A view on the image data of FeatureIdTexture. More...

#include <CesiumGltf/FeatureIdTextureView.h>

Inheritance diagram for CesiumGltf::FeatureIdTextureView:

Public Member Functions
	FeatureIdTextureView () noexcept
	Constructs an uninitialized and invalid view.

	FeatureIdTextureView (const Model &model, const FeatureIdTexture &featureIdTexture, const TextureViewOptions &options=TextureViewOptions()) noexcept
	Construct a view of the data specified by a FeatureIdTexture. More...

int64_t	getFeatureID (double u, double v) const noexcept
	Get the feature ID from the texture at the given texture coordinates. If the texture is somehow invalid, this returns -1. More...

FeatureIdTextureViewStatus	status () const noexcept
	Get the status of this view. More...

std::vector< int64_t >	getChannels () const noexcept
	Get the channels of this feature ID texture. The channels represent the bytes of the actual feature ID, in little-endian order.

Public Member Functions inherited from CesiumGltf::TextureView
	TextureView () noexcept
	Constructs an empty, uninitialized texture view.

	TextureView (const Model &model, const TextureInfo &textureInfo, const TextureViewOptions &options=TextureViewOptions()) noexcept
	Constructs a view of the texture specified by the given TextureInfo. More...

	TextureView (const Sampler &sampler, const ImageAsset &image, int64_t textureCoordinateSetIndex, const ExtensionKhrTextureTransform *pKhrTextureTransformExtension=nullptr, const TextureViewOptions &options=TextureViewOptions()) noexcept
	Constructs a view of the texture specified by the given Sampler and ImageAsset. More...

TextureViewStatus	getTextureViewStatus () const noexcept
	Get the status of this texture view. More...

int64_t	getTexCoordSetIndex () const noexcept
	Get the texture coordinate set index for this view. If this view was constructed with options.applyKhrTextureTransformExtension as true, and if the texture contains the `KHR_texture_transform` extension, then this will return the value from the extension since it is meant to override the original index. However, if the extension does not specify a TEXCOORD set index, then the original index of the texture is returned.

const Sampler *	getSampler () const noexcept
	Get the sampler describing how to sample the data from the property's texture. More...

const ImageAsset *	getImage () const noexcept
	Get the image containing this property's data. If this view was constructed with options.makeImageCopy set to true, this will return a pointer to the copied image. More...

std::optional< KhrTextureTransform >	getTextureTransform () const noexcept
	Get the KHR_texture_transform for this texture if it exists. More...

std::vector< uint8_t >	sampleNearestPixel (double u, double v, const std::vector< int64_t > &channels) const noexcept
	Samples the image at the specified texture coordinates using NEAREST pixel filtering, returning the bytes as uint8_t values. A channels vector must be supplied to specify how many image channels are needed, and in what order the bytes should be retrieved.

Detailed Description

A view on the image data of FeatureIdTexture.

It provides the ability to sample the feature IDs from the FeatureIdTexture using texture coordinates.

Definition at line 74 of file FeatureIdTextureView.h.

Constructor & Destructor Documentation

◆ FeatureIdTextureView()

CesiumGltf::FeatureIdTextureView::FeatureIdTextureView	(	const Model &	model,
		const FeatureIdTexture &	featureIdTexture,
		const TextureViewOptions &	options = `TextureViewOptions()`
	)

noexcept

Construct a view of the data specified by a FeatureIdTexture.

A feature ID texture may contain the KHR_texture_transform extension, which transforms the texture coordinates used to sample the texture. The extension may also override the TEXCOORD set index that was originally specified by the feature ID texture.

If a view is constructed with applyKhrTextureTransformExtension set to true, the view will automatically apply the texture transform to any UV coordinates used to sample the texture. If the extension defines its own TEXCOORD set index, it will override the original value.

Otherwise, if the flag is set to false, UVs will not be transformed and the original TEXCOORD set index will be preserved. The extension's values may still be retrieved using getTextureTransform, if desired.

Parameters

model	The glTF in which to look for the feature ID texture's data.
featureIdTexture	The feature ID texture to create a view for.
applyKhrTextureTransformExtension	Whether to automatically apply the `KHR_texture_transform` extension to the feature ID texture, if it exists.

Member Function Documentation

◆ getFeatureID()

int64_t CesiumGltf::FeatureIdTextureView::getFeatureID	(	double	u,
		double	v
	)		const

noexcept

Get the feature ID from the texture at the given texture coordinates. If the texture is somehow invalid, this returns -1.

Parameters

u	The u-component of the texture coordinates. Must be within [0.0, 1.0].
v	The v-component of the texture coordinates. Must be within [0.0, 1.0].

Returns: The feature ID at the nearest pixel to the texture coordinates.

◆ status()

FeatureIdTextureViewStatus CesiumGltf::FeatureIdTextureView::status ( ) const

inlinenoexcept

Get the status of this view.

If invalid, it will not be safe to sample feature IDs from this view.

Definition at line 125 of file FeatureIdTextureView.h.

The documentation for this class was generated from the following file: