Help Needed: Resizing Images with Cairo in VB6

I'm using the Cairo graphics library in VB6 to work with PDFs by converting them to images for easier manipulation. My goal is to resize these images to a specific maximum width and height without losing the ability to view all details. However, I'm struggling with the resizing function using Cairo in VB6. Here's my attempt:

Code:

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Public Function Resize(ByRef srf As cCairoSurface, ByVal uMaxWidth As Long, ByVal uMaxHeight As Long) As cCairoSurface
    Dim lNewWidth As Long
    Dim lNewHeight As Long
   
    ' Save original image for comparison
    srf.WriteContentToPngFile "d:\path\before_resize.png" (looks as expected)
   
    ' Calculate new dimensions
    ScaleImage srf.Width, srf.Height, uMaxWidth, uMaxHeight, lNewWidth, lNewHeight, scaleDownAsNeeded
   
    ' Create new resized image
    Dim nNew As cCairoSurface
    Set nNew = srf.CreateSimilar(CAIRO_CONTENT_COLOR_ALPHA, lNewWidth, lNewHeight, False)
   
    Dim Ctx As cCairoContext
    Set Ctx = nNew.CreateContext()
   
    ' Fill background (testing purposes)
    Ctx.SetSourceRGBA 1, 0.5, 1, 0.5 (creates a pink surface as expected)
    Ctx.Rectangle 0, 0, lNewWidth, lNewHeight
    Ctx.Fill
   
    ' Attempt to render resized content
    srf.CreateContext.RenderSurfaceContent nNew, 0, 0, 200, 200, CAIRO_FILTER_BEST, 0.5 (does not have any effect)
   
    ' Save resized image for comparison
    nNew.WriteContentToPngFile "d:\path\after_resize.png" 'shows a pink image only.
   
    ' Need assistance correcting my approach.
End Function

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I'm not sure how to properly use the Cairo library for resizing images. Assistance in correcting my approach would be appreciated.

It looks like you have your surfaces backwards - you want to create the context for nNew and write the surface content of srf to it:

Code:

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    nNew.CreateContext.RenderSurfaceContent srf, 0, 0, 200, 200, CAIRO_FILTER_BEST, 0.5 (does not have any effect)

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(I haven't tried it, so there might be other issues, but that one jumped out).

Thank you very much! That was my mistake. It works now.