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ImageCache Class Referenceabstract

#include <imagecache.h>

Public Member Functions

virtual void clear ()=0
 
virtual bool attribute (const std::string &name, TypeDesc type, const void *val)=0
 
virtual bool attribute (const std::string &name, int val)=0
 
virtual bool attribute (const std::string &name, float val)=0
 
virtual bool attribute (const std::string &name, double val)=0
 
virtual bool attribute (const std::string &name, const char *val)=0
 
virtual bool attribute (const std::string &name, const std::string &val)=0
 
virtual bool getattribute (const std::string &name, TypeDesc type, void *val)=0
 Get the named attribute, store it in value.
 
virtual bool getattribute (const std::string &name, int &val)=0
 
virtual bool getattribute (const std::string &name, float &val)=0
 
virtual bool getattribute (const std::string &name, double &val)=0
 
virtual bool getattribute (const std::string &name, char **val)=0
 
virtual bool getattribute (const std::string &name, std::string &val)=0
 
virtual std::string resolve_filename (const std::string &filename) const =0
 
virtual bool get_image_info (ustring filename, int subimage, int miplevel, ustring dataname, TypeDesc datatype, void *data)=0
 
bool get_image_info (ustring filename, ustring dataname, TypeDesc datatype, void *data)
 Back-compatible version of get_image_info – DEPRECATED.
 
virtual bool get_imagespec (ustring filename, ImageSpec &spec, int subimage=0, int miplevel=0, bool native=false)=0
 
virtual const ImageSpecimagespec (ustring filename, int subimage=0, int miplevel=0, bool native=false)=0
 
virtual bool get_pixels (ustring filename, int subimage, int miplevel, int xbegin, int xend, int ybegin, int yend, int zbegin, int zend, TypeDesc format, void *result)=0
 
virtual bool get_pixels (ustring filename, int subimage, int miplevel, int xbegin, int xend, int ybegin, int yend, int zbegin, int zend, int chbegin, int chend, TypeDesc format, void *result, stride_t xstride=AutoStride, stride_t ystride=AutoStride, stride_t zstride=AutoStride)=0
 
virtual Tile * get_tile (ustring filename, int subimage, int miplevel, int x, int y, int z)=0
 
virtual void release_tile (Tile *tile) const =0
 
virtual const void * tile_pixels (Tile *tile, TypeDesc &format) const =0
 
virtual std::string geterror () const =0
 
virtual std::string getstats (int level=1) const =0
 
virtual void reset_stats ()=0
 
virtual void invalidate (ustring filename)=0
 
virtual void invalidate_all (bool force=false)=0
 

Static Public Member Functions

static ImageCachecreate (bool shared=true)
 
static void destroy (ImageCache *x)
 

Detailed Description

Define an API to an abstract class that manages image files, caches of open file handles as well as tiles of pixels so that truly huge amounts of image data may be accessed by an application with low memory footprint.

Member Function Documentation

virtual bool ImageCache::attribute ( const std::string &  name,
TypeDesc  type,
const void *  val 
)
pure virtual

Set an attribute controlling the image cache. Return true if the name and type were recognized and the attrib was set. Documented attributes: int max_open_files : maximum number of file handles held open float max_memory_MB : maximum tile cache size, in MB string searchpath : colon-separated search path for images string plugin_searchpath : colon-separated search path for plugins int autotile : if >0, tile size to emulate for non-tiled images int autoscanline : autotile using full width tiles int automip : if nonzero, emulate mipmap on the fly int accept_untiled : if nonzero, accept untiled images, but if zero, reject untiled images (default=1) int accept_unmipped : if nonzero, accept unmipped images (def=1) int statistics:level : verbosity of statistics auto-printed. int forcefloat : if nonzero, convert all to float. int failure_retries : number of times to retry a read before fail. int deduplicate : if nonzero, detect duplicate textures (default=1) string substitute_image : uses the named image in place of all texture and image references. int unassociatedalpha : if nonzero, keep unassociated alpha images

virtual void ImageCache::clear ( )
pure virtual

Close everything, free resources, start from scratch.

static ImageCache* ImageCache::create ( bool  shared = true)
static

Create a ImageCache and return a pointer. This should only be freed by passing it to ImageCache::destroy()!

If shared==true, it's intended to be shared with other like-minded owners in the same process who also ask for a shared cache. If false, a private image cache will be created.

static void ImageCache::destroy ( ImageCache x)
static

Destroy a ImageCache that was created using ImageCache::create().

virtual bool ImageCache::get_image_info ( ustring  filename,
int  subimage,
int  miplevel,
ustring  dataname,
TypeDesc  datatype,
void *  data 
)
pure virtual

Get information about the named image. Return true if found and the data has been put in *data. Return false if the image doesn't exist, doesn't have the requested data, if the data doesn't match the type requested. or some other failure.

bool ImageCache::get_image_info ( ustring  filename,
ustring  dataname,
TypeDesc  datatype,
void *  data 
)
inline

Back-compatible version of get_image_info – DEPRECATED.

virtual bool ImageCache::get_imagespec ( ustring  filename,
ImageSpec spec,
int  subimage = 0,
int  miplevel = 0,
bool  native = false 
)
pure virtual

Get the ImageSpec associated with the named image (the first subimage & miplevel by default, or as set by 'subimage' and 'miplevel'). If the file is found and is an image format that can be read, store a copy of its specification in spec and return true. Return false if the file was not found or could not be opened as an image file by any available ImageIO plugin.

virtual bool ImageCache::get_pixels ( ustring  filename,
int  subimage,
int  miplevel,
int  xbegin,
int  xend,
int  ybegin,
int  yend,
int  zbegin,
int  zend,
TypeDesc  format,
void *  result 
)
pure virtual

Retrieve the rectangle of pixels spanning [xbegin..xend) X [ybegin..yend) X [zbegin..zend), with "exclusive end" a la STL, specified as integer pixel coordinates in the designated subimage & miplevel, storing the pixel values beginning at the address specified by result. The pixel values will be converted to the type specified by format. It is up to the caller to ensure that result points to an area of memory big enough to accommodate the requested rectangle (taking into consideration its dimensions, number of channels, and data format). Requested pixels outside the valid pixel data region will be filled in with 0 values.

