feat!: remove the sample-generic compatibility layer and reach idsp p…

.github/scripts/ci_ffi.sh

@@ -0,0 +1,28 @@
+#!/usr/bin/env bash
+# Build the C ABI and compile/run a C smoke test against the shipped header.
+#
+# `embedded-dsp-ffi` is a standalone workspace (see its Cargo.toml), so it is
+# addressed by manifest path rather than as a root-workspace member, and its
+# artifacts are redirected under the main `target/` directory.
+set -euo pipefail
+
+repo_root="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)"
+cd "$repo_root"
+
+manifest="crates/embedded-dsp-ffi/Cargo.toml"
+export CARGO_TARGET_DIR="${EDS_FFI_TARGET_DIR:-$repo_root/target/ffi}"
+out_dir="$CARGO_TARGET_DIR/debug"
+
+cargo clippy --manifest-path "$manifest" --all-targets -- -D warnings
+cargo build --manifest-path "$manifest"
+
+# The C compiler is the check: the test uses every exported symbol through the
+# public header, so a Rust/header signature drift fails to compile or link.
+cc -std=c11 -Wall -Wextra -Werror -pedantic \
+    crates/embedded-dsp-ffi/tests/c_smoke.c \
+    -I crates/embedded-dsp-ffi/include \
+    -L "$out_dir" -lembedded_dsp_ffi \
+    -Wl,-rpath,"$out_dir" \
+    -lm -o "$out_dir/eds_c_smoke"
+
+"$out_dir/eds_c_smoke"

.github/scripts/ci_fuzz.sh

@@ -0,0 +1,17 @@
+#!/usr/bin/env bash
+# Bounded differential fuzzing of the FIR and biquad kernels.
+#
+# The targets compare the `f32` kernels against in-process `f64` references, so a
+# found input is a real numerical divergence, not just a crash. Bounded so the
+# job stays well under a minute; run longer locally with FUZZ_RUNS.
+set -euo pipefail
+
+repo_root="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)"
+cd "$repo_root/fuzz"
+
+cargo fuzz build
+
+for target in fir_differential biquad_differential; do
+    echo "fuzzing: $target"
+    cargo fuzz run "$target" -- -runs="${FUZZ_RUNS:-20000}" -max_len=4096
+done

.github/scripts/ci_miri.sh

@@ -0,0 +1,26 @@
+#!/usr/bin/env bash
+# Miri undefined-behaviour check.
+#
+# Two unit tests are skipped, for reasons unrelated to this crate:
+#   * `nalgebra_interop` reaches libm's x86 `sqrtss` inline assembly, which Miri
+#     cannot execute ("inline assembly is not supported").
+#   * `compile_time_atan_helpers_and_private_divi` asserts last-bit `atan`
+#     accuracy against the native libm; Miri's float shims are not bit-identical.
+# Everything else (the 67 remaining unit tests) plus the fixed-point and
+# elementwise integration suites run under Miri.
+#
+# Set MIRI_CARGO to a toolchain-qualified cargo (e.g. "cargo +nightly-2026-07-25")
+# to run against a specific nightly locally.
+set -euo pipefail
+
+repo_root="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)"
+cd "$repo_root"
+
+cargo_bin="${MIRI_CARGO:-cargo}"
+export MIRIFLAGS="${MIRIFLAGS:--Zmiri-disable-isolation}"
+
+$cargo_bin miri test -p embedded-dsp --all-features --lib -- \
+    --skip nalgebra_interop \
+    --skip compile_time_atan_helpers_and_private_divi
+$cargo_bin miri test -p embedded-dsp --all-features --test fixed_basic_types
+$cargo_bin miri test -p embedded-dsp --all-features --test basic_math

