#include <tb_texture_manager.hpp>

Inheritance diagram for TurtleBrains::Graphics::TextureManager:

Public Member Functions
TextureHandle	CreateTextureFromFile (const tbCore::tbString &filename)

TextureHandle	CreateTextureFromFileData (const unsigned char *fileDataInMemory, const size_t &fileSizeInBytes)

TextureHandle	CreateTextureFromPixelData (const unsigned char *pixelDataARGB, const PixelSpace &textureWidth, const PixelSpace &textureHeight)

TextureHandle	CreateTextureEmpty (const PixelSpace &textureWidth, const PixelSpace &textureHeight, const TextureFormat &format=TextureFormat::ColorARGB8)

TextureHandle	CreateTextureReference (const TextureHandle &textureHandle)

void	DestroyTexture (const TextureHandle &textureHandle)

void	BindTexture (const TextureHandle &textureHandle)

void	BindTexture (const TextureHandle &textureHandle, tbCore::uint8 textureUnit)

PixelSpace	GetTextureWidth (const TextureHandle &textureHandle) const

PixelSpace	GetTextureHeight (const TextureHandle &textureHandle) const

void	SetTextureWrapMode (const TextureHandle &textureHandle, TextureWrapMode wrapMode)

void	SetTextureWrapMode (const TextureHandle &textureHandle, TextureWrapMode wrapModeU, TextureWrapMode wrapModeV)

tbCore::uint64	ComputeMemoryUsage (void) const

void	CreateGraphicsContext (void)

void	DestroyGraphicsContext (void)

Static Public Member Functions
static void	PreMultiplyAlpha (tbCore::byte *imageData, const PixelSpace &imageWidth, const PixelSpace &imageHeight)

Friends
class	tbImplementation::TextureManagerCreator

Detailed Description

A basic texture manager to load images from disk or file/pixel data in memory while using a caching technique so using the same file path will not create more textures. TurtleBrains makes use of Sean Barrett's stb_image API to process the file, which supports the following file formats with some limitations:

JPEG baseline (no JPEG progressive)
PNG 8-bit-per-channel only
TGA (not sure what subset, if a subset)
BMP non-1bpp, non-RLE
PSD (composited view only, no extra channels)
GIF (*comp always reports as 4-channel)
HDR (radiance rgbE format)
PIC (Softimage PIC)

Member Function Documentation

void TurtleBrains::Graphics::TextureManager::BindTexture ( const TextureHandle & textureHandle )

Binds the texture associated with the textureHandle to the GL context for rendering calls. An error condition will be triggered if textureHandle is the handle was not initialized or the associated texture has been destroyed.

Parameters

textureHandle of the texture to apply to the GL context.

void TurtleBrains::Graphics::TextureManager::BindTexture	(	const TextureHandle &	textureHandle,
		tbCore::uint8	textureUnit
	)

Binds the texture associated with the textureHandle to the GL context for rendering calls. An error condition will be triggered if textureHandle is the handle was not initialized or the associated texture has been destroyed.

Parameters

textureHandle	of the texture to apply to the GL context.
textureUnit	Which texture unit will be the handle be bound to.

tbCore::uint64 TurtleBrains::Graphics::TextureManager::ComputeMemoryUsage ( void ) const

Returns the number of bytes in memory from all textures currently loaded in the manager/texture cache.

Note: May not count texture memory loaded from ALL other sources, such as the RenderTargets objects.

void TurtleBrains::Graphics::TextureManager::CreateGraphicsContext ( void )

When a new Graphics Context is created this should be called to allow the TextureManager to reload any managed textures to the context, and create any generated textures for generaly use like the Blank Texture.

TextureHandle TurtleBrains::Graphics::TextureManager::CreateTextureEmpty	(	const PixelSpace &	textureWidth,
		const PixelSpace &	textureHeight,
		const TextureFormat &	format = `TextureFormat::ColorARGB8`
	)

Creates a texture with specified width and height then sets all the pixels to white. Textures created empty do not get cached, so be aware that calling this several times with the same width/height will create new textures. Any texture created must be cleaned up by calling DestroyTexture().

Parameters

textureWidth	is the width of the texture to be created, in pixels, must be greater than 0.
textureHeight	is the height of the texture to be created, in pixels, must be greater than 0.

Note: to create multiple references to the texture created by empty pixel data you can use CreateTextureReference().

TextureHandle TurtleBrains::Graphics::TextureManager::CreateTextureFromFile ( const tbCore::tbString & filename )

Checks the cache if the file has already been opened, if not, the file will be opened from disk and processed creating an ARGB texture with OpenGL. Any texture created must be cleaned up by calling DestroyTexture. Although the texture may not actually be destroyed if there are still others referencing the texture object (via other calls to CreateTextureFromFile).

Parameters

filename the path of the file to open and process.

