_BLUE - QB64 Wiki

_BLUE

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The _BLUE function returns the palette intensity or the blue component intensity of a 32-bit image color.


Syntax:

blueintensity% = _BLUE(rgbaColorIndex&[, imageHandle&])


Description:

  • 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 imageHandle& specifies a 32-bit color image, rgbaColorIndex& is interpreted as a 32-bit RGBA color value.
  • If imageHandle& specifies an image that uses a palette, rgbaColorIndex& is interpreted as a palette index.
  • If imageHandle& is not specified, it is assumed to be the current write page.
  • If imageHandle& is an invalid handle, an invalid handle error will occur.
  • If rgbaColorIndex& is outside the range of valid indexes for a given image mode, an illegal function call error occurs.
  • Uses index parameters passed by the _RGB, _RGBA, _RGB32 or _RGBA32 funtions.
  • An image handle is optional.


See Example:


See also:



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