[Gambas-user] How to insert a .png file into a CairoPdfSurface (gb.cairo)

[Willy Raets]

On Sat, 2013-08-24 at 10:54 +0200, Tobias Boege wrote:
> On Sat, 24 Aug 2013, Willy Raets wrote:
> > On Sat, 2013-08-24 at 03:19 +0200, Willy Raets wrote:
> > > Hi All,
> > > 
> > > Been struggling with inserting an existing .png file onto a
> > > CairoPdfSurface (gb.cairo).
> > > 
> > > Done some extensive reading in the documentation but do not seem to find
> > > a method get the job done. Is this not possible or am I misunderstanding
> > > the documentation?
> > > 
> > > Piece of the code of the project:
> > > 
> > > Public Sub MakePdf()
> > >   
> > >   Dim hPdfProjectFile As CairoPdfSurface
> > >   Dim sPdfPath, sPicPath As String
> > >   Dim iX, iY As Float
> > >   sPicPath = User.Home & "/MyFolder/mypicture.png"
> > >   sPdfPath = User.Home & "/MyFolder/project.pdf"
> > >   hPdfProjectFile = New CairoPdfSurface(sPdfPath, 210, 297) 
> > >   Cairo.Begin(hPdfProjectFile)
> > >   '--Draw title --
> > >   iY = 250
> > >   '-- Some code to determine X co??rdinate iX --
> > >   ...
> > >   ...
> > >   Cairo.Font.Bold = True
> > >   Cairo.Font.Size = 18
> > >   Cairo.MoveTo(iX, iY)
> > >   Cairo.DrawText(Start.ProjectLoadedTitle)
> > >   Cairo.Font.Bold = False
> > >   '
> > >   '--Draw project logo --
> > >   iY = 285
> > >   ...                   '<== stuck right here!! 
> > >   '
> > >   '--Draw Document Version--
> > >   iY = 500
> > >   ...
> > >   ...
> > >   Cairo.End
> > > 
> > > End
> > > 
> > > Anyone any ideas, suggestions, links?
> > > 
> > 
> > Just to clarify, I need the .png in sPicPath = User.Home &
> > "/MyFolder/mypicture.png" do be drawn underneath the Title at 
> > section '--Draw project logo --
> > 
> 
> Maybe you could (ab)use Cairo.ImagePattern()? Load the image, call that
> method and assign the result to Cairo.Source. Cairo.Paint() then does the
> job.

I already tried the Cairo.ImagePattern, but didn't know about having to
assign the result to Cairo.Source.

so I have tried this now, but still no result. I am new to cairo and not
completely understand all that it does (my lack of insight).

This is the code I tried now but it doesn't give me a result. What am I
doing wrong?

Public Sub MakePdf()

  Dim hPdfProjectFile As CairoPdfSurface
  Dim sPdfPath, sPicPath As String
  Dim picImage As Image
  Dim iX, iY As Float
  sPicPath = User.Home & "/MyFolder/mypicture.png"
  sPdfPath = User.Home & "/MyFolder/project.pdf"
  hPdfProjectFile = New CairoPdfSurface(sPdfPath, 210, 297) 
  Cairo.Begin(hPdfProjectFile)
  '--Draw title --
  ..
  ..
  '--Draw project logo --
  iX = 230
  iY = 235
  If Exist(sPicturePath) Then
    picImage.Load(sPicturePath)
    Cairo.MoveTo(iX, iY)
    Cairo.Source = Cairo.ImagePattern(picImage)
    Cairo.Paint              '<-- nothing gets painted on PdfSurface
  Endif
  ..


End


> 
> I don't know Cairo but this seems like how it's done here[0]. It works in my
> test case.

Don't know much C but I'll analyse and see if I get any wiser. Thanks
> 
> Regards,
> Tobi
> 
> [0] http://zetcode.com/gfx/cairo/cairoimages/

-- 
Kind regards,

Willy (aka gbWilly)

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