Color -> Color pixel change (Fast, not loop)

I want to be able to have a sort of function, where I can type for example.

changeme(picture1, RGB1, RGB2)

and it would change all pixels matching RGB1 into RGB2, and it must be fast, looping thru each pixel is painstakinly slow.

Dont put a DoEvents statement in your loops ...
I shall demonstrate ....

This only takes a few seconds on my system :

Code:

---

Option Explicit

Private Declare Function GetPixel Lib "gdi32" (ByVal hDc As Long, ByVal x As Long, ByVal y As Long) As Long
Private Declare Function SetPixel Lib "gdi32" (ByVal hDc As Long, ByVal x As Long, ByVal y As Long, ByVal crColor As Long) As Long



Private Sub Form_Load()
    'draw some coloured pixels
    Dim i As Long
    For i = 0 To 10000
        Picture1.PSet (i * Rnd, i * Rnd), vbRed
    Next i
   
    Me.Show
    DoEvents
   
    'now do the change
    changeMe Picture1, RGB(255, 0, 0), RGB(0, 255, 0)
   
End Sub

Private Sub changeMe(xPictureBox As PictureBox, srcColour As Long, dstColour As Long)
    Dim i As Long
    Dim j As Long
    Dim nWidth As Long
    Dim nHeight As Long
    Dim hDc As Long
    nWidth = xPictureBox.ScaleWidth
    nHeight = xPictureBox.ScaleHeight
    hDc = xPictureBox.hDc
   
    xPictureBox.Visible = False
    DoEvents
    For i = 0 To nWidth
        For j = 0 To nHeight
            If (GetPixel(hDc, i, j) = srcColour) Then
                SetPixel hDc, i, j, dstColour
            End If
        Next j
    Next i
    DoEvents
    xPictureBox.Visible = True
End Sub

---

Getpixel/Setpixel are freakingly slow, check out the DMA samples using safe arrays on unlimited realities [/B][/QUOTE] if that's not fast enough, you can code the algoritm in c++ with best performance.

Pfff I think my idea's ok :)

Nope, it really sucks :p screw RGB function

Okay then how about this :

Code:

---

Private Function myRGB(nRed As Long, nGreen As Long, nBlue As Long) As Long
    myRGB = (nRed * 1) + (nGreen * 256) + (nBlue * 65536)
End Function

---

;)

worse... use the hex notation

'twas a joke ked :)

oh yeah , and what was the thing about that number ?

okay, since nobody'll never get it, i'll give you the last hint: base convertion

What do you mean the last hint ?
You never game me any ****ing hints :)