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lerc_reader/
types.rs

1use std::any::TypeId;
2
3use lerc_band_materialize::{
4    copy_band_values_into_slice, BandLayout as MaterializeLayout, BandMaterializer,
5};
6use lerc_core::{BandLayout, BandSetInfo, BlobInfo, Error, PixelData, Result};
7use ndarray::{ArrayD, IxDyn};
8
9use crate::allocation::{checked_mul, default_vec, vec_with_capacity};
10
11#[derive(Debug, Clone, PartialEq)]
12pub struct Decoded {
13    pub info: BlobInfo,
14    pub pixels: PixelData,
15    pub mask: Option<Vec<u8>>,
16}
17
18impl Decoded {
19    pub fn into_ndarray<T: NdArrayElement>(self) -> Result<ArrayD<T>> {
20        let shape = self.info.ndarray_shape();
21        self.pixels.into_ndarray(&shape)
22    }
23
24    pub fn into_mask_ndarray(self) -> Result<Option<ArrayD<u8>>> {
25        let shape = self.info.mask_ndarray_shape();
26        self.mask
27            .map(|mask| {
28                ArrayD::from_shape_vec(IxDyn(&shape), mask).map_err(|err| {
29                    Error::InvalidBlob(format!("failed to build ndarray from decoded mask: {err}"))
30                })
31            })
32            .transpose()
33    }
34}
35
36#[derive(Debug, Clone, PartialEq)]
37pub struct DecodedF64 {
38    pub info: BlobInfo,
39    pub pixels: Vec<f64>,
40    pub mask: Option<Vec<u8>>,
41}
42
43impl DecodedF64 {
44    pub fn into_ndarray(self) -> Result<ArrayD<f64>> {
45        ArrayD::from_shape_vec(IxDyn(&self.info.ndarray_shape()), self.pixels).map_err(|err| {
46            Error::InvalidBlob(format!(
47                "failed to build ndarray from decoded pixels: {err}"
48            ))
49        })
50    }
51
52    pub fn into_mask_ndarray(self) -> Result<Option<ArrayD<u8>>> {
53        let shape = self.info.mask_ndarray_shape();
54        self.mask
55            .map(|mask| {
56                ArrayD::from_shape_vec(IxDyn(&shape), mask).map_err(|err| {
57                    Error::InvalidBlob(format!("failed to build ndarray from decoded mask: {err}"))
58                })
59            })
60            .transpose()
61    }
62}
63
64#[derive(Debug, Clone, PartialEq)]
65pub struct DecodedBandSet {
66    pub info: BandSetInfo,
67    pub bands: Vec<PixelData>,
68    pub band_masks: Vec<Option<Vec<u8>>>,
69}
70
71impl DecodedBandSet {
72    pub fn into_ndarray<T: BandElement>(self) -> Result<ArrayD<T>> {
73        self.into_ndarray_with_layout(BandLayout::Interleaved)
74    }
75
76    pub fn into_ndarray_with_layout<T: BandElement>(self, layout: BandLayout) -> Result<ArrayD<T>> {
77        let shape = self.info.ndarray_shape_for_layout(layout);
78        let values = self.into_vec_with_layout(layout)?;
79        ArrayD::from_shape_vec(IxDyn(&shape), values).map_err(|err| {
80            Error::InvalidBlob(format!(
81                "failed to build ndarray from decoded band set: {err}"
82            ))
83        })
84    }
85
86    pub fn into_vec_with_layout<T: BandElement>(self, layout: BandLayout) -> Result<Vec<T>> {
87        if self.bands.len() == 1 {
88            return T::from_pixel_data(self.bands.into_iter().next().unwrap());
89        }
90
91        let mut materializer = BandMaterializer::new(
92            self.info.bands[0].pixel_count()?,
93            self.info.depth() as usize,
94            self.info.band_count(),
95            materialize_layout(layout),
96        )
97        .map_err(materialize_error)?;
98        for (band_index, band) in self.bands.into_iter().enumerate() {
99            copy_pixel_data_into_materializer(&mut materializer, band_index, band)?;
100        }
101        materializer.finish().map_err(materialize_error)
102    }
103
104    pub fn copy_into_slice<T: BandElement>(self, layout: BandLayout, out: &mut [T]) -> Result<()> {
105        let pixel_count = self.info.bands[0].pixel_count()?;
106        let depth = self.info.depth() as usize;
107        let band_count = self.info.band_count();
108        let expected_len = self.info.value_count()?;
