xview.cpp
// Oliver Eiden <o.eiden@pop.ruhr.de>
// 23.3.99
// changed the mapping from 3-3-2 decoded pixels to 8-8-8 decoded true-color pixels
// now it uses the same mapping as xv, this leads to better visual results
// Patch merged in HEAD by Chris Spiegel <matrix@xirtam.org>
// This library is distributed under the conditions of the GNU LGPL.
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <qimage.h>
#include <kdelibs_export.h>
#include "xview.h"
#define BUFSIZE 1024
static const int b_255_3[]= {0,85,170,255}, // index*255/3
rg_255_7[]={0,36,72,109,145,182,218,255}; // index *255/7
KDE_EXPORT void kimgio_xv_read( QImageIO *_imageio )
{
int x=-1;
int y=-1;
int maxval=-1;
QIODevice *iodev = _imageio->ioDevice();
char str[ BUFSIZE ];
// magic number must be "P7 332"
iodev->readLine( str, BUFSIZE );
if (strncmp(str,"P7 332",6)) return;
// next line #XVVERSION
iodev->readLine( str, BUFSIZE );
if (strncmp(str, "#XVVERSION", 10))
return;
// now it gets interesting, #BUILTIN means we are out.
// if IMGINFO comes, we are happy!
iodev->readLine( str, BUFSIZE );
if (strncmp(str, "#IMGINFO:", 9))
return;
// after this an #END_OF_COMMENTS signals everything to be ok!
iodev->readLine( str, BUFSIZE );
if (strncmp(str, "#END_OF", 7))
return;
// now a last line with width, height, maxval which is
// supposed to be 255
iodev->readLine( str, BUFSIZE );
sscanf(str, "%d %d %d", &x, &y, &maxval);
if (maxval != 255) return;
int blocksize = x*y;
if(x < 0 || y < 0 || blocksize < x || blocksize < y)
return;
// now follows a binary block of x*y bytes.
char *block = (char*) malloc(blocksize);
if(!block)
return;
if (iodev->readBlock(block, blocksize) != blocksize )
{
return;
}
// Create the image
QImage image( x, y, 8, maxval + 1, QImage::BigEndian );
if( image.isNull()) {
free(block);
return;
}
// how do the color handling? they are absolute 24bpp
// or at least can be calculated as such.
int r,g,b;
for ( int j = 0; j < 256; j++ )
{
r = rg_255_7[((j >> 5) & 0x07)];
g = rg_255_7[((j >> 2) & 0x07)];
b = b_255_3[((j >> 0) & 0x03)];
image.setColor( j, qRgb( r, g, b ) );
}
for ( int py = 0; py < y; py++ )
{
uchar *data = image.scanLine( py );
memcpy( data, block + py * x, x );
}
_imageio->setImage( image );
_imageio->setStatus( 0 );
free(block);
return;
}
KDE_EXPORT void kimgio_xv_write( QImageIO *imageio )
{
QIODevice& f = *( imageio->ioDevice() );
// Removed "f.open(...)" and "f.close()" (tanghus)
const QImage& image = imageio->image();
int w = image.width(), h = image.height();
char str[ 1024 ];
// magic number must be "P7 332"
f.writeBlock( "P7 332\n", 7 );
// next line #XVVERSION
f.writeBlock( "#XVVERSION:\n", 12 );
// now it gets interesting, #BUILTIN means we are out.
// if IMGINFO comes, we are happy!
f.writeBlock( "#IMGINFO:\n", 10 );
// after this an #END_OF_COMMENTS signals everything to be ok!
f.writeBlock( "#END_OF_COMMENTS:\n", 18 );
// now a last line with width, height, maxval which is supposed to be 255
sprintf( str, "%i %i 255\n", w, h );
f.writeBlock( str, strlen( str ) );
if ( image.depth() == 1 )
{
image.convertDepth( 8 );
}
uchar* buffer = new uchar[ w ];
for ( int py = 0; py < h; py++ )
{
uchar *data = image.scanLine( py );
for ( int px = 0; px < w; px++ )
{
int r, g, b;
if ( image.depth() == 32 )
{
QRgb *data32 = (QRgb*) data;
r = qRed( *data32 ) >> 5;
g = qGreen( *data32 ) >> 5;
b = qBlue( *data32 ) >> 6;
data += sizeof( QRgb );
}
else
{
QRgb color = image.color( *data );
r = qRed( color ) >> 5;
g = qGreen( color ) >> 5;
b = qBlue( color ) >> 6;
data++;
}
buffer[ px ] = ( r << 5 ) | ( g << 2 ) | b;
}
f.writeBlock( (const char*)buffer, w );
}
delete[] buffer;
imageio->setStatus( 0 );
}

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