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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:

Inheritance graph
[legend]
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)
 Pulls the hardware occlusion query too see if there is a result.

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.

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 hw occlusion test is acctually made.

int getSkipRate ()

Protected Attributes

unsigned int m_uintPixelCount
unsigned int m_uintQuery [1]
bool m_bOcclusionQuery
int m_SkipCounter
bool m_bHWOcclusionSupport

Static Protected Attributes

int m_Skip

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

Definition at line 68 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 directlly after the first pass or frame. Objects not visable must be tested every frame, visable objects may be tested less freqvent.

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 110 of file OgreGLHardwareOcclusionQuery.h.

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.

bool Ogre::GLHardwareOcclusionQuery::pullOcclusionQuery unsigned int *  NumOfFragments  )  [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. Hardware occlusion is an assyncronius process the result may take a frame or so. one idea is to test pass1 and if not visable skip pass2. Also note that objects not visable must be tested evrey frame. Visable objects don't need testing every frame. Testing non visable objects can be don unlit, no texture with low LOD object. 0 will generate all the levels till 1x1. [default: 0]

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 hw occlusion test is acctually made.

If you set it to 2 only 50% of your queries are sent. for all visable objects. 3 will result in 33% of all queries to acctualy be sent and so on. New and none visable objects will be tested all the time. This functionality is here because this class can keep track on visable and none visable objects for you. Once you you set the SkipRate for any hardware occlusion instance it effects all others.

Implements Ogre::HardwareOcclusionQuery.

Definition at line 109 of file OgreGLHardwareOcclusionQuery.h.


Member Data Documentation

bool Ogre::GLHardwareOcclusionQuery::m_bHWOcclusionSupport [protected]
 

Definition at line 123 of file OgreGLHardwareOcclusionQuery.h.

bool Ogre::GLHardwareOcclusionQuery::m_bOcclusionQuery [protected]
 

Definition at line 120 of file OgreGLHardwareOcclusionQuery.h.

int Ogre::GLHardwareOcclusionQuery::m_Skip [static, protected]
 

Definition at line 122 of file OgreGLHardwareOcclusionQuery.h.

int Ogre::GLHardwareOcclusionQuery::m_SkipCounter [protected]
 

Definition at line 121 of file OgreGLHardwareOcclusionQuery.h.

unsigned int Ogre::GLHardwareOcclusionQuery::m_uintPixelCount [protected]
 

Definition at line 118 of file OgreGLHardwareOcclusionQuery.h.

unsigned int Ogre::GLHardwareOcclusionQuery::m_uintQuery[1] [protected]
 

Definition at line 119 of file OgreGLHardwareOcclusionQuery.h.


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

Copyright © 2000-2005 by The OGRE Team
Last modified Wed Feb 23 00:30:22 2005