XmSetColorCalculation

library call

`XmSetColorCalculation`

A function to set the procedure used for default color calculation

    #include <Xm/Xm.h>

    XmColorProc XmSetColorCalculation

    XmColorProc color_proc

## DESCRIPTION

`XmSetColorCalculation` sets the procedure to calculate default colors. This procedure is used to calculate the foreground, top shadow, bottom shadow, and select colors on the basis of a given background color. If called with an argument of NULL, it restores the default procedure used to calculate colors.

color_proc

- Specifies the procedure to use for color calculation.

Following is a description of the XmColorProc type used by `XmSetColorCalculation`:

    void (*color_proc) (background_color, foreground_color, select_color, top_shadow_color,
    bottom_shadow_color)
            XColor  *background_color;
            XColor  *foreground_color;
            XColor  *select_color;
            XColor  *top_shadow_color;
            XColor  *bottom_shadow_color;

Specifies the procedure used to calculate default colors. The procedure is passed a pointer to an XColor structure representing the background color. The pixel, red, green, and blue members of this structure are filled in with values that are valid for the current colormap.

The procedure is passed pointers to XColor structures representing the foreground, select, top shadow, and bottom shadow colors to be calculated. The procedure calculates and fills in the red, green, and blue members of these structures. The procedure should not allocate color cells for any of these colors.

background_color

- Specifies the background color.

foreground_color

- Specifies the foreground color to be calculated.

select_color

- Specifies the select color to be calculated.

top_shadow_color

- Specifies the top shadow color to be calculated.

bottom_shadow_color

- Specifies the bottom shadow color to be calculated.

## RETURN

Returns the color calculation procedure that was used at the time this routine was called.

## RELATED

&cdeman.XmChangeColor;, &cdeman.XmGetColors;, and &cdeman.XmGetColorCalculation;.