Home · All Namespaces · All Classes · Main Classes · Grouped Classes · Modules · Functions

makeimg.cpp Example File
graphicsview/portedcanvas/makeimg.cpp

 /****************************************************************************
 **
 ** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
 ** Contact: Qt Software Information ([email protected])
 **
 ** This file is part of the examples of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:LGPL$
 ** Commercial Usage
 ** Licensees holding valid Qt Commercial licenses may use this file in
 ** accordance with the Qt Commercial License Agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and Nokia.
 **
 ** GNU Lesser General Public License Usage
 ** Alternatively, this file may be used under the terms of the GNU Lesser
 ** General Public License version 2.1 as published by the Free Software
 ** Foundation and appearing in the file LICENSE.LGPL included in the
 ** packaging of this file.  Please review the following information to
 ** ensure the GNU Lesser General Public License version 2.1 requirements
 ** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
 **
 ** In addition, as a special exception, Nokia gives you certain
 ** additional rights. These rights are described in the Nokia Qt LGPL
 ** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this
 ** package.
 **
 ** GNU General Public License Usage
 ** Alternatively, this file may be used under the terms of the GNU
 ** General Public License version 3.0 as published by the Free Software
 ** Foundation and appearing in the file LICENSE.GPL included in the
 ** packaging of this file.  Please review the following information to
 ** ensure the GNU General Public License version 3.0 requirements will be
 ** met: http://www.gnu.org/copyleft/gpl.html.
 **
 ** If you are unsure which license is appropriate for your use, please
 ** contact the sales department at [email protected].
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/

 #include <qimage.h>
 #include <qcolor.h>

 static inline int blendComponent( int v, int av, int s, int as )
 {
     //shadow gets a color inversely proportional to the
     //alpha value
     s = (s*(255-as))/255;
     //then do standard blending
     return as*s + av*v -(av*as*s)/255;
 }

 static inline QRgb blendShade( QRgb v, QRgb s )
 {
     //pick a number: shadow is 1/3 of object
     int as = qAlpha(s)/3;
     int av = qAlpha(v);
     if ( as == 0 || av == 255 )
         return v;

     int a = as + av -(as*av)/255;

     int r = blendComponent( qRed(v),av, qRed(s), as)/a;
     int g = blendComponent( qGreen(v),av, qGreen(s), as)/a;
     int b = blendComponent( qBlue(v),av, qBlue(s), as)/a;

     return qRgba(r,g,b,a);
 }

 int main( int*, char**)
 {
     QImage *img;

     img = new QImage( "in.png" );
     int w,h;
     int y;
     img->setAlphaBuffer( TRUE );
     *img = img->convertDepth( 32 );
     w = img->width();
     h = img->height();
 #if 0
     for ( y = 0; y < h; y ++ ) {
         uint *line = (uint*)img->scanLine( y );
         for ( int x = 0; x < w; x++ ) {
             uint pixel = line[x];
             int r = qRed(pixel);
             int g = qGreen(pixel);
             int b = qBlue(pixel);
             int min = QMIN( r, QMIN( g, b ) );
             int max = QMAX( r, QMAX( g, b ) );
             r -= min;
             g -= min;
             b -= min;
             if ( max !=min ) {
                 r = (r*255)/(max-min);
                 g = (g*255)/(max-min);
                 b = (b*255)/(max-min);
             }
             int a = 255-min;
             a -=  (max-min)/3; //hack more transparency for colors.
             line[x] = qRgba( r, g, b, a );
         }
     }
 #endif
     *img = img->smoothScale( w/2, h/2 );

     qDebug( "saving out.png");
     img->save( "out.png", "PNG" );

     w = img->width();
     h = img->height();

     QImage *img2 = new QImage( w, h, 32 );
     img2->setAlphaBuffer( TRUE );
     for ( y = 0; y < h; y++ ) {
         for ( int x = 0; x < w; x++ ) {
             QRgb shader = img->pixel( x, y );

             int as = qAlpha(shader)/3;

             int r = (qRed(shader)*(255-as))/255;
             int g = (qGreen(shader)*(255-as))/255;
             int b = (qBlue(shader)*(255-as))/255;

             img2->setPixel( x, y, qRgba(r,g,b,as) );
         }
     }

     img2->save( "outshade.png", "PNG" );

 }