Rubberband

Reference for the static Rubberband API — elastic boundary resistance, clamping, and overshoot.

on this page

Apply IsOutOfBounds Clamp GetOvershoot DampenVelocity Worked example: drag and release

See the overview for install, and springs and decay for SpringValue<T>/DecayValue<T>. Rubberband is a static class with float, Vector2, and Vector3 overloads (except where noted) for elastic boundary constraints — the iOS-style resistance that increases as a value moves past its bounds.

Apply

Resists a value past min/max, easing toward maxOvershoot as the value moves further out of bounds.

csharp

static float Apply(float value, float min, float max, float resistance = 0.55f, float maxOvershoot = float.MaxValue)
static Vector2 Apply(Vector2 value, Vector2 min, Vector2 max, float resistance = 0.55f, float maxOvershoot = float.MaxValue)
static Vector3 Apply(Vector3 value, Vector3 min, Vector3 max, float resistance = 0.55f, float maxOvershoot = float.MaxValue)

Parameter	Default	Description
`resistance`	`0.55`	Higher values resist overshoot more; lower values allow more travel past bounds
`maxOvershoot`	`float.MaxValue`	Caps how far the result can move past `min`/`max`

csharp

float constrained = Rubberband.Apply(value, min: 0f, max: 100f, resistance: 0.55f);

IsOutOfBounds

csharp

static bool IsOutOfBounds(float value, float min, float max)
static bool IsOutOfBounds(Vector2 value, Vector2 min, Vector2 max)
static bool IsOutOfBounds(Vector3 value, Vector3 min, Vector3 max)

Clamp

csharp

static float Clamp(float value, float min, float max)
static Vector2 Clamp(Vector2 value, Vector2 min, Vector2 max)
static Vector3 Clamp(Vector3 value, Vector3 min, Vector3 max)

GetOvershoot

csharp

static float GetOvershoot(float value, float min, float max)
static Vector2 GetOvershoot(Vector2 value, Vector2 min, Vector2 max)

NOTE

GetOvershoot has no Vector3 overload.

DampenVelocity

Reduces velocity as a value moves past its bounds, for slowing scroll/drag momentum near edges.

csharp

static float DampenVelocity(float velocity, float value, float min, float max, float dampFactor = 0.5f)
static Vector2 DampenVelocity(Vector2 velocity, Vector2 value, Vector2 min, Vector2 max, float dampFactor = 0.5f)

Parameter	Default	Description
`dampFactor`	`0.5`	Fraction of velocity retained per step while out of bounds

NOTE

DampenVelocity has no Vector3 overload.

Worked example: drag and release

csharp

using Bluecadet.Spring;

const float min = 0f;
const float max = 100f;

// While dragging, apply elastic resistance past the bounds
void OnDrag(float rawPosition)
{
    float displayPosition = Rubberband.Apply(rawPosition, min, max, resistance: 0.55f);
    transform.localPosition = new Vector3(displayPosition, 0, 0);
}

// On release, dampen velocity if out of bounds, then spring back into range
void OnRelease(float rawPosition, float velocity)
{
    if (Rubberband.IsOutOfBounds(rawPosition, min, max))
    {
        velocity = Rubberband.DampenVelocity(velocity, rawPosition, min, max);
        float target = Rubberband.Clamp(rawPosition, min, max);
        _spring.Start(target, velocity);
    }
    else
    {
        _decay.Play(velocity);
    }
}