|
|
|
| Title | Overlay one image on another with a transparent color by using PSet |
|---|
| Description | This example shows how to overlay one image on another with a transparent color by using PSet in Visual Basic 6. |
|---|
| Keywords | PSet, overlay, transparent |
|---|
| Categories | Graphics |
|---|
|
|
|
This program simply loops through the pixels in the images. For each image in top-to-bottom order, the program looks for a color other than the one defined as transparent. When it finds such a color, it stops looking at the images and sets the output pixel's color using PSet.
|
|
Private Sub cmdCombine_Click()
Dim max_input As Integer
Dim transparent As Long
Dim wid As Single
Dim hgt As Single
Dim X As Single
Dim Y As Single
Dim i As Integer
Dim clr As Long
cmdCombine.Enabled = False
MousePointer = vbHourglass
DoEvents
max_input = picInput.ubound
For i = 0 To max_input
picInput(i).AutoRedraw = True
picInput(i).ScaleMode = vbPixels
Next i
picResult.Width = picInput(0).Width
picResult.Height = picInput(0).Height
picResult.ScaleMode = vbPixels
transparent = picTransparent.BackColor
wid = picInput(0).ScaleWidth
hgt = picInput(0).ScaleHeight
For Y = 0 To hgt
For X = 0 To wid
For i = max_input To 0 Step -1
clr = picInput(i).Point(X, Y)
If clr <> transparent Then Exit For
Next i
picResult.PSet (X, Y), clr
Next X
DoEvents
Next Y
picResult.Picture = picResult.Image
cmdCombine.Enabled = True
MousePointer = vbDefault
Beep
End Sub
|
|
|
Note that there are faster ways to access color values in V 6 and VB .NET, and that there are faster methods for merging images if you have an overlay mask. Note also that VB .NET provides tools for setting a transparent color for an image so this problem is trivial in VB .NET.
|
| |
|
| |
|
|
