Collision module and performance

[peterigzParticipant]

My latest round of optimisations is now up to 5.6mill/sec which I’ll settle for for now, really pleased with that. I’ve learnt quite a few things along the way, and also some oddities. It’s definitely ok to modify the fields of a struct in some cases so I won’t worry to much about that, for example this:

Monkey

[crayon-5cba16c0ce008474389588 inline="true" ] Method TFormBoundingBox() 'After the bounding box is updated, it needs to be moved into world space. boxoffset.x = tl_corner.x boxoffset.y = tl_corner.y tl_corner.x+=world.x tl_corner.y+=world.y br_corner.x+=world.x br_corner.y+=world.y End

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[crayon-5cba16c0ce008474389588 inline="true" ] Method TFormBoundingBox() 'After the bounding box is updated, it needs to be moved into world space. boxoffset.x = tl_corner.x boxoffset.y = tl_corner.y tl_corner.x+=world.x tl_corner.y+=world.y br_corner.x+=world.x br_corner.y+=world.y End

[/crayon]

worked out quicker than:

Monkey

[crayon-5cba16c0ce00e041622705 inline="true" ] Method TFormBoundingBox() 'After the bounding box is updated, it needs to be moved into world space. boxoffset = tl_corner.Clone() tl_corner+=world br_corner+=world End

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[crayon-5cba16c0ce00e041622705 inline="true" ] Method TFormBoundingBox() 'After the bounding box is updated, it needs to be moved into world space. boxoffset = tl_corner.Clone() tl_corner+=world br_corner+=world End

[/crayon]

So I guess if your struct already exists and you need to clone it or change values then it can be ok. But in this case:

vec.Normalise()

Where the normalise method modifies the fields of the vector was quite a bit slower than:

vec = vec.Normalise()

Where it returns a new normalised vec. It’s really nice that mx2 gives you that extra control to make a difference with the speed of a program.

[Mark SiblyKeymaster]

Have a look at Operator+=

Mx2 will synthesize one for you, but you can provide your own too.

[Mark SiblyKeymaster]

Also, just cleaning up another issue and there appear to be several places in timelinefx where you use ‘Stack’ or List’ without any type, eg:

Method GetObjectsInBox:Stack(area:tlBox, Layer:Int[], GetData:Int = False)

This was compiling before but wont with the next release. Full list of errors with my release…

D:/dev/monkey2/modules/timelinefx/quadtree.monkey2 [246] : Error : Type ‘Stack<T?> is generic
D:/dev/monkey2/modules/timelinefx/quadtree.monkey2 [291] : Error : Type ‘Stack<T?> is generic
D:/dev/monkey2/modules/timelinefx/quadtree.monkey2 [841] : Error : Type ‘Stack<T?> is generic
D:/dev/monkey2/modules/timelinefx/quadtree.monkey2 [936] : Error : Type ‘Stack<T?> is generic
D:/dev/monkey2/modules/timelinefx/collision.monkey2 [1068] : Error : Type ‘List<T?> is generic

[peterigzParticipant]

Thanks, fixed. Although I still have work to do on some of those quadtree methods. Is there an equivalent to .Last for stacks by the way? I’m guessing Top is the same as First?

I see what you mean about += operator, yes that does seem to sort it. The Clone method really kills it though (about 500k less), a bit odd?

Monkey

[crayon-5cba16c0d781f018771980 inline="true" ] Method Clone:tlVector2() Return New tlVector2(x, y) End

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[crayon-5cba16c0d781f018771980 inline="true" ] Method Clone:tlVector2() Return New tlVector2(x, y) End

[/crayon]

But then again I get different results elsewhere and clone seems fine. I think I’ll just put it down to the compiler and how it evaluates things in its own exotic way!

[Mark SiblyKeymaster]

I mean ‘Operator+=’, not ‘Operator+’, eg:

Monkey

Operator+=( v:tlVector2 ) 'no return value!    x+=v.x    y+=v.y End

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Operator+=( v:tlVector2 )  'no return value!    x+=v.x    y+=v.y End

If you’ve defined an Operator+() but not an Operator+=(), mx2 will rewrite…

p+=v

…as…

p=p+v

…but if you’ve defined Operator+=(), mx2 will use that instead.