.github/scripts/ci_python.sh

@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+# Build the PyO3 extension and run the Python smoke test against it.
+set -euo pipefail
+
+repo_root="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)"
+cd "$repo_root"
+
+manifest="crates/embedded-dsp-py/Cargo.toml"
+export CARGO_TARGET_DIR="${EDS_PY_TARGET_DIR:-$repo_root/target/py}"
+
+cargo build --manifest-path "$manifest"
+
+# Import the cdylib under the name the module's init symbol expects.
+stage="$(mktemp -d)"
+cp "$CARGO_TARGET_DIR/debug/libembedded_dsp.so" "$stage/embedded_dsp.so"
+
+PYTHONPATH="$stage" python3 crates/embedded-dsp-py/tests/smoke.py
+
+rm -rf "$stage"

.github/workflows/ci.yml

@@ -140,6 +140,28 @@ jobs:
             echo "::endgroup::"
           done
 
+  hack:
+    name: Feature powerset (cargo-hack)
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v7
+      - uses: dtolnay/rust-toolchain@stable
+      - uses: taiki-e/install-action@cargo-hack
+      - uses: Swatinem/rust-cache@v2
+      # `--features libm` keeps the always-on base (the crate requires `std` or
+      # `libm`), then every feature is checked individually on top of it.
+      - run: cargo hack check -p embedded-dsp --each-feature --no-dev-deps --features libm
+
+  machete:
+    name: Unused dependencies (cargo-machete)
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v7
+      - uses: dtolnay/rust-toolchain@stable
+      - uses: Swatinem/rust-cache@v2
+      - run: cargo install cargo-machete --locked
+      - run: cargo machete
+
   test:
     name: Test
     runs-on: ubuntu-latest
@@ -174,10 +196,51 @@ jobs:
       - uses: Swatinem/rust-cache@v2
       - run: bash .github/scripts/ci_docs.sh
 
+  ffi:
+    name: C ABI
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v7
+      - uses: dtolnay/rust-toolchain@stable
+      - uses: Swatinem/rust-cache@v2
+      - run: bash .github/scripts/ci_ffi.sh
+
+  python:
+    name: Python bindings
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v7
+      - uses: dtolnay/rust-toolchain@stable
+      - uses: actions/setup-python@v6
+        with:
+          python-version: "3.12"
+      - uses: Swatinem/rust-cache@v2
+      - run: bash .github/scripts/ci_python.sh
+
+  miri:
+    name: Miri (UB)
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v7
+      - uses: dtolnay/rust-toolchain@nightly
+        with:
+          components: miri, rust-src
+      - uses: Swatinem/rust-cache@v2
+      - run: bash .github/scripts/ci_miri.sh
+
+  fuzz:
+    name: Fuzz (bounded)
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v7
+      - uses: dtolnay/rust-toolchain@nightly
+      - uses: Swatinem/rust-cache@v2
+      - run: cargo install cargo-fuzz --locked
+      - run: bash .github/scripts/ci_fuzz.sh
+
   publish-dry-run:
     name: Publish dry-run
     runs-on: ubuntu-latest
-    continue-on-error: true
     steps:
       - uses: actions/checkout@v7
       - uses: dtolnay/rust-toolchain@stable

.github/workflows/mutants.yml

@@ -0,0 +1,40 @@
+name: Mutants
+
+# Weekly mutation testing over the always-compiled core. Informational: it runs on
+# a schedule, never on pull requests.
+#
+# `cargo-mutants` discovers modules from the `mod` declarations it can see. This
+# crate declares its feature modules through the `gated_mod!` macro, which it
+# cannot follow, so only `math`, `types`, and `intrinsics` are mutable today;
+# widen `--file` once discovery covers the feature modules.
+
+on:
+  schedule:
+    - cron: "17 5 * * 1" # Mondays, 05:17 UTC
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+jobs:
+  mutants:
+    name: Mutation testing (shard ${{ matrix.shard }})
+    runs-on: ubuntu-latest
+    timeout-minutes: 120
+    strategy:
+      fail-fast: false
+      matrix:
+        shard: ["1/8", "2/8", "3/8", "4/8", "5/8", "6/8", "7/8", "8/8"]
+    steps:
+      - uses: actions/checkout@v7
+      - uses: dtolnay/rust-toolchain@stable
+      - uses: Swatinem/rust-cache@v2
+      - run: cargo install cargo-mutants --locked
+      - name: Mutate
+        run: |
+          cargo mutants -p embedded-dsp \
+            --file crates/embedded-dsp/src/math.rs \
+            --file crates/embedded-dsp/src/types.rs \
+            --file crates/embedded-dsp/src/intrinsics.rs \
+            --shard "${{ matrix.shard }}" \
+            --timeout 120

