# Ogre::HardwareOcclusionQuery Class Reference

This is a abstract class that that provides the interface for the query class for hardware occlusion. More...

`#include <OgreHardwareOcclusionQuery.h>`

Inheritance diagram for Ogre::HardwareOcclusionQuery:

List of all members.

## Public Member Functions

| HardwareOcclusionQuery ()
| Default object constructor.
virtual | ~HardwareOcclusionQuery ()
| Object destructor.
virtual void | beginOcclusionQuery ()=0
| 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();.
virtual void | endOcclusionQuery ()=0
| Ends the hardware occlusion test.
virtual bool | pullOcclusionQuery (unsigned int *NumOfFragments)=0
| Pulls the hardware occlusion query.
unsigned int | getLastQuerysPixelcount () const
| Let's you get the last pixel count with out doing the hardware occlusion test.
virtual bool | isStillOutstanding (void)=0
| Lets you know when query is done, or still be processed by the Hardware.

## Protected Attributes

unsigned int | mPixelCount
bool | mIsQueryResultStillOutstanding

## Detailed Description

This is a abstract class that that provides the interface for the query class for hardware occlusion.

Author:
  Lee Sandberg Updated on 13/8/2005 by Tuan Kuranes email: tuan.kuranes@free.fr

Definition at line 42 of file OgreHardwareOcclusionQuery.h.

## Constructor & Destructor Documentation

Ogre::HardwareOcclusionQuery::HardwareOcclusionQuery | ( |  | ) |

| Default object constructor.

virtual Ogre::HardwareOcclusionQuery::~HardwareOcclusionQuery | ( |  | ) | `[virtual]`

| Object destructor.

## Member Function Documentation

virtual void Ogre::HardwareOcclusionQuery::beginOcclusionQuery | ( |  | ) | `[pure 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 );

Implemented in Ogre::D3D9HardwareOcclusionQuery, and Ogre::GLHardwareOcclusionQuery.

virtual void Ogre::HardwareOcclusionQuery::endOcclusionQuery | ( |  | ) | `[pure virtual]`

| Ends the hardware occlusion test. Implemented in Ogre::D3D9HardwareOcclusionQuery, and Ogre::GLHardwareOcclusionQuery.

unsigned int Ogre::HardwareOcclusionQuery::getLastQuerysPixelcount | ( |  | ) | const

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.

Definition at line 100 of file OgreHardwareOcclusionQuery.h.

virtual bool Ogre::HardwareOcclusionQuery::isStillOutstanding | ( | void |  | ) | `[pure virtual]`

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

Returns:
  true if query isn't finished.

Implemented in Ogre::D3D9HardwareOcclusionQuery, and Ogre::GLHardwareOcclusionQuery.

virtual bool Ogre::HardwareOcclusionQuery::pullOcclusionQuery | ( | unsigned int * | NumOfFragments | ) | `[pure virtual]`

Pulls the hardware occlusion query.

Note:
  Waits until the query result is available; use isStillOutstanding if just want to test if the result is available.

Return values:

  | NumOfFragments | will get the resulting number of fragments.

Returns:
  True if success or false if not.

Implemented in Ogre::D3D9HardwareOcclusionQuery, and Ogre::GLHardwareOcclusionQuery.

## Member Data Documentation

bool Ogre::HardwareOcclusionQuery::mIsQueryResultStillOutstanding `[protected]`

| Definition at line 116 of file OgreHardwareOcclusionQuery.h.

unsigned int Ogre::HardwareOcclusionQuery::mPixelCount `[protected]`

| Definition at line 114 of file OgreHardwareOcclusionQuery.h. Referenced by Ogre::D3D9HardwareOcclusionQuery::getLastQuerysPixelcount().

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

- OgreHardwareOcclusionQuery.h

Copyright © 2000-2005 by The OGRE Team
This work is licensed under a Creative Commons Attribution-ShareAlike 2.5 License.
Last modified Sun Sep 17 15:39:58 2006