RGB
Computes a valid color value for hi/truecolor modes
Syntax:
Usage:
result = RGB(red, green, blue)
Parameters:
red
red color component value
green
green color component value
blue
blue color component value
Return Value:
The combined color.
Description:
red, green and blue are components ranging 0-255.
The RGB function can be used to compute a valid color value for use while in hi/truecolor modes. It returns an unsigned long, in the format &hAARRGGBB, where RR, GG and BB equal the values passed to this function, in hexadecimal format. AA is the implicit alpha value and is automatically set to &hFF (opaque).
It is possible to retrieve the red, green, blue and alpha values from a color value, by using a combination of And and Shr. The second example below shows how to #Define and use macros to do this.
Note for Windows API programmers: The macro named RGB in the Windows references has been renamed BGR in the FB headers for Windows to avoid collisions.
The RGB function can be used to compute a valid color value for use while in hi/truecolor modes. It returns an unsigned long, in the format &hAARRGGBB, where RR, GG and BB equal the values passed to this function, in hexadecimal format. AA is the implicit alpha value and is automatically set to &hFF (opaque).
It is possible to retrieve the red, green, blue and alpha values from a color value, by using a combination of And and Shr. The second example below shows how to #Define and use macros to do this.
Note for Windows API programmers: The macro named RGB in the Windows references has been renamed BGR in the FB headers for Windows to avoid collisions.
Examples:
See Put (Graphics) example in addition.
ScreenRes 640,480,32 '32 bit color
Line(0,0)-(319,479), RGB(255,0,0) 'draws a bright red box on the left side of the window
Line(639,0)-(320,479), RGB(0,0,255) 'draws a bright blue box on the right side of the window
Sleep 'wait before exiting
Line(0,0)-(319,479), RGB(255,0,0) 'draws a bright red box on the left side of the window
Line(639,0)-(320,479), RGB(0,0,255) 'draws a bright blue box on the right side of the window
Sleep 'wait before exiting
'' setting and retrieving Red, Green, Blue and Alpha values
#define RGBA_R( c ) ( CULng( c ) Shr 16 And 255 )
#define RGBA_G( c ) ( CULng( c ) Shr 8 And 255 )
#define RGBA_B( c ) ( CULng( c ) And 255 )
#define RGBA_A( c ) ( CULng( c ) Shr 24 )
Dim As UByte r, g, b, a
Dim As ULong col = RGB(128, 192, 64)
Print Using "Color: _&H\ \"; Hex(col, 8)
r = RGBA_R( col )
g = RGBA_G( col )
b = RGBA_B( col )
a = RGBA_A( col )
Print
Print Using "Red: _&H\\ = ###"; Hex(r, 2); r
Print Using "Green: _&H\\ = ###"; Hex(g, 2); g
Print Using "Blue: _&H\\ = ###"; Hex(b, 2); b
Print Using "Alpha: _&H\\ = ###"; Hex(a, 2); a
#define RGBA_R( c ) ( CULng( c ) Shr 16 And 255 )
#define RGBA_G( c ) ( CULng( c ) Shr 8 And 255 )
#define RGBA_B( c ) ( CULng( c ) And 255 )
#define RGBA_A( c ) ( CULng( c ) Shr 24 )
Dim As UByte r, g, b, a
Dim As ULong col = RGB(128, 192, 64)
Print Using "Color: _&H\ \"; Hex(col, 8)
r = RGBA_R( col )
g = RGBA_G( col )
b = RGBA_B( col )
a = RGBA_A( col )
Print Using "Red: _&H\\ = ###"; Hex(r, 2); r
Print Using "Green: _&H\\ = ###"; Hex(g, 2); g
Print Using "Blue: _&H\\ = ###"; Hex(b, 2); b
Print Using "Alpha: _&H\\ = ###"; Hex(a, 2); a
- Before fbc 1.08.0:
Dialect Differences:
- Not available in the -lang qb dialect unless referenced with the alias __Rgb.
Differences from QB:
- New to FreeBASIC
See also:
Back to 2D Drawing Functions
