Legacy Document

Inside Macintosh: Imaging With QuickDraw /

Chapter 4 - Color QuickDraw / Color QuickDraw Reference

Color QuickDraw Routines / Drawing With Color QuickDraw Colors

OpColor

Use the OpColor procedure to set the maximum color values for the addPin and subPin arithmetic transfer modes, and the weight color for the blend arithmetic transfer mode.

PROCEDURE OpColor (color: RGBColor); 

color

An RGBColor record that defines a color.

DESCRIPTION

If the current port is defined by a CGrafPort record, the OpColor procedure sets the red, green, and blue values used by the addPin, subPin, and blend arithmetic transfer modes. You specify these red, green, and blue values in the RGBColor record, and you specify this record in the color parameter. This information is actually stored in the rgbOpColor field of the GrafVars record, but you should never need to refer to it directly.

If the current graphics port is defined by a GrafPort record, OpColor has no effect.

SEE ALSO

Arithmetic transfer modes are described in "Arithmetic Transfer Modes" beginning on page 4-29.