🚀 go-pugleaf

tedj@hpcilzb.HP.COM (Ted Johnson) writes:
>Can someone tell me what I'm doing wrong here?  Using Lightspeed C v.2.11,
>I tried to do the following:
>
>		tempPoint = aRect.topLeft;

singer@endor.UUCP (Richard Siegal@THINK Technologies) writes:
>	You're getting confused between C and Pascal. In C there's no easy
>way to get at the variants of a record. Therefore, there's a macro (declared in
>"QuickDraw.h") for "topLeft" and "botRight". Instead of "aRect.topLeft", say
>"topLeft(aRect)", and all will be well.

Although I haven't seen this exact trick used in any Mac C environment
so far, it *is* possible to define Rect so that you can use the
syntax described in Inside Macintosh for accessing its fields:

typedef struct {
	Point topLeft;
	Point botRight;
} Rect;

#define top	topLeft.v
#define left	topLeft.h
#define bottom	botRight.v
#define right	botRight.h

Note that LightSpeed C defines top,left,bottom and right as fields
and topLeft,botRight as macros, while the above implementation does
the reverse, *and* gives you a cleaner syntax.
-- 
Doug Moen
University of Waterloo Computer Graphics Lab
UUCP:     {ihnp4,watmath}!watcgl!kdmoen
INTERNET: kdmoen@cgl.waterloo.edu