Complex scripts

[koskok]

Hi!
Many times I have seen complex scripts.Most times they are huge and I can't undderstand them.Here's an example:

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(e)=>{
    scene.my.mspd3 = -12 * (e.normal(0) * (math.cos(friction + 0.5 * math.pi)) + e.normal(1) * (math.sin(friction + 0.5 * math.pi))) / (((math.cos(friction + 0.5 * math.pi)) ^ 2 + (math.sin(friction + 0.5 * math.pi)) ^ 2) ^ 0.5);
    {(texturematrix(4)) > 0 && (texturematrix(5) + 30 * restitution) >= 0} ? {friction = math.atan((texturematrix(5) + 30 * restitution) / (texturematrix(4)))} : {};
    {(texturematrix(4)) > 0 && (texturematrix(5) + 30 * restitution) < 0} ? {friction = math.atan((texturematrix(5) + 30 * restitution) / (texturematrix(4))) + 2 * math.pi} : {};
    {(texturematrix(4)) < 0} ? {friction = math.atan((texturematrix(5) + 30 * restitution) / (texturematrix(4))) + math.pi} : {};
    {(texturematrix(4)) == 0 && (texturematrix(5) + 30 * restitution) > 0} ? {friction = 0.5 * math.pi} : {};
    {(texturematrix(4)) == 0 && (texturematrix(5) + 30 * restitution) < 0} ? {friction = 1.5 * math.pi} : {};
    {(texturematrix(4)) == 0 && (texturematrix(5) + 30 * restitution) == 0} ? {friction = 0} : {};
    {controlleracc == 4} ? {
        Scene.addcircle({
            pos := e.pos;
            buttonDestroy = "l";
            vel := ((e.pos - [texturematrix(0), texturematrix(1)]) / (sim.time - texturematrix(2))) + ([(e.normal(0)), (e.normal(1))] * 10);
            radius := 0.125;
            collideset := 32;
            drawcake := false;
            oncollide := (e)=>{density = 0};
            heteroCollide := true;
            drawborder := false;
            color := [0, 0, 0, 1];
            density := density * 13;
            friction := 0.0;
            restitution := 0
        })
    } : {};
    textscale = ((scene.my.pos(0) - e.pos(0)) ^ 2 + (scene.my.pos(1) - e.pos(1)) ^ 2) ^ 0.5;
    texturematrix = [e.pos(0), e.pos(1), sim.time, ((math.pow(((texturematrix(0) - e.pos(0)) * (texturematrix(0) - e.pos(0))) + ((texturematrix(1) - e.pos(1)) * (texturematrix(1) - e.pos(1))), 0.5)) / (sim.time - texturematrix(2))), (35 * (scene.my.pos(0) - e.pos(0)) / ((scene.my.pos(0) - e.pos(0)) ^ 2 + (scene.my.pos(1) - e.pos(1)) ^ 2) ^ 0.5), (35 * (scene.my.pos(1) - e.pos(1)) / ((scene.my.pos(0) - e.pos(0)) ^ 2 + (scene.my.pos(1) - e.pos(1)) ^ 2) ^ 0.5), (((scene.my.pos(0) - e.pos(0)) ^ 2 + (scene.my.pos(1) - e.pos(1)) ^ 2) ^ 0.5), 0, 0];
    airfrictionmult = (texturematrix(3) * 10 + 20000 / textscale);
    {controlleracc > 4} ? {controlleracc = 0} : {controlleracc = controlleracc + 1};
    scene.my.force = e.pos(0) * 10
}

Could you please explain them to me?

[Kilinich]

don't waste time - try start from simple one

[koskok]

But I just know simple scripts and a bit more complex

[hiltropper]

you get into long comlex scripts while you are experimentating with them and some scripts seem comlex but they are not (i remember a color script i wrote to get into scripting it filled the whole window but when i look at it now it was damn easy )
try to combinate all scripts you now jet and make them work together...and youll have a complex script

[koskok]

you get into long comlex scripts while you are experimentating with them and some scripts seem comlex but they are not (i remember a color script i wrote to get into scripting it filled the whole window but when i look at it now it was damn easy )
try to combinate all scripts you now jet and make them work together...and youll have a complex script

Right,but I also mean some characters and bunches of characters I don't understand like: ^,*,/,\.

