Still celebrating National IT Professionals Day with 3 months of free Premium Membership. Use Code ITDAY17

x
?
Solved

Unsigned chars

Posted on 2003-11-18
2
Medium Priority
?
325 Views
Last Modified: 2010-04-15
Part of code taken from small JPEG Code Library by Rich Geldreich

bool tga_writer::write_line(const void *Pscan_line)
{
  uchar *Psb = (uchar *)Pscan_line;
      
  if (!Pfile)
    return (true);

  if (fwrite(Pscan_line, bytes_per_line, 1, Pfile) != 1)  // bytes_per_line = 681, in this case
    return (true);

  return (false);
}


// Definition given in header file
typedef unsigned char  uchar;       /*  8 bits     */

in main
=======

uchar *Pdb = Pbuf;

status = Pdst->write_line(Pbuf); // status if of type boolean

My question is
1. how can I assign the contents of Pbuf (within main program) or Pscan_line within

   bool tga_writer::write_line(const void *Pscan_line)

to say an array (1-D or 2-D) so that I can manipulate the contents.

0
Comment
Question by:baharbh
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
2 Comments
 
LVL 45

Expert Comment

by:sunnycoder
ID: 9770228
>1. how can I assign the contents of Pbuf (within main program) or Pscan_line within

>   bool tga_writer::write_line(const void *Pscan_line)

>to say an array (1-D or 2-D) so that I can manipulate the contents.


bool tga_writer::write_line(const void *Pscan_line)
{
 char array [MAX_LINE_LENGTH];
 uchar *Psb = (uchar *)Pscan_line;
   
  if (!Pfile)
   return (true);

  memcpy ( array, Pscan_line, bytes_per_line );     //now your line is in 1D array

 if (fwrite(Pscan_line, bytes_per_line, 1, Pfile) != 1)  // bytes_per_line = 681, in this case
   return (true);

 return (false);
}
0
 
LVL 45

Accepted Solution

by:
sunnycoder earned 2000 total points
ID: 9770251
if MAX_LINE_LENGTH is not know in advance, you can proceed like this


bool tga_writer::write_line(const void *Pscan_line)
{
uchar * array ;            ========== i wrote char in previous post ... correct it
uchar *Psb = (uchar *)Pscan_line;
   
 if (!Pfile)
  return (true);

 array = (uchar *) malloc ( sizeof (uchar) * bytes_per_line );

 memcpy ( array, Pscan_line, bytes_per_line );     //now your line is in 1D array

if (fwrite(Pscan_line, bytes_per_line, 1, Pfile) != 1)  // bytes_per_line = 681, in this case
  return (true);

return (false);
}

also this is C++ and not C ... we have a separate forum for C++
http://oldlook.experts-exchange.com/Programming/Programming_Languages/Cplusplus/
0

Featured Post

What does it mean to be "Always On"?

Is your cloud always on? With an Always On cloud you won't have to worry about downtime for maintenance or software application code updates, ensuring that your bottom line isn't affected.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This is a short and sweet, but (hopefully) to the point article. There seems to be some fundamental misunderstanding about the function prototype for the "main" function in C and C++, more specifically what type this function should return. I see so…
Examines three attack vectors, specifically, the different types of malware used in malicious attacks, web application attacks, and finally, network based attacks.  Concludes by examining the means of securing and protecting critical systems and inf…
Video by: Grant
The goal of this video is to provide viewers with basic examples to understand and use for-loops in the C programming language.
The goal of this video is to provide viewers with basic examples to understand how to create, access, and change arrays in the C programming language.

704 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question