Long live QColorSpace and friends

Adds QColorSpace and QColorTransform classes,
and parsing of a common subset of ICC profiles
found in images, and also parses the ICC profiles
in PNG and JPEGs.

For backwards compatibility no automatic color
handling is done by this patch.

[ChangeLog][QtGui] A QColorSpace class has been added,
and color spaces are now parsed from PNG and JPEG images.
No automatic color space conversion is done however, and
applications must request it.

Change-Id: Ic09935f84640a716467fa3a9ed1e73c02daf3675
Reviewed-by: Eirik Aavitsland <eirik.aavitsland@qt.io>

1 files changed, 86 insertions, 0 deletions

diff --git a/src/gui/painting/qcolortrclut.cpp b/src/gui/painting/qcolortrclut.cpp
new file mode 100644
index 0000000000..268d7252b4
--- /dev/null
+++ b/src/gui/painting/qcolortrclut.cpp
@@ -0,0 +1,86 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtGui module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qcolortrclut_p.h"
+#include "qcolortransferfunction_p.h"
+#include "qcolortransfertable_p.h"
+#include <qmath.h>
+
+QT_BEGIN_NAMESPACE
+
+QColorTrcLut *QColorTrcLut::fromGamma(qreal gamma)
+{
+    QColorTrcLut *cp = new QColorTrcLut;
+
+    for (int i = 0; i <= (255 * 16); ++i) {
+        cp->m_toLinear[i] = ushort(qRound(qPow(i / qreal(255 * 16), gamma) * (255 * 256)));
+        cp->m_fromLinear[i] = ushort(qRound(qPow(i / qreal(255 * 16), qreal(1) / gamma) * (255 * 256)));
+    }
+
+    return cp;
+}
+
+QColorTrcLut *QColorTrcLut::fromTransferFunction(const QColorTransferFunction &fun)
+{
+    QColorTrcLut *cp = new QColorTrcLut;
+    QColorTransferFunction inv = fun.inverted();
+
+    for (int i = 0; i <= (255 * 16); ++i) {
+        cp->m_toLinear[i] = ushort(qRound(fun.apply(i / qreal(255 * 16)) * (255 * 256)));
+        cp->m_fromLinear[i] = ushort(qRound(inv.apply(i / qreal(255 * 16)) * (255 * 256)));
+    }
+
+    return cp;
+}
+
+QColorTrcLut *QColorTrcLut::fromTransferTable(const QColorTransferTable &table)
+{
+    QColorTrcLut *cp = new QColorTrcLut;
+
+    float minInverse = 0.0f;
+    for (int i = 0; i <= (255 * 16); ++i) {
+        cp->m_toLinear[i] = ushort(qBound(0, qRound(table.apply(i / qreal(255 * 16)) * (255 * 256)), 65280));
+        minInverse = table.applyInverse(i / qreal(255 * 16), minInverse);
+        cp->m_fromLinear[i] = ushort(qBound(0, qRound(minInverse * (255 * 256)), 65280));
+    }
+
+    return cp;
+}
+
+QT_END_NAMESPACE