1 files changed, 92 insertions, 0 deletions
diff --git a/ksvg/core/KSVGHelper.cpp b/ksvg/core/KSVGHelper.cpp
new file mode 100644
index 00000000..86d111a6
--- /dev/null
+++ b/ksvg/core/KSVGHelper.cpp
@@ -0,0 +1,92 @@
+/*
+    Copyright (C) 2003 KSVG Team
+    This file is part of the KDE project
+
+    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 "KSVGHelper.h"
+
+using namespace KSVG;
+
+bool KSVGHelper::m_initialised = false;
+
+int KSVGHelper::m_linearRGBFromsRGB[256];
+int KSVGHelper::m_sRGBFromLinearRGB[256];
+
+// Force initialisation of the lookup tables
+static KSVGHelper ksvgHelper;
+
+KSVGHelper::KSVGHelper()
+{
+	if(!m_initialised)
+	{
+		initialise();
+		m_initialised = true;
+	}
+}
+
+void KSVGHelper::initialise()
+{
+	// Set up linearRGB - sRGB conversion tables
+	for(int i = 0; i < 256; i++)
+	{
+		m_linearRGBFromsRGB[i] = calcLinearRGBFromsRGB(i);
+		m_sRGBFromLinearRGB[i] = calcSRGBFromLinearRGB(i);
+	}
+}
+
+int KSVGHelper::calcLinearRGBFromsRGB(int sRGB8bit)
+{
+	double sRGB = sRGB8bit / 255.0;
+	double linearRGB;
+
+	if(sRGB <= 0.04045)
+		linearRGB = sRGB / 12.92;
+	else
+		linearRGB = pow((sRGB + 0.055) / 1.055, 2.4);
+
+	return static_cast<int>(linearRGB * 255 + 0.5);
+}
+
+int KSVGHelper::calcSRGBFromLinearRGB(int linearRGB8bit)
+{
+	double linearRGB = linearRGB8bit / 255.0;
+	double sRGB;
+
+	if(linearRGB <= 0.0031308)
+		sRGB = linearRGB * 12.92;
+	else
+		sRGB = 1.055 * pow(linearRGB, 1 / 2.4) - 0.055;
+
+	return static_cast<int>(sRGB * 255 + 0.5);
+}
+
+extern "C"
+int linearRGBFromsRGB(int sRGB8bit)
+{
+	return KSVGHelper::linearRGBFromsRGB(sRGB8bit);
+}
+
+extern "C"
+int sRGBFromLinearRGB(int linearRGB8bit)
+{
+	return KSVGHelper::sRGBFromLinearRGB(linearRGB8bit);
+}
+
+// vim:ts=4:noet