Image list problem driving me nuts!

S

Simontelescopium

Member
Licensed User
Hi,
This is driving me nuts...
I have two images in an image list and use a simple routine to merge them into a new image, this works but the original also gets changed and I can't see what I am doing wrong, is anyone able to help?

B4X: 
Sub Globals
 'Declare the global variables here.
Dim a(4)
End Sub

Sub App_Start
Init
 frmDraw.Show
 Msgbox("New Icon added to iLPic control at position " & imagemerge(0,1)& " Why has image at position 0 changed?")
End Sub

Sub Init
'do once
imageclass1.New1
End Sub

Sub ImageMerge(BGnd,FGnd)
im1.Image=ilpic.Item(bgnd)
im2.Image=ilpic.Item(fgnd)
frmdraw.Refresh
Msgbox("images before merging")
'ilpic.Item(result)=ilpic.Item(bgnd) 
ilpic.Add(ilpic.Item(bgnd))' copy the background to a new position in the image list
imagenumber=ilpic.Count-1
For w=0 To 7
   For h = 0 To 7
      imageclass1.Image=ilpic.Item(fgnd) ' this is the overlay
      a()=imageclass1.GetPixel(w,h)
      imageclass1.Image=ilpic.Item(imagenumber) ' this is the item that will be modified
      If a(0)>100 Then
         imageclass1.SetPixel(w+8,h+8,a(0),a(1),a(2),a(3))
      End If
   Next
Next
im1.Image=ilpic.Item(bgnd) ' why does this image change?
im2.Image=ilpic.Item(fgnd)
im3.image=ilpic.Item(imagenumber)
frmdraw.Refresh
Return imagenumber
End Sub

As well as the code above all the files are included in the zip
 
Last edited:
klaus

klaus

Expert
Licensed User
Longtime User
You need to save ilpic.Item(bgnd) in a temporary bitmap object.
bmp1 is a BitmapEx object from the ImageLibEx library.

B4X: 
[SIZE=2][FONT=Courier New][COLOR=#0000ff][SIZE=2][FONT=Courier New][COLOR=#0000ff][SIZE=2][FONT=Courier New][COLOR=#0000ff]Sub [/COLOR][/FONT][/SIZE][/COLOR][/FONT][/SIZE][/COLOR][/FONT][/SIZE][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2]ImageMerge(BGnd,FGnd)[/SIZE][/FONT]
[SIZE=2][FONT=Courier New] im1.Image=ilpic.Item(bgnd)[/FONT][/SIZE]
[SIZE=2][FONT=Courier New] im2.Image=ilpic.Item(fgnd)[/FONT][/SIZE]
[SIZE=2][FONT=Courier New] [COLOR=red]bmp1.New3(ilpic.Item(bgnd))[/COLOR][/FONT][/SIZE]
 
