[RESOLVED] picturebox upsidedown-gradient

[Schmidt]

For completeness, to allow an influencing of the Angle of the Gradient-Vector -
the routine I've posted in #18, would need to be changed to:

Private Sub RenderToFormOrPicBox(Canvas, AngDeg0to90, ColorStops)
  Canvas.ScaleMode = vbPixels
  
  Dim CC As cCairoContext, Pat As cCairoPattern, i As Long
  Set CC = Cairo.CreateSurface(Canvas.ScaleWidth, Canvas.ScaleHeight).CreateContext
  
  Set Pat = Cairo.CreateLinearPattern(0, 0, Cos(AngDeg0to90 / 180 * Cairo.PI) * CC.Surface.Width, _
                                            Sin(AngDeg0to90 / 180 * Cairo.PI) * CC.Surface.Height)
  For i = 0 To UBound(ColorStops) 'now add the Color-Stops for this gradient-pattern
      Pat.AddColorStop i / UBound(ColorStops), ColorStops(i)
  Next
  CC.Paint 1, Pat 'now render the gradient-pattern via the CairoContext
  
  Set Canvas.Picture = CC.Surface.Picture
End Sub

I've colored the changes in Blue.

Usage then:
RenderToFormOrPicBox Me, 0, Array(vbCyan, vbBlue) 'horizontal
RenderToFormOrPicBox Me, 90, Array(vbCyan, vbBlue) 'vertical
RenderToFormOrPicBox Me, 45, Array(vbCyan, vbBlue) 'angled

HTH

Olaf