Texture utility functions to determine texture dimension and buffer sizes.

Functions
LLGL_EXPORT std::uint32_t	LLGL::NumMipLevels (std::uint32_t width, std::uint32_t height=1, std::uint32_t depth=1)
	Returns the number of MIP-map levels for a texture with the specified size.
LLGL_EXPORT std::uint32_t	LLGL::NumMipLevels (const TextureType type, const Extent3D &extent)
	Returns the number of MIP-map levels for the specified texture attributes.
LLGL_EXPORT std::uint32_t	LLGL::NumMipLevels (const TextureDescriptor &textureDesc)
	Returns the number of MIP-map levels for the specified texture descriptor.
LLGL_EXPORT std::uint32_t	LLGL::NumMipTexels (const TextureType type, const Extent3D &extent, std::uint32_t mipLevel)
	Returns the number of texture elements (texels) for the specified texture attributes, or zero extent if mipLevel is out of bounds (see NumMipLevels).
LLGL_EXPORT std::uint32_t	LLGL::NumMipTexels (const TextureType type, const Extent3D &extent, const TextureSubresource &subresource)
	Returns the number of texture elements (texels) for the specified texture subresource range.
LLGL_EXPORT std::uint32_t	LLGL::NumMipTexels (const TextureDescriptor &textureDesc, std::uint32_t mipLevel=~0u)
	Returns the number of texture elements (texels) for the specified texture descriptor.
LLGL_EXPORT std::uint32_t	LLGL::NumMipDimensions (const TextureType type)
	Returns the number of MIP-map dimensions for the specified texture type. This is either 1, 2, 3, or 0 if the input is invalid.
LLGL_EXPORT std::uint32_t	LLGL::NumTextureDimensions (const TextureType type)
	Returns the number of texture dimensions for the specified texture type. This is either 1, 2, 3, or 0 if the input is invalid.
LLGL_EXPORT Extent3D	LLGL::GetMipExtent (const TextureType type, const Extent3D &extent, std::uint32_t mipLevel)
	Returns the MIP-map extent (including array layers) for the specified texture type, or an empty extent if mipLevel is out of bounds (see NumMipLevels).
LLGL_EXPORT Extent3D	LLGL::GetMipExtent (const TextureDescriptor &textureDesc, std::uint32_t mipLevel=0)
	Returns the MIP-map extent (including array layers) for the specified texture descriptor.
LLGL_EXPORT std::size_t	LLGL::GetMemoryFootprint (const TextureType type, const Format format, const Extent3D &extent, const TextureSubresource &subresource)
	Returns the memory footprint (in bytes) of a texture subresource with the specified hardware format and extent.
LLGL_EXPORT bool	LLGL::IsMipMappedTexture (const TextureDescriptor &textureDesc)
	Returns true if the specified texture descriptor describes a texture with MIP-mapping enabled.
LLGL_EXPORT bool	LLGL::IsArrayTexture (const TextureType type)
	Returns true if the specified texture type is an array texture.
LLGL_EXPORT bool	LLGL::IsMultiSampleTexture (const TextureType type)
	Returns true if the specified texture type is a multi-sample texture.
LLGL_EXPORT bool	LLGL::IsCubeTexture (const TextureType type)
	Returns true if the specified texture type is a cube texture.
LLGL_EXPORT bool	LLGL::IsTextureSwizzleIdentity (const TextureSwizzleRGBA &swizzle)
	Returns true if the specified texture swizzling is equal to the identity mapping.

Detailed Description

Function Documentation

GetMemoryFootprint()

LLGL_EXPORT std::size_t LLGL::GetMemoryFootprint	(	const TextureType	type,
		const Format	format,
		const Extent3D &	extent,
		const TextureSubresource &	subresource )

Returns the memory footprint (in bytes) of a texture subresource with the specified hardware format and extent.

Parameters

[in]	type	Specifies the texture type which determines how extent and subresource will result into the final texture dimensions.
[in]	format	Specifies the hardware format.
[in]	extent	Specifies the extent of the texture subresource.
[in]	subresource	Specifies the texture subresource.

