Class ColorUtil

Namespace

Hi.Coloring

Assembly

HiGeom.dll

Utility for handling color. Includes handle of RGB and HSL.

public static class ColorUtil

Inheritance

object

ColorUtil

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Properties

EnvDiscreteRgbSeed

public static int EnvDiscreteRgbSeed { get; set; }

Property Value

int

The seed is applied to GetDiscreteRGB_Env(double, double).

ExceptionRed

Exception RGB. Also for nan value.

public static vec3d_t ExceptionRed { get; }

Property Value

vec3d_t

Gray

Generate gray color. RGB=(0.2, 0.2, 0.2).

public static vec3d_t Gray { get; }

Property Value

vec3d_t

NoValueGreen

No value RGB.

public static vec3d_t NoValueGreen { get; }

Property Value

vec3d_t

NullDark

Generate dark RGB for null value. RGB=(0,0,0).

public static vec3d_t NullDark { get; }

Property Value

vec3d_t

UndeterminedPurple

Undetermined RGB.

public static vec3d_t UndeterminedPurple { get; }

Property Value

vec3d_t

Methods

FromDualHexString(string)

Parses an RRGGBB hexadecimal string (optionally prefixed with #) back to an RGB color vector with channels in 0~1. Inverse of ToDualHexString(vec3d_t) up to 8-bit rounding.

public static vec3d_t FromDualHexString(string hex)

Parameters

hex string

The hexadecimal color string, e.g. #3fa0c8.

Returns

vec3d_t

RGB color vector.

GetDiscreteHue(int)

Get the HSL hue of the discrete color of seed: the hue GetDiscreteRgb(int, double, double) hands to HslToRgb(double, double, double). The same seed always gives the same hue.

public static double GetDiscreteHue(int seed)

Parameters

seed int

Color seed. Any integer, negative ones included.

Returns

double

HSL hue in 0~1

Remarks

Each seed advances 0.618 of the usable hues, measured by perceived color difference rather than by degrees. Seeds 1, 2 or 4 apart are therefore far apart in hue; seeds 5, 8 or 13 apart are close.

The usable hues are 30° to 220° and 270° to 300°. Magenta through red-orange (300° to 30°) and deep blue through blue-violet (220° to 270°) never appear.

GetDiscreteRGBWithoutPurpleAndRed(int, double, double)

Get discrete RGB without purple and red color ranges.

public static vec3d_t GetDiscreteRGBWithoutPurpleAndRed(int seed, double saturation = 1, double light = 0.5)

Parameters

seed int

Color seed. Determines the hue value.

saturation double

Saturation value of the color.

light double

Light value of the color.

Returns

vec3d_t

RGB color vector without purple and red ranges.

GetDiscreteRGB_Env(double, double)

Get discrete color using EnvDiscreteRgbSeed. The functionality is the same as GetDiscreteRgb(int, double, double). The function call makes EnvDiscreteRgbSeed plus 1.

public static vec3d_t GetDiscreteRGB_Env(double saturation = 1, double light = 0.5)

Parameters

saturation double

saturation

light double

light

Returns

vec3d_t

RGB

GetDiscreteRgb(int, double, double)

Get discrete color(RGB). The term ‘discrete’ means there is big color difference between nearby seed. This function is good to auto set color for lot of components.

public static vec3d_t GetDiscreteRgb(int seed, double saturation = 1, double light = 0.5)

Parameters

seed int

Color seed. Determines the hue by GetDiscreteHue(int).

saturation double

HSL saturation

light double

HSL light

Returns

vec3d_t

RGB

Remarks

The seed decides only the hue, by GetDiscreteHue(int); saturation and light go to HslToRgb(double, double, double) as given. The same seed always gives the same color. Seeds 0 to 377 give different 8-bit colors; beyond them two seeds can round to the same one.

GetDiscreteRgbByBoundary(int, double, double, double, double)

Get discrete RGB by boundary.

public static vec3d_t GetDiscreteRgbByBoundary(int seed, double hueBegin = 0, double hueEnd = 1, double saturation = 1, double light = 0.5)

Parameters

seed int

Color seed. Determines the hue value.

hueBegin double

The beginning of the hue range.

hueEnd double

The end of the hue range.

saturation double

Saturation value of the color.

light double

Light value of the color.

Returns

vec3d_t

RGB color vector with boundary.

GetGloomyColor(Guid, double, double)

Gloomy color (blue tune by default) seeded by a persisted identity. The same Guid always yields the same color — across loads, threads, processes and platforms — unlike GetGloomyColor(object, double, double), whose identity-hash seed is stable only within one thread's allocation order.

public static vec3d_t GetGloomyColor(this Guid seed, double hueMin = 0.5, double hueMax = 0.7)

Parameters

seed Guid

Persisted identity, e.g. an anchor's Guid.

hueMin double

The beginning of the hue range.

hueMax double

The end of the hue range.

Returns

vec3d_t

RGB color vector.

