Struct KTXHeader

Description of the KTX header. https://www.khronos.org/registry/OpenGL/specs/gl/glspec44.core.pdf.

Namespace: Evergine.Assets.Extensions.KTX
Assembly: Evergine.Assets.dll
Syntax
public struct KTXHeader

Fields

bytesOfKeyValueData

An arbitrary number of key/value pairs may follow the header. This can be used to encode any arbitrary data. The bytesOfKeyValueData field indicates the total number of bytes of key/value data including all keyAndValueByteSize fields, all keyAndValue fields, and all valuePadding fields. The file offset of the first imageSize field is located at the file offset of the bytesOfKeyValueData field plus the value of the bytesOfKeyValueData field plus 4.

Declaration
public uint bytesOfKeyValueData
Field Value
Type Description
uint

endianness

Endianness contains the number 0x04030201 written as a 32-bit integer. If the file is little-endian, this is represented as the bytes 0x01 0x02 0x03 0x04. If the file is big-endian, this is represented as the bytes 0x04 0x03 0x02 0x01. When reading endianness as a 32-bit integer produces the value 0x04030201, the endianness of the file matches the endianness of the program that is reading the file, and no conversion is necessary. When reading endianness as a 32-bit integer produces the value 0x01020304, the endianness of the file is opposite to the endianness of the program that is reading the file. In that case, the program reading the file must convert all header bytes to the endianness of the program (i.e., a little-endian program must convert from big-endian, and a big-endian program must convert to little-endian).

Declaration
public uint endianness
Field Value
Type Description
uint

glBaseInternalformat

For both compressed and uncompressed textures, glBaseInternalFormat specifies the base internal format of the texture, usually one of the values from Table 8.11 of the OpenGL 4.4 specification [OPENGL44] (RGB, RGBA, ALPHA, etc.). For uncompressed textures, this value will be the same as glFormat and is used as the internal format parameter when loading into a context that does not support sized formats, such as an unextended OpenGL ES 2.0 context.

Declaration
public uint glBaseInternalformat
Field Value
Type Description
uint

glFormat

For compressed textures, glFormat must equal 0. For uncompressed textures, glFormat specifies the format parameter passed to glTex{,Sub}Image*D, usually one of the values from Table 8.3 of the OpenGL 4.4 specification [OPENGL44] (RGB, RGBA, BGRA, etc.)

Declaration
public uint glFormat
Field Value
Type Description
uint

glInternalFormat

For compressed textures, glInternalFormat must match the compressed internal format, usually one of the values from table 8.14 of the OpenGL 4.4 specification [OPENGL44]. For uncompressed textures, glInternalFormat specifies the internal format parameter passed to glTexStorageD or glTexImageD, usually one of the sized internal formats from tables 8.12 and 8.13 of the OpenGL 4.4 specification [OPENGL44]. The sized format should be chosen to match the bit depth of the data provided. glInternalFormat is used when loading both compressed and uncompressed textures, except when loading into a context that does not support sized formats, such as an unextended OpenGL ES 2.0 context where the internal format parameter is required to have the same value as the format parameter.

Declaration
public uint glInternalFormat
Field Value
Type Description
uint

glType

For compressed textures, glType must equal 0. For uncompressed textures, glType specifies the type parameter passed to glTex{,Sub}Image*D, usually one of the values from Table 8.2 of the OpenGL 4.4 specification [OPENGL44] (UNSIGNED_BYTE, UNSIGNED_SHORT_5_6_5, etc.).

Declaration
public uint glType
Field Value
Type Description
uint

glTypeSize

glTypeSize specifies the data type size that should be used when endianness conversion is required for the texture data stored in the file. If glType is not 0, this should be the size in bytes corresponding to glType. For texture data that does not depend on platform endianness, including compressed texture data, glTypeSize must equal 1.

Declaration
public uint glTypeSize
Field Value
Type Description
uint

numberOfArrayElements

numberOfArrayElements specifies the number of array elements. If the texture is not an array texture, numberOfArrayElements must equal zero.

Declaration
public uint numberOfArrayElements
Field Value
Type Description
uint

numberOfFaces

numberOfFaces specifies the number of cubemap faces. For cubemaps and cubemap arrays, this should be 6. For non-cubemaps, this should be 1. Cubemap faces are stored in the order: +X, -X, +Y, -Y, +Z, -Z.

Declaration
public uint numberOfFaces
Field Value
Type Description
uint

numberOfMipmapLevels

numberOfMipmapLevels must be 1 for non-mipmapped textures. For mipmapped textures, it equals the number of mipmaps. Mipmaps are stored in order from largest size to smallest size. The first mipmap level is always level 0. A KTX file does not need to contain a complete mipmap pyramid. If numberOfMipmapLevels equals 0, it indicates that a full mipmap pyramid should be generated from level 0 at load time (this is usually not allowed for compressed formats).

Declaration
public uint numberOfMipmapLevels
Field Value
Type Description
uint

pixelDepth

The size of the texture image for level 0, in pixels. No rounding to block sizes should be applied for block-compressed textures. For 1D textures, pixelHeight and pixelDepth must be 0. For 2D and cube textures, pixelDepth must be 0.

Declaration
public uint pixelDepth
Field Value
Type Description
uint

pixelHeight

The size of the texture image for level 0, in pixels. No rounding to block sizes should be applied for block-compressed textures. For 1D textures, pixelHeight and pixelDepth must be 0. For 2D and cube textures, pixelDepth must be 0.

Declaration
public uint pixelHeight
Field Value
Type Description
uint

pixelWidth

The size of the texture image for level 0, in pixels. No rounding to block sizes should be applied for block-compressed textures. For 1D textures, pixelHeight and pixelDepth must be 0. For 2D and cube textures, pixelDepth must be 0.

Declaration
public uint pixelWidth
Field Value
Type Description
uint

Extension Methods