kdelibs/kimgio/ras.cpp
2014-11-13 01:04:59 +02:00

327 lines
9.1 KiB
C++

/* This file is part of the KDE project
Copyright (C) 2003 Dominik Seichter <domseichter@web.de>
Copyright (C) 2004 Ignacio Castaño <castano@ludicon.com>
Copyright (C) 2010 Troy Unrau <troy@kde.org>
This program is free software; you can redistribute it and/or
modify it under the terms of the Lesser GNU General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
*/
#include "ras.h"
#include <QtGui/QImage>
#include <QtCore/QDataStream>
#include <kdebug.h>
namespace { // Private.
// format info from http://www.fileformat.info/format/sunraster/egff.htm
// Header format of saved files.
quint32 rasMagicBigEndian = 0x59a66a95;
// quint32 rasMagicLittleEndian = 0x956aa659; # used to support wrong encoded files
enum RASType {
RAS_TYPE_OLD = 0x0,
RAS_TYPE_STANDARD = 0x1,
RAS_TYPE_BYTE_ENCODED = 0x2,
RAS_TYPE_RGB_FORMAT = 0x3,
RAS_TYPE_TIFF_FORMAT = 0x4,
RAS_TYPE_IFF_FORMAT = 0x5,
RAS_TYPE_EXPERIMENTAL = 0xFFFF
};
enum RASColorMapType {
RAS_COLOR_MAP_TYPE_NONE = 0x0,
RAS_COLOR_MAP_TYPE_RGB = 0x1,
RAS_COLOR_MAP_TYPE_RAW = 0x2
};
struct RasHeader {
quint32 MagicNumber;
quint32 Width;
quint32 Height;
quint32 Depth;
quint32 Length;
quint32 Type;
quint32 ColorMapType;
quint32 ColorMapLength;
enum { SIZE = 32 }; // 8 fields of four bytes each
};
static QDataStream & operator>> ( QDataStream & s, RasHeader & head )
{
s >> head.MagicNumber;
s >> head.Width;
s >> head.Height;
s >> head.Depth;
s >> head.Length;
s >> head.Type;
s >> head.ColorMapType;
s >> head.ColorMapLength;
/*qDebug() << "MagicNumber: " << head.MagicNumber
<< "Width: " << head.Width
<< "Height: " << head.Height
<< "Depth: " << head.Depth
<< "Length: " << head.Length
<< "Type: " << head.Type
<< "ColorMapType: " << head.ColorMapType
<< "ColorMapLength: " << head.ColorMapLength;*/
return s;
}
static bool IsSupported( const RasHeader & head )
{
// check magic number
if ( head.MagicNumber != rasMagicBigEndian) {
return false;
}
// check for an appropriate depth
// we support 8bit+palette, 24bit and 32bit ONLY!
// TODO: add support for 1bit
if ( ! ((head.Depth == 8 && head.ColorMapType == 1)
|| head.Depth == 24 || head.Depth == 32) ){
return false;
}
// the Type field adds support for RLE(BGR), RGB and other encodings
// we support Type 1: Normal(BGR) and Type 3: Normal(RGB) ONLY!
// TODO: add support for Type 2: RLE(BGR) & Type 4,5: TIFF/IFF
if ( ! (head.Type == 1 || head.Type == 3) ){
return false;
}
// Old files didn't have Length set - reject them for now
// TODO: add length recalculation to support old files
if ( !head.Length ) {
return false;
}
return true;
}
static bool LoadRAS( QDataStream & s, const RasHeader & ras, QImage &img )
{
s.device()->seek(RasHeader::SIZE);
// Read palette if needed.
QVector<quint8> palette(ras.ColorMapLength);
if ( ras.ColorMapType == 1 ) {
for (quint32 i = 0; i < ras.ColorMapLength; ++i) { s >> palette[i]; }
}
// each line must be a factor of 16 bits, so they may contain padding
// this will be 1 if padding required, 0 otherwise
int paddingrequired = (ras.Width*(ras.Depth/8) % 2);
// qDebug() << "paddingrequired: " << paddingrequired;
// don't trust ras.Length
QVector<quint8> input(ras.Length);
int i = 0;
while ( ! s.atEnd()) {
s >> input[i];
// I guess we need to find out if we're at the end of a line
if ( paddingrequired && i != 0 && !(i % (ras.Width*(ras.Depth/8))) ) {
s >> input[i];
}
i++;
}
// Allocate image
img = QImage(ras.Width, ras.Height, QImage::Format_ARGB32);
// Reconstruct image from RGB palette if we have a palette
// TODO: make generic so it works with 24bit or 32bit palettes
if ( ras.ColorMapType == 1 && ras.Depth == 8) {
quint8 red, green, blue;
for ( quint32 y = 0; y < ras.Height; y++ ){
for ( quint32 x = 0; x < ras.Width; x++ ) {
red = palette[(int)input[y*ras.Width + x]];
green = palette[(int)input[y*ras.Width + x] + (ras.ColorMapLength/3)];
blue = palette[(int)input[y*ras.Width + x] + 2*(ras.ColorMapLength/3)];
img.setPixel(x, y, qRgb(red, green, blue));
}
}
}
if ( ras.ColorMapType == 0 && ras.Depth == 24 && (ras.Type == 1 || ras.Type == 2)) {
