[Not Solved] Bullets Collide With Entities?

[Deltise]

Currently I'm using randomly generate entities (that are made using an object system) and the player being able to fire bullets using WASD and move with the arrow keys. Within the zombie's AI code, I have it searching collisions by comparing it's own position, with the position of a bullet in the bullet table.

I want the entities to basically take damage from the bullets fired at them by the player but...

(This is in my Entities.lua under each of the enemies' update/AI sections)

Code: Select all

brgx = self.x
brgy = self.y

for i, v in ipairs(bullet) do
bvx = v.x 
bvy = v.y
end

if brgx == bvx and brgy == bvy and self.hitready == true then
self.health = self.health - player.damage
end


if self.health >= 0 then
	for i, v in ipairs(bullet) do
	table.remove(enemies, i)
	end
end

...what happens when I test the game out is that as soon as I fire, all of the entities on the field die without even touching the bullet.
Everything else in the game works fine such as player collision with entity and so on.

Thanks for your help in advance

[Plu]

Code: Select all

if self.health >= 0 then
   for i, v in ipairs(bullet) do
   table.remove(enemies, i)
   end
end

This reads "if my health is more than 0, roll through each entry in bullets and remove the corresponding enemy". That can't be right, can it?

[NightKawata]

This should work: (I forgot to respond earlier)

Code: Select all

if self.health <= 0 then
   for i, v in pairs(enemies) do
     if v == self then
       table.remove(enemies, i)
     end
   end
end

Now let's analyze this:

Code: Select all

if self.health >= 0 then
   for i, v in ipairs(bullet) do
   table.remove(enemies, i)
   end
end

First issue, it checks to see if the health is greater than or equals zero. I'm sure you don't want that.
Second issue, I'm assuming you're killing the enemy here, so why are you iterating through the bullet table?
Next up, that iterator will delete every enemy for as many indexes exist in the bullets, which'll pretty much kill everything. (I'm not 100% sure on that though.)

[MadByte]

There seems to be much more problems then the "if self.health >= 0 then" loop.
Sadly I'm not really familiar with this kind of object creation.

[Deltise]

This should work: (I forgot to respond earlier)

Code: Select all

if self.health <= 0 then
   for i, v in pairs(enemies) do
     if v == self then
       table.remove(enemies, i)
     end
   end
end

Now let's analyze this:

Code: Select all

if self.health >= 0 then
   for i, v in ipairs(bullet) do
   table.remove(enemies, i)
   end
end

First issue, it checks to see if the health is greater than or equals zero. I'm sure you don't want that.
Second issue, I'm assuming you're killing the enemy here, so why are you iterating through the bullet table?
Next up, that iterator will delete every enemy for as many indexes exist in the bullets, which'll pretty much kill everything. (I'm not 100% sure on that though.)

Ah, my mistake, thank you,
How would you approach the bullet collision thing though, where an entity will die even though it hasn't hit the bullet?

EDIT: With this bit of code, the entities don't die at all, probably because my collide condition only registers the top left corner of the bullet, but how would I go about calculating any form of collision between the entity and the bullet?

[Deltise]

Code: Select all

if self.health >= 0 then
   for i, v in ipairs(bullet) do
   table.remove(enemies, i)
   end
end

This reads "if my health is more than 0, roll through each entry in bullets and remove the corresponding enemy". That can't be right, can it?

Yeah, caught that after looking at my code, I was being silly and not paying attention. But I still don't know how to go about creating an if statement that checks if a bullet collided with an entity

[davisdude]

You can do 1 of 3 things (from easiest to hardest):
1) Make the bullet have a rectangular hit-box.
2) Make the enemies have circular hit-boxes (not recommended).
3) Look at the post I had a couple months ago. It has nice code for circle-rectangle collision (which is what you want).
http://www.love2d.org/forums/viewtopic.php?f=4&t=33493
This is a link to the thread.

[Deltise]

You can do 1 of 3 things (from easiest to hardest):
1) Make the bullet have a rectangular hit-box.
2) Make the enemies have circular hit-boxes (not recommended).
3) Look at the post I had a couple months ago. It has nice code for circle-rectangle collision (which is what you want).
http://www.love2d.org/forums/viewtopic.php?f=4&t=33493
This is a link to the thread.

What if their both rectangles :T

[davisdude]

You can do something like this:

Code: Select all

for i = #bullets, 1, -1 do --w and h are width and height, respectivey
  for i = for b = #bullet, 1, -1 do
		for e = #enemy, 1, -1 do	
			if b.x + b.w > e.x and
                        b.x < e.x + e.w and
                        b.y + b.h > e.y and
                        b.y < e.y + e.h then
				print("hit!")
				table.remove(bullet, b)
				table.remove(enemy, e)
			end
		end
	end
end

[Deltise]

You can do something like this:

Code: Select all

for i = #bullets, 1, -1 do --w and h are width and height, respectivey
  for i = for b = #bullet, 1, -1 do
		for e = #enemy, 1, -1 do	
			if b.x + b.w > e.x and
                        b.x < e.x + e.w and
                        b.y + b.h > e.y and
                        b.y < e.y + e.h then
				print("hit!")
				table.remove(bullet, b)
				table.remove(enemy, e)
			end
		end
	end
end

Where exactly would I throw this into? My bulletUpdate?
If so, I get an error at the start saying that it cannot find the height of the bullet, because no bullets are spawned yet at the start of the game