CHANGELOG.md

@@ -3,10 +3,15 @@
 All notable changes to this project are documented in this file. The format follows
 [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
-## [Unreleased]
+## [0.6.0] - 2026-09-13
 
 ### Added
 
+- **C ABI** (`embedded-dsp-ffi`): a standalone `staticlib`/`cdylib` exposing FIR, Direct Form I biquad cascades, the complex FFT, and the audio-EQ designer to C and C++, with a hand-maintained header and a C smoke test that compiles, links, and runs against it in CI.
+- **Python bindings** (`embedded-dsp-py`): a PyO3 stable-ABI (`abi3-py39`) extension module (`embedded_dsp`) exposing the audio-EQ designer, FIR, and biquad cascades, with maturin wheel metadata.
+- **Verification CI**: a Miri undefined-behaviour job, bounded `cargo-fuzz` differential targets (`fuzz/`, `f32` against in-process `f64`) backed by an always-on randomized differential test, a scheduled sharded `cargo-mutants` run over the always-compiled core, `cargo-hack` per-feature builds, and `cargo-machete`.
+- **Unified audio-EQ builder, `IHo`, and WebAudio export** (`filter_design`): `EqFilter` + `EqShape` + `BiquadType` design every RBJ Audio EQ Cookbook response from one fluent, validating builder — including the `IHo` (integrator-over-harmonic-oscillator) section `idsp` had and this crate lacked — and `WebAudioFilter` mirrors a `BiquadFilterNode`'s `type`/`frequency`/`detune`/`Q`/`gain`. Coefficients are bit-checked against `idsp`'s `iir::coefficients` across all nine response types.
+
 - **RBJ EQ parameter conversions**: `biquad_q_from_bw` and `biquad_q_from_shelf_slope` turn an octave bandwidth or a shelf slope into the `q` the biquad designers take. The bandwidth relation is bilinear-transform corrected, so a band keeps its octave width as the centre approaches Nyquist. Also corrected the `biquad_bandpass_coeffs` doc, which named the wrong variant.
 - **Swept-sine inverse filter**: `Sweep::inverse_filter` deconvolves an exponential sweep in one complex multiply per bin, recovering an impulse response at `t = 0`. Matches `idsp` 0.22.1.
 - **Hyperbolic CORDIC**: `cordic_sqrt_atanh2_q31` and `cordic_atanh_q31` add the hyperbolic vectoring mode, within ~`6e-9` of `f64` across the representable domain. The `cosh`/`sinh` rotation and the linear modes are deliberately not ported; see the README note.
@@ -39,6 +44,25 @@ All notable changes to this project are documented in this file. The format foll
 - **LMS/NLMS and the recursive moving average are generic over `DspSample`**: `LmsInstance`/`NlmsInstance` (built on `AdaptiveSample`) and `RecursiveMovingAverage<T, N>` replace four width twins, again keeping the old names as aliases/wrappers. The q15 paths are bit-exact with the kernels they replace; `RecursiveMovingAverage::<N>` becomes `RecursiveMovingAverage::<f32, N>`.
 - **One composition vocabulary (`pipeline`)**: `Process`/`Inplace` are now blanket-derived from `SplitProcess`/`SplitInplace` — a stateless stage implements `SplitProcess<X, Y, ()>` once and inherits `Process` (and, through the second blanket, `DspNode`) — so `Split`, `Chain`, `Gain`, `Limiter`, `Offset`, `Identity`, `Buffer`, `SinglePoleFilter<T>`, `PidInstanceF32/Q15`, and `DcBlockerQ15` lost their hand-written bridges. The split vocabulary's receivers became `&mut self` and its methods were renamed to keep method resolution unambiguous: `SplitProcess::process`/`block` → `process_with_state`/`block_with_state`, `SplitInplace::inplace` → `inplace_with_state`, `SplitViewProcess::process_view` → `process_view_with_state`, `SplitViewInplace::inplace_view` → `inplace_view_with_state`. `DspNode::process_block`'s shorter-buffer clamp and the specialised `Buffer`/`ChunkInOut` block/in-place paths are preserved.
 
