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/* This file is proposed to be part of the KDE libraries.
* Copyright (C) 2003 Laur Ivan <laurivan@eircom.net>
*
* Many thanks to:
* - Bernardo Hung <deciare@gta.igs.net> for the enhanced shadow
* algorithm (currently used)
* - Tim Jansen <tim@tjansen.de> for the API updates and fixes.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License version 2 as published by the Free Software Foundation.
*
* 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 "kshadowengine.h"
#include <qcolor.h>
#include "kshadowsettings.h"
KShadowEngine::KShadowEngine() :
m_shadowSettings( new KShadowSettings )
{
}
KShadowEngine::~KShadowEngine()
{
delete m_shadowSettings;
}
KShadowEngine::KShadowEngine(KShadowSettings *fx) :
m_shadowSettings(0L)
{
setShadowSettings(fx);
}
void KShadowEngine::setShadowSettings(KShadowSettings *fx)
{
delete m_shadowSettings;
m_shadowSettings = fx;
}
KShadowSettings *KShadowEngine::shadowSettings()
{
return m_shadowSettings;
}
QImage KShadowEngine::makeShadow(const QPixmap& textPixmap, const QColor &bgColor)
{
QImage result;
// create a new image for for the shaddow
int w = textPixmap.width();
int h = textPixmap.height();
// avoid calling these methods for every pixel
int bgRed = bgColor.red();
int bgGreen = bgColor.green();
int bgBlue = bgColor.blue();
int thick = m_shadowSettings->thickness() >> 1;
double alphaShadow;
/*
* This is the source pixmap
*/
QImage img = textPixmap.convertToImage().convertDepth(32);
/*
* Resize the image if necessary
*/
if ((result.width() != w) || (result.height() != h))
{
result.create(w, h, 32);
}
result.fill(0); // all black
result.setAlphaBuffer(true);
for (int i = thick; i < w - thick; i++)
{
for (int j = thick; j < h - thick; j++)
{
switch (m_shadowSettings->algorithm())
{
case KShadowSettings::DoubleLinearDecay:
alphaShadow = doubleLinearDecay(img, i, j);
break;
case KShadowSettings::RadialDecay:
alphaShadow = radialDecay(img, i, j);
break;
case KShadowSettings::NoDecay:
alphaShadow = noDecay(img, i, j);
break;
case KShadowSettings::DefaultDecay:
default:
alphaShadow = defaultDecay(img, i, j);
}
alphaShadow = (alphaShadow > m_shadowSettings->maxOpacity()) ? m_shadowSettings->maxOpacity() : alphaShadow;
// update the shadow's i,j pixel.
result.setPixel(i,j, qRgba(bgRed, bgGreen , bgBlue, (int) alphaShadow));
}
}
return result;
}
// Multiplication factor for pixels directly above, under, or next to the text
#define AXIS_FACTOR 2.0
// Multiplication factor for pixels diagonal to the text
#define DIAGONAL_FACTOR 1.0
double KShadowEngine::defaultDecay(QImage& source, int i, int j)
{
if ((i < 1) || (j < 1) || (i > source.width() - 2) || (j > source.height() - 2))
return 0;
double alphaShadow;
alphaShadow =(qGray(source.pixel(i-1,j-1)) * DIAGONAL_FACTOR +
qGray(source.pixel(i-1,j )) * AXIS_FACTOR +
qGray(source.pixel(i-1,j+1)) * DIAGONAL_FACTOR +
qGray(source.pixel(i ,j-1)) * AXIS_FACTOR +
0 +
qGray(source.pixel(i ,j+1)) * AXIS_FACTOR +
qGray(source.pixel(i+1,j-1)) * DIAGONAL_FACTOR +
qGray(source.pixel(i+1,j )) * AXIS_FACTOR +
qGray(source.pixel(i+1,j+1)) * DIAGONAL_FACTOR) / m_shadowSettings->multiplicationFactor();
return alphaShadow;
}
double KShadowEngine::doubleLinearDecay(QImage& source, int i, int j)
{
//printf("img: %p, %d %d\n", (char *) &source, i, j);
return defaultDecay( source, i, j ); // for now
}
double KShadowEngine::radialDecay(QImage& source, int i, int j)
{
//printf("img: %p, %d %d\n", (char *) &source, i, j);
return defaultDecay( source, i, j ); // for now
}
double KShadowEngine::noDecay(QImage& source, int i, int j)
{
// create a new image for for the shaddow
int w = source.width();
int h = source.height();
int sx, sy;
//int thick = m_shadowSettings->thickness() >> 1;
double alphaShadow = 0;
double opacity = 0;
for (int k = 1; k <= m_shadowSettings->thickness(); k++) {
/* Generate a shadow THICKNESS pixels thicker
* on either side than the text image. Ensure
* that i +/- k and j +/- k are within the
* bounds of the text pixmap.
*/
opacity = 0;
for (int l = -k; l <= k; l++) {
if (i < k)
sx = 0;
else if (i >= w - k)
sx = w - 1;
else
sx = i + l;
for (int m = -k; m <= k; m++) {
if (j < k)
sy = 0;
else if (j >= h - k)
sy = h - 1;
else
sy = j + m;
opacity += qGray(source.pixel(sx, sy));
}
}
alphaShadow += opacity / m_shadowSettings->multiplicationFactor();
}
return alphaShadow;
}
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