quint8 red, green, blue;
for ( quint32 y = 0; y < ras.Height; y++ ){
for ( quint32 x = 0; x < ras.Width; x++ ) {
red = input[y*3*ras.Width + x*3 + 2];
green = input[y*3*ras.Width + x*3 + 1];
blue = input[y*3*ras.Width + x*3];
img.setPixel(x, y, qRgb(red, green, blue));
}
}
}
if ( ras.ColorMapType == 0 && ras.Depth == 24 && ras.Type == 3) {
quint8 red, green, blue;
for ( quint32 y = 0; y < ras.Height; y++ ){
for ( quint32 x = 0; x < ras.Width; x++ ) {
red = input[y*3*ras.Width + x*3];
green = input[y*3*ras.Width + x*3 + 1];
blue = input[y*3*ras.Width + x*3 + 2];
img.setPixel(x, y, qRgb(red, green, blue));
}
}
}
if ( ras.ColorMapType == 0 && ras.Depth == 32 && (ras.Type == 1 || ras.Type == 2)) {
quint8 red, green, blue;
for ( quint32 y = 0; y < ras.Height; y++ ){
for ( quint32 x = 0; x < ras.Width; x++ ) {
red = input[y*4*ras.Width + x*4 + 3];
green = input[y*4*ras.Width + x*4 + 2];
blue = input[y*4*ras.Width + x*4 + 1];
img.setPixel(x, y, qRgb(red, green, blue));
}
}
}
if ( ras.ColorMapType == 0 && ras.Depth == 32 && ras.Type == 3 ) {
quint8 red, green, blue;
for ( quint32 y = 0; y < ras.Height; y++ ){
for ( quint32 x = 0; x < ras.Width; x++ ) {
red = input[y*4*ras.Width + x*4 + 1];
green = input[y*4*ras.Width + x*4 + 2];
blue = input[y*4*ras.Width + x*4 + 3];
img.setPixel(x, y, qRgb(red, green, blue));
}
}
}
return true;
}
} // namespace
RASHandler::RASHandler()
{
}
QByteArray RASHandler::name() const
{
return "ras";
}
bool RASHandler::canRead() const
{
if (canRead(device())) {
setFormat("ras");
return true;
}
return false;
}
bool RASHandler::canRead(QIODevice *device)
{
if (!device) {
qWarning("RASHandler::canRead() called with no device");
return false;
}
if (device->isSequential()) {
qWarning("Reading ras files from sequential devices not supported");
return false;
}
qint64 oldPos = device->pos();
QByteArray head = device->read(RasHeader::SIZE); // header is exactly 32 bytes, always FIXME
int readBytes = head.size(); // this should always be 32 bytes
device->seek(oldPos);
if (readBytes < RasHeader::SIZE) {
return false;
}
QDataStream stream(head);
stream.setByteOrder(QDataStream::BigEndian);
RasHeader ras;
stream >> ras;
return IsSupported(ras);
}
bool RASHandler::read(QImage *outImage)
{
QDataStream s( device() );
s.setByteOrder( QDataStream::BigEndian );
// Read image header.
RasHeader ras;
s >> ras;
// TODO: add support for old versions of RAS where Length may be zero in header
s.device()->seek( RasHeader::SIZE + ras.Length + ras.ColorMapLength );
// Check image file format. Type 2 is RLE, which causing seeking to be silly.
if( !s.atEnd() && ras.Type != 2) {
kDebug(399) << "This RAS file is not valid, or an older version of the format.";
return false;
}
// Check supported file types.
if( !IsSupported(ras) ) {
kDebug(399) << "This RAS file is not supported.";
return false;
}
QImage img;
bool result = LoadRAS(s, ras, img);
if( result == false ) {
kDebug(399) << "Error loading RAS file.";
return false;
}
*outImage = img;
return true;
}
/*
bool RASHandler::write(const QImage &image){
return false;
}*/
class RASPlugin : public QImageIOPlugin
{
public:
QStringList keys() const;
Capabilities capabilities(QIODevice *device, const QByteArray &format) const;
QImageIOHandler *create(QIODevice *device, const QByteArray &format = QByteArray()) const;
};
QStringList RASPlugin::keys() const
{
return QStringList() << "ras" << "RAS";
}
QImageIOPlugin::Capabilities RASPlugin::capabilities(QIODevice *device, const QByteArray &format) const
{
if (format == "ras" || format == "RAS")
return Capabilities(CanRead);
// return Capabilities(CanRead | CanWrite);
if (!format.isEmpty())
return 0;
if (!device->isOpen())
return 0;
Capabilities cap;
if (device->isReadable() && RASHandler::canRead(device))
cap |= CanRead;
if (device->isWritable())
cap |= CanWrite;
return cap;
}
QImageIOHandler *RASPlugin::create(QIODevice *device, const QByteArray &format) const
{
QImageIOHandler *handler = new RASHandler;
handler->setDevice(device);
handler->setFormat(format);
return handler;
}
Q_EXPORT_STATIC_PLUGIN(RASPlugin)
Q_EXPORT_PLUGIN2(ras, RASPlugin)