109        if out.len() != expected_len {
110            return Err(Error::InvalidBlob(format!(
111                "output slice length {} does not match decoded band set length {}",
112                out.len(),
113                expected_len
114            )));
115        }
116
117        for (band_index, band) in self.bands.into_iter().enumerate() {
118            copy_pixel_data_into_layout_slice(
119                out,
120                band_index,
121                pixel_count,
122                depth,
123                band_count,
124                layout,
125                band,
126            )?;
127        }
128        Ok(())
129    }
130
131    pub fn into_band_mask_ndarray(self) -> Result<Option<ArrayD<u8>>> {
132        into_band_mask_ndarray(self.info, self.band_masks)
133    }
134}
135
136pub fn into_band_mask_ndarray(
137    info: BandSetInfo,
138    band_masks: Vec<Option<Vec<u8>>>,
139) -> Result<Option<ArrayD<u8>>> {
140    if band_masks.iter().all(Option::is_none) {
141        return Ok(None);
142    }
143
144    let pixel_count = info.bands[0].pixel_count()?;
145    let band_count = info.band_count();
146    let shape = info.band_mask_ndarray_shape();
147
148    if band_count == 1 {
149        let mask = band_masks
150            .into_iter()
151            .next()
152            .flatten()
153            .map(Ok)
154            .unwrap_or_else(|| default_vec(pixel_count, "decoded band mask"))?;
155        return ArrayD::from_shape_vec(IxDyn(&shape), mask)
156            .map(Some)
157            .map_err(|err| {
158                Error::InvalidBlob(format!("failed to build ndarray from decoded mask: {err}"))
159            });
160    }
161
162    let merged_len = checked_mul(pixel_count, band_count, "decoded band mask length")?;
163    let mut merged = vec_with_capacity(merged_len, "decoded band mask")?;
164    for pixel in 0..pixel_count {
165        for band_mask in &band_masks {
166            merged.push(band_mask.as_ref().map(|mask| mask[pixel]).unwrap_or(1));
167        }
168    }
169
170    ArrayD::from_shape_vec(IxDyn(&shape), merged)
171        .map(Some)
172        .map_err(|err| {
173            Error::InvalidBlob(format!(
174                "failed to build ndarray from decoded band mask: {err}"
175            ))
176        })
177}
178
179trait SupportedElementValue: Copy + 'static + IntoF64 {
180    const KIND: BandElementKind;
181}
182
183macro_rules! match_pixel_data_values {
184    ($band:expr, |$values:ident| $body:expr) => {
185        match $band {
186            PixelData::I8($values) => $body,
187            PixelData::U8($values) => $body,
188            PixelData::I16($values) => $body,
189            PixelData::U16($values) => $body,
190            PixelData::I32($values) => $body,
191            PixelData::U32($values) => $body,
192            PixelData::F32($values) => $body,
193            PixelData::F64($values) => $body,
194        }
195    };
196}
197
198fn copy_pixel_data_into_materializer<T: BandElement>(
199    materializer: &mut BandMaterializer<T>,
200    band_index: usize,
201    band: PixelData,
202) -> Result<()> {
203    match_pixel_data_values!(band, |values| {
204        copy_typed_values_into_materializer(materializer, band_index, &values)
205    })
206}
207
208fn copy_typed_values_into_materializer<T: BandElement, U: SupportedElementValue>(
209    materializer: &mut BandMaterializer<T>,
210    band_index: usize,
211    values: &[U],
212) -> Result<()> {
213    if T::KIND == U::KIND {
214        let typed = unsafe { cast_slice::<U, T>(values) };
215        return materializer
216            .copy_band(band_index, typed)
217            .map_err(materialize_error);
218    }
219    if T::KIND == BandElementKind::F64 {
220        return materializer
221            .copy_band_with(band_index, |index| {
222                unsafe_cast::<T, f64>(values[index].into_f64())
223            })
224            .map_err(materialize_error);
225    }
226    Err(Error::InvalidBlob(format!(
