topic Re: Can some one explain this line in Classic/Legacy CodeWarrior

Can some one explain this line

NZ_Design — Thu, 23 Nov 2006 08:39:11 GMT

I a have a graphics libray that I have used in ICC but are now trying to change to code warrier.

I are having issues with library.

I have never come accross this before.

#define gishwfont() (gcurvp->pfont->psymbols == NULL)

if( gishwfont() )
c = ghw_setcursor( type );

ghw_setcursor( type); is never reached.

can some one please explain what this line is saying

#define gishwfont() (gcurvp->pfont->psymbols == NULL)

Re: Can some one explain this line

bigmac — Thu, 23 Nov 2006 10:27:21 GMT

Hello,

NZ-Design wrote:

can some one please explain what this line is saying

#define gishwfont() (gcurvp->pfont->psymbols == NULL)

I would assume there is a structure identified as gcurvp, and this contains an element gcurvp.pfont.psymbols. The code defines a macro that appears to test whether the address of this structure element is located at a valid (non-zero) address, i.e. has been initialised. It would return TRUE if invalid.

Regards,

Mac

Re: Can some one explain this line

Saga — Fri, 24 Nov 2006 02:27:00 GMT

Its a macro, the preprocessor replace it before the compiler starts. So at the moment you write

gishwfont() it's like you write

(gcurvp->pfont->psymbols == NULL)

It will return a true if psymbols inside those structures has a NULL value.

Re: Can some one explain this line

bigmac — Fri, 24 Nov 2006 13:02:25 GMT

Hello,

To correct my previous post -

gcurvp would appear to be a pointer to a structure containing the element pfont, whose value is a pointer to another structure containing the element psymbols. The name suggests that this may also be a pointer to something else. The macro would seem to test the value of psymbols within the second array.

Regards,

Mac