SVG Path Processing

def normalise_svg_path(attr):
    """
    Normalize SVG path data by adding operation codes.
    
    Converts SVG path strings into structured list format with explicit
    operation codes for multi-argument parameters and fixes consecutive
    M/m operators to M/m + L/l sequences.
    
    Parameters:
    - attr: str - SVG path data string (e.g., "M 10 20, M 20 20, L 30 40, Z")
    
    Returns:
    list: Normalized path operations and coordinates
        Example: ['M', [10, 20], 'L', [20, 20], 'L', [30, 40], 'Z', []]
    """

from svglib.utils import normalise_svg_path

# Normalize complex path data
path_data = "M 10 20, M 20 20, L 30 40, 40 40, Z"
normalized = normalise_svg_path(path_data)
# Returns: ['M', [10, 20], 'L', [20, 20], 'L', [30, 40], 'L', [40, 40], 'Z', []]

# Handle path with curves
curve_path = "M 0 0 C 10 10, 20 10, 30 0"
normalized_curve = normalise_svg_path(curve_path)

def split_floats(op, min_num, value):
    """
    Split string of numbers into float list with SVG path operations.
    
    Converts coordinate strings to float arrays and inserts appropriate
    operation codes for multi-coordinate sequences.
    
    Parameters:
    - op: str - SVG path operation ('m', 'M', 'l', 'L', etc.)
    - min_num: int - Minimum number of coordinates per operation
    - value: str - String containing coordinate values
    
    Returns:
    list: Operation codes and coordinate arrays
        Example: ['m', [10.0, 20.0], 'l', [30.0, 40.0]]
    """

def split_arc_values(op, value):
    """
    Parse SVG arc command values.
    
    Handles the complex arc parameter format with rx, ry, rotation,
    large-arc-flag, sweep-flag, and endpoint coordinates.
    
    Parameters:
    - op: str - Arc operation ('A' or 'a')
    - value: str - Arc parameter string
    
    Returns:
    list: Arc operations with parsed parameters
    """

def convert_quadratic_to_cubic_path(q0, q1, q2):
    """
    Convert quadratic Bezier curve to cubic Bezier curve.
    
    ReportLab only supports cubic Bezier curves, so this function converts
    SVG quadratic curves (Q commands) to cubic format (C commands).
    
    Parameters:
    - q0: tuple - Start point (x, y)
    - q1: tuple - Control point (x, y)
    - q2: tuple - End point (x, y)
    
    Returns:
    tuple: Four control points for cubic curve (c0, c1, c2, c3)
    """

from svglib.utils import convert_quadratic_to_cubic_path

# Convert quadratic to cubic
start = (0, 0)
control = (50, 100)
end = (100, 0)

cubic_points = convert_quadratic_to_cubic_path(start, control, end)
c0, c1, c2, c3 = cubic_points
# c0 = (0, 0), c1 ≈ (33.33, 66.67), c2 ≈ (66.67, 66.67), c3 = (100, 0)

def vector_angle(u, v):
    """
    Calculate angle between two vectors.
    
    Used in arc processing to determine sweep angles and orientations.
    
    Parameters:
    - u: tuple - First vector (x, y)
    - v: tuple - Second vector (x, y)
    
    Returns:
    float: Angle between vectors in degrees
    """

def end_point_to_center_parameters(x1, y1, x2, y2, fA, fS, rx, ry, phi=0):
    """
    Convert SVG arc endpoint parameters to center parameters.
    
    SVG uses endpoint parameterization for arcs, but mathematical processing
    often requires center parameterization. This function performs the conversion.
    
    Parameters:
    - x1, y1: float - Start point coordinates
    - x2, y2: float - End point coordinates
    - fA: int - Large arc flag (0 or 1)
    - fS: int - Sweep flag (0 or 1)
    - rx, ry: float - Ellipse radii
    - phi: float - Rotation angle in degrees
    
    Returns:
    tuple: (cx, cy, start_angle, sweep_angle) - Center and angle parameters
    """

def bezier_arc_from_centre(cx, cy, rx, ry, start_ang=0, extent=90):
    """
    Generate Bezier curves approximating an elliptical arc from center parameters.
    
    Converts arc specifications to series of cubic Bezier curves that
    ReportLab can render accurately.
    
    Parameters:
    - cx, cy: float - Arc center coordinates
    - rx, ry: float - Ellipse radii
    - start_ang: float - Start angle in degrees
    - extent: float - Arc extent in degrees
    
    Returns:
    list: List of cubic Bezier curve control points
    """

def bezier_arc_from_end_points(x1, y1, rx, ry, phi, fA, fS, x2, y2):
    """
    Generate Bezier curves for SVG arc from endpoint parameters.
    
    High-level function that combines endpoint-to-center conversion with
    Bezier arc generation for direct SVG arc processing.
    
    Parameters:
    - x1, y1: float - Start point coordinates
    - rx, ry: float - Ellipse radii
    - phi: float - Rotation angle in degrees
    - fA: int - Large arc flag (0 or 1)
    - fS: int - Sweep flag (0 or 1)
    - x2, y2: float - End point coordinates
    
    Returns:
    list: List of cubic Bezier curve control points
    """

from svglib.utils import bezier_arc_from_centre, bezier_arc_from_end_points

# Generate arc from center parameters
curves = bezier_arc_from_centre(
    cx=50, cy=50,  # Center
    rx=30, ry=20,  # Radii
    start_ang=0, extent=90  # Quarter circle
)

# Generate arc from SVG endpoint format
curves = bezier_arc_from_end_points(
    x1=0, y1=50,     # Start point
    rx=30, ry=20,    # Radii
    phi=0,           # No rotation
    fA=0, fS=1,      # Small arc, positive sweep
    x2=50, y2=0      # End point
)