I’m guessing Top is the same as First?

Top is really ‘last’, ie: the last thing pushed/added. blah[0] is ‘first’. You can use a stack pretty much how you’d use a c++ std::vector or java ‘ArrayList’, ie: index with [i], so blah[blah.Length-1] is also ‘last’ or ‘Top’.

[peterigzParticipant]

Thanks Mark, yes I actually realised what you meant about the += and edited my post before you saw I think. I did add that operator to my vec class and it did help so that’s good.

That’s good about Top too, I was hoping it’d be the same as Last

[peterigzParticipant]

Got this pretty much all working now I do have one issue though, I just started updating the docs but now for some reason it hangs when compiling, doesn’t get passed “Parsing”:

Monkey

[crayon-5cba16c0de553525117479 inline="true" ]C:\monkey2\bin>mx2cc_windows makemods timelinefx MX2CC V0.011 ***** Making module 'timelinefx' ***** Parsing...

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[crayon-5cba16c0de553525117479 inline="true" ]C:\monkey2\bin>mx2cc_windows makemods timelinefx MX2CC V0.011   ***** Making module 'timelinefx' *****   Parsing...

[/crayon]

I’m not sure sure what I’ve done other then add in some docs. Latest version is on github: https://github.com/peterigz/timelinefx.monkey2

[Mark SiblyKeymaster]

There are a few issues…but what’s hanging the compiler is a stray ‘=’ before a ‘#End’ in quadtree, ie: search for ‘=#’.

Will fix!

[Mark SiblyKeymaster]

There is also a bit of an issue with markdown ‘#’ clashing with ‘#’ for the preprocessor…need to come up with some kind of work around for this.

[peterigzParticipant]

Thanks! All fixed now. Thought there might be other issues as I had to merge some changes but obviously couldn’t test

[EthernautParticipant]

So I’ve found a little bit of time to play with the collision module, and I have to say it’s working great!

My next step is to try to use this with my own entity system. In my old one, each entity used to have a “Transform” object that provided much of the functionality you already have in tlBox, like coordinates, dimensions, moving with collision, etc., so I’m going to just use tlBox instead this time.

There’s one little thing I wanted to ask what’s the best way to implement: hierarchies, so that moving the parent moves all its children as well. Notice that in this case, objects need to store their local coordinates, and then calculate the world coordinate before they can do anything useful.

Should I add a step somewhere that adds the coordinates together on every frame before displaying and checking collisions? Os is there a better, built in way to do that?

Thanks!

P.S. Here’s a quick test I did to get my feet wet:

Monkey

#Import "<timelinefx>" Using mojo.. Using std.. Using timelinefx.. Const BOX := 0 Const CIRCLE := 1 Const POLY := 2 Function Main() New AppInstance New ColTest App.Run() End ' *************************** Window *************************** Class ColTest Extends Window Field player := New Entity( 200, 240, 40, 40, CIRCLE ) Field box := New Entity( 400, 240, 100, 100, BOX ) Field circle := New Entity( 300, 360, 50, 50, CIRCLE ) Field poly := New Entity( 320, 100, 50, 50, POLY ) Method New() Super.New( "ColTest", 640, 480 ) End Method OnRender( canvas:Canvas ) Override App.RequestRender() player.Update() For Local e := Eachin Entity.all e.Draw( canvas ) Next End End ' *************************** Entity class *************************** Class Entity Field collider:tlBox Field speed:= 5.0 Field result := New tlCollisionResult Global all := New Stack< Entity > Method New( x:Double, y:Double, width:Double, height:Double, shape:Int ) Select shape Case 1 collider = CreateCircle( x, y, width ) Case 2 Local verts := New Float[]( 0, 0, 1, 1, 0, 2, -1, 1 ) collider = CreatePolygon( x, y, verts ) collider.SetScale( width, height ) Default collider = CreateBox( x, y, width, height ) End all.Add( Self ) End Method Update() Local vel := New Vec2f If Keyboard.KeyDown(Key.Up) vel.Y -= speed Elseif Keyboard.KeyDown(Key.Down) vel.Y += speed End If Keyboard.KeyDown(Key.Left) vel.X -= speed Elseif Keyboard.KeyDown(Key.Right) vel.X += speed End collider.Move( vel.X, vel.Y ) For Local e := Eachin all If Not ( e = Self ) result = CheckCollision( collider, e.collider ) PreventOverlap( result ) End Next End Method Draw( canvas:Canvas ) collider.Draw( canvas ) canvas.DrawPoint( collider.WorldX(), collider.WorldY() ) End End

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#Import "<timelinefx>"   Using mojo.. Using std.. Using timelinefx..   Const BOX := 0 Const CIRCLE := 1 Const POLY := 2   Function Main() New AppInstance New ColTest App.Run() End     ' *************************** Window ***************************   Class ColTest Extends Window   Field player := New Entity( 200, 240, 40, 40, CIRCLE ) Field box := New Entity( 400, 240, 100, 100, BOX ) Field circle := New Entity( 300, 360, 50, 50, CIRCLE ) Field poly := New Entity( 320, 100, 50, 50, POLY ) Method New() Super.New( "ColTest", 640, 480 ) End   Method OnRender( canvas:Canvas ) Override App.RequestRender() player.Update() For Local e := Eachin Entity.all e.Draw( canvas ) Next End   End   ' *************************** Entity class ***************************   Class Entity   Field collider:tlBox Field speed:= 5.0 Field result := New tlCollisionResult Global all := New Stack< Entity > Method New( x:Double, y:Double, width:Double, height:Double, shape:Int ) Select shape Case 1 collider = CreateCircle( x, y, width ) Case 2 Local verts := New Float[]( 0, 0, 1, 1, 0, 2, -1, 1 ) collider = CreatePolygon( x, y, verts ) collider.SetScale( width, height ) Default collider = CreateBox( x, y, width, height ) End all.Add( Self ) End Method Update() Local vel := New Vec2f If Keyboard.KeyDown(Key.Up) vel.Y -= speed Elseif Keyboard.KeyDown(Key.Down) vel.Y += speed End If Keyboard.KeyDown(Key.Left) vel.X -= speed Elseif Keyboard.KeyDown(Key.Right) vel.X += speed End collider.Move( vel.X, vel.Y ) For Local e := Eachin all If Not ( e = Self ) result = CheckCollision( collider, e.collider ) PreventOverlap( result ) End Next End Method Draw( canvas:Canvas ) collider.Draw( canvas ) canvas.DrawPoint( collider.WorldX(), collider.WorldY() ) End   End

[peterigzParticipant]

I think my approach was to separate the collision box from the entity rather then try to use it as the thing that manages all the coordinates of the entity. I guess you could do it like that but as tlBox doesn’t come with a local vector (only world) you would have to extend it and then override tForm() to transform stuff from local to world.

So I would have the entity have it’s own vectors to manage its position and update it’s collision box each update, which is a little bit more overhead but ultimately more flexible. That also goes back the other way if you use prevent overlap, whereby the collision box would need to update the entity coordinates after a collision.

Under the particles branch on github there is gameobject which might help (https://github.com/peterigz/timelinefx.monkey2/blob/particles/gameobject.monkey2). I think use a couple of collision boxes, one for actually calculating the collisions, and a container box, which updates to envelope the whole entity for off screen culling and such. I wrote it a while ago though so I’m not sure what everything does!

[EthernautParticipant]

That’s great, thanks! I’ll dig into that gameobject code and see how I could adapt it as soon as I find a bit of time again.

Just out of curiosity, I see that you added a lot more classes and stuff, but has the collision code changed much since last month’s commit (which is what I’m using currently)?

I think I’ll go with a “transform” object just to keep that stuff separated from entity events and components, and I’ll handle the transform inheritance and collisions through the transform class. Thanks for sharing!

[peterigzParticipant]

I haven’t touched the collision code, only added all the extra timelinefx stuff so it should be all the same when I eventually merge it all.

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