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Diffstat (limited to 'src/plugins/imageformats/tga/qtgafile.cpp')
| -rw-r--r-- | src/plugins/imageformats/tga/qtgafile.cpp | 239 |
1 files changed, 239 insertions, 0 deletions
diff --git a/src/plugins/imageformats/tga/qtgafile.cpp b/src/plugins/imageformats/tga/qtgafile.cpp new file mode 100644 index 0000000..af7c876 --- /dev/null +++ b/src/plugins/imageformats/tga/qtgafile.cpp @@ -0,0 +1,239 @@ +/**************************************************************************** +** +** 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. +** +** +** +** +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include "qtgafile.h" + +#include <QtCore/qiodevice.h> +#include <QtCore/qdebug.h> +#include <QtCore/qdatetime.h> + +struct TgaReader +{ + virtual ~TgaReader() {} + virtual QRgb operator()(QIODevice *s) const = 0; +}; + +struct Tga16Reader : public TgaReader +{ + ~Tga16Reader() {} + QRgb operator()(QIODevice *s) const + { + char ch1, ch2; + if (s->getChar(&ch1) && s->getChar(&ch2)) { + quint16 d = (int(ch1) & 0xFF) | ((int(ch2) & 0xFF) << 8); + QRgb result = (d & 0x8000) ? 0xFF000000 : 0x00000000; + result |= (d & 0x7C00 << 6) | (d & 0x03E0 << 3) | (d & 0x001F); + return result; + } else { + return 0; + } + } +}; + +struct Tga24Reader : public TgaReader +{ + QRgb operator()(QIODevice *s) const + { + char r, g, b; + if (s->getChar(&b) && s->getChar(&g) && s->getChar(&r)) + return qRgb(uchar(r), uchar(g), uchar(b)); + else + return 0; + } +}; + +struct Tga32Reader : public TgaReader +{ + QRgb operator()(QIODevice *s) const + { + char r, g, b, a; + if (s->getChar(&b) && s->getChar(&g) && s->getChar(&r) && s->getChar(&a)) + return qRgba(uchar(r), uchar(g), uchar(b), uchar(a)); + else + return 0; + } +}; + +/*! + \class QTgaFile + \since 4.8 + \internal + + File data container for a TrueVision Graphics format file. + + Format is as described here: + http://local.wasp.uwa.edu.au/~pbourke/dataformats/tga/ + http://netghost.narod.ru/gff2/graphics/summary/tga.htm + + Usage is: + \code + QTgaFile tga(myFile); + QImage tgaImage; + if (tga.isValid()) + tgaImage = tga.readImage(); + \endcode + + The class is designed to handle sequential and non-sequential + sources, so during construction the mHeader is read. Then during + the readImage() call the rest of the data is read. + + After passing myFile to the constructor, if the QIODevice *myFile + is read, or has seek() called, the results are undefined - so don't + do that. +*/ + +/*! + Construct a new QTgaFile object getting data from \a device. + + The object does not take ownership of the \a device, but until the + object is destroyed do not do any non-const operations, eg seek or + read on the device. +*/ +QTgaFile::QTgaFile(QIODevice *device) + : mDevice(device) +{ + ::memset(mHeader, 0, HeaderSize); + if (!mDevice->isReadable()) + { + mErrorMessage = QObject::tr("Could not read image data"); + return; + } + if (mDevice->isSequential()) + { + mErrorMessage = QObject::tr("Sequential device (eg socket) for image read not supported"); + return; + } + if (!mDevice->seek(0)) + { + mErrorMessage = QObject::tr("Seek file/device for image read failed"); + return; + } + int bytes = device->read((char*)mHeader, HeaderSize); + if (bytes != HeaderSize) + { + mErrorMessage = QObject::tr("Image mHeader read failed"); + return; + } + if (mHeader[ImageType] != 2) + { + // TODO: should support other image types + mErrorMessage = QObject::tr("Image type not supported"); + return; + } +} + +/*! + \internal + Destroy the device, recovering any resources. +*/ +QTgaFile::~QTgaFile() +{ +} + +/*! + \internal + Reads an image file from the QTgaFile's device, and returns it. + + This method seeks to the absolute position of the image data in the file, + so no assumptions are made about where the devices read pointer is when this + method is called. For this reason only random access devices are supported. + + If the constructor completed successfully, such that isValid() returns true, + then this method is likely to succeed, unless the file is somehow corrupted. + + In the case that the read fails, the QImage returned will be null, such that + QImage::isNull() will be true. +*/ +QImage QTgaFile::readImage() +{ + if (!isValid()) + return QImage(); + + int offset = mHeader[IdLength]; // Mostly always zero + + // Even in TrueColor files a color pallette may be present + if (mHeader[ColorMapType] == 1) + offset += littleEndianInt(&mHeader[CMapLength]) * littleEndianInt(&mHeader[CMapDepth]); + + mDevice->seek(HeaderSize + offset); + + char dummy; + for (int i = 0; i < offset; ++i) + mDevice->getChar(&dummy); + + int bitsPerPixel = mHeader[PixelDepth]; + int imageWidth = width(); + int imageHeight = height(); + + unsigned char desc = mHeader[ImageDescriptor]; + //unsigned char xCorner = desc & 0x10; // 0 = left, 1 = right + unsigned char yCorner = desc & 0x20; // 0 = lower, 1 = upper + + QImage im(imageWidth, imageHeight, QImage::Format_ARGB32); + TgaReader *reader = 0; + if (bitsPerPixel == 16) + reader = new Tga16Reader(); + else if (bitsPerPixel == 24) + reader = new Tga24Reader(); + else if (bitsPerPixel == 32) + reader = new Tga32Reader(); + TgaReader &read = *reader; + + // For now only deal with yCorner, since no one uses xCorner == 1 + // Also this is upside down, since Qt has the origin flipped + if (yCorner) + { + for (int y = 0; y < imageHeight; ++y) + for (int x = 0; x < imageWidth; ++x) + im.setPixel(x, y, read(mDevice)); + } + else + { + for (int y = imageHeight - 1; y >= 0; --y) + for (int x = 0; x < imageWidth; ++x) + im.setPixel(x, y, read(mDevice)); + } + + delete reader; + + // TODO: add processing of TGA extension information - ie TGA 2.0 files + return im; +} |