[RESOLVED] Picturebox and resizing

[Krass]

Hi. I am having trouble with something I think should be fairly simple to fix.

I have a picturebox (its size doesn't matter).

I use pSet to randomly draw yellow pixels in it.

Let's say I end up having a square of 2 x 2 yellow pixels (VERY SMALL), I would then like the picturebox to be resized to exactly fits the pixels I've drawn into it.

The picturebox scalemode is set to pixels, and the autoredraw method doesn't seem to resize the picture box at all (it only does when I load up a .bmp in it).

I thought that "picLetter.width = 2" would have worked because the scalemode is in pixels.. but it doesn't.

picLetter.AutoRedraw = True
    picLetter.ScaleMode = vbPixels

Any tips?

[timeshifter]

When you create the points, create a small checker, and if the current point, X or Y, is larger than a preset value, change it. Then, when you're done plotting points, resize based on those numbers.

[Krass]

If I understand right... Instead of trying to reduce the picturebox size, you're suggesting to start with a very small picturebox and GROW it when drawing pixels to it?

Sounds fair. I could make my picture box 0 width and 0 height. But now let's say I add a pixel at 1,1.. How do I resize that picture box by only 1 pixel? Even tho scalemode is set to pixel, I don't think I'm mastering those techniques..

Thanks for your quick reply.

[timeshifter]

No, I'm suggesting exactly what you want... start with a picture box, pick a set of random numbers that are within it, then resize the picture box to the highest coordinates of the points within the box. Look at this code for an example. Form needs a picture box(duh), two labels and a command button.

Private Sub Command1_Click()
 
    Dim MaxX As Integer
    Dim MaxY As Integer
    
    Dim HighX As Integer
    Dim HighY As Integer
    
    Dim tempX As Integer
    Dim tempY As Integer
    
    Dim counter As Integer
 
    Label1.Caption = "Starting Size: " & Picture1.ScaleWidth & ", " & Picture1.ScaleHeight
    
    MaxX = Picture1.ScaleWidth
    MaxY = Picture1.ScaleHeight
    
    For counter = 1 To 500 'change this to however many points you want plotted
        tempX = Int(Rnd * MaxX)
        tempY = Int(Rnd * MaxY)
        Picture1.PSet (tempX, tempY), vbYellow
        If tempX > HighX Then HighX = tempX
        If tempY > HighY Then HighY = tempY
    Next counter
    
    Picture1.Width = (HighX * 15)
    Picture1.Height = (HighY * 15)
    
    Label2.Caption = "Final Size: " & Picture1.ScaleWidth & ", " & Picture1.ScaleHeight
 
End Sub

[timeshifter]

Well, that's the basic idea, anyway. There's a bit of a flaw with the resizing that I'm trying to pin down... bit of a booger, too...

[Krass]

Thanks for your help.

Those 2 lines are what I needed:

Picture1.Width = (HighX * 15)
Picture1.Height = (HighY * 15)

[timeshifter]

Which are incorrect statements... substitute them with these:

Picture1.Width = Picture1.Width - ((MaxX - HighX) * 15)
    Picture1.Height = Picture1.Height - ((MaxY - HighY) * 15)

That will give you an accurate resizing based on where the points landed.

[Krass]

Okay. I had this part modified already. Thanks. Also, I replaced "15" by Screen.TwipsPerPixelX or Screen.TwipsPerPixelY, which seems to give the same result. Is this good practice?

[Krass]

One more thing. Now that my picturebox is resized how I want it to, I am doing the following:

SavePicture picLetter.Image, "c:\test\LetterMask.bmp"

The size of LetterMask.bmp is not, for example, 4 x 10 (which is the size of the picturebox AFTER resizing)... It is still using the size of the original picturebox size when I first executed the form (80 x 290).

Any idea? In other words I need the savepicture to act on the visible part (after resizing) of the pciturebox only.

Thanks

[timeshifter]

I don't think you can save good images after using PSet... I believe it's the SetPixel or SetPixelV API that you need... but I've only had passing experience with that. I know chemicalNova did a bit of that with me, so I'll yell at him when I see him.. unless someone else can answer your question. I'd take the "Resolved" out of the thread title, if yo still have questions.

[Krass]

Actually I think I might just have solved that problem. I made the picturebox original size 1,1 (or smallest possible). Then when I know my X,Y coordinates of my yellow pixels, I make the picturebox grow. It saves my file right, using a small 2k or 4k (dendant on my pixels emplacements) instead of a static 69k file.

I'm happy with this. Thanks.