Add API for reading and decoding graphical texture files

Add a framework for reading and decoding stored graphical texture file
formats. Includes decoders for the PKM and KTX formats.

This is basically the same texture file reading that was added to
qtdeclarative for 5.11, but has been refactored to be independent of
the scenegraph and opengl.

Task-number: QTBUG-67026
Change-Id: I87d8117550d8a2112f4f58c03e9ac6b3249cbc5a
Reviewed-by: Kai Koehne <kai.koehne@qt.io>
Reviewed-by: Laszlo Agocs <laszlo.agocs@qt.io>

1 files changed, 279 insertions, 0 deletions

diff --git a/src/gui/util/qtexturefiledata.cpp b/src/gui/util/qtexturefiledata.cpp
new file mode 100644
index 0000000000..f9129e86c2
--- /dev/null
+++ b/src/gui/util/qtexturefiledata.cpp
@@ -0,0 +1,279 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 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 "qtexturefiledata_p.h"
+#include <QMetaEnum>
+#if QT_CONFIG(opengl)
+#include <QOpenGLTexture>
+#endif
+
+QT_BEGIN_NAMESPACE
+
+Q_LOGGING_CATEGORY(lcQtGuiTextureIO, "qt.gui.textureio");
+
+class QTextureFileDataPrivate : public QSharedData
+{
+public:
+    QTextureFileDataPrivate()
+    {
+    }
+
+    QTextureFileDataPrivate(const QTextureFileDataPrivate &other)
+        : QSharedData(other),
+          logName(other.logName),
+          data(other.data),
+          offsets(other.offsets),
+          lengths(other.lengths),
+          size(other.size),
+          format(other.format)
+    {
+    }
+
+    ~QTextureFileDataPrivate()
+    {
+    }
+
+    void ensureLevels(int num, bool force = false)
+    {
+        const int newSize = force ? num : qMax(offsets.size(), num);
+        offsets.resize(newSize);
+        lengths.resize(newSize);
+    }
+
+    QByteArray logName;
+    QByteArray data;
+    QVector<int> offsets;
+    QVector<int> lengths;
+    QSize size;
+    quint32 format = 0;
+    quint32 internalFormat = 0;
+    quint32 baseInternalFormat = 0;
+};
+
+
+
+QTextureFileData::QTextureFileData()
+{
+}
+
+QTextureFileData::QTextureFileData(const QTextureFileData &other)
+    : d(other.d)
+{
+}
+
+QTextureFileData &QTextureFileData::operator=(const QTextureFileData &other)
+{
+    d = other.d;
+    return *this;
+}
+
+QTextureFileData::~QTextureFileData()
+{
+}
+
+bool QTextureFileData::isNull() const
+{
+    return !d;
+}
+
+bool QTextureFileData::isValid() const
+{
+    if (!d)
+        return false;
+
+    if (d->data.isEmpty() || d->size.isEmpty() || (!d->format && !d->internalFormat))
+        return false;
+
+    const int numChunks = d->offsets.size();
+    if (numChunks == 0 || (d->lengths.size() != numChunks))
+         return false;
+
+    const qint64 sz = d->data.size();
+    for (int i = 0; i < numChunks; i++) {
+        qint64 offi = d->offsets.at(i);
+        qint64 leni = d->lengths.at(i);
+        if (offi < 0 || offi >= sz || leni <= 0 || (offi + leni > sz))
+            return false;
+    }
+    return true;
+}
+
+void QTextureFileData::clear()
+{
+    d = nullptr;
+}
+
+QByteArray QTextureFileData::data() const
+{
+    return d ? d->data : QByteArray();
+}
+
+void QTextureFileData::setData(const QByteArray &data)
+{
+    if (!d.constData())  //### uh think about this design, this is the only way to create; should be constructor instead at least
+        d = new QTextureFileDataPrivate;
+
+    d->data = data;
+}
+
+int QTextureFileData::dataOffset(int level) const
+{
+    return (d && d->offsets.size() > level) ? d->offsets.at(level) : 0;
+}
+
+void QTextureFileData::setDataOffset(int offset, int level)
+{
+    if (d.constData() && level >= 0) {
+        d->ensureLevels(level + 1);
+        d->offsets[level] = offset;
+    }
+}
+
+int QTextureFileData::dataLength(int level) const
+{
+    return (d && d->lengths.size() > level) ? d->lengths.at(level) : 0;
+}
+
+void QTextureFileData::setDataLength(int length, int level)
+{
+    if (d.constData() && level >= 0) {
+        d->ensureLevels(level + 1);
+        d->lengths[level] = length;
+    }
+}
+
+int QTextureFileData::numLevels() const
+{
+    return d ? d->offsets.size() : 0;
+}
+
+void QTextureFileData::setNumLevels(int num)
+{
+    if (d && num >= 0)
+        d->ensureLevels(num, true);
+}
+
+QSize QTextureFileData::size() const
+{
+    return d ? d->size : QSize();
+}
+
+void QTextureFileData::setSize(const QSize &size)
+{
+    if (d.constData())
+        d->size = size;
+}
+
+quint32 QTextureFileData::glFormat() const
+{
+    return d ? d->format : 0;
+}
+
+void QTextureFileData::setGLFormat(quint32 format)
+{
+    if (d.constData())
+        d->format = format;
+}
+
+quint32 QTextureFileData::glInternalFormat() const
+{
+    return d ? d->internalFormat : 0;
+}
+
+void QTextureFileData::setGLInternalFormat(quint32 format)
+{
+    if (d.constData())
+        d->internalFormat = format;
+}
+
+quint32 QTextureFileData::glBaseInternalFormat() const
+{
+    return d ? d->baseInternalFormat : 0;
+}
+
+void QTextureFileData::setGLBaseInternalFormat(quint32 format)
+{
+    if (d.constData())
+        d->baseInternalFormat = format;
+}
+
+QByteArray QTextureFileData::logName() const
+{
+    return d ? d->logName : QByteArray();
+}
+
+void QTextureFileData::setLogName(const QByteArray &name)
+{
+    if (d.constData())
+        d->logName = name;
+}
+
+QByteArray glFormatName(quint32 fmt)
+{
+    const char *id = 0;
+#if QT_CONFIG(opengl)
+    id = QMetaEnum::fromType<QOpenGLTexture::TextureFormat>().valueToKey(fmt);
+#endif
+    QByteArray res(id ? id : "(?)");
+    res += " [0x" + QByteArray::number(fmt, 16).rightJustified(4, '0') + ']';
+    return res;
+}
+
+QDebug operator<<(QDebug dbg, const QTextureFileData &d)
+{
+    QDebugStateSaver saver(dbg);
+
+    dbg.nospace() << "QTextureFileData(";
+    if (!d.isNull()) {
+        dbg.space() << d.logName() << d.size();
+        dbg << "glFormat:" << glFormatName(d.glFormat());
+        dbg << "glInternalFormat:" << glFormatName(d.glInternalFormat());
+        dbg << "glBaseInternalFormat:" << glFormatName(d.glBaseInternalFormat());
+        dbg.nospace() << "Levels: " << d.numLevels();
+        if (!d.isValid())
+            dbg << " {Invalid}";
+        dbg << ")";
+    } else {
+        dbg << "null)";
+    }
+
+    return dbg;
+}
+
+QT_END_NAMESPACE