See also

GetMemoryFootprint(const Format, std::uint64_t)

Texture::GetMemoryFootprint

Texture::GetMipExtent

Texture::GetFormat

GetMipExtent() [1/2]

LLGL_EXPORT Extent3D LLGL::GetMipExtent	(	const TextureDescriptor &	textureDesc,
		std::uint32_t	mipLevel = 0 )

Returns the MIP-map extent (including array layers) for the specified texture descriptor.

Parameters

[in]	textureDesc	Specifies the texture descriptor.
[in]	mipLevel	Specifies the MIP-map level whose extent is to be determined. The first and largest MIP-map level has index zero.

See also

Texture::GetMipExtent

TextureDescriptor::extent

TextureDescriptor::arrayLayers

GetMipExtent() [2/2]

LLGL_EXPORT Extent3D LLGL::GetMipExtent	(	const TextureType	type,
		const Extent3D &	extent,
		std::uint32_t	mipLevel )

Returns the MIP-map extent (including array layers) for the specified texture type, or an empty extent if mipLevel is out of bounds (see NumMipLevels).

Parameters

[in]	type	Specifies the texture type for which the MIP-map extent is to be determined.
[in]	extent	Specifies the extent of the first MIP-map level.
[in]	mipLevel	Specifies the MIP-map level whose extent is to be determined. The first and largest MIP-map level has index zero.

See also

Texture::GetMipExtent

TextureDescriptor::extent

NumMipLevels(const TextureType, const Extent3D&)

IsArrayTexture()

LLGL_EXPORT bool LLGL::IsArrayTexture

(

const TextureType

type

)

Returns true if the specified texture type is an array texture.

Returns

True if type is either TextureType::Texture1DArray, TextureType::Texture2DArray, TextureType::TextureCubeArray, or TextureType::Texture2DMSArray.

IsCubeTexture()

LLGL_EXPORT bool LLGL::IsCubeTexture

(

const TextureType

type

)

Returns true if the specified texture type is a cube texture.

Returns

True if type is either TextureType::TextureCube or TextureType::TextureCubeArray.

IsMipMappedTexture()

LLGL_EXPORT bool LLGL::IsMipMappedTexture

(

const TextureDescriptor &

textureDesc

)

Returns true if the specified texture descriptor describes a texture with MIP-mapping enabled.

Returns

True if the texture type is not a multi-sampled texture and the number of MIP-map levels in the descriptor is either zero or greater than one.

See also

TextureDescriptor::mipLevels

IsMultiSampleTexture()

LLGL_EXPORT bool LLGL::IsMultiSampleTexture

(

const TextureType

type

)

Returns true if the specified texture type is a multi-sample texture.

Returns

True if type is either TextureType::Texture2DMS, or TextureType::Texture2DMSArray.

IsTextureSwizzleIdentity()

LLGL_EXPORT bool LLGL::IsTextureSwizzleIdentity

(

const TextureSwizzleRGBA &

swizzle

)

Returns true if the specified texture swizzling is equal to the identity mapping.

Returns

True if the components are mapped as follows:

• r equals TextureSwizzle::Red
• g equals TextureSwizzle::Green
• b equals TextureSwizzle::Blue
• a equals TextureSwizzle::Alpha

See also

TextureSwizzle

NumMipDimensions()

LLGL_EXPORT std::uint32_t LLGL::NumMipDimensions

(

const TextureType

type

)

Returns the number of MIP-map dimensions for the specified texture type. This is either 1, 2, 3, or 0 if the input is invalid.

Remarks

MIP-map dimensions do count array layers as a dimension, e.g. for TextureType::Texture2DArray this function returns 3.

See also

Texture::GetMipExtent

NumTextureDimensions

NumMipLevels() [1/3]

LLGL_EXPORT std::uint32_t LLGL::NumMipLevels

(

const TextureDescriptor &

textureDesc

)

Returns the number of MIP-map levels for the specified texture descriptor.

Parameters

[in]

textureDesc

Specifies the descriptor whose parameters are used to determine the number of MIP-map levels.

Remarks

This function will deduce the number MIP-map levels automatically only if the member mipLevels is zero. Otherwise, the value of this member is returned.

