Differenze tra le versioni di "Sfumare radialmente un'immagine mediante le funzioni esterne del API di ImageMagick"
Da Gambas-it.org - Wikipedia.
| Riga 2: | Riga 2: | ||
Per poter fruire in Gambas delle risorse, è necessario avere installata nel sistema e richiamare la seguente libreria condivisa: "''libMagickWand-6.Q16.so.6.0.0'' ". | Per poter fruire in Gambas delle risorse, è necessario avere installata nel sistema e richiamare la seguente libreria condivisa: "''libMagickWand-6.Q16.so.6.0.0'' ". | ||
| − | |||
Le risorse di questa libreria ci consentono - fra l'altro - di sfumare un'immagine con un effetto vortice. | Le risorse di questa libreria ci consentono - fra l'altro - di sfumare un'immagine con un effetto vortice. | ||
| Riga 8: | Riga 7: | ||
Mostriamo un esempio pratico: | Mostriamo un esempio pratico: | ||
Library "libMagickWand-6.Q16:6.0.0" | Library "libMagickWand-6.Q16:6.0.0" | ||
| + | |||
| + | Private Const MagickPathExtent As Integer = 4096 | ||
| + | |||
| + | Public Struct MagickWand | ||
| + | id As Long | ||
| + | name[MagickPathExtent] As Byte | ||
| + | images As Pointer | ||
| + | image_info As Pointer | ||
| + | exception As Pointer | ||
| + | insert_before As Integer | ||
| + | image_pending As Integer | ||
| + | debug_ As Integer | ||
| + | signature As Long | ||
| + | End Struct | ||
Private Enum MagickFalse = 0, MagickTrue | Private Enum MagickFalse = 0, MagickTrue | ||
| Riga 17: | Riga 30: | ||
<FONT Color=gray>' ''MagickWand *NewMagickWand(void)'' | <FONT Color=gray>' ''MagickWand *NewMagickWand(void)'' | ||
' ''Returns a wand required for all other methods in the API.''</font> | ' ''Returns a wand required for all other methods in the API.''</font> | ||
| − | Private Extern NewMagickWand() As | + | Private Extern NewMagickWand() As MagickWand |
<FONT Color=gray>' ''MagickBooleanType MagickReadImage(MagickWand *wand,const char *filename)'' | <FONT Color=gray>' ''MagickBooleanType MagickReadImage(MagickWand *wand,const char *filename)'' | ||
' ''Reads an image or image sequence.''</font> | ' ''Reads an image or image sequence.''</font> | ||
| − | Private Extern MagickReadImage(wand As | + | Private Extern MagickReadImage(wand As MagickWand, filename As String) As Integer |
<FONT Color=gray>' ''MagickBooleanType MagickRadialBlurImage(MagickWand *wand, const double angle)'' | <FONT Color=gray>' ''MagickBooleanType MagickRadialBlurImage(MagickWand *wand, const double angle)'' | ||
' ''Blurs an image.''</font> | ' ''Blurs an image.''</font> | ||
| − | Private Extern MagickRadialBlurImage(wand As | + | Private Extern MagickRadialBlurImage(wand As MagickWand, blur As Float) As Integer |
<FONT Color=gray>' ''MagickBooleanType MagickWriteImages(MagickWand *wand, const char *filename,const MagickBooleanType adjoin)'' | <FONT Color=gray>' ''MagickBooleanType MagickWriteImages(MagickWand *wand, const char *filename,const MagickBooleanType adjoin)'' | ||
' ''Writes an image or image sequence.''</font> | ' ''Writes an image or image sequence.''</font> | ||
| − | Private Extern MagickWriteImages(wand As | + | Private Extern MagickWriteImages(wand As MagickWand, filename As String, adjoin As Boolean) As Integer |
<FONT Color=gray>' ''MagickWand *DestroyMagickWand(MagickWand *wand)'' | <FONT Color=gray>' ''MagickWand *DestroyMagickWand(MagickWand *wand)'' | ||
' ''Deallocates memory associated with an MagickWand.''</font> | ' ''Deallocates memory associated with an MagickWand.''</font> | ||
| − | Private Extern DestroyMagickWand(wand As | + | Private Extern DestroyMagickWand(wand As MagickWand) As MagickWand |
<FONT Color=gray>' ''void MagickWandTerminus(void)'' | <FONT Color=gray>' ''void MagickWandTerminus(void)'' | ||
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'''Public''' Sub Main() | '''Public''' Sub Main() | ||
| − | Dim bo As | + | Dim bo As Integer |
| − | Dim | + | Dim mwand As MagickWand |
Dim fileimmagine, nuovofile As String | Dim fileimmagine, nuovofile As String | ||
| − | + | ||
fileimmagine = "<FONT Color=gray>''/percorso/del/file/immagine''</font>" | fileimmagine = "<FONT Color=gray>''/percorso/del/file/immagine''</font>" | ||