227        "cannot decode {} pixels into ndarray<{}>",
228        data_type_name::<U>(),
229        std::any::type_name::<T>()
230            .rsplit("::")
231            .next()
232            .unwrap_or("unknown"),
233    )))
234}
235
236fn copy_pixel_data_into_layout_slice<T: BandElement>(
237    out: &mut [T],
238    band_index: usize,
239    pixel_count: usize,
240    depth: usize,
241    band_count: usize,
242    layout: BandLayout,
243    band: PixelData,
244) -> Result<()> {
245    match_pixel_data_values!(band, |values| {
246        copy_typed_values_into_layout_slice(
247            out,
248            band_index,
249            pixel_count,
250            depth,
251            band_count,
252            layout,
253            &values,
254        )
255    })
256}
257
258fn copy_typed_values_into_layout_slice<T: BandElement, U: SupportedElementValue>(
259    out: &mut [T],
260    band_index: usize,
261    pixel_count: usize,
262    depth: usize,
263    band_count: usize,
264    layout: BandLayout,
265    values: &[U],
266) -> Result<()> {
267    if T::KIND == U::KIND {
268        let typed = unsafe { cast_slice::<U, T>(values) };
269        return copy_band_values_into_slice(
270            out,
271            typed,
272            pixel_count,
273            depth,
274            band_index,
275            band_count,
276            materialize_layout(layout),
277        )
278        .map_err(materialize_error);
279    }
280    if T::KIND == BandElementKind::F64 {
281        let band_len = pixel_count
282            .checked_mul(depth.max(1))
283            .ok_or_else(|| Error::InvalidBlob("decoded band length overflows usize".into()))?;
284        if values.len() != band_len {
285            return Err(Error::InvalidBlob(
286                "decoded band length does not match its metadata".into(),
287            ));
288        }
289        for (value_index, value) in values.iter().copied().enumerate() {
290            let out_index = match layout {
291                BandLayout::Interleaved => {
292                    if depth <= 1 {
293                        value_index * band_count + band_index
294                    } else {
295                        let pixel = value_index / depth;
296                        let sample = value_index % depth;
297                        (pixel * band_count + band_index) * depth + sample
298                    }
299                }
300                BandLayout::Bsq => band_index * band_len + value_index,
301            };
302            out[out_index] = unsafe_cast::<T, f64>(value.into_f64());
303        }
304        return Ok(());
305    }
306    Err(Error::InvalidBlob(format!(
307        "cannot decode {} pixels into ndarray<{}>",
308        data_type_name::<U>(),
309        std::any::type_name::<T>()
310            .rsplit("::")
311            .next()
312            .unwrap_or("unknown"),
313    )))
314}
315
316unsafe fn cast_slice<U, T>(values: &[U]) -> &[T] {
317    &*(values as *const [U] as *const [T])
318}
319
320fn unsafe_cast<T, U: Copy>(value: U) -> T {
321    unsafe { std::mem::transmute_copy(&value) }
322}
323
324trait IntoF64 {
325    fn into_f64(self) -> f64;
326}
327
328impl IntoF64 for i8 {
329    fn into_f64(self) -> f64 {
330        self as f64
331    }
332}
333impl IntoF64 for u8 {
334    fn into_f64(self) -> f64 {
335        self as f64
336    }
337}
338impl IntoF64 for i16 {
339    fn into_f64(self) -> f64 {
340        self as f64
341    }
342}
343impl IntoF64 for u16 {
344    fn into_f64(self) -> f64 {
345        self as f64
346    }
347}
348impl IntoF64 for i32 {
349    fn into_f64(self) -> f64 {
350        self as f64
351    }
352}
353impl IntoF64 for u32 {
354    fn into_f64(self) -> f64 {
355        self as f64
356    }
357}
358impl IntoF64 for f32 {
359    fn into_f64(self) -> f64 {
360        self as f64
361    }
362}
363impl IntoF64 for f64 {
364    fn into_f64(self) -> f64 {
365        self
366    }
367}
368
369fn data_type_name<T: 'static>() -> &'static str {