+### Removed
+
+- **The duplicate `filtering::Dsm` and `filtering::XorShift32` are gone.** They shadowed the dedicated `dsm::Dsm` / `dither::XorShift32` modules, so only one of each could be re-exported at the crate root. The dedicated modules are now the single implementation, re-exported at the crate root as before, and `filtering` re-exports neither name. `dsm::Dsm` is `Default` + `process()` + `reset()` — the historical `new()`/`process_sample()` names are deliberately **not** carried over. `dither::XorShift32` gains the `next_f32()` / `tpdf_dither_f32()` helpers that only the removed duplicate had.
+
+- **The sample-genericization compatibility layer is removed.** The width-suffixed instance aliases (`FirInstanceF32/Q31/Q15`, `BiquadCascadeInstanceF32/Q15/Q31`, `BiquadCascadeDf2tInstanceF32/Q15/Q31`, `LmsInstanceF32/Q15`, `NlmsInstanceF32/Q15`, `PidInstanceF32/Q31/Q15`, `HilbertTransformF32/Q15`, `RecursiveMovingAverageQ15`) and their thin width wrappers (`fir_f32/q31/q15`, `biquad_cascade_df1_*`, `biquad_cascade_df2t_*`, `lms_*`, `lms_leaky_*`, `nlms_*`, `pid_f32/q31/q15`) are gone. Call the generic API directly instead: `FirInstance<f32>`, `BiquadCascadeInstance<q15>`, `LmsInstance<f32>`, `HilbertTransform<'_, f32>`, `RecursiveMovingAverage<q15, N>`, and the free functions `fir` / `biquad_cascade_df1` / `biquad_cascade_df2t` / `lms` / `lms_leaky` / `nlms`; PID updates are `PidInstance::<T>::process`.
+
+### Changed
+
+- **`filtering` is split into family submodules** (`fir`, `biquad`, `convolution`, `adaptive`, `recursive`, `lockin`, `int_filters`, `normal_form`, `wdf`) behind a re-exporting facade; `embedded_dsp::filtering::*` and the crate-root glob are unchanged. The integration-test suite is likewise consolidated from 46 files into 36 domain-named files, with every test and its `required-features` preserved.
+- **docs.rs shows feature-gate badges** for every module (`#[cfg_attr(docsrs, doc(cfg(...)))]`).
+
+## [0.5.1] - 2026-09-06
+
+### Changed
+
+- **The `fixed` dependency is now optional**, pulled in only by the fixed-point features; default builds no longer compile it.
+- **Dependency bumps**: `defmt` 0.3 → 1.1, plus Dependabot action updates.
+- **CI**: Codecov coverage, a `cargo-deny` audit, Dependabot, and a release workflow.
+
 ## [0.5.0] - 2026-09-01
 
 ### Added

COOKBOOK.md

@@ -22,8 +22,8 @@ Execute high-frequency (20–50 kHz) current loop control in pure Q15 or floatin
 use embedded_dsp::*;
 
 // Setup controller states
-let mut id_pid = PidInstanceQ15::new(8000, 2000, 0);   // D-axis flux PID
-let mut iq_pid = PidInstanceQ15::new(12000, 3000, 0);  // Q-axis torque PID
+let mut id_pid = PidInstance::<q15>::new(8000, 2000, 0);   // D-axis flux PID
+let mut iq_pid = PidInstance::<q15>::new(12000, 3000, 0);  // Q-axis torque PID
 
