Visualizza wikitesto di Convertire un oggetto di tipo "Image" in un file di formato TIFF o ICO con le funzioni esterne del API di Libgdk pixbuf

Attualmente Gambas non è in grado di salvare un Oggetto del tipo nativo "''Image''" nei formati "TIFF" e "ICO".

E' possibile, però, ottenere questi due formati, partendo da una "''Image''", usando alcune funzioni esterne del API di GDK_pixbuf.

E' necessario avere installata nel sistema e richiamare con Gambas la libreria condivisa: "''libgdk_pixbuf-2.0.so.0.4000.0'' ".

Mostriamo un esempio (poiché l'ambiente non è grafico, bisognerà attivare il Componenti ''gb.image'' e ''gb.image.io'').
 Library "libgdk_pixbuf-2.0:0.4000.0"
 
 Private Const GDK_COLORSPACE_RGB As Integer = 0
 
 <FONT Color=gray>' ''GdkPixbuf * gdk_pixbuf_new_from_data (const guchar *data, GdkColorspace colorspace, gboolean has_alpha, int bits_per_sample, int width,''
 ' ''int height, int rowstride, GdkPixbufDestroyNotify destroy_fn, gpointer destroy_fn_data)''
 ' ''Creates a new GdkPixbuf out of in-memory image data.''</font>
 Private Extern gdk_pixbuf_new_from_data(data As Pointer, colorspace As Long, has_alpha As Boolean, bits_per_sample As Integer, width As Integer, height As Integer, rowstride As Integer, fn As Pointer, fn_data As Pointer) As Pointer
 
 <FONT Color=gray>' ''gboolean gdk_pixbuf_save (GdkPixbuf *pixbuf, const char *filename, const char *type, GError **error, ...)''
 ' ''Saves pixbuf to a file in format type. By default, "jpeg", "png", "ico" and "bmp" are possible file formats to save in.''</font>
 Private Extern gdk_pixbuf_save(pixbuf As Pointer, filename As String, type As String, gerror As Pointer, ptr As Pointer) As Boolean
 
 <FONT Color=gray>' ''void g_object_unref (gpointer object)''
 ' ''Decreases the reference count of object.''</font>
 Private Extern g_object_unref(gobject As Pointer)
 
 
 '''Public''' Sub Main()
  
  Dim im As Image
  Dim pb As Pointer
  
  im = Image.Load("<FONT Color=gray>''/percorso/file/immagine/originario''</font>")
   
  pb = gdk_pixbuf_new_from_data(im.Data, GDK_COLORSPACE_RGB, True, 8, im.W, im.H, im.W * (im.Depth / 8), 0, 0)
  If pb == 0 Then Error.Raise("Errore !")
   
  gdk_pixbuf_save(pb, "<FONT Color=gray>''/percorso/file.tif''</font>", "tiff", 0, 0)
   
  g_object_unref(pb)
   
 '''End'''