_HUE32

The _HUE32 function returns the hue value (HSB colorspace) of a given 32-bit ARGB color.

Syntax

hue# = _HUE32(argbColor~&)

Parameters

• argbColor~& is the 32-bit ARGB color value to retrieve the hue value from.
  • ARGB colors are returned by various functions, such as _PALETTECOLOR, POINT and obviously by the color creating _RGB32, _RGBA32, _HSB32 or _HSBA32 functions.

Description

• The value returned is of type DOUBLE in the range 0 to 360 degrees, use CINT to work with integers only.
  • The color wheel starts with red(0), turns to yellow(60), green(120), cyan(180), blue(240), magenta(300) to red(360) again.
  • Mixed colors are represented by values between those 6 base color angles.

Naming differences

• The HSB (B=Brightness) colorspace is also known as HSV (V=Value) and sometimes even called HSI (I=Intensity), but that's all just different names for the same thing.
• However, this function is not suitable for the HSL (L=Lightness) colorspace, which is widely used in the Web/CSS.

Precision drawbacks

• When converting between colorspaces, rounding errors can occur. While the HSB colorspace has virtually infinite precision only limited by the used floating point type, RGB is represented in 8-bit integers (0-255) only, which can lead to quantization errors. In fact, not all colors in HSB can be accurately represented in RGB and vice versa.
• However, if you limit yourself to only passing integer values to _HSB32 or _HSBA32, just as you do for the respective RGB colorspace functions _RGB32 or _RGBA32, then you can get back that exact values by CINTing the results returned by _HUE32, _SATURATION32 and _BRIGHTNESS32.

Availability

• 

  none

• 

  v4.0.0

• 
• 

  yes

• 

  yes

• 

  yes

Examples

PRINT "Creating a color using the HSB colorspace..." c~& = _HSB32(90, 75, 65) PRINT "_HSB32( 90, 75, 65 ) = _RGB32("; _RED32(c~&); ","; _GREEN32(c~&); ","; _BLUE32(c~&); ")" PRINT PRINT "back to HSB values (notice the precision loss)..." PRINT "Hue.......:"; _HUE32(c~&) PRINT "Saturation:"; _SATURATION32(c~&) PRINT "Brightness:"; _BRIGHTNESS32(c~&) PRINT PRINT "but with CINT() we can get back the original values..." PRINT "Hue.......:"; CINT(_HUE32(c~&)) PRINT "Saturation:"; CINT(_SATURATION32(c~&)) PRINT "Brightness:"; CINT(_BRIGHTNESS32(c~&)) END

See also

• _HSB32, _HSBA32
• _SATURATION32, _BRIGHTNESS32
• _RGB32, _RGBA32
• _RED32, _GREEN32, _BLUE32, _ALPHA32

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