waveforms.py

"""
Copyright (c) 2026 Peter Robinson

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This file contains a collection of generator factories that yield floats for cyclic functions.
They are all uses of gb.WaveGeneratorFactory

Example:
    Generate a sine wave for 10 steps:
    
    >>> sine = sine_wave_factory(10)
    >>> values = list(sine())
    >>> print(len(values))  # Will be 8 (rounded to multiple of 4)
    8
"""
import generator_builder as gb
import math



TWO_PI = 2 * math.pi  # Constant for 2π to avoid recalculation

def sine_function(x: float) -> float:
    """Sine wave function mapping [0, 1] to [0, 1].
    
    Generates one complete sine wave cycle that oscillates between 0 and 1.
    
    Args:
        x: Input value in [0, 1] representing position in the cycle.
        
    Returns:
        Output value in [0, 1] representing the sine wave at that position.
        
    Example:
        >>> sine_function(0.0)  # Start of cycle
        0.5
        >>> sine_function(0.25)  # Quarter cycle
        1.0
        >>> sine_function(0.5)   # Half cycle
        0.5
    """
    return (math.sin(TWO_PI * x) + 1) / 2

def square_wave_function(x: float) -> float:
    """Square wave function mapping [0, 1] to [0, 1].
    
    Generates a square wave that is 1.0 for the first half of the cycle
    and 0.0 for the second half.
    
    Args:
        x: Input value in [0, 1] representing position in the cycle.
        
    Returns:
        1.0 if x < 0.5, otherwise 0.0.
        
    Example:
        >>> square_wave_function(0.25)
        1.0
        >>> square_wave_function(0.75)
        0.0
    """
    return 1.0 if x < 0.5 else 0.0

def sawtooth_wave_function(x: float) -> float:
    """Sawtooth wave function mapping [0, 1] to [0, 1].
    
    Generates a sawtooth wave that is similar to the sine function but using line segments instead.
    
    Args:
        x: Input value in [0, 1] representing position in the cycle.
        
    Returns:
        Output value in [0, 1] representing the sawtooth wave at that position.
        
    Example:
        >>> sawtooth_wave_function(0.125)  # First quarter ramp up
        0.75
        >>> sawtooth_wave_function(0.25)   # Peak
        1.0
        >>> sawtooth_wave_function(0.5)    # Midpoint ramp down
        0.5
        >>> sawtooth_wave_function(0.75)   # Trough
        0.0
        >>> sawtooth_wave_function(0.875)  # Last quarter ramp down
        0.25
    """
    if x < 0.25:
        return 0.5 + 2 * x
    elif x < 0.75:
        return  1.5 - 2*x   # simplifying 1.0 - 2 * (x - 0.25)
    else:
        return 2 * (x - 0.75)
    

def sine_wave_factory(*args, **kwargs) -> gb.GeneratorFactory[float]:
    """Function to create a sine wave generator factory.
    
    Provides a convenient way to create a highly configurable instance of WaveGeneratorFactory configured for 
    sine waveforms.
           
    Returns:
        A GeneratorFactory that yields sine wave values in [0, 1].
        
    Example:
        >>> sine = sine_wave_factory(16)
        >>> values = list(sine())
        >>> len(values)
        16
        >>> print([round(v, 2) for v in values])
        [0.5, 0.69, 0.85, 0.96, 1.0, 0.96, 0.85, 0.69, 0.5, 0.31, 0.15, 0.04, 0.0, 0.04, 0.15, 0.31]
    """
    return gb.WaveGeneratorFactory(sine_function, *args, **kwargs)

def square_wave_factory(*args, **kwargs) -> gb.GeneratorFactory[float]:
    """Factory function to create a square wave generator.
    
    Provides a convenient way to create a highly configurable instance of WaveGeneratorFactory  configured for 
    square waveforms.
    
    
    Returns:
        A GeneratorFactory that yields square wave values (0.0 or 1.0).
        
    Example:
        >>> square = square_wave_factory(8)
        >>> values = list(square())
        >>> print(values)
        [1.0, 1.0, 1.0, 1.0, 0.0, 0.0, 0.0, 0.0]
    """
    return gb.WaveGeneratorFactory(square_wave_function, *args, **kwargs)

def sawtooth_wave_factory(*args, **kwargs) -> gb.GeneratorFactory[float]:
    """Factory function to create a sawtooth wave generator.
    
    Provides a convenient way to create a highly configurable instance of WaveGeneratorFactory configured for 
    sawtooth waveforms.
    
    Returns:
        A GeneratorFactory that yields sawtooth wave values in [0, 1].
        
