Logic check and/or better way?

[Rocketdawg]

Hate to be paranoid, but....

I wrote a function that takes the height and width of a full size, uploaded image and returns - allegedly, It seems to anyway - new dimensions with the aspect ratio preserved.

My function seems awkward. Could anyone suggest a better approach?
Thanks!

Function RetainAspectRatio(ByVal imgHeight As Integer, ByVal imgWidth As Integer, ByVal IsItASmallThumb As Boolean) As ArrayList
        Dim blnSizeCheck As Boolean = IsItASmallThumb
        Dim maxheight As Integer
        Dim maxwidth As Integer
        If blnSizeCheck Then
            maxheight = 93
            maxwidth = 125
        Else
            maxheight = 300
            maxwidth = 400
        End If
        imgHeight = Convert.ToDouble(imgHeight)
        imgWidth = Convert.ToDouble(imgWidth)
        'Get the new height and width depending on whether the end result will be a small thumb or medium-size image
        'image
        If (imgWidth > imgHeight) Or (imgWidth = imgHeight) Then
            While imgWidth > maxwidth
                imgWidth = Math.Round(imgWidth - (imgWidth * 0.01), 0)
                imgHeight = Math.Round(imgHeight - (imgHeight * 0.01), 0)
            End While
        ElseIf imgHeight > imgWidth Then
            While (imgHeight > maxheight) Or (imgWidth > maxwidth)
                imgWidth = Math.Round(imgWidth - (imgWidth * 0.01), 0)
                imgHeight = Math.Round(imgHeight - (imgHeight * 0.01), 0)
            End While
        End If
        'send the new dimensions back in an arraylist
        imgWidth = Convert.ToInt32(imgWidth)
        imgHeight = Convert.ToInt32(imgHeight)
        Dim arDimensions As New ArrayList
        arDimensions.Add(imgWidth)
        arDimensions.Add(imgHeight)
        Return arDimensions
    End Function

[-TPM-]

Well I don't see a reason to dim blnSizeCheck, just use IsItASmallThumb.
Also your converting the height and width to a double and the sticking it back into an integer which converts it straight back to an integer again...
Is there a reason your using an arraylist? You could just use a string array like this;

Dim arDimensions(1) As string = {imgWidth, imgHeight}

[-TPM-]

I just noticed you also rounding when you subtract 1% which would make using a double pointless anyway. Looking at your if's and while's again I also realized you only really need the second one 'While (imgHeight > maxheight) Or (imgWidth > maxwidth)' as both need to resolve too true before it'll exit the loop and thus will keep scaling down untill both are withing the size limit

[tailz]

ug that is not the way to do it (if I get what you are trying to do)

I dont have time to test this code but you need to work out the second dimension (depending on if height>width or width>height) based on a scale factor

  dim scale as double 
   If (imgWidth >= imgHeight) Then
      'need to calculate the percent of the width to maxwidth
      scale= maxwidth/imgwidth
    Else  ' If imgHeight > imgWidth Then (dont need the logic check)
        scale= maxheight/imgHeight
   end if
   imgWidth = imgwidth * scale '(or imgwidth *= scale)
   imgHeight = imgheight * scale

Summat like that anyway.

also this line:
If (imgWidth > imgHeight) Or (imgWidth = imgHeight) Then
is the same as:
If (imgWidth >= imgHeight) Then


Hope that helps

GaZ

[Rocketdawg]

Guys

Sorry - been out, but thank you for your replies. I sniffed around, and ended up with this

If imgWidth > maxwidth Or imgHeight > maxheight Then
            If (maxheight / imgHeight) > (maxwidth / imgWidth) Then
                scale = maxheight / imgHeight
            Else
                scale = maxwidth / imgWidth
            End If
            If imgWidth > maxwidth Then
                scale = maxwidth / imgWidth
                imgWidth *= scale
                imgHeight *= scale
            End If
            If imgHeight > maxheight Then
                imgWidth /= scale
                imgHeight /= scale
                scalefactor = maxheight / imgHeight
                imgWidth *= scale
                imgHeight *= scale
            End If
        End If

TPM - right, dumped the arraylist. Kept the boolean. This generates dimensions for one of 2 sizes of saved images, depending on the T or F.

Thanks again

Dawg