colors

This module implements color handling for Nim.

Imports

strutils, algorithm

Types

Color = distinct int: A color stored as RGB, e.g. 0xff00cc. Source Edit

Consts

colAliceBlue = 15792383: Source Edit
colAntiqueWhite = 16444375: Source Edit
colAqua = 65535: Source Edit
colAquamarine = 8388564: Source Edit
colAzure = 15794175: Source Edit
colBeige = 16119260: Source Edit
colBisque = 16770244: Source Edit
colBlack = 0: Source Edit
colBlanchedAlmond = 16772045: Source Edit
colBlue = 255: Source Edit
colBlueViolet = 9055202: Source Edit
colBrown = 10824234: Source Edit
colBurlyWood = 14596231: Source Edit
colCadetBlue = 6266528: Source Edit
colChartreuse = 8388352: Source Edit
colChocolate = 13789470: Source Edit
colCoral = 16744272: Source Edit
colCornflowerBlue = 6591981: Source Edit
colCornsilk = 16775388: Source Edit
colCrimson = 14423100: Source Edit
colCyan = 65535: Source Edit
colDarkBlue = 139: Source Edit
colDarkCyan = 35723: Source Edit
colDarkGoldenRod = 12092939: Source Edit
colDarkGray = 11119017: Source Edit
colDarkGreen = 25600: Source Edit
colDarkKhaki = 12433259: Source Edit
colDarkMagenta = 9109643: Source Edit
colDarkOliveGreen = 5597999: Source Edit
colDarkorange = 16747520: Source Edit
colDarkOrchid = 10040012: Source Edit
colDarkRed = 9109504: Source Edit
colDarkSalmon = 15308410: Source Edit
colDarkSeaGreen = 9419919: Source Edit
colDarkSlateBlue = 4734347: Source Edit
colDarkSlateGray = 3100495: Source Edit
colDarkTurquoise = 52945: Source Edit
colDarkViolet = 9699539: Source Edit
colDeepPink = 16716947: Source Edit
colDeepSkyBlue = 49151: Source Edit
colDimGray = 6908265: Source Edit
colDodgerBlue = 2003199: Source Edit
colFireBrick = 11674146: Source Edit
colFloralWhite = 16775920: Source Edit
colForestGreen = 2263842: Source Edit
colFuchsia = 16711935: Source Edit
colGainsboro = 14474460: Source Edit
colGhostWhite = 16316671: Source Edit
colGold = 16766720: Source Edit
colGoldenRod = 14329120: Source Edit
colGray = 8421504: Source Edit
colGreen = 32768: Source Edit
colGreenYellow = 11403055: Source Edit
colHoneyDew = 15794160: Source Edit
colHotPink = 16738740: Source Edit
colIndianRed = 13458524: Source Edit
colIndigo = 4915330: Source Edit
colIvory = 16777200: Source Edit
colKhaki = 15787660: Source Edit
colLavender = 15132410: Source Edit
colLavenderBlush = 16773365: Source Edit
colLawnGreen = 8190976: Source Edit
colLemonChiffon = 16775885: Source Edit
colLightBlue = 11393254: Source Edit
colLightCoral = 15761536: Source Edit
colLightCyan = 14745599: Source Edit
colLightGoldenRodYellow = 16448210: Source Edit
colLightGrey = 13882323: Source Edit
colLightGreen = 9498256: Source Edit
colLightPink = 16758465: Source Edit
colLightSalmon = 16752762: Source Edit
colLightSeaGreen = 2142890: Source Edit
colLightSkyBlue = 8900346: Source Edit
colLightSlateGray = 7833753: Source Edit
colLightSteelBlue = 11584734: Source Edit
colLightYellow = 16777184: Source Edit
colLime = 65280: Source Edit
colLimeGreen = 3329330: Source Edit
colLinen = 16445670: Source Edit
colMagenta = 16711935: Source Edit
colMaroon = 8388608: Source Edit
colMediumAquaMarine = 6737322: Source Edit
colMediumBlue = 205: Source Edit
colMediumOrchid = 12211667: Source Edit
colMediumPurple = 9662680: Source Edit
colMediumSeaGreen = 3978097: Source Edit
colMediumSlateBlue = 8087790: Source Edit
colMediumSpringGreen = 64154: Source Edit
colMediumTurquoise = 4772300: Source Edit
colMediumVioletRed = 13047173: Source Edit
colMidnightBlue = 1644912: Source Edit
colMintCream = 16121850: Source Edit
colMistyRose = 16770273: Source Edit
colMoccasin = 16770229: Source Edit
colNavajoWhite = 16768685: Source Edit
colNavy = 128: Source Edit
colOldLace = 16643558: Source Edit
colOlive = 8421376: Source Edit
colOliveDrab = 7048739: Source Edit
colOrange = 16753920: Source Edit
colOrangeRed = 16729344: Source Edit
colOrchid = 14315734: Source Edit
colPaleGoldenRod = 15657130: Source Edit
colPaleGreen = 10025880: Source Edit
colPaleTurquoise = 11529966: Source Edit
colPaleVioletRed = 14184595: Source Edit
colPapayaWhip = 16773077: Source Edit
colPeachPuff = 16767673: Source Edit
colPeru = 13468991: Source Edit
colPink = 16761035: Source Edit
colPlum = 14524637: Source Edit
colPowderBlue = 11591910: Source Edit
colPurple = 8388736: Source Edit
colRed = 16711680: Source Edit
colRosyBrown = 12357519: Source Edit
colRoyalBlue = 4286945: Source Edit
colSaddleBrown = 9127187: Source Edit
colSalmon = 16416882: Source Edit
colSandyBrown = 16032864: Source Edit
colSeaGreen = 3050327: Source Edit
colSeaShell = 16774638: Source Edit
colSienna = 10506797: Source Edit
colSilver = 12632256: Source Edit
colSkyBlue = 8900331: Source Edit
colSlateBlue = 6970061: Source Edit
colSlateGray = 7372944: Source Edit
colSnow = 16775930: Source Edit
colSpringGreen = 65407: Source Edit
colSteelBlue = 4620980: Source Edit
colTan = 13808780: Source Edit
colTeal = 32896: Source Edit
colThistle = 14204888: Source Edit
colTomato = 16737095: Source Edit
colTurquoise = 4251856: Source Edit
colViolet = 15631086: Source Edit
colWheat = 16113331: Source Edit
colWhite = 16777215: Source Edit
colWhiteSmoke = 16119285: Source Edit
colYellow = 16776960: Source Edit
colYellowGreen = 10145074: Source Edit

