Livt.Signal

src/window/WindowQ15.lvt

namespace Livt.Signal.Window

using Livt.Signal.Stream

/**
 * Arbitrary fixed-coefficient Q1.15 window with one result per sample.
 */
component WindowQ15<SAMPLES: int>
{
	static assert SAMPLES > 0, "window length must be positive"

	// Published throughput, latency, capacity, and resource contract.
	public const INITIATION_INTERVAL: int = 1
	public const NOMINAL_LATENCY: int = 2
	public const CAPACITY: int = 2
	public const MULTIPLIER_COUNT: int = 1

	// Borrowed streams, retained coefficient table, and the owned datapath.
	inputStream: IQ15SampleStream
	outputStream: IQ15SampleStream
	coefficients: int[SAMPLES]
	primitive: WindowQ15PipelinePrimitive

	/**
	 * Binds borrowed endpoints and exactly SAMPLES fixed Q1.15 coefficients.
	 */
	new(inputStream: IQ15SampleStream, outputStream: flip IQ15SampleStream,
		coefficients: const int[SAMPLES])
	{
		this.inputStream = inputStream
		this.outputStream = outputStream
		this.coefficients = coefficients
		primitive = new WindowQ15PipelinePrimitive(this.coefficients)
	}

	/**
	 * Connects the fixed coefficient-table primitive to the borrowed endpoints.
	 */
	process Drive[]()
	{
		primitive.inputValid = inputStream.valid
		primitive.inputSample = inputStream.sample
		primitive.inputFirst = inputStream.first
		primitive.inputLast = inputStream.last
		primitive.outputReady = outputStream.ready
		inputStream.ready = primitive.inputReady
		outputStream.valid = primitive.outputValid
		outputStream.sample = primitive.outputSample
		outputStream.first = primitive.outputFirst
		outputStream.last = primitive.outputLast
	}
}