_Color_Tint Macro

The _Color_Tint macro is one of the Macro Examples and Mini-Apps included with Daqarta. It allows you to derive a lighter or darker version of an existing color.

On input, user variable QC is the color to be adjusted, and QS is the adjustment value. The lighter or darker result is returned in QC.

Typically, you would use the ColorNum macro to obtain QC for a specified display color, such as QC=ColorNum?c to get the color of the input or output channel specified previously via the Channel Select variable Ch.

QS is a signed integer that will be added separately to each of the Red, Green, and Blue color components of QC. Each will be automatically limited to the range 0-255.

If QS is positive, the overall color retains its same hue but becomes lighter ("tint"). If QS is negative, the color becomes darker ("shade").

As an example, the Pulse Meter Mini-App includes an option (by setting UD=0 instead of the default UD=1) to use Custom Meters with black text on colored backgrounds. The backgrounds are lighter versions of the colors used to draw the main display traces for each input or output channel. This allows you to see at a glance which meter goes with which channel. In this case, _Color_Tint is used with QS=160 to get the lighter tint values.

_Color_Tint Macro Listing:

;<Help=H491C
QR=QC & hFF                    ;Isolate Red component
QG=int(QC>>8) & hFF            ;Green
QB=int(QC>>16) & hFF           ;Blue
QR=QR+QS                       ;Adjust Red
QR=lim(QR,0,255)               ;Limit Red to 0-255
QG=QG+QS                       ;Adjust Green
QG=lim(QG,0,255)               ;Limit Green to 0-255
QB=QB+QS                       ;Adjust Blue
QB=lim(QB,0,255)               ;Limit Blue to 0-255
QC=QR + QG<<8 + QB<<16         ;Reassemble changed color

See also Colors & Line Styles Dialog, colr() Function.