QtPBFImagePlugin/src/pbfhandler.cpp

105 lines
2.2 KiB
C++

#include <QImage>
#include <QIODevice>
#include <QtEndian>
#include <QDebug>
#include "gzip.h"
#include "tile.h"
#include "style.h"
#include "pbfhandler.h"
#define TILE_SIZE 256
#define GZIP_MAGIC 0x1F8B0800
#define GZIP_MAGIC_MASK 0xFFFFFF00
#define PBF_MAGIC 0x1A000000
#define PBF_MAGIC_MASK 0xFF000000
static bool isMagic(quint32 magic, quint32 mask, quint32 value)
{
return ((qFromBigEndian(value) & mask) == magic);
}
static bool isGZIPPBF(quint32 magic)
{
return isMagic(GZIP_MAGIC, GZIP_MAGIC_MASK, magic);
}
static bool isPlainPBF(quint32 magic)
{
return isMagic(PBF_MAGIC, PBF_MAGIC_MASK, magic);
}
bool PBFHandler::canRead() const
{
if (canRead(device())) {
setFormat("pbf");
return true;
} else
return false;
}
bool PBFHandler::canRead(QIODevice *device)
{
quint32 magic;
qint64 size = device->peek((char*)&magic, sizeof(magic));
if (size != sizeof(magic))
return false;
return (isGZIPPBF(magic) || isPlainPBF(magic));
}
bool PBFHandler::read(QImage *image)
{
quint32 magic;
if (device()->peek((char*)&magic, sizeof(magic)) != sizeof(magic))
return false;
QByteArray ba;
if (isGZIPPBF(magic))
ba = Gzip::uncompress(device()->readAll());
else if (isPlainPBF(magic))
ba = device()->readAll();
if (ba.isNull())
return false;
vector_tile::Tile data;
if (!data.ParseFromArray(ba.constData(), ba.size())) {
qCritical() << "Invalid PBF data";
return false;
}
bool ok;
int zoom = format().toInt(&ok);
QSize size = _scaledSize.isValid()
? _scaledSize : QSize(TILE_SIZE, TILE_SIZE);
QPointF scale = _scaledSize.isValid()
? QPointF(_scaledSize.width() / TILE_SIZE, _scaledSize.height() / TILE_SIZE)
: QPointF(1.0, 1.0);
*image = QImage(size, QImage::Format_ARGB32_Premultiplied);
Tile tile(image, ok ? zoom : -1, scale);
_style->render(data, tile);
return true;
}
bool PBFHandler::supportsOption(ImageOption option) const
{
return (option == Size || option == ScaledSize);
}
void PBFHandler::setOption(QImageIOHandler::ImageOption option,
const QVariant &value)
{
if (option == ScaledSize)
_scaledSize = value.toSize();
}
QVariant PBFHandler::option(ImageOption option) const
{
return (option == Size) ? QSize(TILE_SIZE, TILE_SIZE) : QVariant();
}