Move tga support from Qt3d to Qt.

Rev-By: Samuel Rodal
Fix-for: QTBUG-21955

Part of fix for https://bugreports.qt.nokia.com/browse/QTBUG-21955

Having tga plugin inside a Qt add-on causes packaging problems.

There have been many queries over the years for tga support even tho it
is a niche image format.  It is particularly useful for OpenGL work as a
texture format since it is a blittable bitmap, but it is very
innefficient compared to png or jpg.

For this reason only read support is added, and this is documented.
Also add some unit tests.

The unit tests are in the qimagereader suite, and this is the right
place for them as the other formats are tested there.

Noticed that there was an annoying bug with tiff files and chased it
down, in the hope of getting a clean test case PASS.  Looks as tho
there is a bit of work for someone to fix the other FAILs, but the ones
for tga are all passing.

1 files changed, 146 insertions, 0 deletions

diff --git a/src/plugins/imageformats/tga/qtgafile.h b/src/plugins/imageformats/tga/qtgafile.h
new file mode 100644
index 0000000..034200e
--- /dev/null
+++ b/src/plugins/imageformats/tga/qtgafile.h
@@ -0,0 +1,146 @@
+/****************************************************************************
+**
+** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the QtQuick3D module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** GNU Lesser General Public License Usage
+** This file may be used under the terms of the GNU Lesser General Public
+** License version 2.1 as published by the Free Software Foundation and
+** appearing in the file LICENSE.LGPL included in the packaging of this
+** file. Please review the following information to ensure the GNU Lesser
+** General Public License version 2.1 requirements will be met:
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights. These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU General
+** Public License version 3.0 as published by the Free Software Foundation
+** and appearing in the file LICENSE.GPL included in the packaging of this
+** file. Please review the following information to ensure the GNU General
+** Public License version 3.0 requirements will be met:
+** http://www.gnu.org/copyleft/gpl.html.
+**
+** Other Usage
+** Alternatively, this file may be used in accordance with the terms and
+** conditions contained in a signed written agreement between you and Nokia.
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QTGAFILE_H
+#define QTGAFILE_H
+
+#include <QtGui/qcolor.h>
+#include <QtGui/qimage.h>
+
+class QIODevice;
+
+class QTgaFile
+{
+public:
+    enum Compression {
+        NoCompression = 0,
+        RleCompression = 1
+    };
+
+    enum HeaderOffset {
+        IdLength = 0,          /* 00h  Size of Image ID field */
+        ColorMapType = 1,      /* 01h  Color map type */
+        ImageType = 2,         /* 02h  Image type code */
+        CMapStart = 3,         /* 03h  Color map origin */
+        CMapLength = 5,        /* 05h  Color map length */
+        CMapDepth = 7,         /* 07h  Depth of color map entries */
+        XOffset = 8,           /* 08h  X origin of image */
+        YOffset = 10,          /* 0Ah  Y origin of image */
+        Width = 12,            /* 0Ch  Width of image */
+        Height = 14,           /* 0Eh  Height of image */
+        PixelDepth = 16,       /* 10h  Image pixel size */
+        ImageDescriptor = 17,  /* 11h  Image descriptor byte */
+        HeaderSize = 18
+    };
+
+    QTgaFile(QIODevice *);
+    ~QTgaFile();
+
+    inline bool isValid() const;
+    inline QString errorMessage() const;
+    QImage readImage();
+    inline int xOffset() const;
+    inline int yOffset() const;
+    inline int width() const;
+    inline int height() const;
+    inline QSize size() const;
+    inline Compression compression() const;
+
+private:
+    static inline quint16 littleEndianInt(const unsigned char *d);
+
+    QString mErrorMessage;
+    unsigned char mHeader[HeaderSize];
+    QIODevice *mDevice;
+};
+
+inline bool QTgaFile::isValid() const
+{
+    return mErrorMessage.isEmpty();
+}
+
+inline QString QTgaFile::errorMessage() const
+{
+    return mErrorMessage;
+}
+
+/*!
+    \internal
+    Returns the integer encoded in the two little endian bytes at \a d.
+*/
+inline quint16 QTgaFile::littleEndianInt(const unsigned char *d)
+{
+    return d[0] + d[1] * 256;
+}
+
+inline int QTgaFile::xOffset() const
+{
+    return littleEndianInt(&mHeader[XOffset]);
+}
+
+inline int QTgaFile::yOffset() const
+{
+    return littleEndianInt(&mHeader[YOffset]);
+}
+
+inline int QTgaFile::width() const
+{
+    return littleEndianInt(&mHeader[Width]);
+}
+
+inline int QTgaFile::height() const
+{
+    return littleEndianInt(&mHeader[Height]);
+}
+
+inline QSize QTgaFile::size() const
+{
+    return QSize(width(), height());
+}
+
+inline QTgaFile::Compression QTgaFile::compression() const
+{
+    // TODO: for now, only handle type 2 files, with no color table
+    // and no compression
+    return NoCompression;
+}
+
+#endif // QTGAFILE_H