[meTaLiCroSS]

I've tried to find such thing in the forum and I would not able to find something to answer my question, at least I've found this(http://forums.alliedmods.net/showpos...28&postcount=2) and it's useful at least, but it's close of what I want.

I wanted to check with a math code (welcome, not my speciality) the "distance" between two lines on the game, for being accurate, 2 players and 2 objects flying on air, both players owns one of these entities, and I wanted to check (by think forward) if one of these objects intersects with anyother's player object, a virtual collision, to be specific, to check if it crosses anyother's players invisible line to it's flying object, I'm not sure if I spelled it right what i've tried to say, but would be nice to see some math art in action here n.n

Anyway, thanks in advance!

[gladius]

I have an idea of what you want but I am in doubt. You could put a picture to understand.

[ConnorMcLeod]

Try this :

PHP Code:

Float:lines_distance(Float:flPoint1[3], Float:vecDir1[3], Float:flPoint2[3], Float:vecDir2[3])
{
    xs_vec_normalize(vecDir1, vecDir1)
    xs_vec_normalize(vecDir2, vecDir2)
    if( xs_vec_equal(vecDir1, vecDir2) )
    {
        new Float:vecPoint1Point2[3]
        xs_vec_sub(flPoint2, flPoint1, vecPoint1Point2)
        
        new Float:vecDirCross[3]
        xs_vec_cross(vecPoint1Point2, vecDir1, vecDirCross)
        
        return xs_vec_len(vecDirCross) / xs_vec_len(vecDir1)
    }

    new Float:vecPoint1Point2[3]
    xs_vec_sub(flPoint2, flPoint1, vecPoint1Point2)
    
    new Float:vecDirCross[3]
    xs_vec_cross(vecDir1, vecDir2, vecDirCross)

    return floatabs( det3(vecPoint1Point2, vecDir1, vecDir2) ) / xs_vec_len(vecDirCross)
}

Float:det3( Float:vec0[3] , Float:vec1[3] , Float:vec2[3] )
{
    return ( vec0[0]*vec1[1]*vec2[2] + vec1[0]*vec2[1]*vec0[2] + vec2[0]*vec0[1]*vec1[2] - vec0[0]*vec2[1]*vec1[2] - vec1[0]*vec0[1]*vec2[2] - vec2[0]*vec1[1]*vec0[2] )
} 


[meTaLiCroSS]

Originally Posted by ConnorMcLeod Try this : PHP Code: Float:lines_distance(Float:flPoint1[3], Float:vecDir1[3], Float:flPoint2[3], Float:vecDir2[3]) {     xs_vec_normalize(vecDir1, vecDir1)     xs_vec_normalize(vecDir2, vecDir2)     if( xs_vec_equal(vecDir1, vecDir2) )     {         new Float:vecPoint1Point2[3]         xs_vec_sub(flPoint2, flPoint1, vecPoint1Point2)                  new Float:vecDirCross[3]         xs_vec_cross(vecPoint1Point2, vecDir1, vecDirCross)                  return xs_vec_len(vecDirCross) / xs_vec_len(vecDir1)     }     new Float:vecPoint1Point2[3]     xs_vec_sub(flPoint2, flPoint1, vecPoint1Point2)          new Float:vecDirCross[3]     xs_vec_cross(vecDir1, vecDir2, vecDirCross)     return floatabs( det3(vecPoint1Point2, vecDir1, vecDir2) ) / xs_vec_len(vecDirCross) } Float:det3( Float:vec0[3] , Float:vec1[3] , Float:vec2[3] ) {     return ( vec0[0]*vec1[1]*vec2[2] + vec1[0]*vec2[1]*vec0[2] + vec2[0]*vec0[1]*vec1[2] - vec0[0]*vec2[1]*vec1[2] - vec1[0]*vec0[1]*vec2[2] - vec2[0]*vec1[1]*vec0[2] ) }

The bad thing is that I need to pass a direction instead of another position, there exists a possibility for making it with and start pos and a end post for both?

[gladius]

If I am right, this should be fine.

