//! TRACES: FR-MRG-1 | FR-MRG-10
//! Panorama geometry — from several frames to the rotations that relate
//! them, and the projections that lay them out.
//!
//! This is the CPU half of a merge (FR-MRG-10): keypoints, matching, the
//! rotation solve and the choice of output surface. The per-pixel half —
//! rendering, warping, seams, blending — is the GPU's and lives in
//! `dr-gpu`, driven from above; nothing here touches a full-resolution
//! pixel. The split is the whole design (panorama.md §4): everything in
//! this crate is bounded by the number of frames, not the size of the
//! composite, and runs on proxies.
//!
//! # Layout
//!
//! - [`image`] — the grayscale proxy a detector reads: oriented, resampled.
//! - [`features`] — keypoints with descriptors, and the XFeat decoder.
//! - [`xfeat`] — the network under tract (feature `xfeat`).
//! - [`matching`] — mutual nearest neighbours.
//! - [`homography`] — a robust pairwise homography, the focal length read
//!   off it, and the rotation it implies.
//! - [`bundle`] — every rotation and the focal length refined together.
//! - [`align`] — the whole thing, from features to cameras, honest about
//!   what it could not place.
//! - [`projection`] — perspective, cylindrical, spherical.
//! - [`seam`] — which frame each output pixel is taken from.
//! - [`linalg`] — the small dense algebra all of it uses.
//!
//! # What it depends on
//!
//! Nothing, without the `xfeat` feature: the geometry is pure Rust with
//! hand-rolled linear algebra (`linalg` says why) so that it tests without
//! a model, a GPU or a device, on synthetic sets whose answer is known
//! exactly. With the feature it adds the same `ort`-over-tract runtime the
//! rest of the application already carries.

pub mod align;
pub mod bundle;
pub mod features;
pub mod fill;
pub mod homography;
pub mod image;
pub mod linalg;
pub mod matching;
#[cfg(feature = "xfeat")]
pub mod migan;
pub mod projection;
pub mod seam;
#[cfg(feature = "xfeat")]
pub mod xfeat;

pub use align::{align, match_pairs, solve, AlignOptions, Alignment, Link, Pairs, Unaligned};
pub use bundle::Cameras;
pub use features::{Features, Keypoint};
pub use fill::{fill_border, Inpainter, Observer, Params as FillParams};
pub use image::Gray;
pub use projection::Projection;
pub use seam::{SeamMap, SeamOptions};

#[derive(Debug, thiserror::Error)]
pub enum PanoError {
    #[error("bad input: {0}")]
    Input(String),
    #[error("geometry: {0}")]
    Geometry(String),
    #[error("model: {0}")]
    Model(String),
    #[error("could not read the model: {0}")]
    ModelRead(#[source] std::io::Error),
    #[cfg(feature = "xfeat")]
    #[error("inference: {0}")]
    Inference(#[source] ort::Error),
}

#[cfg(feature = "xfeat")]
impl From<ort::Error> for PanoError {
    fn from(e: ort::Error) -> Self {
        PanoError::Inference(e)
    }
}

#[cfg(feature = "xfeat")]
impl From<dr_inference_engine::Error> for PanoError {
    fn from(e: dr_inference_engine::Error) -> Self {
        match e {
            dr_inference_engine::Error::Inference(e) => PanoError::Inference(e),
            dr_inference_engine::Error::Io(e) => PanoError::ModelRead(e),
        }
    }
}