YoungBuck plz - Get & SetBitmapBits

[Sastraxi]

You said you could do a tutorial on this

Can you show me how (I lost my VB5 Graphics programming book)
(yes, and dont laugh at me for losing a book)

[YoungBuck]

I never said that (at least not that I'm aware of, maybe I said it in an alcohol induced stupor) Sastraxi I've never used either one of those functions. I'll see if I can figure them out though.

[YoungBuck]

Maybe this will help...

Option Explicit
Private Const BI_RGB = 0&
Private Const DIB_RGB_COLORS = 0 '  color table in RGBs
Private Type BITMAPINFOHEADER '40 bytes
        biSize As Long
        biWidth As Long
        biHeight As Long
        biPlanes As Integer
        biBitCount As Integer
        biCompression As Long
        biSizeImage As Long
        biXPelsPerMeter As Long
        biYPelsPerMeter As Long
        biClrUsed As Long
        biClrImportant As Long
End Type
Private Type RGBQUAD
        rgbBlue As Byte
        rgbGreen As Byte
        rgbRed As Byte
        rgbReserved As Byte
End Type
Private Type BITMAPINFO
        bmiHeader As BITMAPINFOHEADER
        bmiColors As RGBQUAD
End Type
Private Declare Function CreateCompatibleDC Lib "gdi32" (ByVal hdc As Long) As Long
Private Declare Function CreateDIBSection Lib "gdi32" (ByVal hdc As Long, pBitmapInfo As BITMAPINFO, ByVal un As Long, ByVal lplpVoid As Long, ByVal handle As Long, ByVal dw As Long) As Long
Private Declare Function GetDIBits Lib "gdi32" (ByVal aHDC As Long, ByVal hBitmap As Long, ByVal nStartScan As Long, ByVal nNumScans As Long, lpBits As Any, lpBI As BITMAPINFO, ByVal wUsage As Long) As Long
Private Declare Function SetDIBitsToDevice Lib "gdi32" (ByVal hdc As Long, ByVal x As Long, ByVal y As Long, ByVal dx As Long, ByVal dy As Long, ByVal SrcX As Long, ByVal SrcY As Long, ByVal Scan As Long, ByVal NumScans As Long, Bits As Any, BitsInfo As BITMAPINFO, ByVal wUsage As Long) As Long
Private Declare Function SelectObject Lib "gdi32" (ByVal hdc As Long, ByVal hObject As Long) As Long
Private Declare Function DeleteDC Lib "gdi32" (ByVal hdc As Long) As Long
Private Declare Function DeleteObject Lib "gdi32" (ByVal hObject As Long) As Long
Private Declare Function BitBlt Lib "gdi32" (ByVal hDestDC As Long, ByVal x As Long, ByVal y As Long, ByVal nWidth As Long, ByVal nHeight As Long, ByVal hSrcDC As Long, ByVal xSrc As Long, ByVal ySrc As Long, ByVal dwRop As Long) As Long
Private Declare Function GetDC Lib "user32" (ByVal hwnd As Long) As Long

Dim iBitmap As Long, iDC As Long
Private Sub Form_Paint()
    'KPD-Team 2000
    'URL: http://www.allapi.net/
    'E-Mail: [email protected]
    '-> Compile this code for better performance
    Dim bi24BitInfo As BITMAPINFO, bBytes() As Byte, Cnt As Long
    With bi24BitInfo.bmiHeader
        .biBitCount = 24
        .biCompression = BI_RGB
        .biPlanes = 1
        .biSize = Len(bi24BitInfo.bmiHeader)
        .biWidth = 100
        .biHeight = 100
    End With
    ReDim bBytes(1 To bi24BitInfo.bmiHeader.biWidth * bi24BitInfo.bmiHeader.biHeight * 3) As Byte
    iDC = CreateCompatibleDC(0)
    iBitmap = CreateDIBSection(iDC, bi24BitInfo, DIB_RGB_COLORS, ByVal 0&, ByVal 0&, ByVal 0&)
    SelectObject iDC, iBitmap
    BitBlt iDC, 0, 0, bi24BitInfo.bmiHeader.biWidth, bi24BitInfo.bmiHeader.biHeight, GetDC(0), 0, 0, vbSrcCopy
    GetDIBits iDC, iBitmap, 0, bi24BitInfo.bmiHeader.biHeight, bBytes(1), bi24BitInfo, DIB_RGB_COLORS
    For Cnt = LBound(bBytes) To UBound(bBytes)
        If bBytes(Cnt) < 50 Then
            bBytes(Cnt) = 0
        Else
            bBytes(Cnt) = bBytes(Cnt) - 50
        End If
    Next Cnt
    SetDIBitsToDevice Me.hdc, 0, 0, bi24BitInfo.bmiHeader.biWidth, bi24BitInfo.bmiHeader.biHeight, 0, 0, 0, bi24BitInfo.bmiHeader.biHeight, bBytes(1), bi24BitInfo, DIB_RGB_COLORS
    DeleteDC iDC
    DeleteObject iBitmap
End Sub

[Sastraxi]

The SetPixelV would probably be the fastest way to draw directly to the picturebox. If this isn't fast enough you can draw directly to an offscreen DC and then just blt it directly from memory into the picture box (alot more code), let me know if you need an example for that....

-YoungBuck

You said that, and I thought it must mean using Get&Set bitmap bits because I had heard of it and I knew that that's what it did.

[Sastraxi]

Anyways, I think I have found a much more simple way, using only GetObject, SetBitmapBits, and GetBitmapBits!

'mod1.bas
Public ColourCodes() as Long
Public HookIM as Long

Public WW
Public HH


Public Declare Function GetBitmapBits Lib "gdi32" 
Alias "GetBitmapBits" (ByVal hBitmap As Long, ByVal dwCount As Long, lpBits As Any) As Long

Public Declare Function SetBitmapBits Lib "gdi32" Alias "SetBitmapBits" (ByVal hBitmap As Long, ByVal dwCount As Long, lpBits As Any) As Long

Public Declare Function GetObject Lib "gdi32" Alias "GetObjectA" (ByVal hObject As Long, ByVal nCount As Long, lpObject As Any) As Long

Public Type BITMAP '14 bytes
        bmType As Long
        bmWidth As Long
        bmHeight As Long
        bmWidthBytes As Long
        bmPlanes As Integer
        bmBitsPixel As Integer
        bmBits As Long
End Type

Public iBit as BITMAP
Public NullBitmap as BITMAP

Function HookBitmap(bImage as Long)

   hookIM = bImage
   HookBitmap = GetObject(bImage,14,iBit)

End Function

Function DestroyHook()

   Set iBit = NullBitmap

End Function

Function GetPixels

   ww=iBit.bmWidth
   hh=iBit.bmHeight
   ReDim ColourCodes(1 to ww, 1 to hh) as Long
   GetPixels = GetBitmapBits(hookIM,ww*hh,ColourCodes(1,1))

End Function

Function SetPixels

   SetPixels = SetBitmapBits(hookIM,ww*hh,ColourCodes(1,1))

End Function

Usage:

Picture1.AutoRedraw = True

HookBitmap Picture1.Image
GetPixels

For I = 1 to WW
For J = 1 to HH

Randomize
ColourCodes(I,J)=RGB(RND*255,RND*255,RND*255)

Next J
Next I

SetPixels
DestroyHook

Picture1.Refresh