Remarks

Uses an FNV-1a hash over ToByteArray() rather than GetHashCode() or GetHashCode(): the latter are not guaranteed stable across runtimes, and string hashing is randomized per process on .NET Core.

GetGloomyColor(object, double, double)

The default value is blue tune.

public static vec3d_t GetGloomyColor(this object seed, double hueMin = 0.5, double hueMax = 0.7)

Parameters

seed object

hueMin double

hueMax double

Returns

vec3d_t

Remarks

The hue is seeded by GetHashCode(). For a type that does not override it, that is the CLR identity hash — drawn per thread on the first call — so the color depends on which thread asks first and in what order, and two loads of the same data get different colors. When a persisted identity is available, prefer GetGloomyColor(Guid, double, double).

GetRgb(double, RatioRgbFuncEnum)

Get RGB by funcEnum.

public static vec3d_t GetRgb(double v, RatioRgbFuncEnum funcEnum)

Parameters

v double

value

funcEnum RatioRgbFuncEnum

function enum

Returns

vec3d_t

RGB

GetRgbByErf(double)

Get RGB interpolated from blue to green to red by erf function. The range suits for -2 to 0 to 2.

public static vec3d_t GetRgbByErf(double v)

Parameters

v double

input of the erf

Returns

vec3d_t

RGB

GetRgbByHslOffset(vec3d_t, vec3d_t)

Convert RGB by HSL offset. This is a three step process: RGB convert to HSL, HSL+=hslOffset, HSL convert to RGB.

public static vec3d_t GetRgbByHslOffset(vec3d_t rgb, vec3d_t hslOffset)

Parameters

rgb vec3d_t

RGB

hslOffset vec3d_t

HSL offset

Returns

vec3d_t

RGB

GetRgbByLinearRatio(double)

0 ~ 0.5 ~ 1 is linearly interpolated to blue to green to red. The below range data is pure blue. The exceeding range data is pure red.

public static vec3d_t GetRgbByLinearRatio(double ratio)

Parameters

ratio double

the interpolation range is 0~1

Returns

vec3d_t

RGB

GetRgbByNormalizedErf(double)

0 ~ 0.5 ~ 1 is interpolated to blue to green to red. The below range data is pure blue. The exceeding range data is pure red. return GetRgbByLinearRatio(MathUtil.Erf(ratio*2) / MathUtil.Erf(2));

public static vec3d_t GetRgbByNormalizedErf(double ratio)

Parameters

ratio double

the interpolation range is 0~1

Returns

vec3d_t

RGB

GetRgbByNormalizedPositiveErf(double)

0 ~ 0.5 ~ 1 is interpolated to blue to green to red. The below range data is pure blue. The exceeding range data is pure red. Only the positive half form is used. return GetRgbByLinearRatio(MathUtil.Erf(ratio*2) / MathUtil.Erf(2));

public static vec3d_t GetRgbByNormalizedPositiveErf(double ratio)

Parameters

ratio double

the interpolation range is 0~1

Returns

vec3d_t

RGB

GetRgbByPositiveErf(double)

Get RGB interpolated from blue to green to red by modified erf function.

public static vec3d_t GetRgbByPositiveErf(double v)

Parameters

v double

input of the modified erf

Returns

vec3d_t

color

Remarks

If v is equal or lower than 0, the color is blue; if v is equal or larger than 1, the color is red; otherwise, the color varied from blue to green to red by modified erf function.

GetRgbByPositiveErf(double, double, double)

Get RGB interpolated from blue to green to red by modified erf function.

public static vec3d_t GetRgbByPositiveErf(double v, double floor, double ceil)

Parameters

v double

input of the modified erf

floor double

floor value of v

ceil double

ceil value of v

Returns

vec3d_t

color

Remarks

If v is equal or lower than floor, the color is blue; if v is equal or larger than ceil, the color is red; otherwise, the color varied from blue to green to red by modified erf function.

HslToRgb(vec3d_t)

Convert color convention from HSL to RGB.

public static vec3d_t HslToRgb(vec3d_t hsl)

Parameters

hsl vec3d_t

HSL

Returns

vec3d_t

RGB

HslToRgb(double, double, double)

Convert color convention from HSL to RGB.

public static vec3d_t HslToRgb(double hue, double saturation, double light)

Parameters

hue double

hue

saturation double

saturation

light double

light

Returns

vec3d_t

RGB

RgbToHsl(vec3d_t)

Convert color convention from RGB to HSL.

public static vec3d_t RgbToHsl(vec3d_t rgb)

Parameters

rgb vec3d_t

RGB

Returns

vec3d_t

HSL

RgbToHsl(double, double, double)

Convert color convention from RGB to HSL.

public static vec3d_t RgbToHsl(double r, double g, double b)

Parameters

r double

red

g double

green

b double

blue

Returns

vec3d_t

HSL

ToDualHexString(vec3d_t)

Converts an RGB color vector to a hexadecimal string representation.

public static string ToDualHexString(vec3d_t rgb)

Parameters

rgb vec3d_t

The RGB color vector to convert.

Returns

string

A hexadecimal string representation of the RGB color.