many images on a canvas

[sionco]

Hi, I have 199 small images that move around the screen, the following code draws them correctly, but the transparent background of the png image (imgOid) isn´t transparent, would each have to have it´s own canvas, what´s the best way of doing this:

Sub Timer1_Tick

   Dim i As Int
   For i = 0 To 199 '200 images and ´rects´
      
      
      oidCanvas.DrawRect(Rect2(i),Colors.Transparent,True,1)
      Activity.Invalidate2(Rect2(i))
      Rect2(i).Top = oids(i).y
      Rect2(i).Left = oids(i).x
      Rect2(i).Bottom = oids(i).y + pSize
      Rect2(i).Right = oids(i).x + pSize
      oidCanvas.DrawBitmap(imgOid,Null,Rect2(i))
      Activity.Invalidate2(Rect2(i))
      
      If oids(i).x + pSize > 99%x Then
         oids(i).vx = -1 
      Else If oids(i).x < 1%x Then
         oids(i).vx = 1
      End If
      If oids(i).y + pSize > 99%y Then
         oids(i).vy = -1 
      Else If oids(i).y < 48 Then
         oids(i).vy = 1
      End If
       oids(i).x = oids(i).x + oids(i).vx
       oids(i).y = oids(i).y + oids(i).vy
         
   Next
   
      
      

      
End Sub

:sign0104:

 

[Erel]

You should use a single canvas. Do you mean that the transparent region of the images is lost? Can you post a screenshot?

 

[klaus]

Your code should work, but if the background in your imgOid png image is not transparent then it will not be displayed transparent.

Best regards.

 

[sionco]

Hi, a long time in my reply , but-

the background of the png image is transparent:


and here are two screenshots, which show the green men overlapping each other

 

[klaus]

Could you post the project as a zip file or at least a small one that shows the problem. So we can test it in the same conditions as you and find out what happens.

Best regards.

 

[klaus]

What do you mean with 'overlapping' ?

When you draw the 200 images it seems that you want to remove the image from the previous set with this line:

oidCanvas.DrawRect(Rect2(i),Colors.Transparent,True,1)

Do you really want to remove these images one after the other ?
You could 'erase' them all once drawing a rectangle on the whole screen.

The transparency of your image is OK.
In the attached test program shows it. Moving the finger moves the image.

Best regards.