Thread: [VB6] - Alpha Blending

On form u need HScrollBar
That is a simple code of Alpha blending

Code:

Private Const GWL_EXSTYLE As Long = (-20)
Private Const WS_EX_RIGHT As Long = &H1000
Private Const WS_EX_LEFTSCROLLBAR As Long = &H4000
Private Const WS_EX_LAYERED As Long = &H80000
Private Const WS_EX_TRANSPARENT = &H20&
Private Const LWA_COLORKEY As Long = &H1
Private Const LWA_ALPHA As Long = &H2

Private Declare Function GetWindowLong Lib "User32" Alias "GetWindowLongA" (ByVal hwnd As Long, ByVal nIndex As Long) As Long
Private Declare Function SetWindowLong Lib "User32" Alias "SetWindowLongA" (ByVal hwnd As Long, ByVal nIndex As Long, ByVal dwNewLong As Long) As Long
Private Declare Function SetLayeredWindowAttributes Lib "User32" (ByVal hwnd As Long, ByVal crKey As Long, ByVal bAlpha As Long, ByVal dwFlags As Long) As Long

Private Sub Form_Load()
   Dim style As Long
   HScroll1.Min = 10
   HScroll1.Max = 255
   HScroll1.Value = 127
   style = GetWindowLong(Me.hwnd, GWL_EXSTYLE)
   If Not (style And WS_EX_LAYERED = WS_EX_LAYERED) Then
    style = style Or WS_EX_LAYERED
    SetWindowLong Me.hwnd, GWL_EXSTYLE, style
    SetLayeredWindowAttributes Me.hwnd, 0&, HScroll1.Value, LWA_ALPHA
   End If
End Sub

Private Sub HScroll1_Change()
   HScroll1_Scroll
End Sub

Private Sub HScroll1_Scroll()
   SetLayeredWindowAttributes Me.hwnd, 0&, HScroll1.Value, LWA_ALPHA
End Sub

in Attachments professional code of Alpha Blending

[...]

Introduction to DiBits
The gdi32.dll is the dynamic library handling all window’s application graphics processing, with the exception of Direct-X.
One of its functions is called GetDIBits which loads all the data of a bitmap in to an array, really quickly.

The Purpose of such a function is to help programmers, process image data really quickly, since this function writes instructions directly into the video memory.

Revision:
The GetDIBits function retrieves the bits of the specified bitmap and copies them into a buffer using the specified format.

How To Use GetDIBits
Firstly we need to create a context to process our graphic into.

Usage:
CreateCompatibleDC(hdc)
hdc refers to the device context to be compatible with.
If zero is put, the context will be compatible with the application’s current screen.

Code:

Type BITMAPINFOHEADER
  biSize        As Long 
  '4 Bytes to hold a fixed value
  biWidth       As Long 
  '4 Bytes to hold the bitmap’s width
  biHeight      As Long
  '4 Bytes to hold the bitmap’s height
  biPlanes      As Integer
  '2 Bytes to hold the bitmap’s Plane
  biBitCount    As Integer
  '2 Bytes to hold the bits per pixel
  '16 Colors, 16 Color gray = 4
  'Gray, 256 Color = 8
  'True Color = 24
  'True Color & Transparency = 32
  biCompression As Long
  '4 Bytes to hold thecompression type (if any)
  biSizeImage   As Long
  biXPelsPerMeter As Long
  biYPelsPerMeter As Long
  biClrUsed       As Long
  'My guess use a byte to show the next line
  biClrImportant  As Long
  'Is this importand?
End Type

i'm pretty like that code, because is awesome...

don't forget on main form put

Code:

Const Rad As Currency = 1.74532925199433E-02

This is only a foretaste of this code, lots and lots of lines but... with comments

virustotal.com/pl/file/eb1713638114026d0c1e61dea2e8cd88c167dd0dd5dd0d60ef de907a49ea81d3/analysis/1386621905/