kzc_etc.h File Reference

Wrapper for Ericsson texture compression. More...

#include <kanzi/core/legacy/memory/kzc_memory_manager.hpp>
#include <kanzi/core/legacy/kzs_types.hpp>
#include <kanzi/core/legacy/debug/kzs_error.hpp>

Enumerations
enum	KzcEtcCompressionMode {   KZC_ETC_COMPRESSION_MODE_FAST, KZC_ETC_COMPRESSION_MODE_MEDIUM, KZC_ETC_COMPRESSION_MODE_SLOW, KZC_ETC_COMPRESSION_MODE_FAST_PERCEPTUAL,   KZC_ETC_COMPRESSION_MODE_MEDIUM_PERCEPTUAL, KZC_ETC_COMPRESSION_MODE_SLOW_PERCEPTUAL }
	ETC compression modes. More...

Functions
kzsError	kzcEtcCompressImageToBuffer (const struct KzcMemoryManager *memoryManager, const kzU8 *imageData, kzInt width, kzInt height, kzU8 *destinationBuffer, enum KzcEtcCompressionMode compressionMode, kzUint *out_bytesWritten)
	Compress an rgb888 format image in imageData to compressed ETC format. More...
kzsError	kzcEtcUncompressImageToBuffer (const struct KzcMemoryManager *memoryManager, const kzU8 *compressedImage, kzInt width, kzInt height, kzInt active_width, kzInt active_height, kzU8 *destinationImage, kzUint *out_bytesWritten)
	Uncompress a compressed rgb888 format image to destination buffer. More...
kzUint	kzcEtcGetCompressedBufferMemorySize (kzUint width, kzUint height)
	Return number of bytes required for the storage of an ETC texture of the given dimensions. More...

Detailed Description

Wrapper for Ericsson texture compression.

Original implementation licenced free of charge by Ericsson. See kzc_etc.c for licence.

For technical details, see OES_compressed_ETC1_RGB8_texture extension in the OpenGL ES extensions database.

For explanation of the compression routine see Strom, Akenine-Moller:'iPACKMAN: High-Quality, Low-Complexity Texture Compression for Mobile Phones'.

(iPackman == ETC)

Copyright 2008-2017 by Rightware. All rights reserved.

Enumeration Type Documentation

enum KzcEtcCompressionMode

ETC compression modes.

Enumerator
KZC_ETC_COMPRESSION_MODE_FAST	FAST only tests the two most likely base colors.
KZC_ETC_COMPRESSION_MODE_MEDIUM	The MEDIUM version tests all colors in a 3x3x3 cube around the average colors. This increases the likelihood that the differential mode is selected.
KZC_ETC_COMPRESSION_MODE_SLOW	The SLOW version tests all colors in a a 5x5x5 cube around the average colors. It also tries the nondifferential mode for each block even if the differential succeeds.
KZC_ETC_COMPRESSION_MODE_FAST_PERCEPTUAL	FAST with PERCEPTUAL error metric.
KZC_ETC_COMPRESSION_MODE_MEDIUM_PERCEPTUAL	MEDIUM with PERCEPTUAL error metric.
KZC_ETC_COMPRESSION_MODE_SLOW_PERCEPTUAL	SLOW with PERCEPTUAL error metric.

Function Documentation

kzsError kzcEtcCompressImageToBuffer	(	const struct KzcMemoryManager *	memoryManager,
		const kzU8 *	imageData,
		kzInt	width,
		kzInt	height,
		kzU8 *	destinationBuffer,
		enum KzcEtcCompressionMode	compressionMode,
		kzUint *	out_bytesWritten
	)

Compress an rgb888 format image in imageData to compressed ETC format.

Width MUST be divisible by 2 and height by 4. To compress images of other sizes pad the image data to correct size first.

Parameters

[in]	imageData	rgb888 format image data
[in]	width	of image in imageData in pixels
[in]	height	of image in imageData in pixels
[in]	destinationBuffer	buffer to write the compressed data into. Must be preallocated to at least correct size.
[out]	out_bytesWritten	number of bytes written to output

kzsError kzcEtcUncompressImageToBuffer	(	const struct KzcMemoryManager *	memoryManager,
		const kzU8 *	compressedImage,
		kzInt	width,
		kzInt	height,
		kzInt	active_width,
		kzInt	active_height,
		kzU8 *	destinationImage,
		kzUint *	out_bytesWritten
	)

Uncompress a compressed rgb888 format image to destination buffer.

Parameters

[in]	compressedImage	ETC compressed texture
[in]	width	of compressed texture in actual pixels
[in]	height	of compressed texture in actual pixels
[in]	active_width	of uncompressed texture. Can be less than width.
[in]	active_height	of uncompressed texture. Can be less than height.

kzUint kzcEtcGetCompressedBufferMemorySize	(	kzUint	width,
		kzUint	height
	)

Return number of bytes required for the storage of an ETC texture of the given dimensions.