scm_task Struct Reference

An scm_task represents a page load task, as executed by a loader thread. More...

#include <scm-task.hpp>

Inheritance diagram for scm_task:

Public Member Functions
	scm_task (int, long long)
	Construct a load task. More...
	scm_task (int, long long, uint64, int, int, int, GLuint, scm_cache *)
	Construct a load task. Map the PBO to provide a destination for the loader. More...
void	make_page (int, int)
	Upload the pixel buffer to the OpenGL texture object. More...
bool	load_page (const char *, TIFF *)
	Load a page. On success, mark the buffer as dirty. More...
void	dump_page ()
	Discard the pixel buffer. More...
Public Member Functions inherited from scm_item
	scm_item ()
	Initialize an invalid SCM page reference.
	scm_item (int f, long long i)
	Initialize a valid SCM page reference.
bool	is_valid () const
	Return true if this is a valid SCM page reference.
bool	operator< (const scm_item &that) const
	Determine the order of two SCM page references.

Public Attributes
uint64	o
	SCM TIFF file offset of this page.
int	n
	Page size.
int	c
	Page channel per pixel.
int	b
	Page bits per channel.
GLuint	u
	Pixel unpack buffer object.
bool	d
	Pixel unpack buffer dirty flag.
void *	p
	Pixel unpack buffer map address.
scm_cache *	C
	Destination cache.
Public Attributes inherited from scm_item
int	f
	File index.
long long	i
	Page index.

Detailed Description

An scm_task represents a page load task, as executed by a loader thread.

It encapsulates all of the parameters of the page to be loaded and includes the OpenGL state necessary to perform an asynchronous upload of the loaded data.

Constructor & Destructor Documentation

scm_task::scm_task	(	int	f,
		long long	i
	)

Construct a load task.

Parameters

f	File index
i	Page index

scm_task::scm_task	(	int	f,
		long long	i,
		uint64	o,
		int	n,
		int	c,
		int	b,
		GLuint	u,
		scm_cache *	C
	)

Construct a load task. Map the PBO to provide a destination for the loader.

Parameters

f	File index
i	Page index
o	TIFF offset
n	Page size in pixels
c	Page channels per pixel
b	Page bits per channel
u	Pixel buffer object
C	Destination cache

Member Function Documentation

void scm_task::make_page	(	int	x,
		int	y
	)

Upload the pixel buffer to the OpenGL texture object.

Parameters

x	Location of upper-left pixel
y	Location of upper-left pixel

bool scm_task::load_page	(	const char *	name,
		TIFF *	T
	)

Load a page. On success, mark the buffer as dirty.

This method is called by a loader thread and exists solely to marshal the entensive argument list of the global function scm_load_page.

Parameters

name	TIFF name (used for generating error pages)
T	TIFF pointer

void scm_task::dump_page

(

)

Discard the pixel buffer.

This used when a load task was created but its data should not be uploaded to VRAM. This may be because the task could not be added to the load queue, because the loader thread failed, or because the page was rejected for cache inertion due priority.

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The documentation for this struct was generated from the following files:

• scm-task.hpp
• scm-task.cpp