Return true if the file is found and could be opened by an available ImageIO plugin, otherwise return false.

virtual bool ImageCache::get_pixels ( ustring  filename,
int  subimage,
int  miplevel,
int  xbegin,
int  xend,
int  ybegin,
int  yend,
int  zbegin,
int  zend,
int  chbegin,
int  chend,
TypeDesc  format,
void *  result,
stride_t  xstride = AutoStride,
stride_t  ystride = AutoStride,
stride_t  zstride = AutoStride 
)
pure virtual

Retrieve the rectangle of pixels spanning [xbegin..xend) X [ybegin..yend) X [zbegin..zend), channels [chbegin..chend), with "exclusive end" a la STL, specified as integer pixel coordinates in the designated subimage & miplevel, storing the pixel values beginning at the address specified by result and with the given x, y, and z strides (in bytes). The pixel values will be converted to the type specified by format. If the strides are set to AutoStride, they will be automatically computed assuming a contiguous data layout. It is up to the caller to ensure that result points to an area of memory big enough to accommodate the requested rectangle (taking into consideration its dimensions, number of channels, and data format). Requested pixels outside the valid pixel data region will be filled in with 0 values.

Return true if the file is found and could be opened by an available ImageIO plugin, otherwise return false.

virtual Tile* ImageCache::get_tile ( ustring  filename,
int  subimage,
int  miplevel,
int  x,
int  y,
int  z 
)
pure virtual

Find a tile given by an image filename, subimage & miplevel, and pixel coordinates. An opaque pointer to the tile will be returned, or NULL if no such file (or tile within the file) exists or can be read. The tile will not be purged from the cache until after release_tile() is called on the tile pointer the same number of times that get_tile() was called (refcnt). This is thread-safe!

virtual bool ImageCache::getattribute ( const std::string &  name,
TypeDesc  type,
void *  val 
)
pure virtual

Get the named attribute, store it in value.

virtual std::string ImageCache::geterror ( ) const
pure virtual

If any of the API routines returned false indicating an error, this routine will return the error string (and clear any error flags). If no error has occurred since the last time geterror() was called, it will return an empty string.

virtual std::string ImageCache::getstats ( int  level = 1) const
pure virtual

Return the statistics output as a huge string.

virtual const ImageSpec* ImageCache::imagespec ( ustring  filename,
int  subimage = 0,
int  miplevel = 0,
bool  native = false 
)
pure virtual

Return a pointer to an ImageSpec associated with the named image (the first subimage & miplevel by default, or as set by 'subimage' and 'miplevel') if the file is found and is an image format that can be read, otherwise return NULL.

This method is much more efficient than get_imagespec(), since it just returns a pointer to the spec held internally by the ImageCache (rather than copying the spec to the user's memory). However, the caller must beware that the pointer is only valid as long as nobody (even other threads) calls invalidate() on the file, or invalidate_all(), or destroys the ImageCache.

virtual void ImageCache::invalidate ( ustring  filename)
pure virtual

Invalidate any loaded tiles or open file handles associated with the filename, so that any subsequent queries will be forced to re-open the file or re-load any tiles (even those that were previously loaded and would ordinarily be reused). A client might do this if, for example, they are aware that an image being held in the cache has been updated on disk. This is safe to do even if other procedures are currently holding reference-counted tile pointers from the named image, but those procedures will not get updated pixels until they release the tiles they are holding.

virtual void ImageCache::invalidate_all ( bool  force = false)
pure virtual

Invalidate all loaded tiles and open file handles. This is safe to do even if other procedures are currently holding reference-counted tile pointers from the named image, but those procedures will not get updated pixels until they release the tiles they are holding. If force is true, everything will be invalidated, no matter how wasteful it is, but if force is false, in actuality files will only be invalidated if their modification times have been changed since they were first opened.

virtual void ImageCache::release_tile ( Tile *  tile) const
pure virtual

After finishing with a tile, release_tile will allow it to once again be purged from the tile cache if required.

virtual void ImageCache::reset_stats ( )
pure virtual

Reset most statistics to be as they were with a fresh ImageCache. Caveat emptor: this does not flush the cache itelf, so the resulting statistics from the next set of texture requests will not match the number of tile reads, etc., that would have resulted from a new ImageCache.

virtual std::string ImageCache::resolve_filename ( const std::string &  filename) const
pure virtual

Given possibly-relative 'filename', resolve it using the search path rules and return the full resolved filename.

virtual const void* ImageCache::tile_pixels ( Tile *  tile,
TypeDesc &  format 
) const
pure virtual

For a tile retrived by get_tile(), return a pointer to the pixel data itself, and also store in 'format' the data type that the pixels are internally stored in (which may be different than the data type of the pixels in the disk file).


The documentation for this class was generated from the following file: