GetBValue, GetGValue, GetRValue Functions

Purpose

The GetBValue, GetGValue, and GetRValue function retrieves an intensity value for a color component of a 32-bit red, green, blue (RGB) value.

Syntax

Byte = GetBValue(rgb)

Byte = GetGValue(rgb)

Byte = GetRValue(rgb)

rgb

: 32-bit RGB value

Description

The return value of GetBValue is the intensity of the blue component of the specified RGB color.

The return value of GetGValue is the intensity of the green component of the specified RGB color.

The return value of GetRValue is the intensity of the red component of the specified RGB color.

The intensity value is in the range 0 through 255.

Example

OpenW # 1

Local col%, nBlue%, nGreen%, nRed%, x%

// background color for a window

Win_1.BackColor = RGB(120, 250, 120)

// to get the whole color value

col% = Win_1.BackColor

// or for one pixel

// col% = GetPixel(Win_1.hDC , 380, 280)

Text 75, 10, "red"

Text 110, 10, "green"

Text 150, 10, "blue"

If col% > 0

nRed% = GetRValue(col)

nBlue% = GetBValue(col)

nGreen% = GetGValue(col)

Text 70, 40, nRed%

Text 110, 40, nGreen%

Text 150, 40, nBlue%

EndIf

Remarks

The GetBValue, GetGValue, and GetRValue functions are actually simple byte shift functions and does not parse system colours. For example, when you assign a predefined color constant like colBtnFace (= $8000000F) you won't get the RGB-values of the color, but GetBValue(colBtnFace) = 0, GetGValue(colBtnFace) = 0, and GetRValue(colBtnFace) = 0.

In addition, these functions do not work with the ARGB colours used with GDI+; to get the individual colour components you can use the GetByten() functions as in the following example:

Local ARGB_Aquamarine = &HFF7FFFD4

Print Hex$(GetByte0(ARGB_Aquamarine)) // Alpha Value

Print Hex$(GetByte1(ARGB_Aquamarine)) // Red Value

Print Hex$(GetByte2(ARGB_Aquamarine)) // Green Value

Print Hex$(GetByte3(ARGB_Aquamarine)) // Blue Value

Print Hex$(GetRValue(ARGB_Aquamarine)) // Gets the Blue, not Red, Value

Print Hex$(GetBValue(ARGB_Aquamarine)) // Gets the Red, not Blue, Value