Input Handling

Input handling in PurrDiction centers around the generic PredictedIdentity<INPUT, STATE> base class. Implement GetFinalInput(ref INPUT input) to gather per‑frame input, and optionally UpdateInput(ref INPUT input) to cache edge‑triggered inputs (e.g., key down) from Unity’s frame loop.

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Key Concepts

• INPUT must be a struct implementing IPredictedData.

• Implement protected virtual void GetFinalInput(ref INPUT input) to populate inputs deterministically each tick.

• Use protected virtual void UpdateInput(ref INPUT input) inside Unity’s frame loop to accumulate one‑shot inputs.

• Use protected virtual void SanitizeInput(ref INPUT input) to clamp or normalize values for determinism.

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Basic Example

public struct SimpleWASDInput : IPredictedData {
    public NormalizedFloat horizontal;
    public NormalizedFloat vertical;
    public bool jump;
    public bool dash;
    public void Dispose() {}
}

public class SimpleCC : PredictedIdentity<SimpleWASDInput, SimpleCCState>
{
    protected override void GetFinalInput(ref SimpleWASDInput input)
    {
        input.horizontal = Input.GetAxisRaw("Horizontal");
        input.vertical   = Input.GetAxisRaw("Vertical");
        input.dash       = Input.GetKey(KeyCode.LeftShift);
    }

    protected override void UpdateInput(ref SimpleWASDInput input)
    {
        // Edge-triggered input is cached here and consumed once per tick
        input.jump |= Input.GetKeyDown(KeyCode.Space);
    }

    protected override void SanitizeInput(ref SimpleWASDInput input)
    {
        var move = Vector2.ClampMagnitude(new Vector2(input.horizontal, input.vertical), 1f);
        input.horizontal = move.x;
        input.vertical   = move.y;
    }
}

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Extrapolation and Repeat

• Remote players can use extrapolated input if the latest input is missing.

• Control behavior via fields on PredictedIdentity<INPUT, STATE>:

  • Extrapolate Input: enables extrapolation for remote input.

  • Repeat Input Factor: caps how many ticks a prior input can be reused.

• Override ModifyExtrapolatedInput(ref INPUT input) to disable non‑continuous inputs during extrapolation (e.g., jump = false).

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Why This Pattern

• Determinism: All input used in simulation is captured, sanitized, and stored per tick.

• One‑shot safety: Edge‑triggered inputs are gathered in UpdateInput and consumed once, preventing repeats.

• Flexibility: Works with any control scheme while keeping authoritative reconciliation stable.