How can I calculate relative distance in a script?

[windtalkers]

Hi, I'm new in algodoo, I want to wirte a little script in a laser, which may calculate relative distance between the laser and the hinge, can anyone help me?
Thank you in advance.

[bozbez]

You know the positions of both objects?

[TC42]

Use the distance forumula once you know the points!
D = sqrt((x1 - x2)^2 + (y1 -y2)^2)

In algodoo that would be

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scene.my.distance = ((scene.my.point1(0) - scene.my.point2(0))^2 + (scene.my.point1(1) - scene.my.point2(1))^2)^0.5

[windtalkers]

@bozbez, Tc42: thx, now I can fix my problem.


Well, by the way, I use a laser to spawn balls, so I make a box first, filling a little script in onHitByLaser:

(e)=>{
scene.addcircle({
pos:=e.pos;
radius:=0.2; vel:= [5,1];
heterocollide:=true
})
}

Now my first problem is: when I use a laser (triggered by one key, for example, Q ) to shine the box, then more than one balls were spawned.
What I really want is: only one ball spawned every time I press Q to shine the box, I don't know how to do it with alogdoo, can you help me?

The second problem: how can I add a tracer on the ball through the script? Please don't tell me I can copy the tracer and paste it in the script, I want to know how to write a script to make the tracer and the ball are spawned and move together, something like the tracer is sticked to the ball.

Any information will be appreciated.

PS: I learned the little script which posted here from Jesse Bax.

[Sparky]

scene.addpen({size:=0.5; pos:=e.pos}) that should work.
and for the oher problem..... search the forums i remmember reading it here somewhere....
hope this helped

[Sparky]

oh i think your first problem might be imposable to solve,but i'll keep looking....

[windtalkers]

scene.addpen({size:=0.5; pos:=e.pos}) that should work.

Thank you! But it doesn't work, no tracer attaches the ball.

[bozbez]

This is going to be a long post.
Anyway, lets start with the problem of multiple ball spawning.

Step 1: Create a box, make it semi-transparent and put it on collision layer g (it can be on any other collision layer, but i keep things like this on g).

Step 2: Put two lasers with the same collision layer as the box in the box. Make both their maxrays = 1.

Step 3: Make one of the lasers have the activation key you want.

Step 4: In the laser with the activation key's onLaserHit, paste

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(e)=>{scene.my.nexttick = sim.tick + 1}

Step 5: In the onLaserHit of the other laser, paste

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(e)=>{
    scene.my.nexttick > sim.tick ? {
        scene.my.alreadyspwned < 1 ? {
            {CODE GOES HERE};
            scene.my.alreadyspwned = 1
        } : {}
    } : {scene.my.alreadyspwned = 0}
}

Step 6: Put in your code where it is pretty obvious to put your code (Remove the brackets around the CODE GOES HERE). (I'll address the tracer problem later)

Step 7: Mount the box with lasers on where you want it to be mounted.

Step 8: Because we haven't declared the variables in the console, the first time you activate the laser, nothing will happen, but it should work the second time.

Step 9: Test if it works! (Each time you activate the laser, no more than one circle should be spawned.)

Step 10: If it doesn't work, post a reply.

Now lets address the tracer problem. If you want a tracer to be glued onto an object you spawn, you have to give the object an geomID. So a simple example would be:

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Scene.addCircle {
    color := [0,1,0,0];
    collideSet := 1;
    geomID := 222545;
    pos := e.pos;
    radius := 0.25
};

Now, in the tracer, you need the geom and relpoint parameters. So:

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Scene.addPen {
    geom := 222545;
    relPoint := [0.0, 0.0];
    color := [0, 1, 0, 1];
    fadeTime := 1.5;
    size := 0.2;
}

Notice the geom parameter is the geomID. The relPoint is the position of the tracer relative to the center of the object.

Hope that explains things!

[windtalkers]

Hope that explains things!

@bozbez: You are a great tutor! Thank you very much! yay!

[Rideg]

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Scene.addCircle({Properties_Goes_in_Here; geomID := 123}); Scene.addPen({geom := 123; relPoint := [0, 0]})

Useful for zDepths advanced codes and much more reliable than pos := e.pos when it comes to tracer spawning. Hope you find this of any use.

[windtalkers]

Code: Select all

Scene.addCircle({Properties_Goes_in_Here; geomID := 123}); Scene.addPen({geom := 123; relPoint := [0, 0]})

Useful for zDepths advanced codes and much more reliable than pos := e.pos when it comes to tracer spawning. Hope you find this of any use.

Thank you very much!