Message-ID: <33D367F6.3E61@lr.net>
Date: Mon, 21 Jul 1997 09:45:26 -0400
From: Isaac Waldron <waldroni AT lr DOT net>
Reply-To: waldroni AT lr DOT net
Organization: The Computer Nerd
MIME-Version: 1.0
To: fighteer AT cs DOT com
CC: djgpp AT delorie DOT com
Subject: Re: Allocation of memory.
References: <33D210A6 DOT 5EDF AT lr DOT net> <33D28EF5 DOT 69F2 AT cs DOT com>
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John M. Aldrich wrote:
> 
> Isaac Waldron wrote:
> >
> > I am trying to dynamically allocate memory for a buffer.  I wrote a
> > header file that loads and displays pcx files.  I need to use a buffer
> > for the decompressed image.
> >
> [code snipped]
> > It always exits with a "Not enough memory" error.
> >
> > Any help would be appreciated.
> 
> Please try to post the exact code that you use.  You may have made some
> error that doesn't show up in your example.  But here are some things to
> check:
> 
> - Is 'bufsize' initialized?
> - Do you in fact have enough free memory?  (run 'go32-v2' without
> arguments)
> - Does replacing 'bufsize' in the call to malloc() with a constant value
> like 10 work?
> - Have you #included <stdlib.h>, which declares the prototype for
> malloc()?
> - If you compile with the '-O' and '-Wall' switches, do you get any
> warnings?
> 
> hth
> 
> --
> John M. Aldrich <fighteer AT cs DOT com>
> 
> * Anything that happens, happens.
> * Anything that, in happening, causes something else to happen,
>   causes something else to happen.
> * Anything that, in happening, causes itself to happen again, happens
>   again.
> * It doesn't necessarily do it in chronological order, though.
> 
>                                        --- Douglas Adams
Ok, i'll attach the code. It won't be very good, definately unoptimized,
but that's ok.  BTW, bufsize was initialized, I have plenty of memory,
stdlib.h was included, and i'll have to try the -Wall switch.

-- 
-Begin Signature-
Isaac Waldron <waldroni AT lr DOT net> N1YZI
http://www.geocities.com/SiliconValley/Lakes/5703/home.html
-End Signature-

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/*
pcx.h

A C++ header of functions for loading and display of .pcx pictures

Author: Isaac Waldron
*/

#define __pcx
#ifndef __mode13
#include "mode13.h"
#endif
#include <stdlib.h>
#include <iostream.h>
#include <memory.h>
#include <stdio.h>
#include <dos.h>

struct PCXHeader
{
        char manufacturer;
        char version;
        char encoding;
        char bpp;
        int xStart, yStart;
        int xEnd, yEnd;
        int xRes, yRes;
        char egaPal[48];
        char reserved;
        char numPlanes;
        int bpl;
        int pType;
        char padding[58];
};

class PCXImage
{
        public:
        PCXImage(char *filename, short int newX, short int newY)
        {
                FILE *fh;
                unsigned int bufsize, datatotal, dataindex;
                unsigned char data, runlength;
                fh = fopen(filename, "rb");
                if (fh == NULL)
                {
                        SetText();
                        cout << "The file could not be found.";
                        exit(EXIT_FAILURE);
                };

                fread(&header, sizeof(PCXHeader), 1, fh);
                if (header.manufacturer != 10)
                {
                        SetText();
                        cout << "The file is not a valid PCX file.";
                        exit(EXIT_FAILURE);
                };

                height = header.yEnd - header.yStart + 1;
                width = header.xEnd - header.xStart + 1;
                bufsize = width * height;
                imagebuffer = malloc(bufsize);
                if (imagebuffer == NULL)
                {
                        SetText();
                        cout << "Not enough memory.";
                        exit(EXIT_FAILURE);
                };
                fseek(fh, 128, SEEK_SET);
                datatotal = bufsize;
                dataindex = 0;
                while (dataindex < datatotal)
                {
                        data = getc(fh);
                        if (data > 192)
                        {
                                runlength = data - 192;
                                data = getc(fh);
                                while (runlength-- > 0)
                                {
                                        imagebuffer[dataindex++] = data;
                                };
                        }
                        else
                        {
                                imagebuffer[dataindex++] = data;
                        };
                };
                fseek(fh, -768, SEEK_END);
                for (dataindex = 0; dataindex < 768; dataindex++)
                {
                        palette[dataindex] = getc(fh) >> 2;
                };
                fclose(fh);
                x = newX;
                y = newY;
        };

        void PCXDraw()
        {
                unsigned int bufsize, windex, hindex, dest;
                unsigned char *source = imagebuffer;
                bufsize = width * height;
                dest = x + (y * 320);
                for (hindex = 0; hindex < height; hindex++)
                {
                        for (windex = 0; windex < width; windex++, source++)
                        {
                                _farpokeb(VideoRAM, dest + windex, source[0]);
                        };
                        dest += 320;
                };
         };

         ~PCXImage()
         {
                free(imagebuffer);
         };

         protected:
         struct PCXHeader header;
         unsigned char *imagebuffer;
         unsigned char palette[768];
         unsigned char palOrig[768];
         int height, width, x, y;
};


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