1 files changed, 93 insertions, 0 deletions
diff --git a/libkscan/kgammatable.cpp b/libkscan/kgammatable.cpp
new file mode 100644
index 00000000..4f1ef64f
--- /dev/null
+++ b/libkscan/kgammatable.cpp
@@ -0,0 +1,93 @@
+/* This file is part of the KDE Project
+   Copyright (C) 2002 Klaas Freitag <freitag@suse.de>  
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public
+   License as published by the Free Software Foundation; either
+   version 2 of the License, or (at your option) any later version.
+
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public License
+   along with this library; see the file COPYING.LIB.  If not, write to
+   the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+   Boston, MA 02110-1301, USA.
+*/
+
+#include <math.h>
+
+#include <kdebug.h>
+#include "kgammatable.h"
+
+KGammaTable::KGammaTable( int gamma, int brightness, int contrast  ) 
+    : QObject()
+{
+   g = gamma < 1 ? 1 : gamma;
+   b = brightness;
+   c = contrast;
+   gt.resize(256);
+   calcTable();
+}
+
+const KGammaTable& KGammaTable::operator=(const KGammaTable& gt)
+{
+   if( this != &gt )
+   {
+      g = gt.g;
+      b = gt.b;
+      c = gt.c;
+
+      calcTable();
+   }
+
+   return( *this );
+}
+
+inline SANE_Word adjust( SANE_Word x, int gl,int bl,int cl)
+{
+   //printf("x : %d, x/256 : %lg, g : %d, 100/g : %lg",
+   //       x,(double)x/256.0,g,100.0/(double)g);
+   x = ( SANE_Int )(256*pow((double)x/256.0,100.0/(double)gl));
+   x = ((65536/(128-cl)-256)*(x-128)>>8)+128+bl;
+   if(x<0) x = 0; else if(x>255) x = 255;
+   //printf(" -> %d\n",x);
+   return x;
+}
+
+void KGammaTable::calcTable( )
+{
+   int br = (b<<8)/(128-c);
+   int gr = g;
+   int cr = c;
+
+   if( gr == 0 )
+   {
+      kdDebug(29000) << "Cant calc table -> would raise div. by zero !" << endl;
+      return;
+   }
+   
+   for( SANE_Word i = 0; i<256; i++)
+      gt[i] = adjust(i, gr, br, cr );
+
+   dirty = false;
+}
+
+void KGammaTable::setAll( int gamma, int brightness, int contrast )
+{
+    g = gamma < 1 ? 1 : gamma;
+    b = brightness;
+    c = contrast;
+
+    dirty = true;
+}
+
+
+SANE_Word* KGammaTable::getTable()
+{
+    if( dirty ) calcTable();
+    return( gt.data());
+}
+#include "kgammatable.moc"