HSL To RGB

This algorithm converts HSL color model to RGB color model.

• C#
• VB.Net
• C
• C++
• PHP

									Public Structure RGB
	Private _r As Byte
	Private _g As Byte
	Private _b As Byte

	Public Sub New(r As Byte, g As Byte, b As Byte)
		Me._r = r
		Me._g = g
		Me._b = b
	End Sub

	Public Property R() As Byte
		Get
			Return Me._r
		End Get
		Set(value As Byte)
			Me._r = value
		End Set
	End Property

	Public Property G() As Byte
		Get
			Return Me._g
		End Get
		Set(value As Byte)
			Me._g = value
		End Set
	End Property

	Public Property B() As Byte
		Get
			Return Me._b
		End Get
		Set(value As Byte)
			Me._b = value
		End Set
	End Property

	Public Overloads Function Equals(rgb As RGB) As Boolean
		Return (Me.R = rgb.R) AndAlso (Me.G = rgb.G) AndAlso (Me.B = rgb.B)
	End Function
End Structure

Public Structure HSL
	Private _h As Integer
	Private _s As Single
	Private _l As Single

	Public Sub New(h As Integer, s As Single, l As Single)
		Me._h = h
		Me._s = s
		Me._l = l
	End Sub

	Public Property H() As Integer
		Get
			Return Me._h
		End Get
		Set(value As Integer)
			Me._h = value
		End Set
	End Property

	Public Property S() As Single
		Get
			Return Me._s
		End Get
		Set(value As Single)
			Me._s = value
		End Set
	End Property

	Public Property L() As Single
		Get
			Return Me._l
		End Get
		Set(value As Single)
			Me._l = value
		End Set
	End Property

	Public Overloads Function Equals(hsl As HSL) As Boolean
		Return (Me.H = hsl.H) AndAlso (Me.S = hsl.S) AndAlso (Me.L = hsl.L)
	End Function
End Structure

Public Shared Function HSLToRGB(hsl As HSL) As RGB
	Dim r As Byte = 0
	Dim g As Byte = 0
	Dim b As Byte = 0

	If hsl.S = 0 Then
		r = CByte(Math.Truncate(hsl.L * 255))
		g = CByte(Math.Truncate(hsl.L * 255))
		b = CByte(Math.Truncate(hsl.L * 255))
	Else
		Dim v1 As Single, v2 As Single
		Dim hue As Single = CSng(hsl.H) / 360

		v2 = If((hsl.L < 0.5), (hsl.L * (1 + hsl.S)), ((hsl.L + hsl.S) - (hsl.L * hsl.S)))
		v1 = 2 * hsl.L - v2

		r = CByte(Math.Truncate(255 * HueToRGB(v1, v2, hue + (1.0F / 3))))
		g = CByte(Math.Truncate(255 * HueToRGB(v1, v2, hue)))
		b = CByte(Math.Truncate(255 * HueToRGB(v1, v2, hue - (1.0F / 3))))
	End If

	Return New RGB(r, g, b)
End Function

Private Shared Function HueToRGB(v1 As Single, v2 As Single, vH As Single) As Single
	If vH < 0 Then
		vH += 1
	End If

	If vH > 1 Then
		vH -= 1
	End If

	If (6 * vH) < 1 Then
		Return (v1 + (v2 - v1) * 6 * vH)
	End If

	If (2 * vH) < 1 Then
		Return v2
	End If

	If (3 * vH) < 2 Then
		Return (v1 + (v2 - v1) * ((2.0F / 3) - vH) * 6)
	End If

	Return v1
End Function
								

Example

									Dim data As New HSL(138, 0.5F, 0.76F)
Dim value = HSLToRGB(data)
								

Output

									R: 163
G: 224
B: 181