370    if TypeId::of::<T>() == TypeId::of::<i8>() {
371        "i8"
372    } else if TypeId::of::<T>() == TypeId::of::<u8>() {
373        "u8"
374    } else if TypeId::of::<T>() == TypeId::of::<i16>() {
375        "i16"
376    } else if TypeId::of::<T>() == TypeId::of::<u16>() {
377        "u16"
378    } else if TypeId::of::<T>() == TypeId::of::<i32>() {
379        "i32"
380    } else if TypeId::of::<T>() == TypeId::of::<u32>() {
381        "u32"
382    } else if TypeId::of::<T>() == TypeId::of::<f32>() {
383        "f32"
384    } else if TypeId::of::<T>() == TypeId::of::<f64>() {
385        "f64"
386    } else {
387        "unknown"
388    }
389}
390
391pub trait NdArrayElement: Sized + Clone {
392    fn from_pixel_data(pixels: PixelData) -> Result<Vec<Self>>;
393}
394
395mod private {
396    pub trait Sealed {}
397
398    impl Sealed for i8 {}
399    impl Sealed for u8 {}
400    impl Sealed for i16 {}
401    impl Sealed for u16 {}
402    impl Sealed for i32 {}
403    impl Sealed for u32 {}
404    impl Sealed for f32 {}
405    impl Sealed for f64 {}
406}
407
408#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
409pub enum BandElementKind {
410    I8,
411    U8,
412    I16,
413    U16,
414    I32,
415    U32,
416    F32,
417    F64,
418}
419
420pub trait BandElement: NdArrayElement + private::Sealed + Copy + Default + 'static {
421    const KIND: BandElementKind;
422}
423
424macro_rules! impl_exact_ndarray_element {
425    ($ty:ty, $variant:ident, $name:literal) => {
426        impl NdArrayElement for $ty {
427            fn from_pixel_data(pixels: PixelData) -> Result<Vec<Self>> {
428                match pixels {
429                    PixelData::$variant(values) => Ok(values),
430                    other => Err(Error::InvalidBlob(format!(
431                        "cannot decode {} pixels into ndarray<{}>",
432                        other.data_type().name(),
433                        $name
434                    ))),
435                }
436            }
437        }
438    };
439}
440
441impl_exact_ndarray_element!(i8, I8, "i8");
442impl_exact_ndarray_element!(u8, U8, "u8");
443impl_exact_ndarray_element!(i16, I16, "i16");
444impl_exact_ndarray_element!(u16, U16, "u16");
445impl_exact_ndarray_element!(i32, I32, "i32");
446impl_exact_ndarray_element!(u32, U32, "u32");
447impl_exact_ndarray_element!(f32, F32, "f32");
448
449impl NdArrayElement for f64 {
450    fn from_pixel_data(pixels: PixelData) -> Result<Vec<Self>> {
451        Ok(pixels.to_f64())
452    }
453}
454
455macro_rules! impl_band_element {
456    ($ty:ty, $kind:ident) => {
457        impl BandElement for $ty {
458            const KIND: BandElementKind = BandElementKind::$kind;
459        }
460
461        impl SupportedElementValue for $ty {
462            const KIND: BandElementKind = BandElementKind::$kind;
463        }
464    };
465}
466
467impl_band_element!(i8, I8);
468impl_band_element!(u8, U8);
469impl_band_element!(i16, I16);
470impl_band_element!(u16, U16);
471impl_band_element!(i32, I32);
472impl_band_element!(u32, U32);
473impl_band_element!(f32, F32);
474impl_band_element!(f64, F64);
475
476fn materialize_layout(layout: BandLayout) -> MaterializeLayout {
477    match layout {
478        BandLayout::Interleaved => MaterializeLayout::Interleaved,
479        BandLayout::Bsq => MaterializeLayout::Bsq,
480    }
481}
482
483fn materialize_error(err: lerc_band_materialize::MaterializeError) -> Error {
484    Error::InvalidBlob(err.to_string())
485}
486
487trait PixelDataExt {
488    fn into_ndarray<T: NdArrayElement>(self, shape: &[usize]) -> Result<ArrayD<T>>;
489}
490
491impl PixelDataExt for PixelData {
492    fn into_ndarray<T: NdArrayElement>(self, shape: &[usize]) -> Result<ArrayD<T>> {
493        ArrayD::from_shape_vec(IxDyn(shape), T::from_pixel_data(self)?).map_err(|err| {
494            Error::InvalidBlob(format!(
495                "failed to build ndarray from decoded pixels: {err}"
496            ))
497        })
498    }
499}