Ogre::GLHardwareOcclusionQuery Class Reference

This is a class that is the base class of the query class for hardware occlusion. More...

#include <OgreGLHardwareOcclusionQuery.h>

Inheritance diagram for Ogre::GLHardwareOcclusionQuery:

List of all members.


Public Member Functions
	GLHardwareOcclusionQuery ()
	Default object constructor.
	~GLHardwareOcclusionQuery ()
	Object destructor.
void	beginOcclusionQuery ()
	Starts the hardware occlusion query Simple usage: Create one or more OcclusionQuery object one per outstanding query or one per tested object OcclusionQuery* m_pOcclusionQuery; createOcclusionQuery( &m_pOcclusionQuery ); In the rendering loop: Draw all occluders m_pOcclusionQuery->startOcclusionQuery(); Draw the polygons to be tested m_pOcclusionQuery->endOcclusionQuery();.
void	endOcclusionQuery ()
	Ends the hardware occlusion test.
bool	pullOcclusionQuery (unsigned int *NumOfFragments, const HW_OCCLUSIONQUERY flag)
	Pulls the hardware occlusion query too see if there is a result.
unsigned int	getLastQuerysPixelcount ()
	Let's you get the last pixel count with out doing the hardware occlusion test.
bool	isStillOutstanding (void)
void	setSkipRate (int skip)
	Remarks This function allows you to set how often the hardware occlusion really sent to the driver if you set it to 0 every hardware occlusion test is actually made.
int	getSkipRate ()
virtual bool	HardwareOcclusionQuery::isStillOutstanding (void)=0
	Lets you know when query is done, or still be processed by the Hardware.
Protected Attributes
unsigned int	mPixelCount
GLuint	mQueryID
bool	m_bOcclusionQuery
int	mSkipCounter
int	mSkipInterval
bool	mHasOcclusionSupport

Detailed Description

This is a class that is the base class of the query class for hardware occlusion.

Author:: Lee Sandberg email: lee@abcmedia.se Updated on 4/8/2005 by Tuan Kuranes email: tuan.kuranes@free.fr

Definition at line 69 of file OgreGLHardwareOcclusionQuery.h.

Constructor & Destructor Documentation

Ogre::GLHardwareOcclusionQuery::GLHardwareOcclusionQuery ( )

Default object constructor.

Ogre::GLHardwareOcclusionQuery::~GLHardwareOcclusionQuery ( )

Object destructor.

Member Function Documentation

void Ogre::GLHardwareOcclusionQuery::beginOcclusionQuery ( ) [virtual]

Starts the hardware occlusion query Simple usage: Create one or more OcclusionQuery object one per outstanding query or one per tested object OcclusionQuery* m_pOcclusionQuery; createOcclusionQuery( &m_pOcclusionQuery ); In the rendering loop: Draw all occluders m_pOcclusionQuery->startOcclusionQuery(); Draw the polygons to be tested m_pOcclusionQuery->endOcclusionQuery();.
Results must be pulled using: UINT m_uintNumberOfPixelsVisable; pullOcclusionQuery( &m_dwNumberOfPixelsVisable ); You may not get the result directly after the first pass or frame. Objects not visible must be tested every frame, visible objects may be tested less frequently.
Implements Ogre::HardwareOcclusionQuery.

void Ogre::GLHardwareOcclusionQuery::endOcclusionQuery ( ) [virtual]

Ends the hardware occlusion test.

Implements Ogre::HardwareOcclusionQuery.

unsigned int Ogre::GLHardwareOcclusionQuery::getLastQuerysPixelcount ( ) [virtual]

Let's you get the last pixel count with out doing the hardware occlusion test.

Returns:
The last fragment count from the last test. Remarks This function won't give you new values, just the old value.

Implements Ogre::HardwareOcclusionQuery.
Definition at line 92 of file OgreGLHardwareOcclusionQuery.h.

int Ogre::GLHardwareOcclusionQuery::getSkipRate ( ) [virtual]

Implements Ogre::HardwareOcclusionQuery.
Definition at line 111 of file OgreGLHardwareOcclusionQuery.h.

virtual bool Ogre::HardwareOcclusionQuery::HardwareOcclusionQuery::isStillOutstanding ( void ) [pure virtual, inherited]

Lets you know when query is done, or still be processed by the Hardware.

Returns:
true if query isn't finished.

bool Ogre::GLHardwareOcclusionQuery::isStillOutstanding ( void )

bool Ogre::GLHardwareOcclusionQuery::pullOcclusionQuery ( unsigned int * NumOfFragments,

const HW_OCCLUSIONQUERY flag

) [virtual]

Pulls the hardware occlusion query too see if there is a result.

Return values:

NumOfFragments will get the resulting number of fragments.

Returns:
True if success or false if not. In DX9 mode specifying OCCLUSIONQUERY_FLUSH as the flag, will case the driver to flush whatever API calls are batched. In OpenGL mode it makes no difference if you specify OCCLUSIONQUERY_FLUSH or OCCLUSIONQUERY_NOFLUSH.

Implements Ogre::HardwareOcclusionQuery.

void Ogre::GLHardwareOcclusionQuery::setSkipRate ( int skip ) [virtual]

Remarks This function allows you to set how often the hardware occlusion really sent to the driver if you set it to 0 every hardware occlusion test is actually made.
If you set it to 2 only 50% of your queries are sent. for all visible objects. 3 will result in 33% of all queries to actually be sent and so on. New and none visible objects will be tested all the time. This functionality is here because this class can keep track on visible and none visible objects for you. Once you you set the SkipRate for any hardware occlusion instance it effects all others.
Implements Ogre::HardwareOcclusionQuery.
Definition at line 110 of file OgreGLHardwareOcclusionQuery.h.