Distance Between Two 2D Points

[gamecreator]

I was trying to find these in the documentation and then Math.h but didn't see them. Do we have a function that gets the distance between two 2D points or at least a square root function?

[franck22000]

Hello, here you are (My version for LE2 so you have to juste change the TVec2...):

 

float getDistance(TVec2 fVector1, TVec2 fVector2)
{
float _X = fVector2.X - fVector1.X;
float _Y = fVector2.Y - fVector1.Y;

return std::sqrt(_X * _X + _Y * _Y);
}

[YouGroove]

Or you just can you two Vector3, with each Z value = 0

and just give X and Y for these two Vector3

[franck22000]

??? I dont understand what you said YouGroove.

[Mumbles]

Or you just can you two Vector3, with each Z value = 0

and just give X and Y for these two Vector3

 

There's no point using a 3 component vector for 2D calculations because the Z will never be used. It's the same reason we don't usually use 4 component vectors for points in 3D space.

[shadmar]

Sqrt in lua can be done like this :

 

math.sqrt(some number) 

or

(some number)^0.5

[gamecreator]

Thank you franck but it looks like using sqrt breaks Android apps. That's why I asked specifically if there is a Leadwerks version of it.

[franck22000]

Oh sorry ! Well it is strange that std::sqrt does not work since it is from the c++ standard library.

 

You can use this square root function then it should work if you dont need a very accurate precision

 

float sqrt(float x)
{
union
{
int i;
float x;
} u;
u.x = x;
u.i = (1<<29) + (u.i >> 1) - (1<<22);

u.x = u.x + x/u.x;
u.x = 0.25f*u.x + x/u.x;

return u.x;
} 

[gamecreator]

No prob at all. I was sure it would work too but I figured there's a reason that Josh provides math functions that probably already exist in C++ and I guess compatibility is it. I'll give your latest function a shot. Thanks very much franck!

[Josh]

Math::Sqrt() is also there.

 

And this:

http://www.leadwerks.com/werkspace/page/documentation/_/command-reference/vec3/vec3distancetopoint-r403

[gamecreator]

Math::Sqrt() is also there.

I'm 99% sure it wasn't in the header but I'll look again when I get home. It's definitely not here though.

 

And this:

http://www.leadwerks.com/werkspace/page/documentation/_/command-reference/vec3/vec3distancetopoint-r403

Thanks! Will try this. And thanks, YouGroove, for originally suggesting it.

[Mumbles]

Math::Sqrt() is also there.

 

And this:

http://www.leadwerks.com/werkspace/page/documentation/_/command-reference/vec3/vec3distancetopoint-r403

Thanks! Will try this. And thanks, YouGroove, for originally suggesting it.

 

Oh, I see what YouGroove was saying now. I thought he was saying to use Franck's code, but with three component vectors as the parameters.

 

I feel a bit silly now...

[gamecreator]

float DistanceBetween2DPoints(Vec2 p1, Vec2 p2)
{
return Vec3(p1.x,p1.y,0).DistanceToPoint(Vec3(p2.x,p2.y,0));
}

[Admin]

Math functions are just provided for consistency.

 

sqrt should work, since Leadwerks calls it internally. Maybe you need to type std::sqrt() or include "Math.h" or <Math.h>?

[gamecreator]

Thanks. As you said, I tested this again in my other thread and it works. Sorry guys. My Android app definitely crashed before but I have no idea why now. I was sure at the time it was just because of adding sqrt (I didn't need to add any headers and it compiled fine on Express).