Data structure for a DXT5 compressed texture block. More...

Public Member Functions
void	Decompress (RGBAWord8_t pOutput, uintptr_t uStride=sizeof(RGBAWord8_t) 4) const
	Decompress a single 4x4 block compressed with DXT5.

void	Compress (const RGBAWord8_t pInput, uintptr_t uStride=sizeof(RGBAWord8_t) 4)

Public Attributes
uint8_t	m_uAlpha1
	First alpha endpoint in 8 bit intensity.

uint8_t	m_uAlpha2
	Second alpha endpoint in 8 bit intensity.

uint8_t	m_uAlphaIndexes [2][3]
	Two 24 bit little endian values that contain 3 bits per pixel indexes for the 4x4 tile.

uint16_t	m_uRGB565Color1
	First color endpoint in R5:G6:B5 little endian format.

uint16_t	m_uRGB565Color2
	Second color endpoint in R5:G6:B5 little endian format.

uint8_t	m_uColorIndexes [4]
	2 bits per pixel color indexes for 4x4 tile

Detailed Description

Data structure for a DXT5 compressed texture block.

This structure is a 1:1 mapping of a 16 byte DXT5 encoded data block used by many modern video cards. The first 8 bytes represent the alpha for the 4x4 block and the next 8 bytes represent the color for the 4x4 block.

The data compressor and decompresser are designed to be able to use frame buffers as input and output to reduce the need for intermediate buffers for speed.

See also: Burger::Dxt1Packet_t and Burger::Dxt3Packet_t

Member Function Documentation

◆ Compress()

void Burger::Dxt5Packet_t::Compress	(	const RGBAWord8_t *	pInput,
		uintptr_t	uStride = sizeof(RGBAWord8_t) *4 )

◆ Decompress()

void Burger::Dxt5Packet_t::Decompress	(	RGBAWord8_t *	pOutput,
		uintptr_t	uStride = sizeof(RGBAWord8_t)*4 ) const

Decompress a single 4x4 block compressed with DXT5.

Given a 16 byte block of DXT5 compressed data, extract the 4x4 RGBA color block.

Parameters

pOutput	Pointer to the start of an array of sixteen RGBAWord8_t encoded 32 bit pixels
uStride	Byte width of each scan line for the block of uncompressed data. The default is sizeof(RGBAWord8_t)*4 to create a single array of 16 RGBAWord8_t pixels in a linear row.

Member Data Documentation

◆ m_uAlpha1

uint8_t Burger::Dxt5Packet_t::m_uAlpha1

First alpha endpoint in 8 bit intensity.

◆ m_uAlpha2

uint8_t Burger::Dxt5Packet_t::m_uAlpha2

Second alpha endpoint in 8 bit intensity.

◆ m_uAlphaIndexes

uint8_t Burger::Dxt5Packet_t::m_uAlphaIndexes[2][3]

Two 24 bit little endian values that contain 3 bits per pixel indexes for the 4x4 tile.

◆ m_uColorIndexes

uint8_t Burger::Dxt5Packet_t::m_uColorIndexes[4]

2 bits per pixel color indexes for 4x4 tile

◆ m_uRGB565Color1

uint16_t Burger::Dxt5Packet_t::m_uRGB565Color1

First color endpoint in R5:G6:B5 little endian format.

◆ m_uRGB565Color2

uint16_t Burger::Dxt5Packet_t::m_uRGB565Color2

Second color endpoint in R5:G6:B5 little endian format.

Public Member Functions

Public Attributes