libktx Reference 4.3.1
Libraries and tools to create and read KTX image texture files.
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Reader

Read KTX-formatted data. More...

Functions

KTX_error_code ktxTexture2_TranscodeBasis (ktxTexture2 *This, ktx_transcode_fmt_e outputFormat, ktx_transcode_flags transcodeFlags)
 Transcode a KTX2 texture with BasisLZ/ETC1S or UASTC images.
 
KTX_error_code ktxTexture_CreateFromStream (ktxStream *pStream, ktxTextureCreateFlags createFlags, ktxTexture **newTex)
 Create a ktx1 or ktx2 texture according to the stream data.
 
KTX_error_code ktxTexture_CreateFromStdioStream (FILE *stdioStream, ktxTextureCreateFlags createFlags, ktxTexture **newTex)
 Create a ktxTexture1 or ktxTexture2 from a stdio stream according to the stream data.
 
KTX_error_code ktxTexture_CreateFromNamedFile (const char *const filename, ktxTextureCreateFlags createFlags, ktxTexture **newTex)
 Create a ktxTexture1 or ktxTexture2 from a named KTX file according to the file contents.
 
KTX_error_code ktxTexture_CreateFromMemory (const ktx_uint8_t *bytes, ktx_size_t size, ktxTextureCreateFlags createFlags, ktxTexture **newTex)
 Create a ktxTexture1 or ktxTexture2 from KTX-formatted data in memory according to the data contents.
 
ktx_uint8_t * ktxTexture_GetData (ktxTexture *This)
 Return a pointer to the texture image data.
 
ktx_size_t ktxTexture_GetDataSize (ktxTexture *This)
 Return the total size of the texture image data in bytes.
 
ktx_uint32_t ktxTexture_GetElementSize (ktxTexture *This)
 Return the size in bytes of an elements of a texture's images.
 
KTX_error_code ktxTexture_IterateLevelFaces (ktxTexture *This, PFNKTXITERCB iterCb, void *userdata)
 Iterate over the levels or faces in a ktxTexture object.
 
ktx_uint32_t ktxTexture_GetRowPitch (ktxTexture *This, ktx_uint32_t level)
 Return pitch betweeb rows of a texture image level in bytes.
 
KTX_error_code ktxTexture1_CreateFromStdioStream (FILE *stdioStream, ktxTextureCreateFlags createFlags, ktxTexture1 **newTex)
 Create a ktxTexture1 from a stdio stream reading from a KTX source.
 
KTX_error_code ktxTexture1_CreateFromNamedFile (const char *const filename, ktxTextureCreateFlags createFlags, ktxTexture1 **newTex)
 Create a ktxTexture1 from a named KTX file.
 
KTX_error_code ktxTexture1_CreateFromMemory (const ktx_uint8_t *bytes, ktx_size_t size, ktxTextureCreateFlags createFlags, ktxTexture1 **newTex)
 Create a ktxTexture1 from KTX-formatted data in memory.
 
KTX_error_code ktxTexture1_CreateFromStream (ktxStream *pStream, ktxTextureCreateFlags createFlags, ktxTexture1 **newTex)
 Create a ktxTexture1 from KTX-formatted data from a ktxStream.
 
void ktxTexture1_Destroy (ktxTexture1 *This)
 Destroy a ktxTexture1 object.
 
KTX_error_code ktxTexture1_GetImageOffset (ktxTexture1 *This, ktx_uint32_t level, ktx_uint32_t layer, ktx_uint32_t faceSlice, ktx_size_t *pOffset)
 Find the offset of an image within a ktxTexture's image data.
 
ktx_size_t ktxTexture1_GetDataSizeUncompressed (ktxTexture1 *This)
 Return the total size in bytes of the uncompressed data of a ktxTexture1.
 
ktx_size_t ktxTexture1_GetImageSize (ktxTexture1 *This, ktx_uint32_t level)
 Calculate & return the size in bytes of an image at the specified mip level.
 
KTX_error_code ktxTexture1_IterateLevels (ktxTexture1 *This, PFNKTXITERCB iterCb, void *userdata)
 Iterate over the mip levels in a ktxTexture1 object.
 
KTX_error_code ktxTexture1_IterateLoadLevelFaces (ktxTexture1 *This, PFNKTXITERCB iterCb, void *userdata)
 Iterate over the images in a ktxTexture1 object while loading the image data.
 
KTX_error_code ktxTexture1_LoadImageData (ktxTexture1 *This, ktx_uint8_t *pBuffer, ktx_size_t bufSize)
 Load all the image data from the ktxTexture1's source.
 
KTX_error_code ktxTexture2_CreateFromStdioStream (FILE *stdioStream, ktxTextureCreateFlags createFlags, ktxTexture2 **newTex)
 Create a ktxTexture2 from a stdio stream reading from a KTX source.
 
KTX_error_code ktxTexture2_CreateFromNamedFile (const char *const filename, ktxTextureCreateFlags createFlags, ktxTexture2 **newTex)
 Create a ktxTexture2 from a named KTX file.
 
KTX_error_code ktxTexture2_CreateFromMemory (const ktx_uint8_t *bytes, ktx_size_t size, ktxTextureCreateFlags createFlags, ktxTexture2 **newTex)
 Create a ktxTexture2 from KTX-formatted data in memory.
 
