Calculate distance between 2 pixels

[Christoph_]

How can I calculate the distance between 2 Pixels which I load into an Array ?

[zcoacoaz]

Get the location of the pixel further away from the top left of the screen and subtract the location of the other pixel from it ?

You aren't going to get a very good answer unless you give more info.

Edited October 8, 2006 by Xenogis

[Helge]

Func GetDistance($x1, $y1, $x2, $y2)
    Return Sqrt(($x2 - $x1)^2 + ($y2 - $y1)^2)
EndFunc

[Paulie]

Func GetDistance($x1, $y1, $x2, $y2)
    Return Sqrt(($x2 - $x1)^2 + ($y2 - $y1)^2)
EndFuncoÝ÷ Ûú®¢×«b}}¿ch¬n( z»azuõým «­¢+ÙÕ¹}A¥á±¥ÍÐ ÀÌØí}`Ä°ÀÌØí}dÄ°ÀÌØí}`È°ÀÌØí}dȤ)¥´ÀÌØíIÌÈ)%ÀÌØí}`ÄÐìÀÌØí}`ÈQ¡¸($ÀÌØía¥ÍÐôÀÌØí}`Ä´ÀÌØí}`È)±Í%ÀÌØí}`ıÐìÀÌØí}`ÈÑ¡¸($ÀÌØía¥ÍÐôÀÌØí}`È´ÀÌØí}`Ä)±Í($ÀÌØía¥ÍÐôÀ)¹%()%ÀÌØí}dÄÐìÀÌØí}dÈQ¡¸($ÀÌØíe¥ÍÐôÀÌØí}dÄ´ÀÌØí}dÈ)±Í%ÀÌØí}`ıÐìÀÌØí}`ÈÑ¡¸($ÀÌØíe¥ÍÐôÀÌØí}dÈ´ÀÌØí}dÄ)±Í($ÀÌØíe¥ÍÐôÀ)¹%()1½°ÀÌØíIÌÈô ÀÌØíe¥ÍÑxȤ¬ ÀÌØía¥ÍÑxȤ)1½°ÀÌØíIÌôI½Õ¹¡MÅÉÐ ÀÌØíIÌȤ°Ä¤)IÑÕɸÀÌØíIÌ)¹Õ¹

Try this

Edited October 8, 2006 by Paulie

[Helge]

What if X2/Y2 is bigger then X1/Y1 though?

Actually it doesn't matter.

MsgBox(64, "", GetDistance(10, 10, 50, 50))
MsgBox(64, "", GetDistance(50, 50, 10, 10))

Func GetDistance($x1, $y1, $x2, $y2)
    Return Sqrt(($x2 - $x1)^2 + ($y2 - $y1)^2)
EndFunc

Edit : forgot a line

Edited October 8, 2006 by Helge

[Paulie]

Actually it doesn't matter.

MsgBox(64, "", GetDistance(10, 10, 50, 50))
MsgBox(64, "", GetDistance(50, 50, 10, 10))

Func GetDistance($x1, $y1, $x2, $y2)
    Return Sqrt(($x2 - $x1)^2 + ($y2 - $y1)^2)
EndFunc

Edit : forgot a line

lol use helge's then Edited October 8, 2006 by Paulie

[gamerman2360]

Func GetDistance($x1, $y1, $x2, $y2)
    Return Sqrt(($x2 - $x1)^2 + ($y2 - $y1)^2)
EndFunc

Oh no! The distance formula!! It followed me all the way from geometry class!

Actually that only works if your doing something like wanting the real distance between 2 points. If you want something like, the distance between 2 checker pieces(movement wise), you just need to find out which number(x or y distance) is bigger.

Edited October 8, 2006 by gamerman2360

[jvanegmond]

What if X2/Y2 is bigger then X1/Y1 though?

In a normal case this would happen:

X1 = 5

X2 = 1

X difference = 4

X difference squared = 16

Just looking at the X-coordinates:

X1 = 1

X2 = 5

X difference = -4

X difference squared = 16

You see that when squared, it doesn't matter at all.

[jvanegmond]

Oh no! The distance formula!! It followed me all the way from geometry class!

Actually that only works if your doing something like wanting the real distance between 2 points. If you want something like, the distance between 2 checker pieces(movement wise), you just need to find out which number(x or y distance) is bigger.

Yes, but if you're talking about checkers. Your moves would be limited, and that's a whole different case, and therefore cannot be solved with pythagoras.

[Paulie]

In a normal case this would happen:

X1 = 5

X2 = 1

X difference = 4

X difference squared = 16

Just looking at the X-coordinates:

X1 = 1

X2 = 5

X difference = -4

X difference squared = 16

You see that when squared, it doesn't matter at all.

Yeah, i realized this not to long after i posted mine

but its the weekend, and i'm mot thinking right...

[jvanegmond]

Yeah, i realized this not to long after i posted mine

but its the weekend, and i'm mot thinking right...

Alcohol?

[gamerman2360]

In a normal case this would happen:

X1 = 5

X2 = 1

X difference = 4

X difference squared = 16

Just looking at the X-coordinates:

X1 = 1

X2 = 5

X difference = -4

X difference squared = 16

You see that when squared, it doesn't matter at all.

What should actually happen is that ex: Sqrt(9) would return +9 and -9. (Since 3^2 = 9 and (-3)^2 = 9)

Since we don't have that ability, the absolute value is givin.

If you wanted to be mathmatically correct Sqrt() should be called something like AbsSqrt().

Edited October 8, 2006 by gamerman2360

[jvanegmond]

What should actually happen is that ex: Sqrt(9) would return +9 and -9. (Since 3^2 = 9 and (-3)^2 = 9)

Since we don't have that ability, the absolute value is givin.

