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Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!rutgers!mephisto!utkcs2!alphard!battle
From: battle@alphard.cs.utk.edu (David Battle)
Newsgroups: comp.windows.x,comp.graphics
Subject: Re: New version of PBMPLUS released.
Message-ID: <1419@utkcs2.cs.utk.edu>
Date: 29 Nov 89 14:19:08 GMT
References: <14701@well.UUCP> <1408@utkcs2.cs.utk.edu>
Sender: news@utkcs2.cs.utk.edu
Reply-To: battle@alphard.cs.utk.edu (David Battle)
Followup-To: comp.windows.x
Organization: CS Dept -- University of TN, Knoxville
Lines: 55

In article <1408@utkcs2.cs.utk.edu> battle@alphard.cs.utk.edu (I) write:
>I am having trouble using PBMPLUS on a DECstation 3100.  In particular
>I am trying to make a dump of a color (8 bits/pixel) window and change
>it to a portable pixmap.  Here is the error I get:
>
>battle> xwd | xwdtoppm > bitmap.out
>xwdtoppm: unknown XWD file version: 117440512
>
>I am using the version of xwd which came with the X.V11R3 distribution
>from MIT.
>
>What am I doing wrong?
>
>						-David Battle
>						battle@utkux1.utk.edu
>						battle@battle.esd.ornl.gov

Note that 117440512 in hex is 07000000 and that the "correct" xwd version
number is 7.  Obviously a byte ordering problem.  Oddly enough this particular
bug seems to have resulted from a bug in DEC's optimizer (at least it went
away when I removed -O from the CCFLAGS).

I discovered another bug which appears to be with the code itself.  In
xwdtoppm.c around line 250 the code reads:

        /* Read X11 colormap. */
        for ( i = 0; i < h11P->colormap_entries; i++ )
            {
            if ( fread( &x11col, sizeof(X11XColor), 1, file ) != 1 )
                pm_error( "couldn't read X11 XWD colormap", 0,0,0,0,0 );
            /**** 1 ****/
            if ( *maxvalP != 65535 )
                {
                x11col.red = (long) x11col.red * *maxvalP / 65535;
                x11col.green = (long) x11col.green * *maxvalP / 65535;
                x11col.blue = (long) x11col.blue * *maxvalP / 65535;
                }
            PPM_ASSIGN(
                colors[x11col.pixel], x11col.red, x11col.green, x11col.blue );
            }


Most likely, the following code should be inserted at the line which I
have marked /**** 1 ****/:

if(byte_swap) {
    x11col.pixel = bs_long(x11col.pixel);
    x11col.red = bs_short(x11col.red);
    x11col.green = bs_short(x11col.green);
    x11col.blue = bs_short(x11col.blue);
}

This seems to have fixed the other problems I was having.

					-David


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