KTX_error_code ktxTexture2_CreateFromStream (ktxStream *stream, ktxTextureCreateFlags createFlags, ktxTexture2 **newTex)
 Create a ktxTexture2 from KTX-formatted data from a stream.
 
void ktxTexture2_Destroy (ktxTexture2 *This)
 Destroy a ktxTexture2 object.
 
void ktxTexture2_GetComponentInfo (ktxTexture2 *This, uint32_t *pNumComponents, uint32_t *pComponentByteLength)
 Return information about the components of an image in a texture.
 
ktx_uint32_t ktxTexture2_GetNumComponents (ktxTexture2 *This)
 Return the number of components in an image of the texture.
 
KTX_error_code ktxTexture2_GetImageOffset (ktxTexture2 *This, ktx_uint32_t level, ktx_uint32_t layer, ktx_uint32_t faceSlice, ktx_size_t *pOffset)
 Find the offset of an image within a ktxTexture's image data.
 
khr_df_transfer_e ktxTexture2_GetOETF_e (ktxTexture2 *This)
 Retrieve the opto-electrical transfer function of the images.
 
ktx_uint32_t ktxTexture2_GetOETF (ktxTexture2 *This)
 Retrieve the opto-electrical transfer function of the images.
 
khr_df_model_e ktxTexture2_GetColorModel_e (ktxTexture2 *This)
 Retrieve the DFD color model of the images.
 
ktx_bool_t ktxTexture2_GetPremultipliedAlpha (ktxTexture2 *This)
 Retrieve whether the RGB components have been premultiplied by the alpha component.
 
ktx_bool_t ktxTexture2_NeedsTranscoding (ktxTexture2 *This)
 Query if the images are in a transcodable format.
 
ktx_size_t ktxTexture2_GetDataSizeUncompressed (ktxTexture2 *This)
 Return the total size in bytes of the uncompressed data of a ktxTexture2.
 
ktx_size_t ktxTexture2_GetImageSize (ktxTexture2 *This, ktx_uint32_t level)
 Calculate & return the size in bytes of an image at the specified mip level.
 
KTX_error_code ktxTexture2_IterateLevels (ktxTexture2 *This, PFNKTXITERCB iterCb, void *userdata)
 Iterate over the mip levels in a ktxTexture2 object.
 
KTX_error_code ktxTexture2_IterateLoadLevelFaces (ktxTexture2 *This, PFNKTXITERCB iterCb, void *userdata)
 Iterate over the images in a ktxTexture2 object while loading the image data.
 
KTX_error_code ktxTexture2_LoadImageData (ktxTexture2 *This, ktx_uint8_t *pBuffer, ktx_size_t bufSize)
 Load all the image data from the ktxTexture2's source.
 

Detailed Description

Read KTX-formatted data.

Function Documentation

◆ ktxTexture1_CreateFromMemory()

KTX_error_code ktxTexture1_CreateFromMemory ( const ktx_uint8_t *  bytes,
ktx_size_t  size,
ktxTextureCreateFlags  createFlags,
ktxTexture1 **  newTex 
)

Create a ktxTexture1 from KTX-formatted data in memory.

The address of a newly created texture reflecting the contents of the serialized KTX data is written to the location pointed at by newTex.

The create flag KTX_TEXTURE_CREATE_LOAD_IMAGE_DATA_BIT should not be set, if the ktxTexture1 is ultimately to be uploaded to OpenGL or Vulkan. This will minimize memory usage by allowing, for example, loading the images directly from the source into a Vulkan staging buffer.

The create flag KTX_TEXTURE_CREATE_RAW_KVDATA_BIT should not be used. It is provided solely to enable implementation of the libktx v1 API on top of ktxTexture1.

Parameters
[in]bytespointer to the memory containing the serialized KTX data.
[in]sizelength of the KTX data in bytes.
[in]createFlagsbitmask requesting specific actions during creation.
[in,out]newTexpointer to a location in which store the address of the newly created texture.
Returns
KTX_SUCCESS on success, other KTX_* enum values on error.
Exceptions
KTX_INVALID_VALUEEither bytes is NULL or size is 0.

For other exceptions, see ktxTexture1_CreateFromStdioStream().

◆ ktxTexture1_CreateFromNamedFile()

KTX_error_code ktxTexture1_CreateFromNamedFile ( const char *const  filename,
ktxTextureCreateFlags  createFlags,
ktxTexture1 **  newTex 
)

Create a ktxTexture1 from a named KTX file.

The address of a newly created texture reflecting the contents of the file is written to the location pointed at by newTex.

The file name must be encoded in utf-8. On Windows convert unicode names to utf-8 with WideCharToMultiByte(CP_UTF8, ...) before calling.

The create flag KTX_TEXTURE_CREATE_LOAD_IMAGE_DATA_BIT should not be set, if the ktxTexture1 is ultimately to be uploaded to OpenGL or Vulkan. This will minimize memory usage by allowing, for example, loading the images directly from the source into a Vulkan staging buffer.

The create flag KTX_TEXTURE_CREATE_RAW_KVDATA_BIT should not be used. It is provided solely to enable implementation of the libktx v1 API on top of ktxTexture1.

Parameters
[in]filenamepointer to a char array containing the file name.
[in]createFlagsbitmask requesting specific actions during creation.
[in,out]newTexpointer to a location in which store the address of the newly created texture.
Returns
KTX_SUCCESS on success, other KTX_* enum values on error.
Exceptions
KTX_FILE_OPEN_FAILEDThe file could not be opened.
KTX_INVALID_VALUEfilename is NULL.

For other exceptions, see ktxTexture1_CreateFromStdioStream().

