IClipMapImageCache Class Reference

#include <clipMapCache.h>

Inheritance diagram for IClipMapImageCache:

Detailed Description

Interface for a clipmap image cache.

See also:: AtlasClipMap

Public Member Functions

virtual ~IClipMapImageCache ()

virtual void initialize (ClipMap *clipmap)=0

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

virtual void setInterestCenter (const Point2I &origin)=0

Indicate our interest area center.

virtual bool beginRectUpdates (ClipMap::ClipStackEntry &cse)=0

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)=0

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

virtual void finishRectUpdates (ClipMap::ClipStackEntry &cse)=0

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

virtual bool isDataAvailable (U32 mipLevel, const RectI &region) const =0

Is cached data available for a given region?

virtual bool isRenderToTargetCache ()=0

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

Constructor & Destructor Documentation

virtual IClipMapImageCache::~IClipMapImageCache ( ) [inline, virtual]

Member Function Documentation

virtual void IClipMapImageCache::initialize ( ClipMap * clipmap ) [pure 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.

Implemented in ClipMapBlenderCache, ClipMapImageCache_Debug, and ClipMapUniqueCache.

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

Indicate our interest area center.

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

Implemented in ClipMapBlenderCache, ClipMapImageCache_Debug, and ClipMapUniqueCache.

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

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

Implemented in ClipMapBlenderCache, ClipMapImageCache_Debug, and ClipMapUniqueCache.

virtual void IClipMapImageCache::doRectUpdate	(	U32	mipLevel,
		ClipMap::ClipStackEntry &	cse,
		const RectI &	srcRegion,
		const RectI &	dstRegion
	)			`[pure 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.

Implemented in ClipMapBlenderCache, ClipMapImageCache_Debug, and ClipMapUniqueCache.

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

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

Implemented in ClipMapBlenderCache, ClipMapImageCache_Debug, and ClipMapUniqueCache.

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

Is cached data available for a given region?

Implemented in ClipMapBlenderCache, ClipMapImageCache_Debug, and ClipMapUniqueCache.

virtual bool IClipMapImageCache::isRenderToTargetCache ( ) [pure virtual]

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

Implemented in ClipMapBlenderCache, ClipMapImageCache_Debug, and ClipMapUniqueCache.