_HSBA32

The _HSBA32 function specifies a color using the HSB colorspace and returns the 32-bit ARGB color value representing the color with the specified hue, saturation, brightness and opacity level (alpha channel).

Syntax

color32value~& = _HSBA32(hue#, saturation#, brightness#, alpha#)

Parameters

• hue# specifies the hue DOUBLE of the desired color from 0 to 360 degrees.
  • 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 can be build by specifying values between the 6 base color angles.
• saturation# specifies the saturation DOUBLE of the desired color from 0 to 100 percent.
  • 100% is the richest color possible, as closer you come to 0%, as more the color is fading ending at dull gray.
  • The intensity of the gray (i.e. black >> darkgray >> midgray >> lightgray >> white) depends on the brightness# value.
• brightness# specifies the brightness DOUBLE of the desired color from 0 to 100 percent.
  • 100% is the brightest (highest intensity), as closer you come to 0%, as darker is the color always ending in black regardless of the given hue# and saturation#.
• alpha# specifies the opacity DOUBLE of the desired color from 0 to 100 percent.
  • 100% results into a fully opaque color, 0% is a fully transparent color.
  • Values in between that range determine the degree to which the new color will intermix (_BLEND) with existing screen colors.

Description

• The value returned is always a 32-bit _UNSIGNED LONG ARGB color value, as is the POINT value.
• Return variable types must be _UNSIGNED LONG or LONG, otherwise the resulting color may lose the _BLUE value.
• Parameter values outside the allowed ranges are clipped.
• This function returns _UNSIGNED LONG 32-bit hexadecimal values from &H00000000 to &HFFFFFFFF.
• You may use _HSB32 if you don't need control over the alpha channel, but just want opaque colors.
• When (_UNSIGNED) LONG values are PUT to file, the ARGB values become BGRA. Use LEFT$(MKL$(color32value~&), 3) to place 3 colors.

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

Example 1

Drawing a color wheel by looping through hue and saturation.

SCREEN _NEWIMAGE(640, 480, 32) FOR ang# = 0 TO 360 STEP 0.25 FOR rad# = 0 TO 200 STEP 0.25 x% = rad# * COS(_D2R(ang#)) y% = rad# * SIN(_D2R(ang#)) PSET (320 + x%, 240 - y%), _HSBA32(ang#, rad# / 2, 100, 100) NEXT rad# NEXT ang# END

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Example 2

Drawing a 3D model of the HSB colorspace with a cut to see inside.

SCREEN _NEWIMAGE(640, 480, 32) FOR hei# = 0 TO 200 STEP 5 FOR ang# = 5 TO 285 STEP 0.25 FOR rad# = 0 TO 200 STEP 1 x% = rad# * COS(_D2R(ang#)) y% = rad# * SIN(_D2R(ang#)) z% = hei# XYfrom3D x%, y%, z% PSET (330 + x%, -z% + 340), _HSBA32(ang#, rad# / 2, hei# / 2, 100) IF rad# = 0 _ANDALSO (hei# = 0 OR hei# = 200) THEN IF hei# = 0 THEN IF ang# = 5 THEN bmpx% = 330 + x%: bmpy% = -z% + 340 ELSE IF ang# = 5 THEN tmpx% = 330 + x%: tmpy% = -z% + 340 END IF ELSEIF rad# = 200 _ANDALSO (hei# = 0 OR hei# = 200) THEN PSET (330 + x%, -z% + 340), &HFFFFFFFF IF hei# = 0 THEN IF ang# = 5 THEN bspx% = 330 + x%: bspy% = -z% + 340 IF ang# = 285 THEN bepx% = 330 + x%: bepy% = -z% + 340 ELSE IF ang# = 5 THEN tspx% = 330 + x%: tspy% = -z% + 340 IF ang# = 285 THEN tepx% = 330 + x%: tepy% = -z% + 340 END IF END IF NEXT rad# NEXT ang# NEXT hei# LINE (bspx%, bspy%)-(bmpx%, bmpy%), &HFFFFFFFF LINE (bmpx%, bmpy%)-(bepx%, bepy%), &HFFFFFFFF LINE (tspx%, tspy%)-(tmpx%, tmpy%), &HFFFFFFFF LINE (tmpx%, tmpy%)-(tepx%, tepy%), &HFFFFFFFF LINE (bspx%, bspy%)-(tspx%, tspy%), &HFFFFFFFF LINE (bmpx%, bmpy%)-(tmpx%, tmpy%), &HFFFFFFFF LINE (bepx%, bepy%)-(tepx%, tepy%), &HFFFFFFFF END SUB XYfrom3D (x%, y%, z%) x% = (x% + (y% * .5)) z% = (z% + (y% * .5)) END SUB

See also

• _HSB32, _HUE32
• _SATURATION32, _BRIGHTNESS32
• _RGBA32, _RGB, _RGBA
• _RED32, _GREEN32, _BLUE32
• _PALETTECOLOR, _BLEND, _DONTBLEND
• HEX$ 32 Bit Values
• SaveImage SUB
• Hexadecimal Color Values

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