    Example:
        >>> sawtooth = sawtooth_wave_factory(12)
        >>> values = list(sawtooth())
        >>> print([round(v, 2) for v in values])
        [0.5, 0.67, 0.83, 1.0, 0.83, 0.67, 0.5, 0.33, 0.17, 0.0, 0.17, 0.33]
    """
    return gb.WaveGeneratorFactory(sawtooth_wave_function, *args, **kwargs)

if __name__ == "__main__":
    print("Testing float generators...")
    
    print("\n1. Testing sine wave:")
    sine_gen = sine_wave_factory(steps=10, repeats=1)  # (10//4)*4 = 8 steps
    values = list(sine_gen())
    print(f"Sine wave (8 steps): {[round(v, 2) for v in values]}")
    assert len(values) == 8
    assert all(0.0 <= v <= 1.0 for v in values)

    print('\n2. Testing sine wave with step range:')
    sine_rand = sine_wave_factory(steps=(4,16), repeats=1)
    values = list(sine_rand())
    print(f'Sine wave output: {[round(v, 2) for v in values]}')
    assert 4 <= len(values) <= 16
    assert all(0.0 <= v <= 1.0 for v in values)
    
    print("\n3. Testing sawtooth wave:")
    sawtooth_gen = sawtooth_wave_factory(10, repeats=1) # (10//4)*4 = 8 steps
    values = list(sawtooth_gen())
    print(f"Sawtooth wave output: {[round(v, 2) for v in values]}")
    assert len(values) == 8
    assert all(0.0 <= v <= 1.0 for v in values)
    
    print('\n4. Testing sawtooth wave with step range:')
    sawtooth_rand = sawtooth_wave_factory(steps=(8,16), repeats=1)
    values = list(sawtooth_rand())
    print(f'Sawtooth wave output: {[round(v, 2) for v in values]}')
    assert 8 <= len(values) <= 16
    assert all(0.0 <= v <= 1.0 for v in values) 

    print("\n5. Testing square wave:")
    square_gen = square_wave_factory(steps=10, repeats=1) # (10//4)*4 = 8 steps
    values = list(square_gen())
    print(f"Square wave output: {values}")
    assert len(values) == 8
    assert all(v in [0.0, 1.0] for v in values)
    high_count = sum(1 for v in values if v == 1.0)
    low_count = sum(1 for v in values if v == 0.0)
    assert high_count == low_count
    
    print('\n6. Testing square wave with step range:')
    square_rand = square_wave_factory(steps=(4,12), repeats=1)
    values = list(square_rand())
    print(f'Square wave output: {values}')
    assert 4 <= len(values) <= 12
    assert all(v in [0.0, 1.0] for v in values)
    high_count = sum(1 for v in values if v == 1.0)
    low_count = sum(1 for v in values if v == 0.0)
    assert high_count == low_count

    print("\n7. Testing Constant:")
    const_gen = gb.Constant(0.5)
    values = [next(const_gen()) for _ in range(5)]
    print(f"Constant (0.5): {values}")
    assert all(v == 0.5 for v in values)
    
    print("\n8. Testing Constant:")
    const_for_gen = gb.Constant(0.75, 5)
    values = list(const_for_gen())
    print(f"Constant (0.75, 5 steps): {values}")
    assert len(values) == 5
    assert all(v == 0.75 for v in values)
    
    print("\n9. Testing value ranges:")
    generators = [
        ("Sine wave", sine_wave_factory(100, repeats=1)),
        ("Sawtooth wave", sawtooth_wave_factory(100, repeats=1)),
        ("Square wave", square_wave_factory(100, repeats=1)),
        ("Constant", gb.Constant(0.3)),
        ("ConstantFor", gb.Constant(0.7, 100))
    ]
    
    for name, gen_builder in generators:
        gen = gen_builder()
        limit = 100
        for i, value in enumerate(gen):
            if i >= limit:
                break
            assert 0.0 <= value <= 1.0, f"{name} produced value {value} outside [0,1]"
        print(f"{name}: All values in [0,1]")
    
    print("\n10. Testing sine wave with offset:")
    sine_offset_gen = sine_wave_factory(8, offset=0.75, repeats=1)
    values = list(sine_offset_gen())
    print(f"Sine wave (8 steps, offset=0.75): {[round(v, 2) for v in values]}")
    assert len(values) == 8
    assert all(0.0 <= v <= 1.0 for v in values)
    
    print('\n11. Testing sawtooth wave with offset:')
    sawtooth_offset_gen = sawtooth_wave_factory(8, offset=0.5, repeats=1)
    values = list(sawtooth_offset_gen())
    print(f'Sawtooth wave (8 steps, offset=0.5): {[round(v, 2) for v in values]}')
    assert len(values) == 8
    assert all(0.0 <= v <= 1.0 for v in values)
    
    print("\n12. Testing square wave with offset:")
    square_offset_gen = square_wave_factory(8, offset=0.75, repeats=1)
    values = list(square_offset_gen())
    print(f"Square wave (8 steps, offset=0.75): {values}")
    assert len(values) == 8
    assert all(v in [0.0, 1.0] for v in values)
    
    print("\n13. Testing offset produces different values than non-offset:")
    sine_no_offset = list(sine_wave_factory(8, repeats=1)())
    sine_with_offset = list(sine_wave_factory(8, offset=0.5, repeats=1)())
    assert sine_no_offset != sine_with_offset, "Offset should produce different values"
    print("Offset successfully produces different wave values")
    
    print("\nAll tests completed!")