AcquireCacheView

AcquireCacheView() gets pixels from the in-memory or disk pixel cache as defined by the geometry parameters. A pointer to the pixels is returned if the pixels are transferred, otherwise a NULL is returned.

The format of the AcquireCacheView method is:

  const PixelPacket *AcquireCacheView(const ViewInfo *view_info,
    const long x,const long y,const unsigned long columns,
    const unsigned long rows,ExceptionInfo *exception)

A description of each parameter follows:

view_info

The address of a structure of type ViewInfo.

x,y,columns,rows

These values define the perimeter of a region ofpixels.

exception

Return any errors or warnings in this structure.

CloseCacheView

CloseCacheView() closes the specified view returned by a previous call to OpenCacheView().

The format of the CloseCacheView method is:

  void CloseCacheView(ViewInfo *view_info)

A description of each parameter follows:

view_info

The address of a structure of type ViewInfo.

GetCacheView

GetCacheView() gets pixels from the in-memory or disk pixel cache as defined by the geometry parameters. A pointer to the pixels is returned if the pixels are transferred, otherwise a NULL is returned.

The format of the GetCacheView method is:

  PixelPacket *GetCacheView(ViewInfo *view_info,const long x,const long y,
    const unsigned long columns,const unsigned long rows)

A description of each parameter follows:

pixels

Method GetCacheView returns a null pointer if an erroroccurs, otherwise a pointer to the view_info pixels.

view_info

The address of a structure of type ViewInfo.

x,y,columns,rows

These values define the perimeter of a region ofpixels.

GetCacheViewIndexes

GetCacheViewIndexes() returns the indexes associated with the specified view.

The format of the GetCacheViewIndexes method is:

  IndexPacket *GetCacheViewIndexes(const ViewInfo *view_info)

A description of each parameter follows:

view_info

The address of a structure of type ViewInfo.

GetCacheViewPixels

GetCacheViewPixels() returns the pixels associated with the specified view.

The format of the GetCacheViewPixels method is:

  PixelPacket *GetCacheViewPixels(const ViewInfo *view_info)

A description of each parameter follows:

view_info

The address of a structure of type ViewInfo.

OpenCacheView

OpenCacheView() opens a view into the pixel cache.

The format of the OpenCacheView method is:

  ViewInfo *OpenCacheView(Image *image)

A description of each parameter follows:

image

The image.

SetCacheView

SetCacheView() gets pixels from the in-memory or disk pixel cache as defined by the geometry parameters. A pointer to the pixels is returned if the pixels are transferred, otherwise a NULL is returned.

The format of the SetCacheView method is:

  PixelPacket *SetCacheView(ViewInfo *view_info,const long x,const long y,
    const unsigned long columns,const unsigned long rows)

A description of each parameter follows:

view_info

The address of a structure of type ViewInfo.

x,y,columns,rows

These values define the perimeter of a region ofpixels.

SyncCacheView

SyncCacheView() saves the view_info pixels to the in-memory or disk cache. The method returns MagickTrue if the pixel region is synced, otherwise MagickFalse.

The format of the SyncCacheView method is:

  MagickBooleanType SyncCacheView(ViewInfo *view_info)

A description of each parameter follows:

view_info

The address of a structure of type ViewInfo.