See also

NumMipLevels(const TextureType, const Extent3D&)

NumMipLevels() [2/3]

LLGL_EXPORT std::uint32_t LLGL::NumMipLevels	(	const TextureType	type,
		const Extent3D &	extent )

Returns the number of MIP-map levels for the specified texture attributes.

Parameters

[in]	type	Specifies the texture type for which the MIP-map extent is to be determined.
[in]	extent	Specifies the extent of the first MIP-map level.

See also

NumMipLevels(std::uint32_t, std::uint32_t, std::uint32_t)

NumMipLevels() [3/3]

LLGL_EXPORT std::uint32_t LLGL::NumMipLevels	(	std::uint32_t	width,
		std::uint32_t	height = 1,
		std::uint32_t	depth = 1 )

Returns the number of MIP-map levels for a texture with the specified size.

Parameters

[in]	width	Specifies the texture width.
[in]	height	Specifies the texture height or number of layers for 1D array textures. By default 1 (if 1D textures are used).
[in]	depth	Specifies the texture depth or number of layers for 2D array textures. By default 1 (if 1D or 2D textures are used).

Remarks

The height and depth are optional parameters, so this function can be easily used for 1D, 2D, and 3D textures.

Returns

\(\left\lfloor 1 + log_2\left(\max\left\{ \texttt{width}, \texttt{height}, \texttt{depth} \right\} \right) \right\rfloor\)

NumMipTexels() [1/3]

LLGL_EXPORT std::uint32_t LLGL::NumMipTexels	(	const TextureDescriptor &	textureDesc,
		std::uint32_t	mipLevel = ~0u )

Returns the number of texture elements (texels) for the specified texture descriptor.

Parameters

[in]	textureDesc	Specifies the texture descriptor for which the number of MIP-map texels are determined.
[in]	mipLevel	Optional parameter to specify only a single MIP-map level. If this is 0xFFFFFFFF, the number of texels for the entire MIP-map chain is determined. By default 0xFFFFFFFF. The size of the MIP-map chain is determined by textureDesc.mipLevels.

See also

NumMipTexels(const TextureType, const Extent3D&, std::uint32_t)

TextureDescriptor::mipLevels

NumMipTexels() [2/3]

LLGL_EXPORT std::uint32_t LLGL::NumMipTexels	(	const TextureType	type,
		const Extent3D &	extent,
		const TextureSubresource &	subresource )

Returns the number of texture elements (texels) for the specified texture subresource range.

Parameters

[in]	type	Specifies the texture type for which the number of texels are to be determined.
[in]	extent	Specifies the extent of the first MIP-map level.
[in]	subresource	Specifies the subresource range. Which dimension in extent specifies the number of array layers depends on the texture type.

See also

TextureDescriptor::arrayLayers

TextureSubresource::baseArrayLayer

TextureSubresource::numArrayLayers

NumMipTexels(const TextureType, const Extent3D&, std::uint32_t)

NumMipTexels() [3/3]

LLGL_EXPORT std::uint32_t LLGL::NumMipTexels	(	const TextureType	type,
		const Extent3D &	extent,
		std::uint32_t	mipLevel )

Returns the number of texture elements (texels) for the specified texture attributes, or zero extent if mipLevel is out of bounds (see NumMipLevels).

Parameters

[in]	type	Specifies the texture type for which the number of texels are to be determined.
[in]	extent	Specifies the extent of the first MIP-map level.
[in]	mipLevel	Specifies the MIP-map level whose number of texels is to be determined. The first and largest MIP-map level has index zero.

See also

TextureDescriptor::type

NumMipLevels(const TextureType, const Extent3D&)

NumTextureDimensions()

LLGL_EXPORT std::uint32_t LLGL::NumTextureDimensions

(

const TextureType

type

)

Returns the number of texture dimensions for the specified texture type. This is either 1, 2, 3, or 0 if the input is invalid.

Remarks

Texture dimensions don't count array layers as a dimension, e.g. for TextureType::Texture2DArray this function returns 2.

See also

TextureDescriptor::extent

NumMipDimensions