◆ ktxTexture1_CreateFromStdioStream()

KTX_error_code ktxTexture1_CreateFromStdioStream ( FILE *  stdioStream,
ktxTextureCreateFlags  createFlags,
ktxTexture1 **  newTex 
)

Create a ktxTexture1 from a stdio stream reading from a KTX source.

The address of a newly created texture reflecting the contents of the stdio stream is written to the location pointed at by newTex.

The create flag KTX_TEXTURE_CREATE_LOAD_IMAGE_DATA_BIT should not be set, if the ktxTexture1 is ultimately to be uploaded to OpenGL or Vulkan. This will minimize memory usage by allowing, for example, loading the images directly from the source into a Vulkan staging buffer.

The create flag KTX_TEXTURE_CREATE_RAW_KVDATA_BIT should not be used. It is provided solely to enable implementation of the libktx v1 API on top of ktxTexture1.

Parameters
[in]stdioStreamstdio FILE pointer created from the desired file.
[in]createFlagsbitmask requesting specific actions during creation.
[in,out]newTexpointer to a location in which store the address of the newly created texture.
Returns
KTX_SUCCESS on success, other KTX_* enum values on error.
Exceptions
KTX_INVALID_VALUEnewTex is NULL.
KTX_FILE_DATA_ERRORSource data is inconsistent with the KTX specification.
KTX_FILE_READ_ERRORAn error occurred while reading the source.
KTX_FILE_UNEXPECTED_EOFNot enough data in the source.
KTX_OUT_OF_MEMORYNot enough memory to create the texture object, load the images or load the key-value data.
KTX_UNKNOWN_FILE_FORMATThe source is not in KTX format.
KTX_UNSUPPORTED_TEXTURE_TYPEThe source describes a texture type not supported by OpenGL or Vulkan, e.g, a 3D array.

◆ ktxTexture1_CreateFromStream()

KTX_error_code ktxTexture1_CreateFromStream ( ktxStream pStream,
ktxTextureCreateFlags  createFlags,
ktxTexture1 **  newTex 
)

Create a ktxTexture1 from KTX-formatted data from a ktxStream.

The address of a newly created texture reflecting the contents of the serialized KTX data is written to the location pointed at by newTex.

The create flag KTX_TEXTURE_CREATE_LOAD_IMAGE_DATA_BIT should not be set, if the ktxTexture1 is ultimately to be uploaded to OpenGL or Vulkan. This will minimize memory usage by allowing, for example, loading the images directly from the source into a Vulkan staging buffer.

The create flag KTX_TEXTURE_CREATE_RAW_KVDATA_BIT should not be used. It is provided solely to enable implementation of the libktx v1 API on top of ktxTexture1.

Parameters
[in]pStreampointer to the stream to read KTX data from.
[in]createFlagsbitmask requesting specific actions during creation.
[in,out]newTexpointer to a location in which store the address of the newly created texture.
Returns
KTX_SUCCESS on success, other KTX_* enum values on error.

For exceptions, see ktxTexture1_CreateFromStdioStream().

◆ ktxTexture1_Destroy()

void ktxTexture1_Destroy ( ktxTexture1 This)

Destroy a ktxTexture1 object.

This frees the memory associated with the texture contents and the memory of the ktxTexture1 object. This does not delete any OpenGL or Vulkan texture objects created by ktxTexture1_GLUpload or ktxTexture1_VkUpload.

Parameters
[in]Thispointer to the ktxTexture1 object to destroy

◆ ktxTexture1_GetDataSizeUncompressed()

ktx_size_t ktxTexture1_GetDataSizeUncompressed ( ktxTexture1 This)

Return the total size in bytes of the uncompressed data of a ktxTexture1.

This always returns the value of This->dataSize. The function is provided for symmetry with ktxTexture2.

Parameters
[in]Thispointer to the ktxTexture1 object of interest.
Returns
The size of the data in the texture.

◆ ktxTexture1_GetImageOffset()

KTX_error_code ktxTexture1_GetImageOffset ( ktxTexture1 This,
ktx_uint32_t  level,
ktx_uint32_t  layer,
ktx_uint32_t  faceSlice,
ktx_size_t *  pOffset 
)

Find the offset of an image within a ktxTexture's image data.

As there is no such thing as a 3D cubemap we make the 3rd location parameter do double duty.

Parameters
[in]Thispointer to the ktxTexture object of interest.
[in]levelmip level of the image.
[in]layerarray layer of the image.
[in]faceSlicecube map face or depth slice of the image.
[in,out]pOffsetpointer to location to store the offset.
Returns
KTX_SUCCESS on success, other KTX_* enum values on error.
Exceptions
KTX_INVALID_OPERATIONlevel, layer or faceSlice exceed the dimensions of the texture.
KTX_INVALID_VALIDThis is NULL.

◆ ktxTexture1_GetImageSize()

ktx_size_t ktxTexture1_GetImageSize ( ktxTexture1 This,
ktx_uint32_t  level 
)

Calculate & return the size in bytes of an image at the specified mip level.

For arrays, this is the size of layer, for cubemaps, the size of a face and for 3D textures, the size of a depth slice.

The size reflects the padding of each row to KTX_GL_UNPACK_ALIGNMENT.

Parameters
[in]Thispointer to the ktxTexture1 object of interest.
[in]levellevel of interest.

◆ ktxTexture1_IterateLevels()

KTX_error_code ktxTexture1_IterateLevels ( ktxTexture1 This,
PFNKTXITERCB  iterCb,
void *  userdata 
)

Iterate over the mip levels in a ktxTexture1 object.

