CTextureManager Class Reference

Texture manager with asynchronous loading and automatic DDS conversion/compression. More...

#include <TextureManager.h>

Public Member Functions
	CTextureManager (PIVFS vfs, bool highQuality, bool disableGL)
	Construct texture manager. More...
	~CTextureManager ()
CTexturePtr	CreateTexture (const CTextureProperties &props)
	Create a texture with the given GL properties. More...
CTexturePtr	GetErrorTexture ()
	Returns a magenta texture. More...
bool	MakeProgress ()
	Work on asynchronous texture loading operations, if any. More...
bool	GenerateCachedTexture (const VfsPath &path, VfsPath &outputPath)
	Synchronously converts and compresses and saves the texture, and returns the output path (minus a "cache/" prefix). More...

Private Member Functions
	NONCOPYABLE (CTextureManager)

Private Attributes
CTextureManagerImpl *	m

Detailed Description

Texture manager with asynchronous loading and automatic DDS conversion/compression.

Input textures can be any format. They will be converted to DDS using settings defined in files named "texture.xml", in the same directory as the texture and in its parent directories. See CTextureConverter for the XML syntax. The DDS file will be cached for faster loading in the future.

Typically the graphics code will initialise many textures at the start of the game, mostly for off-screen objects, by calling CreateTexture(). Loading texture data may be very slow (especially if it needs to be converted to DDS), and we don't want the game to become unresponsive. CreateTexture therefore returns an object immediately, without loading the texture. If the object is never used then the data will never be loaded.

Typically, the renderer will call CTexture::Bind() when it wants to use the texture. This will trigger the loading of the texture data. If it can be loaded quickly (i.e. there is already a cached DDS version), then it will be loaded before the function returns, and the texture can be rendered as normal.

If loading will take a long time, then Bind() binds a default placeholder texture and starts loading the texture in the background. It will use the correct texture when the renderer next calls Bind() after the load has finished.

It is also possible to prefetch textures which are not being rendered yet, but are expected to be rendered soon (e.g. for off-screen terrain tiles). These will be loaded in the background, when there are no higher-priority textures to load.

The same texture file can be safely loaded multiple times with different GL parameters (but this should be avoided whenever possible, as it wastes VRAM).

For release packages, DDS files can be precached by appending ".dds" to their name, which will be used instead of doing runtime conversion. This means most players should never experience the slow asynchronous conversion behaviour. These cache files will typically be packed into an archive for faster loading; if no archive cache is available then the source file will be converted and stored as a loose cache file on the user's disk.

Definition at line 71 of file TextureManager.h.

Constructor & Destructor Documentation

CTextureManager::CTextureManager	(	PIVFS	vfs,
		bool	highQuality,
		bool	disableGL
	)

Construct texture manager.

vfs must be the VFS instance used for all textures loaded from this object. highQuality is slower and intended for batch-conversion modes. disableGL is intended for tests, and will disable all GL uploads.

Definition at line 615 of file TextureManager.cpp.

CTextureManager::~CTextureManager

(

)

Definition at line 620 of file TextureManager.cpp.

Member Function Documentation

CTexturePtr CTextureManager::CreateTexture

(

const CTextureProperties &

props

)

Create a texture with the given GL properties.

The texture data will not be loaded immediately.

Definition at line 625 of file TextureManager.cpp.

bool CTextureManager::GenerateCachedTexture	(	const VfsPath &	path,
		VfsPath &	outputPath
	)

Synchronously converts and compresses and saves the texture, and returns the output path (minus a "cache/" prefix).

This is intended for pre-caching textures in release archives.

Returns

true on success

Definition at line 640 of file TextureManager.cpp.

CTexturePtr CTextureManager::GetErrorTexture

(

)

Returns a magenta texture.

Use this for highlighting errors (e.g. missing terrain textures).

Definition at line 630 of file TextureManager.cpp.

bool CTextureManager::MakeProgress

(

)

Work on asynchronous texture loading operations, if any.

Returns true if it did any work. The caller should typically loop this per frame until it returns false or exceeds the allocated time for this frame.

Definition at line 635 of file TextureManager.cpp.

CTextureManager::NONCOPYABLE ( CTextureManager  )

private

Member Data Documentation

CTextureManagerImpl* CTextureManager::m

private

Definition at line 115 of file TextureManager.h.

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

• /home/sathyam/0ad.svn/source/graphics/TextureManager.h
• /home/sathyam/0ad.svn/source/graphics/TextureManager.cpp