# Wand-view

## CloneWandView

CloneWandView() makes a copy of the specified wand view.

The format of the CloneWandView method is:

    WandView *CloneWandView(const WandView *wand_view)

A description of each parameter follows:

wand_view
  the wand view.

## DestroyWandView

DestroyWandView() deallocates memory associated with a wand view.

The format of the DestroyWandView method is:

    WandView *DestroyWandView(WandView *wand_view)

A description of each parameter follows:

wand_view
  the wand view.

## DuplexTransferWandViewIterator

DuplexTransferWandViewIterator() iterates over three wand views in parallel and calls your transfer method for each scanline of the view. The source and duplex pixel extent is not confined to the image canvas-- that is you can include negative offsets or widths or heights that exceed the image dimension. However, the destination wand view is confined to the image canvas-- that is no negative offsets or widths or heights that exceed the image dimension are permitted.

The callback signature is:

    MagickBooleanType DuplexTransferImageViewMethod(const WandView *source,
      const WandView *duplex,WandView *destination,const ssize_t y,
      const int thread_id,void *context)

Use this pragma if the view is not single threaded:

        #pragma omp critical

to define a section of code in your callback transfer method that must be executed by a single thread at a time.

The format of the DuplexTransferWandViewIterator method is:

    MagickBooleanType DuplexTransferWandViewIterator(WandView *source,
      WandView *duplex,WandView *destination,
      DuplexTransferWandViewMethod transfer,void *context)

A description of each parameter follows:

source
  the source wand view.
duplex
  the duplex wand view.
destination
  the destination wand view.
transfer
  the transfer callback method.
context
  the user defined context.

## GetWandViewException

GetWandViewException() returns the severity, reason, and description of any error that occurs when utilizing a wand view.

The format of the GetWandViewException method is:

    char *GetWandViewException(const WandView *wand_view,
      ExceptionType *severity)

A description of each parameter follows:

wand_view
  the pixel wand_view.
severity
  the severity of the error is returned here.

## GetWandViewExtent

GetWandViewExtent() returns the wand view extent.

The format of the GetWandViewExtent method is:

    RectangleInfo GetWandViewExtent(const WandView *wand_view)

A description of each parameter follows:

wand_view
  the wand view.

## GetWandViewIterator

GetWandViewIterator() iterates over the wand view in parallel and calls your get method for each scanline of the view. The pixel extent is not confined to the image canvas-- that is you can include negative offsets or widths or heights that exceed the image dimension. Any updates to the pixels in your callback are ignored.

The callback signature is:

    MagickBooleanType GetImageViewMethod(const WandView *source,
      const ssize_t y,const int thread_id,void *context)

Use this pragma if the view is not single threaded:

        #pragma omp critical

to define a section of code in your callback get method that must be executed by a single thread at a time.

The format of the GetWandViewIterator method is:

    MagickBooleanType GetWandViewIterator(WandView *source,
      GetWandViewMethod get,void *context)

A description of each parameter follows:

source
  the source wand view.
get
  the get callback method.
context
  the user defined context.

## GetWandViewPixels

GetWandViewPixels() returns the wand view pixel_wands.

The format of the GetWandViewPixels method is:

    PixelWand *GetWandViewPixels(const WandView *wand_view)

A description of each parameter follows:

wand_view
  the wand view.

## GetWandViewWand

GetWandViewWand() returns the magick wand associated with the wand view.

The format of the GetWandViewWand method is:

    MagickWand *GetWandViewWand(const WandView *wand_view)

A description of each parameter follows:

wand_view
  the wand view.

## IsWandView

IsWandView() returns MagickTrue if the parameter is verified as a wand view object.

The format of the IsWandView method is:

    MagickBooleanType IsWandView(const WandView *wand_view)

A description of each parameter follows:

wand_view
  the wand view.

## NewWandView

NewWandView() returns a wand view required for all other methods in the Wand View API.

The format of the NewWandView method is:

    WandView *NewWandView(MagickWand *wand)

A description of each parameter follows:

wand
  the wand.

## NewWandViewExtent

NewWandViewExtent() returns a wand view required for all other methods in the Wand View API.

The format of the NewWandViewExtent method is:

    WandView *NewWandViewExtent(MagickWand *wand,const ssize_t x,
      const ssize_t y,const size_t width,const size_t height)

A description of each parameter follows:

wand
  the magick wand.
x,y,columns,rows
  These values define the perimeter of a extent of pixel_wands view.

## SetWandViewDescription

SetWandViewDescription() associates a description with an image view.

The format of the SetWandViewDescription method is:

    void SetWandViewDescription(WandView *image_view,const char *description)

A description of each parameter follows:

wand_view
  the wand view.
description
  the wand view description.

## SetWandViewIterator

SetWandViewIterator() iterates over the wand view in parallel and calls your set method for each scanline of the view. The pixel extent is confined to the image canvas-- that is no negative offsets or widths or heights that exceed the image dimension. The pixels are initially undefined and any settings you make in the callback method are automagically synced back to your image.

The callback signature is:

    MagickBooleanType SetImageViewMethod(ImageView *destination,
      const ssize_t y,const int thread_id,void *context)

Use this pragma if the view is not single threaded:

        #pragma omp critical

to define a section of code in your callback set method that must be executed by a single thread at a time.

The format of the SetWandViewIterator method is:

    MagickBooleanType SetWandViewIterator(WandView *destination,
      SetWandViewMethod set,void *context)

A description of each parameter follows:

destination
  the wand view.
set
  the set callback method.
context
  the user defined context.

## TransferWandViewIterator

TransferWandViewIterator() iterates over two wand views in parallel and calls your transfer method for each scanline of the view. The source pixel extent is not confined to the image canvas-- that is you can include negative offsets or widths or heights that exceed the image dimension. However, the destination wand view is confined to the image canvas-- that is no negative offsets or widths or heights that exceed the image dimension are permitted.

The callback signature is:

    MagickBooleanType TransferImageViewMethod(const WandView *source,
      WandView *destination,const ssize_t y,const int thread_id,
      void *context)

Use this pragma if the view is not single threaded:

        #pragma omp critical

to define a section of code in your callback transfer method that must be executed by a single thread at a time.

The format of the TransferWandViewIterator method is:

    MagickBooleanType TransferWandViewIterator(WandView *source,
      WandView *destination,TransferWandViewMethod transfer,void *context)

A description of each parameter follows:

source
  the source wand view.
destination
  the destination wand view.
transfer
  the transfer callback method.
context
  the user defined context.

## UpdateWandViewIterator

UpdateWandViewIterator() iterates over the wand view in parallel and calls your update method for each scanline of the view. The pixel extent is confined to the image canvas-- that is no negative offsets or widths or heights that exceed the image dimension are permitted. Updates to pixels in your callback are automagically synced back to the image.

The callback signature is:

    MagickBooleanType UpdateImageViewMethod(WandView *source,const ssize_t y,
      const int thread_id,void *context)

Use this pragma if the view is not single threaded:

        #pragma omp critical

to define a section of code in your callback update method that must be executed by a single thread at a time.

The format of the UpdateWandViewIterator method is:

    MagickBooleanType UpdateWandViewIterator(WandView *source,
      UpdateWandViewMethod update,void *context)

A description of each parameter follows:

source
  the source wand view.
update
  the update callback method.
context
  the user defined context.