ClipMapUniqueCache Class Reference

#include <clipMapUniqueCache.h>

Inheritance diagram for ClipMapUniqueCache:

Detailed Description

Fill clipmap with data from a single large image source.

Public Member Functions

ClipMapUniqueCache (IClipMapImageSource *uniqueSource)

virtual ~ClipMapUniqueCache ()

virtual void initialize (ClipMap *cm)

Initialize the image cache that can hold at least clipMapSize*clipMapSize pixels of data.

virtual void setInterestCenter (const Point2I &origin)

Indicate our interest area center.

virtual bool beginRectUpdates (ClipMap::ClipStackEntry &cse)

Indicate that we are going to be updating a series of rectangles on specified level of the clipstack.

virtual void doRectUpdate (U32 mipLevel, ClipMap::ClipStackEntry &cse, const RectI &srcRegion, const RectI &dstRegion)

Indicate that we're updating a specific rectangle on a clipstack.

virtual void finishRectUpdates (ClipMap::ClipStackEntry &cse)

And finally, give the cache a chance to finish processing for a specified clipstack level.

virtual bool isDataAvailable (U32 mipLevel, const RectI &region) const

Is cached data available for a given region?

virtual bool isRenderToTargetCache ()

If true, we'll allocate render targets rather than normal diffuse maps.

Private Attributes

IClipMapImageSource * mUniqueSource

U32 mClipMapSize

Constructor & Destructor Documentation

ClipMapUniqueCache::ClipMapUniqueCache ( IClipMapImageSource * uniqueSource )

virtual ClipMapUniqueCache::~ClipMapUniqueCache ( ) [virtual]

Member Function Documentation

virtual void ClipMapUniqueCache::initialize ( ClipMap * cm ) [virtual]

Initialize the image cache that can hold at least clipMapSize*clipMapSize pixels of data.

In general the image cache will allocate a bit more than that so it can be efficient in pre-empting requests.

The image cache will also store mipmap data for the interest point, at least clipMapSize px at each miplevel. e.g., for a parameter of 512, we would have available in the cache at all times 512*512*clipMapDepth pixels. Ideally, we would ensure at least one page quanta's worth of extra data is present at all levels so we can fulfill new data requests quickly.

For instance, if we have 128px paged tiles, we'd want to have at least 512/128 = 4 base tiles and 2 border tiles on each axis, so 36 loaded tiles at all times at the source level of detail. This is about two and a quarter megabytes of data per clipmap level, so a cache of about 7 levels * 2.25mb = 15.75mb in system memory for a 32k px source texture. We don't need any "mip" levels - just pure source data for every cliplevel greater than or equal to the clipmap size.

As we may need to regenerate the full clipmap in the case of zombification, we can't discard the top level of data, even though it is never needed in the course of normal clipmap operation.

Implements IClipMapImageCache.

virtual void ClipMapUniqueCache::setInterestCenter ( const Point2I & origin ) [virtual]

Indicate our interest area center.

The cache is for a fixed size area, so we disallow changing that area size.

Implements IClipMapImageCache.

virtual bool ClipMapUniqueCache::beginRectUpdates ( ClipMap::ClipStackEntry & cse ) [virtual]

Indicate that we are going to be updating a series of rectangles on specified level of the clipstack.

Implements IClipMapImageCache.

virtual void ClipMapUniqueCache::doRectUpdate	(	U32	mipLevel,
		ClipMap::ClipStackEntry &	cse,
		const RectI &	srcRegion,
		const RectI &	dstRegion
	)			`[virtual]`

Indicate that we're updating a specific rectangle on a clipstack.

Parameters:

	srcRegion	The region on the source mip level we are updating from.
	dstRegion	The region on the clipmap layer we'll be updating into.

Implements IClipMapImageCache.

virtual void ClipMapUniqueCache::finishRectUpdates ( ClipMap::ClipStackEntry & cse ) [virtual]

And finally, give the cache a chance to finish processing for a specified clipstack level.

Implements IClipMapImageCache.

virtual bool ClipMapUniqueCache::isDataAvailable	(	U32	mipLevel,
		const RectI &	region
	)			const `[virtual]`

Is cached data available for a given region?

Implements IClipMapImageCache.

virtual bool ClipMapUniqueCache::isRenderToTargetCache ( ) [virtual]

If true, we'll allocate render targets rather than normal diffuse maps.

Implements IClipMapImageCache.

Member Data Documentation

IClipMapImageSource* ClipMapUniqueCache::mUniqueSource [private]

U32 ClipMapUniqueCache::mClipMapSize [private]