Struct ColorGradientAlphaStop

Represents a single alpha stop within a ColorGradient. Alpha stops define an independent transparency curve that is evaluated separately from the color stops and applied to the final output color.

Implements
Inherited Members
Namespace: Scylla.Core.Util.Palette
Assembly: ScyllaCore.dll
Syntax
public readonly struct ColorGradientAlphaStop : IEquatable<ColorGradientAlphaStop>, IComparable<ColorGradientAlphaStop>
Remarks

Independent alpha control. When a gradient has alpha stops, the alpha channel is evaluated from the alpha stop curve rather than from the color stops' alpha values. This enables the Photoshop-style workflow where color transitions and transparency transitions are controlled independently.

Value semantics. ColorGradientAlphaStop is a readonly struct, providing zero-allocation, stack-allocated value semantics.

Ordering. Stops are ordered by Offset via IComparable<T>. The parent ColorGradient sorts alpha stops by offset at construction time.

Interpolation. Interpolation selects the easing curve applied to the segment between this stop and the next, mirroring the color-stop API. None (the default) produces a straight-line blend.

Midpoint. The Midpoint value shifts the interpolation balance point between this stop and its successor. A value of 0.5 (default) produces standard linear interpolation. Lower values shift the blend toward this stop, higher values toward the next.

Constructors

ColorGradientAlphaStop(float, float, ColorGradientStopInterpolation, float)

Creates a new alpha stop at the specified offset with the given alpha value and per-segment easing curve.

Declaration
public ColorGradientAlphaStop(float offset, float alpha, ColorGradientStopInterpolation interpolation, float midpoint = 0.5)
Parameters
Type Name Description
float offset

Normalized position along the gradient, must be in [0, 1].
float alpha

Alpha (opacity) value, must be in [0, 1].
ColorGradientStopInterpolation interpolation

Per-segment easing curve override.
float midpoint

Interpolation midpoint between this stop and the next. Must be in (0, 1). Defaults to DEFAULT_MIDPOINT.
Exceptions
Type Condition
ArgumentOutOfRangeException

Thrown if offset is outside [0, 1], alpha is outside [0, 1], or midpoint is outside (0, 1).

ColorGradientAlphaStop(float, float, float)

Creates a new alpha stop at the specified offset with the given alpha value.

Declaration
public ColorGradientAlphaStop(float offset, float alpha, float midpoint = 0.5)
Parameters
Type Name Description
float offset

Normalized position along the gradient, must be in [0, 1].
float alpha

The alpha (opacity) value, must be in [0, 1].
float midpoint

The interpolation midpoint between this stop and the next. Must be in (0, 1). Defaults to DEFAULT_MIDPOINT.
Exceptions
Type Condition
ArgumentOutOfRangeException

Thrown if offset is outside [0, 1], alpha is outside [0, 1], or midpoint is outside (0, 1).

Fields

DEFAULT_MIDPOINT

The default midpoint value (centered, no shift).

Declaration
public const float DEFAULT_MIDPOINT = 0.5
Field Value
Type Description
float

Properties

Alpha

The alpha (opacity) value at this stop, in the range [0, 1]. A value of 0 is fully transparent, 1 is fully opaque.

Declaration
public float Alpha { get; }
Property Value
Type Description
float

Interpolation

Per-segment easing curve applied to the transition from this stop to the next. Defaults to None (straight-line blend). Mirrors the color-stop API so authoring feels symmetric across the two rails.

Declaration
public ColorGradientStopInterpolation Interpolation { get; }
Property Value
Type Description
ColorGradientStopInterpolation

Midpoint

The interpolation midpoint between this stop and its successor, in the range (0, 1). Defaults to DEFAULT_MIDPOINT (0.5). Shifting the midpoint changes where the 50% blend point falls in the transition.

Declaration
public float Midpoint { get; }
Property Value
Type Description
float

Offset

The normalized position of this stop along the gradient, in the range [0, 1]. A value of 0 represents the start and 1 represents the end.

Declaration
public float Offset { get; }
Property Value
Type Description
float

Methods

CompareTo(ColorGradientAlphaStop)

Compares this stop with another by Offset for sorting.

Declaration
public int CompareTo(ColorGradientAlphaStop other)
Parameters
Type Name Description
ColorGradientAlphaStop other

The stop to compare with.
Returns
Type Description
int

A negative value if this stop's offset is less than other's, zero if equal, or a positive value if greater.

Equals(ColorGradientAlphaStop)

Determines whether this stop is equal to another. Two alpha stops are equal if their offsets, alpha values, interpolation, and midpoints all match within float tolerance.

Declaration
public bool Equals(ColorGradientAlphaStop other)
Parameters
Type Name Description
ColorGradientAlphaStop other

The stop to compare with.
Returns
Type Description
bool

true if both stops are equal.

Equals(object)

Declaration
public override bool Equals(object obj)
Parameters
Type Name Description
object obj
Returns
Type Description
bool
Overrides

GetHashCode()

Declaration
public override int GetHashCode()
Returns
Type Description
int
Overrides

ToString()

Returns a human-readable string of this stop in the format "0.50 (A=0.75, M=0.50)".

Declaration
public override string ToString()
Returns
Type Description
string
Overrides

Operators

operator ==(ColorGradientAlphaStop, ColorGradientAlphaStop)

Equality operator comparing offset, alpha, interpolation, and midpoint.

Declaration
public static bool operator ==(ColorGradientAlphaStop left, ColorGradientAlphaStop right)
Parameters
Type Name Description
ColorGradientAlphaStop left
ColorGradientAlphaStop right
Returns
Type Description
bool

operator !=(ColorGradientAlphaStop, ColorGradientAlphaStop)

Inequality operator.

Declaration
public static bool operator !=(ColorGradientAlphaStop left, ColorGradientAlphaStop right)
Parameters
Type Name Description
ColorGradientAlphaStop left
ColorGradientAlphaStop right
Returns
Type Description
bool

Implements

See Also