This is almost identical to ktxTexture_IterateLevelFaces. The difference is that the blocks of image data for non-array cube maps include all faces of a mip level.

This function works even if This->pData == 0 so it can be used to obtain offsets and sizes for each level by callers who have loaded the data externally.

Parameters
[in]Thishandle of the 1 opened on the data.
[in,out]iterCbthe address of a callback function which is called with the data for each image block.
[in,out]userdatathe address of application-specific data which is passed to the callback along with the image data.
Returns
KTX_SUCCESS on success, other KTX_* enum values on error. The following are returned directly by this function. iterCb may return these for other causes or may return additional errors.
Exceptions
KTX_FILE_DATA_ERRORMip level sizes are increasing not decreasing
KTX_INVALID_VALUEThis is NULL or iterCb is NULL.

◆ ktxTexture1_IterateLoadLevelFaces()

KTX_error_code ktxTexture1_IterateLoadLevelFaces ( ktxTexture1 This,
PFNKTXITERCB  iterCb,
void *  userdata 
)

Iterate over the images in a ktxTexture1 object while loading the image data.

This operates similarly to ktxTexture_IterateLevelFaces except that it loads the images from the ktxTexture1's source to a temporary buffer while iterating. The callback function must copy the image data if it wishes to preserve it as the temporary buffer is reused for each level and is freed when this function exits.

This function is helpful for reducing memory usage when uploading the data to a graphics API.

Parameters
[in]Thispointer to the ktxTexture1 object of interest.
[in,out]iterCbthe address of a callback function which is called with the data for each image.
[in,out]userdatathe address of application-specific data which is passed to the callback along with the image data.
Returns
KTX_SUCCESS on success, other KTX_* enum values on error. The following are returned directly by this function. iterCb may return these for other causes or may return additional errors.
Exceptions
KTX_FILE_DATA_ERRORmip level sizes are increasing not decreasing
KTX_INVALID_OPERATIONthe ktxTexture1 was not created from a stream, i.e there is no data to load, or this ktxTexture1's images have already been loaded.
KTX_INVALID_VALUEThis is NULL or iterCb is NULL.
KTX_OUT_OF_MEMORYnot enough memory to allocate a block to hold the base level image.

◆ ktxTexture1_LoadImageData()

KTX_error_code ktxTexture1_LoadImageData ( ktxTexture1 This,
ktx_uint8_t *  pBuffer,
ktx_size_t  bufSize 
)

Load all the image data from the ktxTexture1's source.

The data is loaded into the provided buffer or to an internally allocated buffer, if pBuffer is NULL.

Parameters
[in]Thispointer to the ktxTexture object of interest.
[in]pBufferpointer to the buffer in which to load the image data.
[in]bufSizesize of the buffer pointed at by pBuffer.
Returns
KTX_SUCCESS on success, other KTX_* enum values on error.
Exceptions
KTX_INVALID_VALUEThis is NULL.
KTX_INVALID_VALUEbufSize is less than the the image data size.
KTX_INVALID_OPERATIONThe data has already been loaded or the ktxTexture was not created from a KTX source.
KTX_OUT_OF_MEMORYInsufficient memory for the image data.

◆ ktxTexture2_CreateFromMemory()

KTX_error_code ktxTexture2_CreateFromMemory ( const ktx_uint8_t *  bytes,
ktx_size_t  size,
ktxTextureCreateFlags  createFlags,
ktxTexture2 **  newTex 
)

Create a ktxTexture2 from KTX-formatted data in memory.

The address of a newly created ktxTexture2 reflecting the contents of the serialized KTX data is written to the location pointed at by newTex.

The create flag KTX_TEXTURE_CREATE_LOAD_IMAGE_DATA_BIT should not be set, if the ktxTexture is ultimately to be uploaded to OpenGL or Vulkan. This will minimize memory usage by allowing, for example, loading the images directly from the source into a Vulkan staging buffer.

The create flag KTX_TEXTURE_CREATE_RAW_KVDATA_BIT should not be used. It is provided solely to enable implementation of the libktx v1 API on top of ktxTexture.

Parameters
[in]bytespointer to the memory containing the serialized KTX data.
[in]sizelength of the KTX data in bytes.
[in]createFlagsbitmask requesting specific actions during creation.
[in,out]newTexpointer to a location in which store the address of the newly created texture.
Returns
KTX_SUCCESS on success, other KTX_* enum values on error.
Exceptions
KTX_INVALID_VALUEEither bytes is NULL or size is 0.

For other exceptions, see ktxTexture_CreateFromStdioStream().

◆ ktxTexture2_CreateFromNamedFile()

KTX_error_code ktxTexture2_CreateFromNamedFile ( const char *const  filename,
ktxTextureCreateFlags  createFlags,
ktxTexture2 **  newTex 
)

Create a ktxTexture2 from a named KTX file.

The address of a newly created ktxTexture2 reflecting the contents of the file is written to the location pointed at by newTex.

The file name must be encoded in utf-8. On Windows convert unicode names to utf-8 with WideCharToMultiByte(CP_UTF8, ...) before calling.

The create flag KTX_TEXTURE_CREATE_LOAD_IMAGE_DATA_BIT should not be set, if the ktxTexture is ultimately to be uploaded to OpenGL or Vulkan. This will minimize memory usage by allowing, for example, loading the images directly from the source into a Vulkan staging buffer.

The create flag KTX_TEXTURE_CREATE_RAW_KVDATA_BIT should not be used. It is provided solely to enable implementation of the libktx v1 API on top of ktxTexture.

