dueca::GLSweeper Class Reference

Object that takes care of initializing GL interfacing code in a specific thread, and calling swapbuffers. More...

#include <GLSweeper.hxx>

Inheritance diagram for dueca::GLSweeper:

Collaboration diagram for dueca::GLSweeper:

Public Member Functions
	GLSweeper (Entity *e, const char *part, const PrioritySpec &ts)
	Constructor.
bool	complete ()
	Continued construction.
	~GLSweeper ()
	Destructor.
bool	getDoubleBuffer () const
	query double buffering.
bool	getAlphaBuffer () const
	query alpha buffer
int	getDepthBufferSize () const
	get minimum depth buffer size.
int	getStencilBufferSize () const
	get minimum stencil buffer size.
Public Member Functions inherited from dueca::Module
virtual	~Module ()
	Destructor.
virtual bool	isInitialPrepared ()
	To check whether the module is prepared to be prepared.
ObjectType	getObjectType () const
	The object type within DUECA.
virtual void	initialStartModule (const TimeSpec &time)
	Initial start opportunity.
virtual void	finalStopModule (const TimeSpec &time)
	Final stop command.
const Entity *	getMyEntity ()
	Return a pointer to the entity to which this module belongs.
const ModuleState &	getState ()
	Return the module state.
Public Member Functions inherited from dueca::NamedObject
const std::string	getEntity () const
	Returns the "entity" part of the name.
const std::string	getClass () const
	Returns the "class" part of the name.
const std::string	getPart () const
	Returns the sub-entity or "part" part of the name.
const NameSet &	getNameSet () const
	This returns the complete name set.
const GlobalId &	getId () const
	This returns the id.

Static Public Member Functions
static const ParameterTable *	getMyParameterTable ()
	Return the parameter table.

Static Public Attributes
static const char *const	classname
	Name of the module.

Additional Inherited Members
Protected Member Functions inherited from dueca::Module
	Module (const Entity *e, const char *m_class, const char *part)
	Constructor.
virtual void	setSafetyStop ()
	Put a brake on this module's activities.
Protected Member Functions inherited from dueca::NamedObject
	NamedObject (const GlobalId &id)
	Reserve for AssociateObject.
	NamedObject (const NameSet &ns)
	Normal constructor, protected, because it has no use to create a NamedObject by itself.
virtual	~NamedObject ()
	Destructor.
Protected Attributes inherited from dueca::Module
ModuleState	state
	Flag to remember whether we are stopped due to some error with hardware device manipulation.

Detailed Description

Object that takes care of initializing GL interfacing code in a specific thread, and calling swapbuffers.

If you use this method of GL programming, all gl windowing code must be in the same thread. The GLSweeper module must run last in this thread, you can achieve this by giving it a negative (the lowest) value for the "order" of its PrioritySpec.

This only works reliably when you don't use any GL code from other threads (so no gtk or other windows). If you do use windowing code, combine all windowing code in one thread, normally priority 0.

I you have no other windowing code, you can use a priority other than 0 for the sweeper. To create this priority, specify something like the following in your dueca.cnf file, e.g. with

(dueca-list
 (make-environment
   'multi-thread #t
   'priority-nice 0         ; becomes priority level 1, non-realtime
   'priority-fifo 10 11 12  ; become priority levels 2, 3, 4, realtime
   ...
 )
)

Note that the priority specifications replace the highest-priority variable. In this example the highest priority level becomes 4, and you need to specify this when making the ticker.

Here an piece of example configuration for dueca.mod:

;; NOTE that this is only allowed when not using a GL
;; interface for the priority 0 thread!!!!!
(define opengl-priority      (make-priority-spec 1     0))
(define opengl-priority-last (make-priority-spec 1   -99))

If you want to use the sweeper for testing and development purposes (solo, single machine, etc.), use priority level 0

(define opengl-priority      (make-priority-spec 0     0))
(define opengl-priority-last (make-priority-spec 0   -99))

The rest of the configuration is as follows. Remember to first create the sweeper, otherwise the gl using module will use the gl facilities of your default graphics toolkit (or find none at all).

;; in the entity creation list .....
(list
 ;; make the GL sweeper. With the priority, it will come in the
 ;; graphics thread, but as last one, after all
 (make-module 'gl-sweeper "" opengl-priority-last

              ;; some parameters that control the timing.
              'set-timing opengl-last
              'check-timing 15000 20000

              ;; a set of parameters that specify the type of GL display
              'double-buffer #t
              'alpha-buffer #t
              'depth-buffer-size 16
              'stencil-buffer-size 0

              ;; specify the toolkit that runs this GL code
              ;; this example uses glut, check DUECA's startup blurp
              ;; to see which protocols are available
              'set-protocol
                (make-glut-protocol)
              )

 ;; your GL modules.
 (make-module 'my-opengl-module "" opengl-priority
              'set-timing opengl-timing
              ;; additional options to your liking)
              )

A final note is on the timing. Ideally, the sweeper runs after you have received new data in your module. This might be tricky, and you might need some tweaking. The sweeper by default runs on the clock, and, although you specify a priority that is after the priority of the module, the sweeper may have been scheduled and started by the time your module is scheduled, and then it will run first. Try tweaking the timing to get things right.

Constructor & Destructor Documentation

GLSweeper()

dueca::GLSweeper::GLSweeper	(	Entity *	e,
		const char *	part,
		const PrioritySpec &	ts )

Constructor.

Is normally called from scheme/the creation script.

Member Function Documentation

complete()

bool dueca::GLSweeper::complete ( )

virtual

Continued construction.

This is called after all script parameters have been read and filled in, according to the parameter table. Your running environment, e.g. for OpenGL drawing, is also prepared. Any lengty initialisations (like reading the 4 GB of wind tables) should be done here. Return false if something in the parameters is wrong (by the way, it would help if you printed what!) May be deleted.

Reimplemented from dueca::Module.

getDoubleBuffer()

bool dueca::GLSweeper::getDoubleBuffer ( ) const

inline

query double buffering.

Returns

true if double buffer used

getAlphaBuffer()

bool dueca::GLSweeper::getAlphaBuffer ( ) const

inline

query alpha buffer

Returns

true if alpha buffer used

getDepthBufferSize()

int dueca::GLSweeper::getDepthBufferSize ( ) const

inline

get minimum depth buffer size.

Returns

The number of bits in the depth buffer.

getStencilBufferSize()

int dueca::GLSweeper::getStencilBufferSize ( ) const

inline

get minimum stencil buffer size.

Returns

The number of bits in the stencil buffer

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

• /home/abuild/rpmbuild/BUILD/dueca-4.1.3/extra/GLSweeper.hxx