16 replies to this topic

[Necdilzor]

I'm making a top down bomberman-like game. When the player puts a bomb on the floor 3 seconds pass and it explodes, but how do I make it blow only the 2 rocks above,below, at the left and right of it and not all the rocks?

Thanks.

[AB10784]

use distance_to_object to check if the bomb is close enough to the bricks, then instance_destroy

Edited by AB10784, 07 May 2009 - 07:16 PM.

[Necdilzor]

Didn't work :S

[AB10784]

Can you please give an example of object names, the code you are using for each object as well?

Edit: spelling

Edited by AB10784, 07 May 2009 - 08:31 PM.

[ThatSnail]

Run collision_line() in a while loop, so that it detects all rocks colliding horizontally and vertically two blocks.

while(collision_line(x-64,y,x+64,y,obj_rock,false,true)>=0)
	{
	with(collision_line(x-64,y,x+64,y,obj_rock,false,true)>=0)
		{
		instance_destroy();
		}
	}

Do the same thing for the vertical line, changing the arguments for collision_line() to match it.

collision_line(x1,y1,x2,y2,obj,prec,notme) This function tests whether there is a collision between the line segment from (x1,y1) to (x2,y2) and entities of object obj. This is a powerful function. You can e.g. use it to test whether an instance can see another instance by checking whether the line segment between them intersects a wall.

[bbb0280]

make an explosion sprite, no an explosion object

then instance create, obj_explosion
\
if_place_meeting(obj_explosion) instance_destroy()

[Necdilzor]

I put this code:

while(collision_line(x-48,y,x+48,y,objRock,false,true)>=0)
	{
	with(collision_line(x-48,y,x+48,y,objRock,false,true)>=0)
		{
		instance_destroy();
		}
	}

and when I placed a bomb in-game it freezed.

Edited by Necdilzor, 07 May 2009 - 09:08 PM.

[ThatSnail]

I put this code:

while(collision_line(x-48,y,x+48,y,objRock,false,true)>=0)
	{
	with(collision_line(x-48,y,x+48,y,objRock,false,true)>=0)
		{
		instance_destroy();
		}
	}

and when I placed a bomb in-game it freezed.

My mistake.

while(collision_line(x-48,y,x+48,y,objRock,false,true)>=0)
	{
	with(collision_line(x-48,y,x+48,y,objRock,false,true))
		{
		instance_destroy();
		}
	}

I'm an idiot . Had >=0 at the end of the with statement.

Edited by Snail Productions, 07 May 2009 - 09:10 PM.

[Necdilzor]

yes it works! but only horizontally, maybe something is missing?

[AB10784]

LOL infinate loop, nice on the first go Snail.. JK I did that on accident in one of my games and was like wtf why does it freeze!! Not to mention once i accidentally made an object increase its speed exponentially when I pressed an arrow key.. LOL


anyways try to duplicate the code then change the + to - and vice versa.?

EDIT: scratch that ^^ change the x's to y's leave the +/-

Edit2: man Im retarded..... Remove the + and - modifiers from the x and put them on y

Edit: @ Snail productions

Btw, if you're getting annoyed at me just hinting at the code instead of downright posting it, then ask.

^ LOL

Edited by AB10784, 07 May 2009 - 09:38 PM.

[ThatSnail]

yes it works! but only horizontally, maybe something is missing?

Glad it works
I deliberately left out the vertical code because I didn't want to just hand it to you (more or less wanted to teach you how to do it). But it's pretty much the same thing; duplicate the code, and just alter the collision_line() arguments. Hope that helps.

Edit:
@AB10784:
Yeah, infinite loops are evil . Also you're right about the xy thing. Basically changing the endpoints of the lines.

Edited by Snail Productions, 07 May 2009 - 09:28 PM.

[Necdilzor]

what arguments do I have to alter? the X's and Y's?

[ThatSnail]

what arguments do I have to alter? the X's and Y's?

Yes.

collision_line(x-48,y,x+48,y,objRock,false,true);

The first two arguments (x-48,y) are coordinates for the first endpoint. The second two arguments (x+48,y) are coordinates for the second endpoint. The line is horizontal, from 48 pixels left of x to 48 points to the right of x. In the vertical line, you want it from 48 points above y to 48 below it.

Btw, if you're getting annoyed at me just hinting at the code instead of downright posting it, then ask.

[Necdilzor]

I'm new to GML and I haven't found out yet how to do it vertically. Could you post the code please?

Edited by Necdilzor, 07 May 2009 - 09:50 PM.

[ThatSnail]

I'm new to GML and I haven't found out yet how to do it vertically.

Full code here.

while(collision_line(x-48,y,x+48,y,objRock,false,true)>=0)
	{
	with(collision_line(x-48,y,x+48,y,objRock,false,true))
		{
		instance_destroy();
		}
	}
while(collision_line(x,y-48,x,y+48,objRock,false,true)>=0)
	{
	with(collision_line(x,y-48,x,y+48,objRock,false,true))
		{
		instance_destroy();
		}
	}

Explanation:
The vertical code is:

collision_line(x,y-48,x,y+48,objRock,false,true)>=0

The first coordinate here would be (x,y-48), 48 pixels above the object's position. (x,y+48) is the second coordinate, 48 pixels below. So the first instance (lowest instance id) that intersects that line is detected. If that is greater than or equal to 0 (it exists), then destroy it, and check for any other rocks intersecting the line again. Keep doing this until the collision_line() returns a negative number (meaning there are no more rocks in the line), and then stop the while loop.

Pretty complex for beginning GML. I suggest you look up the while statement in the manual for a better explanation.
Anyways, hope this helps, and good luck with your game

[Necdilzor]

EDIT: Damn, I didn't write it right! It works now, thanks a lot for your help!

Edited by Necdilzor, 07 May 2009 - 10:17 PM.

[ThatSnail]

EDIT: Damn, I didn't write it right! It works now, thanks a lot for your help!

No probs . Good luck!