pxdct 0.2.4

Discrete cosine transform
Documentation
/*
 * // Copyright (c) Radzivon Bartoshyk 11/2025. All rights reserved.
 * //
 * // Redistribution and use in source and binary forms, with or without modification,
 * // are permitted provided that the following conditions are met:
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 * // 1.  Redistributions of source code must retain the above copyright notice, this
 * // list of conditions and the following disclaimer.
 * //
 * // 2.  Redistributions in binary form must reproduce the above copyright notice,
 * // this list of conditions and the following disclaimer in the documentation
 * // and/or other materials provided with the distribution.
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 * // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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use std::error::Error;
use std::fmt::{Display, Formatter};

#[derive(Debug)]
pub enum PxdctError {
    OutOfMemory(usize),
    CantCreateUnderlyingFft(String),
    InvalidSizeMultiplier(usize, usize),
    FftError(String),
    ZeroSizedDct,
    ScratchBufferIsTooSmall(usize, usize),
}

impl Error for PxdctError {}

impl Display for PxdctError {
    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
        match self {
            PxdctError::CantCreateUnderlyingFft(s) => f.write_str(s),
            PxdctError::OutOfMemory(length) => {
                f.write_fmt(format_args!("Cannot allocate {length} bytes to vector",))
            }
            PxdctError::InvalidSizeMultiplier(s0, s1) => f.write_fmt(format_args!(
                "Size {s0} is assumed to be multiplier of {s1} to execute many DFT, but it wasn't"
            )),
            PxdctError::FftError(s) => f.write_fmt(format_args!("Underlying fft error {s}")),
            PxdctError::ZeroSizedDct => f.write_str("Zero sized DCT is not allowed"),
            PxdctError::ScratchBufferIsTooSmall(a, b) => f.write_fmt(format_args!(
                "Scratch is expected to be at least {a} bytes, but was {b}"
            )),
        }
    }
}