Procs

proc `==`(a, b: Color): bool {...}{.borrow.}

Compares two colors.

var
  a = Color(0xff_00_ff)
  b = colFuchsia
  c = Color(0x00_ff_cc)
assert a == b
assert not a == c

Source Edit

proc `+`(a, b: Color): Color {...}{.raises: [], tags: [].}

Adds two colors.

This uses saturated arithmetic, so that each color component cannot overflow (255 is used as a maximum).

Example:

var
  a = Color(0xaa_00_ff)
  b = Color(0x11_cc_cc)
assert a + b == Color(0xbb_cc_ff)

Source Edit

proc `-`(a, b: Color): Color {...}{.raises: [], tags: [].}

Subtracts two colors.

This uses saturated arithmetic, so that each color component cannot underflow (0 is used as a minimum).

Example:

var
  a = Color(0xff_33_ff)
  b = Color(0x11_ff_cc)
assert a - b == Color(0xee_00_33)

Source Edit

proc extractRGB(a: Color): tuple[r, g, b: range[0 .. 255]] {...}{.raises: [], tags: [].}

Extracts the red/green/blue components of the color a.

Example:

var
  a = Color(0xff_00_ff)
  b = Color(0x00_ff_cc)
type
  Col = range[0..255]
# assert extractRGB(a) == (r: 255.Col, g: 0.Col, b: 255.Col)
# assert extractRGB(b) == (r: 0.Col, g: 255.Col, b: 204.Col)
echo extractRGB(a)
echo typeof(extractRGB(a))
echo extractRGB(b)
echo typeof(extractRGB(b))

Source Edit

proc intensity(a: Color; f: float): Color {...}{.raises: [], tags: [].}

Returns a with intensity f. f should be a float from 0.0 (completely dark) to 1.0 (full color intensity).

Example:

var
  a = Color(0xff_00_ff)
  b = Color(0x00_42_cc)
assert a.intensity(0.5) == Color(0x80_00_80)
assert b.intensity(0.5) == Color(0x00_21_66)

Source Edit

proc `$`(c: Color): string {...}{.raises: [], tags: [].}

Converts a color into its textual representation.

Example:

assert $colFuchsia == "#FF00FF"

Source Edit

proc parseColor(name: string): Color {...}{.raises: [ValueError], tags: [].}

Parses name to a color value.

If no valid color could be parsed ValueError is raised. Case insensitive.

Example:

var
  a = "silver"
  b = "#0179fc"
  c = "#zzmmtt"
assert parseColor(a) == Color(0xc0_c0_c0)
assert parseColor(b) == Color(0x01_79_fc)
doAssertRaises(ValueError): discard parseColor(c)

Source Edit

proc isColor(name: string): bool {...}{.raises: [], tags: [].}

Returns true if name is a known color name or a hexadecimal color prefixed with #. Case insensitive.

Example:

var
  a = "silver"
  b = "#0179fc"
  c = "#zzmmtt"
assert a.isColor
assert b.isColor
assert not c.isColor

Source Edit

proc rgb(r, g, b: range[0 .. 255]): Color {...}{.raises: [], tags: [].}

Constructs a color from RGB values.

Example:

assert rgb(0, 255, 128) == Color(0x00_ff_80)

Source Edit

Templates

template mix(a, b: Color; fn: untyped): untyped

Uses fn to mix the colors a and b.

fn is invoked for each component R, G, and B. If fn's result is not in the range[0..255], it will be saturated to be so.

Example:

var
  a = Color(0x0a2814)
  b = Color(0x050a03)

proc myMix(x, y: int): int =
  2 * x - 3 * y

assert mix(a, b, myMix) == Color(0x05_32_1f)

Source Edit