[Coco] question C++

[Luis Fernández]

Thanks, I hope to understand this format, which is extremely complex

---------------------------------------------------------------------------------
Making 
CoCoDskUtilPack V 1.0.10.zip  
http://cococoding.com/cocodskutil/ Thank Aaron Wolfe
My personal blog: http://www.luis45ccs.blogspot.com
---------------------------------------------------------------------------------

> Date: Thu, 22 Mar 2012 14:50:30 +1100
> From: jekent at optusnet.com.au
> To: coco at maltedmedia.com
> Subject: Re: [Coco] question C++
> 
> 
> 
> On 22/03/2012 1:30 AM, Mark McDougall wrote:
> > On 22/03/2012 12:03 AM, Luis Fernández wrote:
> >
> >> ANYONE can tell me the meaning&  here
> >> write_buf (h, 1,&  val);
> >
> > The '&' is the 'address of' operator, so it passes the address of the 
> > 'val' variable.
> >
> >> static void write_buf_const (dmk_handle h, int count, uint8_t val)
> >> {
> >>   while (count--)
> >>     write_buf (h, 1, &val);
> >> }
> >
> > This looks like it writes 'count' number of pad bytes of value 'val'.
> >
> > Regards,
> >
> 
> val is passed on the stack to the write_buf_const procedure.
> I assume dmk_handle is a type definition for a structure pointer type 
> for the buffer.
> "handle" I suspect refers to a pointer type.
> 
> so you might have something like
> 
> struct dmk_buff {
>    unit8_t *inptr;
>    unit8_t *outptr;
>    int count;
>    uint8_t buffer[MAX_BUF_SIZE]]
> };
> 
> typdef struct dmk_buff *dmk_handle;
> 
> although the _t in uint8_t indicates that it is a type definition, and 
> dmk_handle does not indicate it's a type definition, but I assume it is.
> 
> anyway .... what it seems to be doing is passing the address of val to 
> the write_buf routine and the write_buf routine will access val via it's 
> address passed as a pointer value . i.e.
> 
> void write_buf( dmk_handle h, int fill_count, uint8_t *valptr )
> {
>    int i;
> 
>    h->inptr = &h->buffer[h->count];
>    for( i=0; i<fill_count; i++ )
>    {
>      *h->inptr++ = *valptr;
>       h->count++;
>    }
> }
> 
> 
> unit8_count will be 1.
> write_buf will fetch val, using it's address and write it to the buffer 
> via the input pointer
> 
> h->count mean that h is pointing to a structure contain a member 
> variable "count".
> 
> I hope that's right.
> 
> John.
> 
> -- 
> http://www.johnkent.com.au
> http://members.optusnet.com.au/jekent
> 
> 
> --
> Coco mailing list
> Coco at maltedmedia.com
> http://five.pairlist.net/mailman/listinfo/coco