terrio 0.2.0

Pure-Rust geospatial raster, vector and point cloud data I/O: read, write, convert and reproject GIS formats without C dependencies
Documentation 
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

//! Point clouds as vector layers of points with attributes, and back; rasters as points.

use super::{Dimension, PointCloud, ValueType, Values};
use crate::crs::SpatialRef;
use crate::{Error, Result};
use wbvector::{Feature, FieldDef, FieldType, FieldValue, Geometry, GeometryType, Layer};

/// How to turn points into a vector layer.
#[derive(Debug, Clone, Default, PartialEq)]
pub struct ToLayerOptions {
    /// The layer name. By default, `points`.
    pub name: Option<String>,
    /// The dimensions written as attributes. Empty means all but `x` and `y`.
    pub dimensions: Vec<String>,
    /// Write 2D points; by default the points are 3D, with `z` as their third coordinate.
    pub two_d: bool,
}

/// A vector layer of the points, one feature each, with the dimensions as attributes.
pub fn to_layer(cloud: &PointCloud, options: &ToLayerOptions) -> Result<Layer> {
    let xs = cloud.coords("x").ok_or_else(|| Error::InvalidArgument("the points have no x".into()))?;
    let ys = cloud.coords("y").ok_or_else(|| Error::InvalidArgument("the points have no y".into()))?;
    let zs = cloud.coords("z");
    let dims: Vec<&Dimension> = if options.dimensions.is_empty() {
        cloud.dimensions.iter().filter(|d| d.name != "x" && d.name != "y").collect()
    } else {
        options
            .dimensions
            .iter()
            .map(|n| {
                cloud.dim(n).ok_or_else(|| {
                    Error::InvalidArgument(format!("no dimension '{n}' (dimensions: {})", cloud.dimension_names().join(", ")))
                })
            })
            .collect::<Result<_>>()?
    };
    let mut layer = Layer::new(options.name.clone().unwrap_or_else(|| "points".into())).with_geom_type(GeometryType::Point);
    let integer = |d: &Dimension| {
        d.scale.is_none() && d.offset.is_none() && !matches!(d.values.value_type(), ValueType::F32 | ValueType::F64 | ValueType::U64)
    };
    for d in &dims {
        layer.add_field(FieldDef::new(d.name.clone(), if integer(d) { FieldType::Integer } else { FieldType::Float }));
    }
    cloud.crs.apply_to_layer(&mut layer);
    let ints: Vec<bool> = dims.iter().map(|d| integer(d)).collect();
    layer.features.reserve(cloud.len());
    for i in 0..cloud.len() {
        let geometry = match (zs, options.two_d) {
            (Some(z), false) => Geometry::point_z(xs[i], ys[i], z[i]),
            _ => Geometry::point(xs[i], ys[i]),
        };
        let attributes = dims
            .iter()
            .zip(&ints)
            .map(|(d, int)| if *int { FieldValue::Integer(d.values.get_f64(i) as i64) } else { FieldValue::Float(d.get(i)) })
            .collect();
        layer.push(Feature { fid: i as u64, geometry: Some(geometry), attributes });
    }
    Ok(layer)
}

/// A point cloud of a layer's point geometries (multipoints contribute each of their points), with
/// its numeric attributes as dimensions. Attributes named like the standard LAS dimensions
/// (`intensity`, `classification`...) keep their LAS types; others become `float64` extra-bytes
/// dimensions. `z` comes from the geometries, or from a `z` attribute.
pub fn from_layer(layer: &Layer) -> Result<PointCloud> {
    let fields = layer.schema.fields();
    let numeric: Vec<usize> =
        (0..fields.len()).filter(|&k| matches!(fields[k].field_type, FieldType::Integer | FieldType::Float | FieldType::Boolean)).collect();
    let mut x = Vec::new();
    let mut y = Vec::new();
    let mut z = Vec::new();
    let mut attrs: Vec<Vec<f64>> = vec![Vec::new(); numeric.len()];
    let z_field = numeric.iter().position(|&k| fields[k].name.eq_ignore_ascii_case("z"));
    for f in &layer.features {
        let coords: Vec<wbvector::Coord> = match &f.geometry {
            Some(Geometry::Point(c)) => vec![c.clone()],
            Some(Geometry::MultiPoint(cs)) => cs.clone(),
            _ => continue,
        };
        for c in coords {
            x.push(c.x);
            y.push(c.y);
            let values: Vec<f64> = numeric
                .iter()
                .map(|&k| match f.attributes.get(k) {
                    Some(FieldValue::Integer(v)) => *v as f64,
                    Some(FieldValue::Float(v)) => *v,
                    Some(FieldValue::Boolean(b)) => f64::from(u8::from(*b)),
                    _ => f64::NAN,
                })
                .collect();
            z.push(c.z.or_else(|| z_field.map(|p| values[p])).unwrap_or(0.0));
            for (a, v) in attrs.iter_mut().zip(values) {
                a.push(v);
            }
        }
    }
    if x.is_empty() {
        return Err(Error::InvalidArgument(format!("layer '{}' has no point geometries", layer.name)));
    }
    let mut dims = vec![Dimension::new("x", Values::F64(x)), Dimension::new("y", Values::F64(y)), Dimension::new("z", Values::F64(z))];
    for (k, a) in numeric.iter().zip(attrs) {
        let name = fields[*k].name.to_ascii_lowercase();
        if matches!(name.as_str(), "x" | "y" | "z") || dims.iter().any(|d| d.name == name) {
            continue;
        }
        match super::standard_value_type(&name) {
            Some(t) => dims.push(Dimension::new(&name, Values::F64(a).cast(t))),
            None => dims.push(Dimension::new(&fields[*k].name, Values::F64(a))),
        }
    }
    Ok(super::write::from_dimensions(dims, SpatialRef::from_layer(layer)))
}

/// A point cloud of a raster band: one point at the centre of each valid cell, with the cell
/// value as `z`.
pub fn from_raster(ds: &crate::RasterDataset, band: usize) -> Result<PointCloud> {
    let r = &ds.raster;
    if band >= r.bands {
        return Err(Error::InvalidArgument(format!("no band {} (the raster has {})", band + 1, r.bands)));
    }
    let gt = ds.geo_transform();
    let nodata = ds.nodata();
    let view = r.band_view(band);
    let values = view.as_slice();
    let (mut x, mut y, mut z) = (Vec::new(), Vec::new(), Vec::new());
    for row in 0..r.rows {
        for col in 0..r.cols {
            let v = values[row * r.cols + col];
            if v.is_nan() || nodata.is_some_and(|nd| v == nd) {
                continue;
            }
            x.push(gt[0] + (col as f64 + 0.5) * gt[1] + (row as f64 + 0.5) * gt[2]);
            y.push(gt[3] + (col as f64 + 0.5) * gt[4] + (row as f64 + 0.5) * gt[5]);
            z.push(v);
        }
    }
    let n = x.len();
    let dims = vec![
        Dimension::new("x", Values::F64(x)),
        Dimension::new("y", Values::F64(y)),
        Dimension::new("z", Values::F64(z)),
        Dimension::new("intensity", Values::zeros(ValueType::U16, n)),
        Dimension::new("return_number", Values::U8(vec![1; n])),
        Dimension::new("number_of_returns", Values::U8(vec![1; n])),
        Dimension::new("classification", Values::zeros(ValueType::U8, n)),
    ];
    Ok(super::write::from_dimensions(dims, ds.crs()))
}