[BEHAVIOR] Chipmunk Physics

Im curious about performance on mobile, also will this work with C3 ?

You'd have to test it and see how it performs on mobile. I've only tested the html5 export and I was never concerned with performance tests because this is just a wrapper to an existing js library.

Also as with any third party plugin/behavior in C2 it won't work in C3 unless it's converted over. No plans to do so though.

R0J0hound , I'm having an issue with tile collisions polygons. It seems like the polygons are generated fine when the tile is index of 0, but if it is a different index, like tile 1 or 2, etc, the polygons don't combine together.

Is there a way for me to confirm if this is the case? How can I fix this if it is?

..maybe a bug in the tilemap object??

edit: the tilemap's collision rects property value in debug remains the same when I replace tile type 1 with tile type 0, so maybe it's a chipmunk bug.

Okay, so.. here is some more info..

Seems like if I modify the tile's collision poly, then Chipmunk separates it into another group or something. Moving the points back won't revert it, I had to right click and set the collision poly to bounding box for it to combine properly.

Maybe there is a flag somewhere that is set if you set the poly to bounding box, and it is toggled when moving the points?

Anyways.. kind of interesting.. Basically if a tile is considered a polygon(not bounding box), then it won't combine with tiles that are considered of bounding box type.

That's expected. It's C2, not the behavior that combines tiles with bounding box collision polygons. I haven't looked in a bit but I'm sure it keeps track with a flag. Once a tile's collision polygon is modified it can't be combined with neighboring tiles. I mean we could come up with something to do it but it wouldn't be fast.

Alright- makes sense.

I only need the bounding box type for my specific case, I was just confused at first but figured out I had to reset poly to bounding box (can't just drag the points to the corners).

Chipmunk still is very great to use- one of my main reasons I use Construct2.

I'm glad it's still useful.

Is anyone else having problems with the built-in save/load system, the physics seem to lag behind a fair bit.

https://www.dropbox.com/s/gsuj4ni4vnjvfj6/chipmunk%20problems.capx?dl=0

Have you or anyone else found a solution to the pausing after loading a savestate?

Saving the game seems to record the tickcount and time, etc... I noticed that loading after waiting a bit causes the pause to be prolonged.. I think the Chipmunk behavior is waiting for the time to catch up to the simulation.. Because when you load, the time/tickcount goes back in time..

So now, I'm going to explore the plugin and see what can be done about it..

edit: yep, when I wait and then save game.. then reload the game and immediate load the state, it instantly starts moving because the time being loaded is in the future.

I did not implement saving and loading state with this. I haven't reasoned about what side effects this would cause but it probably causes the effects you see.

Okay, yeah.

Not sure how this will effect things, but this is what I did to remove the pausing:

	// called when saving the full state of the game
	behinstProto.saveToJSON = function ()
	{
		// return a Javascript object containing information about your behavior's state
		// note you MUST use double-quote syntax (e.g. "property": value) to prevent
		// Closure Compiler renaming and breaking the save format
		return {
			// e.g.
			//"myValue": this.myValue
			"lastUpdateTick": this.behavior.lastUpdateTick
		};
	};
	
	// called when loading the full state of the game
	behinstProto.loadFromJSON = function (o)
	{
		// load from the state previously saved by saveToJSON
		// 'o' provides the same object that you saved, e.g.
		// this.myValue = o["myValue"];
		this.behavior.lastUpdateTick = o["lastUpdateTick"];
		// note you MUST use double-quote syntax (e.g. o["property"]) to prevent
		// Closure Compiler renaming and breaking the save format
	};
[/code:1khl2d9h]

I did that because I noticed this:

[code:1khl2d9h]behinstProto.tick = function ()
	{
		var timescale = this.runtime.timescale;
		if (this.runtime.tickcount > this.behavior.lastUpdateTick && timescale > 0)
		{[/code:1khl2d9h]

Since loading a savestate changes the tickcount, it waits until the tickcount catches back up to where the behavior has it set to.

Not sure if it will have any side-effects.

The idea there is to only run the physics simulation once per tick. You probably could just check if the last run tick is different than the current one:

this.runtime.tickcount != this.behavior.lastUpdateTick

Oh! okay, that makes sense. I'll do it that way rather than mess with the saving/loading stuff. thanks!

R0J0hound

I want to create a rigid joint like that:

https://drive.google.com/file/d/0B8g2b8 ... sp=sharing

but Physic behavior not support "collision Filter", so I have to use Chipmunk behavior.

How do I create a rigid joint by only one action in Chipmunk Behavior?

Thank you!

hi , have chipmunk grabling hook tutorial or exaple capax ?