nuovofile = "<FONT Color=gray>''/percorso/del/nuovo/file/dell'immagine/spostata''</font>" | nuovofile = "<FONT Color=gray>''/percorso/del/nuovo/file/dell'immagine/spostata''</font>" | ||
| Riga 51: | Riga 64: | ||
MagickWandGenesis() | MagickWandGenesis() | ||
| − | + | mwand = NewMagickWand() | |
| − | bo = MagickReadImage( | + | bo = MagickReadImage(mwand, fileimmagine) |
| − | If bo = MagickFalse Then | + | If bo == MagickFalse Then |
| − | Termina( | + | Termina(mwand) |
Error.Raise("Impossibile caricare l'immagine !") | Error.Raise("Impossibile caricare l'immagine !") | ||
Endif | Endif | ||
<FONT Color=gray>' ''Modifica l'immagine con l'effetto sfumato con vortice:''</font> | <FONT Color=gray>' ''Modifica l'immagine con l'effetto sfumato con vortice:''</font> | ||
| − | MagickRadialBlurImage( | + | MagickRadialBlurImage(mwand, 50.0) |
| − | bo = MagickWriteImages( | + | bo = MagickWriteImages(mwand, nuovofile, MagickTrue) |
| − | If bo = MagickFalse Then | + | If bo == MagickFalse Then |
| − | Termina( | + | Termina(mwand) |
Error.Raise("Impossibile creare il nuovo file dell'immagine sfumata !") | Error.Raise("Impossibile creare il nuovo file dell'immagine sfumata !") | ||
Endif | Endif | ||
| − | Termina( | + | Termina(mwand) |
'''End''' | '''End''' | ||
| − | '''Private''' Procedure Termina(mw As | + | '''Private''' Procedure Termina(mw As MagickWand) <FONT Color=gray>' ''Libera la memoria e termina il programma''</font> |
DestroyMagickWand(mw) | DestroyMagickWand(mw) | ||
Versione attuale delle 06:03, 20 nov 2022
Il sistema ImageMagick consente di creare, modificare e convertire immagini bitmap. Può altresì leggere e scrivere immagini di oltre 200 formati.
Per poter fruire in Gambas delle risorse, è necessario avere installata nel sistema e richiamare la seguente libreria condivisa: "libMagickWand-6.Q16.so.6.0.0 ".
Le risorse di questa libreria ci consentono - fra l'altro - di sfumare un'immagine con un effetto vortice.
Mostriamo un esempio pratico:
Library "libMagickWand-6.Q16:6.0.0"
Private Const MagickPathExtent As Integer = 4096
Public Struct MagickWand
id As Long
name[MagickPathExtent] As Byte
images As Pointer
image_info As Pointer
exception As Pointer
insert_before As Integer
image_pending As Integer
debug_ As Integer
signature As Long
End Struct
Private Enum MagickFalse = 0, MagickTrue
' void MagickWandGenesis(void)
' Initializes the MagickWand environment.
Private Extern MagickWandGenesis()
' MagickWand *NewMagickWand(void)
' Returns a wand required for all other methods in the API.
Private Extern NewMagickWand() As MagickWand
' MagickBooleanType MagickReadImage(MagickWand *wand,const char *filename)
' Reads an image or image sequence.
Private Extern MagickReadImage(wand As MagickWand, filename As String) As Integer
' MagickBooleanType MagickRadialBlurImage(MagickWand *wand, const double angle)
' Blurs an image.
Private Extern MagickRadialBlurImage(wand As MagickWand, blur As Float) As Integer
' MagickBooleanType MagickWriteImages(MagickWand *wand, const char *filename,const MagickBooleanType adjoin)
' Writes an image or image sequence.
Private Extern MagickWriteImages(wand As MagickWand, filename As String, adjoin As Boolean) As Integer
' MagickWand *DestroyMagickWand(MagickWand *wand)
' Deallocates memory associated with an MagickWand.
Private Extern DestroyMagickWand(wand As MagickWand) As MagickWand
' void MagickWandTerminus(void)
' Terminates the MagickWand environment.
Private Extern MagickWandTerminus()
Public Sub Main()
Dim bo As Integer
Dim mwand As MagickWand
Dim fileimmagine, nuovofile As String
fileimmagine = "/percorso/del/file/immagine"
nuovofile = "/percorso/del/nuovo/file/dell'immagine/spostata"
MagickWandGenesis()
mwand = NewMagickWand()
bo = MagickReadImage(mwand, fileimmagine)
If bo == MagickFalse Then
Termina(mwand)
Error.Raise("Impossibile caricare l'immagine !")
Endif
' Modifica l'immagine con l'effetto sfumato con vortice:
MagickRadialBlurImage(mwand, 50.0)
bo = MagickWriteImages(mwand, nuovofile, MagickTrue)
If bo == MagickFalse Then
Termina(mwand)
Error.Raise("Impossibile creare il nuovo file dell'immagine sfumata !")
Endif
Termina(mwand)
End
Private Procedure Termina(mw As MagickWand) ' Libera la memoria e termina il programma
DestroyMagickWand(mw)
Wait 0.01
MagickWandTerminus()
End