 // ADC current measurements (Phase A, B, C) in Q15 format
 let i_a: q15 = 12000;
@@ -46,8 +46,8 @@ park_q15(i_alpha, i_beta, sin_theta, cos_theta, &mut i_d, &mut i_q);
 // 4. Current Loop PID Regulators
 let target_i_d: q15 = 0;      // Zero d-axis current (maximum torque per ampere)
 let target_i_q: q15 = 15000;  // Commanded torque
-let v_d = pid_q15(&mut id_pid, target_i_d.saturating_sub(i_d));
-let v_q = pid_q15(&mut iq_pid, target_i_q.saturating_sub(i_q));
+let v_d = id_pid.process(target_i_d.saturating_sub(i_d));
+let v_q = iq_pid.process(target_i_q.saturating_sub(i_q));
 
 // 5. Inverse Park Transform (rotating dq -> stationary αβ voltage commands)
 let mut v_alpha: q15 = 0;
@@ -77,15 +77,15 @@ let post_shift = biquad_quantize_and_scale_q15(
 
 // 3. Initialise DMA block processor
 let mut biquad_state = [0i16; 4];
-let mut biquad = BiquadCascadeInstanceQ15::init(1, &q15_coeffs, &mut biquad_state, post_shift);
+let mut biquad = BiquadCascadeInstance::<q15>::with_post_shift(1, &q15_coeffs, &mut biquad_state, post_shift);
 let mut dc_blocker = DcBlockerQ15::new(32112); // R ≈ 0.98
 
 // In DMA callback / audio loop
 fn process_dma_buffer(
     dma_rx: &[q15],
     dma_tx: &mut [q15],
     dc_blocker: &mut DcBlockerQ15,
-    biquad: &mut BiquadCascadeInstanceQ15,
+    biquad: &mut BiquadCascadeInstance<'_, q15>,
 ) {
     let mut temp = [0i16; 64];
     let len = dma_rx.len().min(temp.len());
@@ -96,7 +96,7 @@ fn process_dma_buffer(
     }
 
     // Step B: Biquad Filtering
-    biquad_cascade_df1_q15(biquad, &temp[..len], &mut dma_tx[..len]);
+    biquad_cascade_df1(biquad, &temp[..len], &mut dma_tx[..len]);
 }
 ```
 

Cargo.toml

@@ -4,9 +4,13 @@ members = [
     "crates/embedded-dsp",
     "crates/embedded-dsp-studio",
 ]
+# Standalone link targets, built by their own CI jobs and kept out of
+# `--workspace` builds: `fuzz` needs a nightly toolchain, and the C ABI must not
+# inherit `embedded-dsp`'s `defmt` feature into its cdylib link.
+exclude = ["fuzz", "crates/embedded-dsp-ffi"]
 
 [workspace.package]
-version = "0.5.1"
+version = "0.6.0"
 edition = "2024"
 rust-version = "1.93"
 authors = ["Gerzain Mata <leftger@gmail.com>"]
@@ -16,6 +20,11 @@ readme = "README.md"
 
 [workspace.lints.rust]
 unsafe_code = "deny"
+# `docsrs` is set by `[package.metadata.docs.rs].rustdoc-args` (see the crate
+# manifest) so `#[cfg_attr(docsrs, doc(cfg(...)))]` adds feature-gate badges on
+# docs.rs only. Declaring the custom cfg keeps `unexpected_cfgs` quiet under
+# `-D warnings` on stable, where the cfg is never set.
+unexpected_cfgs = { level = "warn", check-cfg = ["cfg(docsrs)"] }
 
 [workspace.lints.clippy]
 # The DSP kernels are written as index loops over parallel arrays; many index
@@ -25,7 +34,7 @@ unsafe_code = "deny"
 needless_range_loop = "allow"
 
 [workspace.dependencies]
-embedded-dsp = { path = "crates/embedded-dsp", version = "0.5.1", default-features = false }
+embedded-dsp = { path = "crates/embedded-dsp", version = "0.6.0", default-features = false }
 fixed = { version = "1.31.0", default-features = false }
 libm = { version = "0.2.11" }
 defmt = { version = "1.1", default-features = false }