RGB
Computes a valid color value for hi/truecolor modes
result = RGB(red, green, blue)
red
The combined color.
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 integer 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.
See Put (Graphics) example in addition.
Syntax
Usage
result = RGB(red, green, blue)
Parameters
red
red color component value
greengreen color component value
blueblue 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 integer 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.
Example
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 ) ( CUInt( c ) Shr 16 And 255 )
#define RGBA_G( c ) ( CUInt( c ) Shr 8 And 255 )
#define RGBA_B( c ) ( CUInt( c ) And 255 )
#define RGBA_A( c ) ( CUInt( c ) Shr 24 )
Dim As UInteger r, g, b, a
Dim As UInteger 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 ) ( CUInt( c ) Shr 16 And 255 )
#define RGBA_G( c ) ( CUInt( c ) Shr 8 And 255 )
#define RGBA_B( c ) ( CUInt( c ) And 255 )
#define RGBA_A( c ) ( CUInt( c ) Shr 24 )
Dim As UInteger r, g, b, a
Dim As UInteger 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
Dialect Differences
- Not available in the -lang qb dialect.
Differences from QB
- New to FreeBASIC
See also