Parameters
[in]filenamepointer to a char array containing the file name.
[in]createFlagsbitmask requesting specific actions during creation.
[in,out]newTexpointer to a location in which store the address of the newly created texture.
Returns
KTX_SUCCESS on success, other KTX_* enum values on error.
Exceptions
KTX_FILE_OPEN_FAILEDThe file could not be opened.
KTX_INVALID_VALUEfilename is NULL.

For other exceptions, see ktxTexture_CreateFromStdioStream().

◆ ktxTexture2_CreateFromStdioStream()

KTX_error_code ktxTexture2_CreateFromStdioStream ( FILE *  stdioStream,
ktxTextureCreateFlags  createFlags,
ktxTexture2 **  newTex 
)

Create a ktxTexture2 from a stdio stream reading from a KTX source.

The address of a newly created ktxTexture2 reflecting the contents of the stdio stream is written to the location pointed at by newTex.

The create flag KTX_TEXTURE_CREATE_LOAD_IMAGE_DATA_BIT should not be set, if the ktxTexture is ultimately to be uploaded to OpenGL or Vulkan. This will minimize memory usage by allowing, for example, loading the images directly from the source into a Vulkan staging buffer.

The create flag KTX_TEXTURE_CREATE_RAW_KVDATA_BIT should not be used. It is provided solely to enable implementation of the libktx v1 API on top of ktxTexture.

Parameters
[in]stdioStreamstdio FILE pointer created from the desired file.
[in]createFlagsbitmask requesting specific actions during creation.
[in,out]newTexpointer to a location in which store the address of the newly created texture.
Returns
KTX_SUCCESS on success, other KTX_* enum values on error.
Exceptions
KTX_INVALID_VALUEnewTex is NULL.
KTX_FILE_DATA_ERRORSource data is inconsistent with the KTX specification.
KTX_FILE_READ_ERRORAn error occurred while reading the source.
KTX_FILE_UNEXPECTED_EOFNot enough data in the source.
KTX_OUT_OF_MEMORYNot enough memory to create the texture object, load the images or load the key-value data.
KTX_UNKNOWN_FILE_FORMATThe source is not in KTX format.
KTX_UNSUPPORTED_TEXTURE_TYPEThe source describes a texture type not supported by OpenGL or Vulkan, e.g, a 3D array.

◆ ktxTexture2_CreateFromStream()

KTX_error_code ktxTexture2_CreateFromStream ( ktxStream stream,
ktxTextureCreateFlags  createFlags,
ktxTexture2 **  newTex 
)

Create a ktxTexture2 from KTX-formatted data from a stream.

The address of a newly created ktxTexture2 reflecting the contents of the serialized KTX data is written to the location pointed at by newTex.

The create flag KTX_TEXTURE_CREATE_LOAD_IMAGE_DATA_BIT should not be set, if the ktxTexture is ultimately to be uploaded to OpenGL or Vulkan. This will minimize memory usage by allowing, for example, loading the images directly from the source into a Vulkan staging buffer.

The create flag KTX_TEXTURE_CREATE_RAW_KVDATA_BIT should not be used. It is provided solely to enable implementation of the libktx v1 API on top of ktxTexture.

Parameters
[in]streampointer to the stream to read KTX data from.
[in]createFlagsbitmask requesting specific actions during creation.
[in,out]newTexpointer to a location in which store the address of the newly created texture.
Returns
KTX_SUCCESS on success, other KTX_* enum values on error.
Exceptions
KTX_INVALID_VALUEEither bytes is NULL or size is 0.

For other exceptions, see ktxTexture_CreateFromStdioStream().

◆ ktxTexture2_Destroy()

void ktxTexture2_Destroy ( ktxTexture2 This)

Destroy a ktxTexture2 object.

This frees the memory associated with the texture contents and the memory of the ktxTexture2 object. This does not delete any OpenGL or Vulkan texture objects created by ktxTexture2_GLUpload or ktxTexture2_VkUpload.

Parameters
[in]Thispointer to the ktxTexture2 object to destroy

◆ ktxTexture2_GetColorModel_e()

khr_df_model_e ktxTexture2_GetColorModel_e ( ktxTexture2 This)

Retrieve the DFD color model of the images.

Parameters
[in]Thispointer to the ktxTexture2 object of interest.
Returns
A khr_df_transfer enum value specifying the color model.

◆ ktxTexture2_GetComponentInfo()

void ktxTexture2_GetComponentInfo ( ktxTexture2 This,
uint32_t *  pNumComponents,
uint32_t *  pComponentByteLength 
)

Return information about the components of an image in a texture.

Parameters
[in]Thispointer to the ktxTexture object of interest.
[in,out]pNumComponentspointer to location in which to write the number of components in the textures images.
[in,out]pComponentByteLengthpointer to the location in which to write byte length of a component.

◆ ktxTexture2_GetDataSizeUncompressed()

ktx_size_t ktxTexture2_GetDataSizeUncompressed ( ktxTexture2 This)

Return the total size in bytes of the uncompressed data of a ktxTexture2.

If supercompressionScheme == KTX_SS_NONE or KTX_SS_BASIS_LZ, returns the value of This->dataSize else if supercompressionScheme == KTX_SS_ZSTD or KTX_SS_ZLIB, it returns the sum of the uncompressed sizes of each mip level plus space for the level padding. With no supercompression the data size and uncompressed data size are the same. For Basis supercompression the uncompressed size cannot be known until the data is transcoded so the compressed size is returned.