If you wanted to be mathmatically correct Sqrt() should be called something like AbsSqrt().

I agree. However, when you are talking distance. It doesn't matter wether you go 9 units forward or 9 units backwards. The distance is always 9 units.

I learned to use a -Sqrt and a +sqrt in formulas that I create, because calculators always return AbsSqrt() as you call it.

[Christoph_]

Jesus, many replies in not many minutes.

I'm talking about movement; I've written a small bot which works well so far, however I'm still working on it to optimize it.

I've a routine which scans the screen for targets & pixelsearch returns only the first found <<< sucks. Only workaround to get the closest target is to run multiple scans in multiple areas, which is not good either as it is not flexible.

So I scan the screen line per line right now (to sort false positives out) which is pretty fast (drops fps a little for something like 0,2s or so).

Now I want to drop the first target into an Array, get distance; check the next targt -> if distance to next target is bigger, drop it, if the distance is smaller replace the target in the Array until the scan has run through the screen, the Array will contain the next target location with the shortest route. You could use it for OCR as well though.

That's why I was asking.

The old greek should do the trick I think.

Edited October 8, 2006 by Christoph_

[jvanegmond]

I just so happen to have the perfect example for you:

I was building this as a step-up to a full-scaled Evolution simulator.

You should look at in particular where I use $Distance = Sqrt((($IndiX[$x]-$IndiX[$z])^2)+(($IndiY[$x]-$IndiY and check it against $SmallestDistance.

The rest of the code is just there to make it work in my case.

expandcollapse popup

#include <GUIConstants.au3>
#include <Color.au3>

Global $IndiNo = 0, $Population = 0, $Deaths = 0
Global $IndiX[500],$IndiY[500],$IndiHandle[500],$IndiColor[500]
Global $SmallestZ

Create(0xFF0000)
Create(0xFF0000)
Create(0xFF0000)

Create(0x00FF00)
Create(0x00FF00)
Create(0x00FF00)

While $Population > 1
    $Lowest = 100
    For $x = 0 to $IndiNo
        If $IndiHandle[$x] Then
            If $x < $Lowest Then
                $Lowest = $x
            EndIf
        EndIf
    Next
    For $x = $Lowest to $IndiNo
        If $IndiHandle[$x] Then ;not dead
            
            $SmallestZ = False
            $SmallestDistance = Sqrt(((@DesktopWidth)^2)+((@DesktopHeight)^2))
            
            For $z = $Lowest to $IndiNo
                If $IndiHandle[$z] AND ($x<>$z) Then ;not dead
                    ;If $IndiColor[$x] <> $IndiColor[$z] Then
                        
                        $Distance = Sqrt((($IndiX[$x]-$IndiX[$z])^2)+(($IndiY[$x]-$IndiY[$z])^2))
                        
                        If $Distance < $SmallestDistance Then
                            
                            $SmallestDistance = $Distance
                            $SmallestZ = $z
                            
                        EndIf
                    ;EndIf
                EndIf
            Next
            
            If $SmallestZ Then
                $z = $SmallestZ
                
                $XOk = 0
                $YOk = 0
                If ($IndiX[$x]-$IndiX[$z]) > 0 Then
                    $IndiX[$x] -= 1
                ElseIf ($IndiX[$x]-$IndiX[$z]) < 0 Then
                    $IndiX[$x] += 1
                Else
                    $XOk = 1
                EndIf
                
                If ($IndiY[$x]-$IndiY[$z]) > 0 Then
                    $IndiY[$x] -= 1
                ElseIf ($IndiY[$x]-$IndiY[$z]) < 0 Then
                    $IndiY[$x] += 1
                Else
                    $YOk = 1
                EndIf
                
                If $XOk AND $YOk Then
                    Kill($x)
                    Kill($z)
                    $Red = (_ColorGetRed($IndiColor[$x]) + _ColorGetRed($IndiColor[$z])) / 2
                    $Green = (_ColorGetGreen($IndiColor[$x]) + _ColorGetGreen($IndiColor[$z])) / 2
                    $Blue = (_ColorGetBlue($IndiColor[$x]) + _ColorGetBlue($IndiColor[$z])) / 2
                    $Output = "0x" & Hex($Red,2) & Hex($Green,2) & Hex($Blue,2)
                    Create($Output)
                    If Random(0,1,1) Then
                        Create($Output)
                    Else
                        Create(Random(0,0xFFFFFF,1))
                    EndIf
                EndIf
            EndIf
        EndIf
    Next
    
    Update()
WEnd

Func Create($Color)
    For $x = 0 to $Population
        If Not $IndiHandle[$x] Then
            ExitLoop
        EndIf
    Next
    $IndiX[$x] = Random(0,@DesktopWidth-30,1)
    $IndiY[$x] = Random(0,@DesktopHeight-30,1)
    $IndiColor[$x] = $Color
    
    $IndiHandle[$x] = GUICreate($x,40,40,$IndiX[$x],$IndiY[$x],-1,$WS_EX_TOOLWINDOW)
    GUISetBkColor($IndiColor[$x])
    
    WinSetOnTop($IndiHandle[$x],"", 1)
    GUISetState()

    $Population += 1
    $IndiNo += 1
EndFunc

Func Update()
    For $x = $Lowest to $IndiNo
        If $IndiHandle[$x] Then ;not dead
            WinMove($IndiHandle[$x],"",$IndiX[$x],$IndiY[$x])
        EndIf
    Next
EndFunc

Func Kill($n)
    GUIDelete($IndiHandle[$n])
    $IndiHandle[$n] = ""
    $Population -= 1
    $Deaths += 1
EndFunc

Edited October 8, 2006 by Manadar

[Christoph_]

Ah cool, yes it's very close to my idea.

I will complete my scan routine tomorrow