QB64-PE/internal/help/_BLUE.txt

{{DISPLAYTITLE:_BLUE}}
The [[_BLUE]] function returns the palette intensity or the blue component intensity of a 32-bit image color.


{{PageSyntax}}
:: blueintensity% = '''_BLUE('''{{Parameter|rgbaColorIndex&}}[, {{Parameter|imageHandle&}}]''')'''


{{PageDescription}}
* {{Parameter|rgbaColorIndex&}} is the ''RGBA'' color value or palette index of the color to retrieve the blue component intensity from.
* The [[LONG]] intensity value returned ranges from 0 (no intensity, not present) to 255 (full intensity).
* If {{Parameter|imageHandle&}} specifies a 32-bit color image, {{Parameter|rgbaColorIndex&}} is interpreted as a 32-bit ''RGBA'' color value.
* If {{Parameter|imageHandle&}} specifies an image that uses a palette, {{Parameter|rgbaColorIndex&}} is interpreted as a palette index.
* If {{Parameter|imageHandle&}} is not specified, it is assumed to be the current write page.
* If {{Parameter|imageHandle&}} is an invalid handle, an [[ERROR Codes|invalid handle]] error will occur.
* If {{Parameter|rgbaColorIndex&}} is outside the range of valid indexes for a given image mode, an [[ERROR Codes|illegal function call]] error occurs.
* Uses index parameters passed by the {{KW|_RGB}}, {{KW|_RGBA}}, {{KW|_RGB32}} or {{KW|_RGBA32}} funtions.
* An image handle is optional.


''See Example:'' 
* [[POINT]]


{{PageSeeAlso}}
* [[_RED]], [[_GREEN]]
* [[_RGB]], [[RGB32]]
* [[_LOADIMAGE]] 


{{PageNavigation}}