TextureHandle TurtleBrains::Graphics::TextureManager::CreateTextureFromFileData	(	const unsigned char *	fileDataInMemory,
		const size_t &	fileSizeInBytes
	)

Creates a texture from the data of a file already in memory, this is not the uncompressed pixel data. Textures created from file data do not get cached, so be aware that calling this several times with the same file data will create new textures. Any texture created must be cleaned up by calling DestroyTexture().

Parameters

fileDataInMemory	should contain an entire supported file in memory which can be removed after the call.
fileSizeInBytes	is how many bytes make up the file.

Note: to create multiple references to the texture created by file data you can use CreateTextureReference().

TextureHandle TurtleBrains::Graphics::TextureManager::CreateTextureFromPixelData	(	const unsigned char *	pixelDataARGB,
		const PixelSpace &	textureWidth,
		const PixelSpace &	textureHeight
	)

Creates a texture from the data of each pixel color, this is the uncompressed 32bit ARGB pixel data format. A 1x1 texture would be 4 bytes, first byte Alpha, second Red, then Green and final byte Blue. Textures created from pixel data do not get cached, so be aware that calling this several times with the same pixel data will create new textures. Any texture created must be cleaned up by calling DestroyTexture().

Parameters

pixelDataARGB	must contain at least (textureWidth * textureHeight * 4) bytes of data for each byte.
textureWidth	is the width of the supplied pixelData in pixels wide, must be greater than 0.
textureHeight	is the height of the supplied pixelData in pixels tall, must be greater than 0.

Note: to create multiple references to the texture created by pixel data you can use CreateTextureReference().

TextureHandle TurtleBrains::Graphics::TextureManager::CreateTextureReference ( const TextureHandle & textureHandle )

This does not actually create a texture but will increase the reference count so it does not get unloaded/cleaned on the call to DestroyTexture. This is meant to allow textured created by file data or pixel data to be shared more easily in the reference counted manner. Any texture created must be cleaned up by calling DestroyTexture().

Parameters

textureHandle The texture associated with this handle will increment the reference count and be returned back. Must be a valid TextureHandle or an error condition will be triggered.

void TurtleBrains::Graphics::TextureManager::DestroyGraphicsContext ( void )

This should be called just before the graphics context is destroyed so the TextureManager can cleanup any resources and deal with the managed textures.

void TurtleBrains::Graphics::TextureManager::DestroyTexture ( const TextureHandle & textureHandle )

Decrements the textures reference count and if needed will destroys the texture, removing it from the OpenGL pipeline and cleaning any other associated resources. Each texture handle is reference counted, so every call to Create needs a matching call to destroy.

Parameters

textureHandle of the texture to destroy and remove completely from the GL context and TextureManager.

PixelSpace TurtleBrains::Graphics::TextureManager::GetTextureHeight ( const TextureHandle & textureHandle ) const

Returns the width of the texture associated with the textureHandle provided. If InvalidTexture() is provided 0 will be returned. An error condition will be triggered if textureHandle is the handle was not initialized or the associated texture has been destroyed.

PixelSpace TurtleBrains::Graphics::TextureManager::GetTextureWidth ( const TextureHandle & textureHandle ) const

Returns the width of the texture associated with the textureHandle provided. If InvalidTexture() is provided 0 will be returned. An error condition will be triggered if textureHandle is the handle was not initialized or the associated texture has been destroyed.

static void TurtleBrains::Graphics::TextureManager::PreMultiplyAlpha	(	tbCore::byte *	imageData,
		const PixelSpace &	imageWidth,
		const PixelSpace &	imageHeight
	)

static

This will take the imageData in ARGB format, and pre-multiplies the RGB channels by the alpha channel since the TurtleBrains shader and blend mode is set for premultiplied alpha.

Parameters

imageData	The data to be modified in place.
imageWidth	The width of the image in pixels.
imageHight	The height of the image in pixels.

void TurtleBrains::Graphics::TextureManager::SetTextureWrapMode	(	const TextureHandle &	textureHandle,
		TextureWrapMode	wrapMode
	)

Set the TextureWrapMode for a specific texture to change how the U and V coordinates behave outside the 0 to 1 range.

textureHandle The texture to change the wrap mode for, if not bound this may incur state changes but previously bound texture will remain bound after finished. wrapMode The mode to use for both U and V coordinates. wrapModeU The mode to use for the horizontal U coordinates. wrapModeV The mode to use for the vertical V coordinates.

void TurtleBrains::Graphics::TextureManager::SetTextureWrapMode	(	const TextureHandle &	textureHandle,
		TextureWrapMode	wrapModeU,
		TextureWrapMode	wrapModeV
	)

Set the TextureWrapMode for a specific texture to change how the U and V coordinates behave outside the 0 to 1 range.

textureHandle The texture to change the wrap mode for, if not bound this may incur state changes but previously bound texture will remain bound after finished. wrapMode The mode to use for both U and V coordinates. wrapModeU The mode to use for the horizontal U coordinates. wrapModeV The mode to use for the vertical V coordinates.

Public Member Functions

Static Public Member Functions

Friends

Detailed Description

Member Function Documentation