PHP Code:

Float:lines_distance(Float:flLine1Point1[3], Float:flLine1Point2[3], Float:flLine2Point1[3], Float:flLine2Point2[3]) 
{ 
    new Float:vecDir1[3], Float:vecDir2[3]
    
    xs_vec_sub(flLine1Point1, flLine1Point2, vecDir1)
    xs_vec_sub(flLine2Point1, flLine2Point2, vecDir2)
    
    xs_vec_normalize(vecDir1, vecDir1) 
    xs_vec_normalize(vecDir2, vecDir2) 
    
    new Float:vecLine1Line2[3] 
    xs_vec_sub(flLine2Point1, flLine1Point1, vecLine1Line2)
    
    if(xs_vec_equal(vecDir1, vecDir2)) 
    {         
        new Float:vecDirCross[3] 
        xs_vec_cross(vecLine1Line2, vecDir1, vecDirCross) 
        
        return xs_vec_len(vecDirCross) / xs_vec_len(vecDir1) 
    } 
    
    new Float:vecDirCross[3] 
    xs_vec_cross(vecDir1, vecDir2, vecDirCross) 

    return xs_vec_mul_escalar2(vecLine1Line2, vecDirCross) / xs_vec_len(vecDirCross)
}

xs_vec_mul_escalar2(Float:vec1[], Float:vec2[])
{
    return vec1[0] * vec2[0] + vec1[1] * vec2[1] + vec1[2] * vec2[2]
} 


[meTaLiCroSS]

Originally Posted by gladius If I am right, this should be fine. PHP Code: Float:lines_distance(Float:flLine1Point1[3], Float:flLine1Point2[3], Float:flLine2Point1[3], Float:flLine2Point2[3])  {      new Float:vecDir1[3], Float:vecDir2[3]          xs_vec_sub(flLine1Point1, flLine1Point2, vecDir1)     xs_vec_sub(flLine2Point1, flLine2Point2, vecDir2)          xs_vec_normalize(vecDir1, vecDir1)      xs_vec_normalize(vecDir2, vecDir2)           new Float:vecLine1Line2[3]      xs_vec_sub(flLine2Point1, flLine1Point1, vecLine1Line2)          if(xs_vec_equal(vecDir1, vecDir2))      {                  new Float:vecDirCross[3]          xs_vec_cross(vecLine1Line2, vecDir1, vecDirCross)                   return xs_vec_len(vecDirCross) / xs_vec_len(vecDir1)      }           new Float:vecDirCross[3]      xs_vec_cross(vecDir1, vecDir2, vecDirCross)      return xs_vec_mul_escalar2(vecLine1Line2, vecDirCross) / xs_vec_len(vecDirCross) } xs_vec_mul_escalar2(Float:vec1[], Float:vec2[]) {     return vec1[0] * vec2[0] + vec1[1] * vec2[1] + vec1[2] * vec2[2] }

As from I see you're getting the direction between these 2 points and that can result in a true statement when 2 lines can "intersect only when extended" but not as this real length, or i'm just saying bullshit? haha

[gladius]

I am getting director vector from two points in one line and getting director vector from two lines.

[joropito]

Put a drawing about what you need.

You write the distance between 2 lines, so you have to get 2 vectors and get the difference. The result will be a vector (vector - vector = vector). If you want a distance in units, just get the lenght of the resulting vector.

Remember that 2 lines will not always be parallel. If you wan't distance between 2 "always parallel" lines, then it's fair easy to get it but it's the same principle.

[gladius]

Originally Posted by joropito Put a drawing about what you need. You write the distance between 2 lines, so you have to get 2 vectors and get the difference. The result will be a vector (vector - vector = vector). If you want a distance in units, just get the lenght of the resulting vector. Remember that 2 lines will not always be parallel. If you wan't distance between 2 "always parallel" lines, then it's fair easy to get it but it's the same principle.

Two lines are parallel if their direction vectors are equal.

PHP Code:

if( xs_vec_equal(vecDir1, vecDir2) ) 


About ...distance between 2 lines, so you have to get 2 vectors and get the difference. The result will be a vector (vector - vector = vector)...

This subtraction only finds a relationship between lines.

Real distance are calculate like I did in my example. Also it return a number, you must proportionate the correct unit type.

[joropito]

Originally Posted by gladius Two lines are parallel if their direction vectors are equal. PHP Code: if( xs_vec_equal(vecDir1, vecDir2) )  About ...distance between 2 lines, so you have to get 2 vectors and get the difference. The result will be a vector (vector - vector = vector)... This subtraction only finds a relationship between lines. Real distance are calculate like I did in my example. Also it return a number, you must proportionate the correct unit type.

Sure, you can get a distance from 2 points, or at least a minimum distance from a point and a line.
What happens if both lines are not parallel? Somewhere they will be closer and somewhere not.