[SIZE=2][FONT=Courier New] frmdraw.Refresh[/FONT][/SIZE]
[/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff] Msgbox[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2]([/SIZE][/FONT][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#800000][FONT=Courier New][SIZE=2][COLOR=#800000][FONT=Courier New][SIZE=2][COLOR=#800000]"images before merging"[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2])[/SIZE][/FONT]
[/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#008000][FONT=Courier New][SIZE=2][COLOR=#008000][FONT=Courier New][SIZE=2][COLOR=#008000]'ilpic.Item(result)=ilpic.Item(bgnd) [/COLOR][/SIZE][/FONT]
[SIZE=2][FONT=Courier New][COLOR=#008000]' ilpic.Add(ilpic.Item(bgnd))' place the background into the image list[/COLOR][/FONT][/SIZE]
[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2] [COLOR=red]ilpic.Add(bmp1.Value)[/COLOR][/SIZE][/FONT][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#008000][FONT=Courier New][SIZE=2][COLOR=#008000][FONT=Courier New][SIZE=2][COLOR=#008000]' place the background into the image list[/COLOR][/SIZE][/FONT]
[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2] imagenumber=ilpic.Count-[/SIZE][/FONT][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#800080][FONT=Courier New][SIZE=2][COLOR=#800080][FONT=Courier New][SIZE=2][COLOR=#800080]1[/COLOR][/SIZE][/FONT]
[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff] For[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2] w=[/SIZE][/FONT][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#800080][FONT=Courier New][SIZE=2][COLOR=#800080][FONT=Courier New][SIZE=2][COLOR=#800080]0 [/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]To [/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#800080][FONT=Courier New][SIZE=2][COLOR=#800080][FONT=Courier New][SIZE=2][COLOR=#800080]7[/COLOR][/SIZE][/FONT]
[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]   For[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2] h = [/SIZE][/FONT][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#800080][FONT=Courier New][SIZE=2][COLOR=#800080][FONT=Courier New][SIZE=2][COLOR=#800080]0 [/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]To [/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#800080][FONT=Courier New][SIZE=2][COLOR=#800080][FONT=Courier New][SIZE=2][COLOR=#800080]7[/COLOR][/SIZE][/FONT]
[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2]     imageclass1.Image=ilpic.Item(fgnd) [/SIZE][/FONT][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#008000][FONT=Courier New][SIZE=2][COLOR=#008000][FONT=Courier New][SIZE=2][COLOR=#008000]' this is the overlay[/COLOR][/SIZE][/FONT]
[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2]     a()=imageclass1.GetPixel(w,h)[/SIZE][/FONT]
[SIZE=2][FONT=Courier New]     imageclass1.Image=ilpic.Item(imagenumber) [/FONT][/SIZE][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#008000][FONT=Courier New][SIZE=2][COLOR=#008000][FONT=Courier New][SIZE=2][COLOR=#008000]' this is the item that will be modified[/COLOR][/SIZE][/FONT]
[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]     If[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2] a([/SIZE][/FONT][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#800080][FONT=Courier New][SIZE=2][COLOR=#800080][FONT=Courier New][SIZE=2][COLOR=#800080]0[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2])>[/SIZE][/FONT][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#800080][FONT=Courier New][SIZE=2][COLOR=#800080][FONT=Courier New][SIZE=2][COLOR=#800080]100 [/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]Then[/COLOR][/SIZE][/FONT]
[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2]       imageclass1.SetPixel(w+[/SIZE][/FONT][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#800080][FONT=Courier New][SIZE=2][COLOR=#800080][FONT=Courier New][SIZE=2][COLOR=#800080]8[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2],h+[/SIZE][/FONT][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#800080][FONT=Courier New][SIZE=2][COLOR=#800080][FONT=Courier New][SIZE=2][COLOR=#800080]8[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2],a([/SIZE][/FONT][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#800080][FONT=Courier New][SIZE=2][COLOR=#800080][FONT=Courier New][SIZE=2][COLOR=#800080]0[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2]),a([/SIZE][/FONT][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#800080][FONT=Courier New][SIZE=2][COLOR=#800080][FONT=Courier New][SIZE=2][COLOR=#800080]1[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2]),a([/SIZE][/FONT][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#800080][FONT=Courier New][SIZE=2][COLOR=#800080][FONT=Courier New][SIZE=2][COLOR=#800080]2[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2]),a([/SIZE][/FONT][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#800080][FONT=Courier New][SIZE=2][COLOR=#800080][FONT=Courier New][SIZE=2][COLOR=#800080]3[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2]))[/SIZE][/FONT]
[/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]     End [/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]If[/COLOR][/SIZE][/FONT]
[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]   Next[/COLOR][/SIZE][/FONT]
[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff] Next[/COLOR][/SIZE][/FONT]
[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2] im1.Image=ilpic.Item(bgnd) [/SIZE][/FONT][/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#008000][FONT=Courier New][SIZE=2][COLOR=#008000][FONT=Courier New][SIZE=2][COLOR=#008000]' why does this image change?[/COLOR][/SIZE][/FONT]
[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2] im2.Image=ilpic.Item(fgnd)[/SIZE][/FONT]
[SIZE=2][FONT=Courier New] im3.image=ilpic.Item(imagenumber)[/FONT][/SIZE]
[SIZE=2][FONT=Courier New] frmdraw.Refresh[/FONT][/SIZE]
[SIZE=2][FONT=Courier New] [COLOR=red]bmp1.Dispose[/COLOR][/FONT][/SIZE]
[/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff] Return[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2] imagenumber[/SIZE][/FONT]
[/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]End Sub[/COLOR][/SIZE][/FONT]
[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT]
Attached a modified version.

Best regards.
 

Attachments

  • drawNEW.sbp
    2.3 KB · Views: 205
Last edited:
agraham

agraham

Expert
Licensed User
Longtime User
The "problem" is here
B4X: 
ilpic.Add(ilpic.Item(bgnd))
An ImageList holds references to images, not actual images. You think you are copying the image but you are not, you are merely adding a reference to the image so positions 0 and 2 hold the same reference to the single instance of the image. Download my http://www.b4x.com/forum/additional-libraries/3171-imagelibex-library.html and read the "Bitmap memory overview" topic that tries to describe references. Both BitmapEx and Icon have Clone methods that provide a proper copy of the image if you need it.
 
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