Parameters
[in]Thispointer to the ktxTexture1 object of interest.

◆ ktxTexture2_GetImageOffset()

KTX_error_code ktxTexture2_GetImageOffset ( ktxTexture2 This,
ktx_uint32_t  level,
ktx_uint32_t  layer,
ktx_uint32_t  faceSlice,
ktx_size_t *  pOffset 
)

Find the offset of an image within a ktxTexture's image data.

As there is no such thing as a 3D cubemap we make the 3rd location parameter do double duty. Only works for non-supercompressed textures as there is no way to tell where an image is for a supercompressed one.

Parameters
[in]Thispointer to the ktxTexture object of interest.
[in]levelmip level of the image.
[in]layerarray layer of the image.
[in]faceSlicecube map face or depth slice of the image.
[in,out]pOffsetpointer to location to store the offset.
Returns
KTX_SUCCESS on success, other KTX_* enum values on error.
Exceptions
KTX_INVALID_OPERATIONlevel, layer or faceSlice exceed the dimensions of the texture.
KTX_INVALID_OPERATIONTexture is supercompressed.
KTX_INVALID_VALIDThis is NULL.

◆ ktxTexture2_GetImageSize()

ktx_size_t ktxTexture2_GetImageSize ( ktxTexture2 This,
ktx_uint32_t  level 
)

Calculate & return the size in bytes of an image at the specified mip level.

For arrays, this is the size of a layer, for cubemaps, the size of a face and for 3D textures, the size of a depth slice.

The size reflects the padding of each row to KTX_GL_UNPACK_ALIGNMENT.

Parameters
[in]Thispointer to the ktxTexture2 object of interest.
[in]levellevel of interest. *

◆ ktxTexture2_GetNumComponents()

ktx_uint32_t ktxTexture2_GetNumComponents ( ktxTexture2 This)

Return the number of components in an image of the texture.

Returns the number of components indicated by the DFD's sample information in accordance with the color model. For uncompressed formats it will be the actual number of components in the image. For block-compressed formats, it will be 1 or 2 according to the format's DFD color model. For Basis compressed textures, the function examines the ids of the channels indicated by the DFD and uses that information to determine and return the number of components in the image before encoding and deflation so it can be used to help choose a suitable transcode target format.

Parameters
[in]Thispointer to the ktxTexture object of interest.
Returns
the number of components.

◆ ktxTexture2_GetOETF()

ktx_uint32_t ktxTexture2_GetOETF ( ktxTexture2 This)

Retrieve the opto-electrical transfer function of the images.

Deprecated:
Retained for backward compatibility. Use ktxTexture2_GetOETF_e()
Parameters
[in]Thispointer to the ktxTexture2 object of interest.
Returns
A khr_df_transfer enum value specifying the OETF, returned as ktx_uint32_t.

◆ ktxTexture2_GetOETF_e()

khr_df_transfer_e ktxTexture2_GetOETF_e ( ktxTexture2 This)

Retrieve the opto-electrical transfer function of the images.

Parameters
[in]Thispointer to the ktxTexture2 object of interest.
Returns
A khr_df_transfer enum value specifying the OETF.

◆ ktxTexture2_GetPremultipliedAlpha()

ktx_bool_t ktxTexture2_GetPremultipliedAlpha ( ktxTexture2 This)

Retrieve whether the RGB components have been premultiplied by the alpha component.

Parameters
[in]Thispointer to the ktxTexture2 object of interest.
Returns
KTX_TRUE if the components are premultiplied, KTX_FALSE otherwise.

◆ ktxTexture2_IterateLevels()

KTX_error_code ktxTexture2_IterateLevels ( ktxTexture2 This,
PFNKTXITERCB  iterCb,
void *  userdata 
)

Iterate over the mip levels in a ktxTexture2 object.

This is almost identical to ktxTexture_IterateLevelFaces(). The difference is that the blocks of image data for non-array cube maps include all faces of a mip level.

This function works even if This->pData == 0 so it can be used to obtain offsets and sizes for each level by callers who have loaded the data externally.

Intended for use only when supercompressionScheme == SUPERCOMPRESSION_NONE.

Parameters
[in]Thishandle of the ktxTexture opened on the data.
[in,out]iterCbthe address of a callback function which is called with the data for each image block.
[in,out]userdatathe address of application-specific data which is passed to the callback along with the image data.
Returns
KTX_SUCCESS on success, other KTX_* enum values on error. The following are returned directly by this function. iterCb may return these for other causes or may return additional errors.
Exceptions
KTX_FILE_DATA_ERRORMip level sizes are increasing not decreasing
KTX_INVALID_OPERATIONsupercompressionScheme != SUPERCOMPRESSION_NONE.
KTX_INVALID_VALUEThis is NULL or iterCb is NULL.

◆ ktxTexture2_IterateLoadLevelFaces()

KTX_error_code ktxTexture2_IterateLoadLevelFaces ( ktxTexture2 This,
PFNKTXITERCB  iterCb,
void *  userdata 
)

Iterate over the images in a ktxTexture2 object while loading the image data.

This operates similarly to ktxTexture_IterateLevelFaces() except that it loads the images from the ktxTexture2's source to a temporary buffer while iterating. If supercompressionScheme == KTX_SS_ZSTD or KTX_SS_ZLIB, it will inflate the data before passing it to the callback. The callback function must copy the image data if it wishes to preserve it as the temporary buffer is reused for each level and is freed when this function exits.

