Copy the KDE 3.5 branch to branches/trinity for new KDE 3.5 features.

BUG:215923


git-svn-id: svn://anonsvn.kde.org/home/kde/branches/trinity/kdebase@1054174 283d02a7-25f6-0310-bc7c-ecb5cbfe19da

1 files changed, 194 insertions, 0 deletions

diff --git a/kdesktop/kshadowengine.cpp b/kdesktop/kshadowengine.cpp
new file mode 100644
index 000000000..12d0319d3
--- /dev/null
+++ b/kdesktop/kshadowengine.cpp
@@ -0,0 +1,194 @@
+/* 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;
+}