Zombie game - Help needed for pathfinding

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Zombie game - Help needed for pathfinding

in Programming Questions • 1 year ago

Hello everyone, I wonder if anyone would help me with an issues I have regarding pathfinding.

I am making a 2D zombie shooter and I am working on making my zombies separate rather than group together. With a lot of help from a friend (who wrote this section of code) I have now got an algorithm that:

Checks for the nearest zombie

Works out the possible move it can make

Checks to see if there is another zombie in the way

If not then it can move

If there is, see if you can move on the x axis (and vice versa)

BUT! When the program is run, some of the zombies will not make the required move, so I have zombies dotted around the screen just not moving - unless I make the player move somewhere else to make the zombie move again.

I don't want to paste the whole program into this post as there is too much of it, but have a look at the above function and you may be able to help!

void seekTarget() {
Mover closestZombie = null;
float distanceToClosestZombie = 10000; // arbitrary large number
float distance;
int tryX = x;
int tryY = y;
// find which of the other zombies is nearest to this one,
// and what distance separates them
for (Mover m: movers) {
if (m == this) {
// don't compare this zombie to itself!
continue;
}
distance = dist(x, y, m.x, m.y);
if (distance < distanceToClosestZombie) {
// the zombie being tested is the closest found yet
closestZombie = m;
distanceToClosestZombie = distance;
}
}
// work out the "ideal" new x and y coordinates, assuming
// for now that the closest zombie is not in the way
// (we'll find that out in a moment)
/*if(targetX > x) {
tryX++;
//println("working");
} else if(targetX < x) {
tryX--;
//println("working");
}
if (targetY > y) {
tryY++;
//println("working");
} else if(targetY < y) {
tryY--;
//println("working");
}*/
if(targetX > player.x) {
//tryX = tryX + int(zombieSpeed);
tryX--;
image(zombieLEFT, tryX, tryY);
println("working");
} else if(targetX < player.x) {
tryX++;
//tryX = tryX - int(zombieSpeed);
image(zombieRIGHT, tryX, tryY);
}
if(targetY > player.y) {
tryY--;
//tryY = tryY - int(zombieSpeed);
image(zombieUP, tryX, tryY);
} else if(targetY < player.y) {
tryY++;
//tryY = tryY + int(zombieSpeed);
image(zombieDOWN, tryX, tryY);
}
// if the closest zombie is not already too close, make the
// ideal move computed above
if (distanceToClosestZombie > MIN_ZOMBIE_SEPARATION) {
x = tryX;
y = tryY;
}
// otherwise, only make a move that will cause the separation
// between this zombie and its closest neighbour to either
// increase or remain the same
else {
if (dist(tryX, tryY, closestZombie.x, closestZombie.y) >=
distanceToClosestZombie) {
// the ideal move increases or doesn't change the separation
x = tryX;
y = tryY;
}
else if (dist(tryX, y, closestZombie.x, closestZombie.y) >=
distanceToClosestZombie) {
// only the horizontal component of the ideal move increases
// or doesn't change the separation
x = tryX;
}
else if (dist(x, tryY, closestZombie.x, closestZombie.y) >=
distanceToClosestZombie) {
// only the vertical component of the ideal move increases
// or doesn't change the separation
y = tryY;
}
}
}

The Mover is the zombie :)

Ah - My mate thinks it is to do with the fact that I also have a move() function separate to this, and that I need to integrate it into the above function, below is the other move() function:

void move() {
int wouldBeX = x;
int wouldBeY = y;
//Move along X axis to find player
if (x < player.x) {
x++;
image(zombieRIGHT, x, y);
}
else if (x > player.x) {
x--;
image(zombieLEFT, x, y);
}
//Move along Y axis to find player
if (y < player.y) {
y++;
image(zombieDOWN, x, y);
}
else if (y > player.y) {
y--;
image(zombieUP, x, y);
}
for (Mover m: movers) {
//tryToMove(m, wouldBeX, wouldBeY);
}
}

Thanks!

Replies(4)

docbones

Re: Zombie game - Help needed for pathfinding

1 year ago

Hi,

Maybe you can find help with the A* algorythm, designed for pathfinding. Here's a smart introduction :
A* pathfinding for beginners (naturally, "beginner" isn't pejorative, we're all beginners somewhere... ;)

Hope it helps.

Chrisir

Re: Zombie game - Help needed for pathfinding

1 year ago

The Code is too long to read and understand completely

1st Remark

you have

if(targetX > player.x) {

and

} else if(targetX < player.x) {

what if they are the same?
same goes for y...

2nd Remark

Did you test this:

if (m == this) {

3rd Remark

try to enter some random

smiley_fa..

Re: Zombie game - Help needed for pathfinding

1 year ago

Thanks Docbones - I have thought about the A* pathfinding algorithm but was told it was far too complicated for what I'm trying to do.

Thanks Chrisir - The likelihood of the zombies possible x & y co-ordinates being the same is really minuscule so I haven't coded for that event. As far as the (m == this) goes, that's just so the zombie doesn't test itself when looking for other zombies that are close to it - cos that would be silly :P And what do you mean "try to enter some random"?

But thank you both for replying - I understand the code is really long for one post but I wasn't really sure on how I could change that and still get my problem across :)

Chrisir

Re: Zombie game - Help needed for pathfinding

1 year ago

As far as the (m == this) goes, that's just so the zombie doesn't test itself

I know - but does it work? Check with println or so.

try to enter some random

that was the idea to have every 5th step or so slightly varied by a random number - so it's a little more random walk / less determinated

see random() in the reference

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