + 40 + velY >= collisionY[counter] && collisionY[counter] + 100 >= spriteY + velY) {

            velX = 0;
            velY = 0;

            collisions = counter;

        } else {

            if(counter == collisions && jumping == false) {

                fall();

            }

        }

    }

}

public void changeColor(int rowGive, int columnGive, Graphics g) {

    if(map[rowGive][columnGive] == 1) {

        g.setColor(Color.BLACK);

        if(counter < 30) {

            collisionX[counter] = x;
            collisionY[counter] = y;

        }

        counter++;

    } else {

        g.setColor(Color.WHITE);

    }

}

public void fall() {

    velY = 5;

}

public void drawToScreen() {

    Graphics g2 = getGraphics();
    g2.drawImage(image, 0, 0, width * scale, height * scale, null);
    g2.dispose();

}

public void run() {

    init();

    long wait;
    long elapsed;
    long start;

    while(running) {

        start = System.nanoTime();
        update();
        draw();
        drawToScreen();

        elapsed = System.nanoTime() - start;

        wait = targetTime - elapsed / 1000000;

        if(wait < 0) wait = 5;

        try {

            thread.sleep(wait);

        } catch(Exception e) {

            e.printStackTrace();

        }

    }

}

public void keyPressed(KeyEvent e) {

    int code = e.getKeyCode();

    if(code == KeyEvent.VK_RIGHT) {

        velX = 5;

    }
    if(code == KeyEvent.VK_LEFT) {
        velX = -5;

    }
    if(code == KeyEvent.VK_SPACE && jumping == false) {

        jumping = true;

        velY = -5;
        jump[0] = spriteY - 100;

    }

}
public void keyReleased(KeyEvent e) {



}
public void keyTyped(KeyEvent e) {


}

}

1

There are 1 answers

0
AngelTrs On

For the sprite to stop sticking and continue to fall, your program needs to distinguish between the different types of collision: a collision with 'bottom-tile', the ground, versus a tile above or next to the sprite that doesn't stop gravity. Currently your collision section treats all types of collisions the same by stopping all of the sprites movement.

A simple solution would be to make all of your 'bottom-tiles' a different number in your matrix. For example:

{1, 2, 2, 1, 1, 1, 1, 1},
{1, 0, 0, 2, 0, 0, 1, 1},
{1, 0, 0, 0, 0, 1, 2, 1},
{1, 0, 0, 0, 1, 2, 0, 1},
{1, 0, 0, 1, 2, 0, 0, 1},
{1, 0, 0, 2, 0, 0, 0, 1},
{1, 0, 0, 0, 0, 0, 0, 1},
{1, 1, 1, 1, 1, 1, 1, 1}

The complex solution would be to make your program differentiate the 'bottom-tiles' by checking to see if the tile above it is a white-tile (non-collision tile.) If it is this, then this tile can be hit from above and can stop the sprite from falling.

In both cases, you would then alter your collision section to only stop the sprite from falling if it collides with a 'bottom-tile'. If it collides with a tile on the sides or above, you can make the sprite bounce in the opposite direction.