This function is helpful for reducing memory usage when uploading the data to a graphics API.

Intended for use only when supercompressionScheme == KTX_SS_NONE, KTX_SS_ZSTD or KTX_SS_ZLIB. As there is no access to the ktxTexture's data on conclusion of this function, destroying the texture on completion is recommended.

Parameters
[in]Thispointer to the ktxTexture2 object of interest.
[in,out]iterCbthe address of a callback function which is called with the data for each image.
[in,out]userdatathe address of application-specific data which is passed to the callback along with the image data.
Returns
KTX_SUCCESS on success, other KTX_* enum values on error. The following are returned directly by this function. iterCb may return these for other causes or may return additional errors.
Exceptions
KTX_FILE_DATA_ERRORmip level sizes are increasing not decreasing
KTX_INVALID_OPERATIONthe ktxTexture2 was not created from a stream, i.e there is no data to load, or this ktxTexture2's images have already been loaded.
KTX_INVALID_OPERATIONsupercompressionScheme != KTX_SS_NONE, supercompressionScheme != KTX_SS_ZSTD, and supercompressionScheme != KTX_SS_ZLIB.
KTX_INVALID_VALUEThis is NULL or iterCb is NULL.
KTX_OUT_OF_MEMORYnot enough memory to allocate a block to hold the base level image.

◆ ktxTexture2_LoadImageData()

KTX_error_code ktxTexture2_LoadImageData ( ktxTexture2 This,
ktx_uint8_t *  pBuffer,
ktx_size_t  bufSize 
)

Load all the image data from the ktxTexture2's source.

The data will be inflated if supercompressionScheme == KTX_SS_ZSTD or KTX_SS_ZLIB. The data is loaded into the provided buffer or to an internally allocated buffer, if pBuffer is NULL. Callers providing their own buffer must ensure the buffer large enough to hold the inflated data for files deflated with Zstd or ZLIB. See ktxTexture2_GetDataSizeUncompressed().

The texture's levelIndex, dataSize, DFD and supercompressionScheme will all be updated after successful inflation to reflect the inflated data.

Parameters
[in]Thispointer to the ktxTexture object of interest.
[in]pBufferpointer to the buffer in which to load the image data.
[in]bufSizesize of the buffer pointed at by pBuffer.
Returns
KTX_SUCCESS on success, other KTX_* enum values on error.
Exceptions
KTX_INVALID_VALUEThis is NULL.
KTX_INVALID_VALUEbufSize is less than the the image data size.
KTX_INVALID_OPERATIONThe data has already been loaded or the ktxTexture was not created from a KTX source.
KTX_OUT_OF_MEMORYInsufficient memory for the image data.

◆ ktxTexture2_NeedsTranscoding()

ktx_bool_t ktxTexture2_NeedsTranscoding ( ktxTexture2 This)

Query if the images are in a transcodable format.

Parameters
[in]Thispointer to the ktxTexture2 object of interest.

◆ ktxTexture2_TranscodeBasis()

KTX_error_code ktxTexture2_TranscodeBasis ( ktxTexture2 This,
ktx_transcode_fmt_e  outputFormat,
ktx_transcode_flags  transcodeFlags 
)

Transcode a KTX2 texture with BasisLZ/ETC1S or UASTC images.

If the texture contains BasisLZ supercompressed images, Inflates them from back to ETC1S then transcodes them to the specified block-compressed format. If the texture contains UASTC images, inflates them, if they have been supercompressed with zstd, then transcodes then to the specified format, The transcoded images replace the original images and the texture's fields including the DFD are modified to reflect the new format.

These types of textures must be transcoded to a desired target block-compressed format before they can be uploaded to a GPU via a graphics API.

The following block compressed transcode targets are available: KTX_TTF_ETC1_RGB, KTX_TTF_ETC2_RGBA, KTX_TTF_BC1_RGB, KTX_TTF_BC3_RGBA, KTX_TTF_BC4_R, KTX_TTF_BC5_RG, KTX_TTF_BC7_RGBA, KTX_TTF_PVRTC1_4_RGB, KTX_TTF_PVRTC1_4_RGBA, KTX_TTF_PVRTC2_4_RGB, KTX_TTF_PVRTC2_4_RGBA, KTX_TTF_ASTC_4x4_RGBA, KTX_TTF_ETC2_EAC_R11, KTX_TTF_ETC2_EAC_RG11, KTX_TTF_ETC and KTX_TTF_BC1_OR_3.

KTX_TTF_ETC automatically selects between KTX_TTF_ETC1_RGB and KTX_TTF_ETC2_RGBA according to whether an alpha channel is available. KTX_TTF_BC1_OR_3 does likewise between KTX_TTF_BC1_RGB and KTX_TTF_BC3_RGBA. Note that if KTX_TTF_PVRTC1_4_RGBA or KTX_TTF_PVRTC2_4_RGBA is specified and there is no alpha channel KTX_TTF_PVRTC1_4_RGB or KTX_TTF_PVRTC2_4_RGB respectively will be selected.

Transcoding to ATC & FXT1 formats is not supported by libktx as there are no equivalent Vulkan formats.

The following uncompressed transcode targets are also available: KTX_TTF_RGBA32, KTX_TTF_RGB565, KTX_TTF_BGR565 and KTX_TTF_RGBA4444.

The following transcodeFlags are available.