[TC42]

Those are regular math characters...
^ means "to the power of" it is the same as math.pow() ex.. 2^3 = 8
* is just a multiplication operator ex.. 2 * 2 * 2 = 8
/ is used for division, similar * ex.. 8/2 = 4; // is used for comments, ex..
scene.my.sandwich = 13; //sets the value of the variable "sandwich" to 13

I think \ has some use with using text in geval, but I never found out, since I used a workaround.

Math.atan() is exactly what it says it is... Arc tangent()
Math.pi is also... 3.1415926535...
e.normal is the angle of contact, I think... I'm not really sure about that though.
Controlleracc and texturematrix are used to store values.
{} ? {} : {} is the structure of an if statement ex.. {condition} ? {true} : {false}
E.pos is the position of an object, stored in an x/y array ex.. [3, -2]
sim.time is the elapsed time since the simulation was started.

I would recommend putting this code into another editor, such as the arduino IDE, because editors like those highlight grouping symbols, so if you have the cursor near one parenthesis, it will highlight the matching, close-parenthesis one.

Where did you come across this code? If you know what it does (and you know some trigonometry) you should be able to read it and understand it...

[koskok]

Those are regular math characters...
^ means "to the power of" it is the same as math.pow() ex.. 2^3 = 8
* is just a multiplication operator ex.. 2 * 2 * 2 = 8
/ is used for division, similar * ex.. 8/2 = 4; // is used for comments, ex..
scene.my.sandwich = 13; //sets the value of the variable "sandwich" to 13

I think \ has some use with using text in geval, but I never found out, since I used a workaround.

Math.atan() is exactly what it says it is... Arc tangent()
Math.pi is also... 3.1415926535...
e.normal is the angle of contact, I think... I'm not really sure about that though.
Controlleracc and texturematrix are used to store values.
{} ? {} : {} is the structure of an if statement ex.. {condition} ? {true} : {false}
E.pos is the position of an object, stored in an x/y array ex.. [3, -2]
sim.time is the elapsed time since the simulation was started.

I would recommend putting this code into another editor, such as the arduino IDE, because editors like those highlight grouping symbols, so if you have the cursor near one parenthesis, it will highlight the matching, close-parenthesis one.

Where did you come across this code? If you know what it does (and you know some trigonometry) you should be able to read it and understand it...

I came across it in a missile.That script above is onHit by laser on a box.It is for the propulsion of the missile.

[daniels220]

\ should "escape" a character—e.g. a quote, something like (contrived, no reason to actually use eval here, but w/e):

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geval("scene.my.someText = \"test\"")

If statements should have the form () ? {} : {}, not {} ? {} : {}—the condition doesn't need the braces, although it is a good idea to surround it with parens for ease of reading. Technically it will work as just cond ? {true} : {false}, but if your condition has &&, ||, function calls, etc in it, it's easier to read if you know where it starts and stops.

e.normal isn't the angle of contact, it's a unit vector (an [x,y] array, also, but with a different meaning than e.pos, and with a scalar "length" of 1, i.e. x^2 + y^2 = 1) in the direction of the angle of contact. You have to use atan and some trickery to get the actual angle. It's good for spawning, though, because you can say something like pos := e.pos + e.normal (spawns 1 in front of the spawner), vel := e.normal * 100 (projectile starts at 100 m/s).

[electronicboy]

Also, / is the divide operator

[Someone Else]

I actually use sine and cosine to get an angle out of e.normal, instead of tangent.

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//From my Portals series, which currently has a length of 1 because Algodoo spazzed and forgot my progress on level 2:
(normal)=>{math.acos(normal(1)) * ({math.asin(normal(0)) > 0} ? {1} : {-1})}

Stick this into the console (F11). You can then use, for example, scene.my.normal2angle(e.normal) to derive the angle from this.

Note that I use what is probably an odd coordinate system- 0 rads is up, positive numbers progress clockwise from there, negative numbers progress counterclockwise, math.pi rads is down.

Also, \n is a new line, \t is a tab, \\ is a backslash. There may be more, I don't know. These go into strings, to cause special characters to appear in some cases.

Try this:

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text = "a\\\nb\tc"

Should result in:

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a\
b      c