clifford 0.3.0

Geometric Algebra (Clifford Algebra) for Rust: rotors, motors, PGA for 3D rotations and rigid transforms
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

//! Error types for PGA conversions and constraint violations.
//!
//! This module provides error types used when:
//! - Converting between clifford PGA types and nalgebra types
//! - Constructing PGA types that must satisfy geometric constraints

use thiserror::Error;

/// Error type for point conversions to nalgebra types.
///
/// This error occurs when trying to convert a PGA point to a nalgebra point,
/// but the conversion cannot succeed because the PGA point is at infinity.
#[cfg(any(
    feature = "nalgebra-0_32",
    feature = "nalgebra-0_33",
    feature = "nalgebra-0_34"
))]
#[derive(Clone, Copy, Debug, PartialEq, Eq, Error)]
pub enum PointConversionError {
    /// The point is at infinity (homogeneous weight ≈ 0).
    ///
    /// Ideal points (points at infinity) cannot be represented as
    /// nalgebra `Point2` or `Point3` types, which require finite coordinates.
    #[error("point is at infinity (w ≈ 0)")]
    PointAtInfinity,
}

/// Error type for motor constraint violations.
///
/// Motors must satisfy the geometric constraint to represent valid rigid transformations.
/// See: <https://rigidgeometricalgebra.org/wiki/index.php?title=Geometric_constraint>
#[derive(Clone, Copy, Debug, PartialEq, Eq, Error)]
pub enum MotorConstraintError {
    /// Motor violates the geometric constraint.
    ///
    /// The geometric constraint requires: `s·e₀₁₂₃ + e₂₃·e₀₁ + e₃₁·e₀₂ + e₁₂·e₀₃ = 0`
    ///
    /// This ensures the motor represents a proper rigid transformation (rotation + translation).
    #[error("motor violates geometric constraint: s·e₀₁₂₃ ≠ -v·m")]
    GeometricConstraintViolation,

    /// Motor has zero weight norm (degenerate).
    ///
    /// The weight norm `s² + e₂₃² + e₃₁² + e₁₂²` must be non-zero for a valid motor.
    #[error("motor has zero weight norm")]
    ZeroWeightNorm,
}

/// Error type for line constraint violations.
///
/// Lines in 3D PGA must satisfy the Plücker condition to represent valid geometric lines.
/// See: <https://rigidgeometricalgebra.org/wiki/index.php?title=Geometric_constraint>
#[derive(Clone, Copy, Debug, PartialEq, Eq, Error)]
pub enum LineConstraintError {
    /// Line violates the Plücker condition.
    ///
    /// The Plücker condition requires: `direction · moment = 0`
    /// i.e., `e₀₁·e₂₃ + e₀₂·e₃₁ + e₀₃·e₁₂ = 0`
    ///
    /// This ensures the line components describe a valid line in 3D space.
    #[error("line violates Plücker condition: direction·moment ≠ 0")]
    PluckerConditionViolation,

    /// Line has zero direction (degenerate).
    ///
    /// The direction `(e₀₁, e₀₂, e₀₃)` must be non-zero for a valid line.
    #[error("line has zero direction")]
    ZeroDirection,
}