See also
ktxtexture2_CompressBasis().
Parameters
[in]Thispointer to the ktxTexture2 object of interest.
[in]outputFormata value from the ktx_texture_transcode_fmt_e enum specifying the target format.
[in]transcodeFlagsbitfield of flags modifying the transcode operation.
See also
ktx_texture_decode_flags_e.
Returns
KTX_SUCCESS on success, other KTX_* enum values on error.
Exceptions
KTX_FILE_DATA_ERRORSupercompression global data is corrupted.
KTX_INVALID_OPERATIONThe texture's format is not transcodable (not ETC1S/BasisLZ or UASTC).
KTX_INVALID_OPERATIONSupercompression global data is missing, i.e., the texture object is invalid.
KTX_INVALID_OPERATIONImage data is missing, i.e., the texture object is invalid.
KTX_INVALID_OPERATIONoutputFormat is PVRTC1 but the texture does does not have power-of-two dimensions.
KTX_INVALID_VALUEoutputFormat is invalid.
KTX_TRANSCODE_FAILEDSomething went wrong during transcoding.
KTX_UNSUPPORTED_FEATUREKTX_TF_PVRTC_DECODE_TO_NEXT_POW2 was requested or the specified transcode target has not been included in the library being used.
KTX_OUT_OF_MEMORYNot enough memory to carry out transcoding.

◆ ktxTexture_CreateFromMemory()

KTX_error_code ktxTexture_CreateFromMemory ( const ktx_uint8_t *  bytes,
ktx_size_t  size,
ktxTextureCreateFlags  createFlags,
ktxTexture **  newTex 
)

Create a ktxTexture1 or ktxTexture2 from KTX-formatted data in memory according to the data contents.

See ktxTexture1_CreateFromMemory or ktxTexture2_CreateFromMemory for details.

◆ ktxTexture_CreateFromNamedFile()

KTX_error_code ktxTexture_CreateFromNamedFile ( const char *const  filename,
ktxTextureCreateFlags  createFlags,
ktxTexture **  newTex 
)

Create a ktxTexture1 or ktxTexture2 from a named KTX file according to the file contents.

See ktxTexture1_CreateFromNamedFile or ktxTexture2_CreateFromNamedFile for details.

◆ ktxTexture_CreateFromStdioStream()

KTX_error_code ktxTexture_CreateFromStdioStream ( FILE *  stdioStream,
ktxTextureCreateFlags  createFlags,
ktxTexture **  newTex 
)

Create a ktxTexture1 or ktxTexture2 from a stdio stream according to the stream data.

See ktxTexture1_CreateFromStdioStream or ktxTexture2_CreateFromStdioStream for details.

◆ ktxTexture_CreateFromStream()

KTX_error_code ktxTexture_CreateFromStream ( ktxStream pStream,
ktxTextureCreateFlags  createFlags,
ktxTexture **  newTex 
)

Create a ktx1 or ktx2 texture according to the stream data.

See ktxTexture1_CreateFromStream or ktxTexture2_CreateFromStream for details.

◆ ktxTexture_GetData()

ktx_uint8_t * ktxTexture_GetData ( ktxTexture This)

Return a pointer to the texture image data.

Parameters
[in]Thispointer to the ktxTexture object of interest.

◆ ktxTexture_GetDataSize()

ktx_size_t ktxTexture_GetDataSize ( ktxTexture This)

Return the total size of the texture image data in bytes.

For a ktxTexture2 with supercompressionScheme != KTX_SS_NONE this will return the deflated size of the data.

Parameters
[in]Thispointer to the ktxTexture object of interest.

◆ ktxTexture_GetElementSize()

ktx_uint32_t ktxTexture_GetElementSize ( ktxTexture This)

Return the size in bytes of an elements of a texture's images.

For uncompressed textures an element is one texel. For compressed textures it is one block.

Parameters
[in]Thispointer to the ktxTexture object of interest.

◆ ktxTexture_GetRowPitch()

ktx_uint32_t ktxTexture_GetRowPitch ( ktxTexture This,
ktx_uint32_t  level 
)

Return pitch betweeb rows of a texture image level in bytes.

For uncompressed textures the pitch is the number of bytes between rows of texels. For compressed textures it is the number of bytes between rows of blocks. The value is padded to GL_UNPACK_ALIGNMENT, if necessary. For all currently known compressed formats padding will not be necessary.

Parameters
[in]Thispointer to the ktxTexture object of interest.
[in]levellevel of interest.
Returns
the row pitch in bytes.

◆ ktxTexture_IterateLevelFaces()

KTX_error_code ktxTexture_IterateLevelFaces ( ktxTexture This,
PFNKTXITERCB  iterCb,
void *  userdata 
)

Iterate over the levels or faces in a ktxTexture object.

Blocks of image data are passed to an application-supplied callback function. This is not a strict per-image iteration. Rather it reflects how OpenGL needs the images. For most textures the block of data includes all images of a mip level which implies all layers of an array. However, for non-array cube map textures the block is a single face of the mip level, i.e the callback is called once for each face.

This function works even if This->pData == 0 so it can be used to obtain offsets and sizes for each level by callers who have loaded the data externally.

Parameters
[in]Thispointer to the ktxTexture object of interest.
[in,out]iterCbthe address of a callback function which is called with the data for each image block.
[in,out]userdatathe address of application-specific data which is passed to the callback along with the image data.
Returns
KTX_SUCCESS on success, other KTX_* enum values on error. The following are returned directly by this function. iterCb may return these for other causes or may return additional errors.
Exceptions
KTX_FILE_DATA_ERRORMip level sizes are increasing not decreasing
KTX_INVALID_VALUEThis is NULL or iterCb is NULL.