1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177

//! # Basic usage
//!
//! Visiting the accessors of a glTF asset.
//!
//! ```
//! # fn run() -> Result<(), Box<std::error::Error>> {
//! # let gltf = gltf::Gltf::open("examples/Box.gltf")?;
//! for accessor in gltf.accessors() {
//!     println!("Accessor #{}", accessor.index());
//!     println!("offset: {}", accessor.offset());
//!     println!("count: {}", accessor.count());
//!     println!("data_type: {:?}", accessor.data_type());
//!     println!("dimensions: {:?}", accessor.dimensions());
//! }
//! # Ok(())
//! # }
//! # fn main() {
//! #    let _ = run().expect("runtime error");
//! # }
//! ```
//!
//! # Utility functions
//!
//! Reading the values from the `vec3` accessors of a glTF asset.
//!
//! ## Note
//!
//! The [`Iter`] utility is a low-level iterator intended for use in special
//! cases. The average user is expected to use reader abstractions such as
//! [`mesh::Reader`].
//!
//! [`Iter`]: struct.Iter.html
//! [`mesh::Reader`]: ../mesh/struct.Reader.html
//!
//! ```
//! # fn run() -> Result<(), Box<dyn std::error::Error>> {
//! # use gltf::accessor::{DataType, Dimensions, Iter};
//! let (gltf, buffers, _) = gltf::import("examples/Box.gltf")?;
//! let get_buffer_data = |buffer: gltf::Buffer| buffers.get(buffer.index()).map(|x| &*x.0);
//! for accessor in gltf.accessors() {
//!     match (accessor.data_type(), accessor.dimensions()) {
//!         (DataType::F32, Dimensions::Vec3) => {
//!             let iter = Iter::<[f32; 3]>::new(accessor, get_buffer_data);
//!             for item in iter {
//!                 println!("{:?}", item);
//!             }
//!         }
//!         _ => {},
//!     }
//! }
//! # Ok(())
//! # }
//! # fn main() {
//! #    let _ = run().expect("runtime error");
//! # }
//! ```

use crate::{buffer, Document};

pub use json::accessor::ComponentType as DataType;
pub use json::accessor::Type as Dimensions;

/// Utility functions.
#[cfg(feature = "utils")]
#[cfg_attr(docsrs, doc(cfg(feature = "utils")))]
pub mod util;

/// Contains data structures for sparse storage.
pub mod sparse;

#[cfg(feature = "utils")]
#[doc(inline)]
pub use self::util::{Item, Iter};

/// A typed view into a buffer view.
#[derive(Clone, Debug)]
pub struct Accessor<'a> {
    /// The parent `Document` struct.
    document: &'a Document,

    /// The corresponding JSON index.
    index: usize,

    /// The corresponding JSON struct.
    json: &'a json::accessor::Accessor,
}

impl<'a> Accessor<'a> {
    /// Constructs an `Accessor`.
    pub(crate) fn new(
        document: &'a Document,
        index: usize,
        json: &'a json::accessor::Accessor,
    ) -> Self {
        Self {
            document,
            index,
            json,
        }
    }

    /// Returns the internal JSON index.
    pub fn index(&self) -> usize {
        self.index
    }

    /// Returns the size of each component that this accessor describes.
    pub fn size(&self) -> usize {
        self.data_type().size() * self.dimensions().multiplicity()
    }

    /// Returns the buffer view this accessor reads from.
    ///
    /// This may be `None` if the corresponding accessor is sparse.
    pub fn view(&self) -> Option<buffer::View<'a>> {
        self.json
            .buffer_view
            .map(|view| self.document.views().nth(view.value()).unwrap())
    }

    /// Returns the offset relative to the start of the parent buffer view in bytes.
    pub fn offset(&self) -> usize {
        self.json.byte_offset as usize
    }

    /// Returns the number of components within the buffer view - not to be confused
    /// with the number of bytes in the buffer view.
    pub fn count(&self) -> usize {
        self.json.count as usize
    }

    /// Returns the data type of components in the attribute.
    pub fn data_type(&self) -> DataType {
        self.json.component_type.unwrap().0
    }

    /// Optional application specific data.
    pub fn extras(&self) -> &'a json::Extras {
        &self.json.extras
    }

    /// Specifies if the attribute is a scalar, vector, or matrix.
    pub fn dimensions(&self) -> Dimensions {
        self.json.type_.unwrap()
    }

    /// Returns the minimum value of each component in this attribute.
    pub fn min(&self) -> Option<json::Value> {
        self.json.min.clone()
    }

    /// Returns the maximum value of each component in this attribute.
    pub fn max(&self) -> Option<json::Value> {
        self.json.max.clone()
    }

    /// Optional user-defined name for this object.
    #[cfg(feature = "names")]
    #[cfg_attr(docsrs, doc(cfg(feature = "names")))]
    pub fn name(&self) -> Option<&'a str> {
        self.json.name.as_deref()
    }

    /// Specifies whether integer data values should be normalized.
    pub fn normalized(&self) -> bool {
        self.json.normalized
    }

    /// Returns sparse storage of attributes that deviate from their initialization
    /// value.
    pub fn sparse(&self) -> Option<sparse::Sparse<'a>> {
        self.json
            .sparse
            .as_ref()
            .map(|json| sparse::Sparse::new(self.document, json))
    }
}