qt6-bb10/src/gui/image/qxbmhandler.cpp

338 lines
8.7 KiB
C++

// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
#include <qplatformdefs.h>
#include "private/qxbmhandler_p.h"
#ifndef QT_NO_IMAGEFORMAT_XBM
#include <qimage.h>
#include <qiodevice.h>
#include <qloggingcategory.h>
#include <qvariant.h>
#include <private/qtools_p.h>
#include <stdio.h>
QT_BEGIN_NAMESPACE
using namespace QtMiscUtils;
Q_DECLARE_LOGGING_CATEGORY(lcImageIo)
/*****************************************************************************
X bitmap image read/write functions
*****************************************************************************/
static inline int hex2byte(char *p)
{
return QtMiscUtils::fromHex(p[0]) * 16 | QtMiscUtils::fromHex(p[1]);
}
static bool read_xbm_header(QIODevice *device, int& w, int& h)
{
const int buflen = 300;
const int maxlen = 4096;
char buf[buflen + 1];
qint64 readBytes = 0;
qint64 totalReadBytes = 0;
buf[0] = '\0';
// skip initial comment, if any
while (buf[0] != '#') {
readBytes = device->readLine(buf, buflen);
// if readBytes >= buflen, it's very probably not a C file
if (readBytes <= 0 || readBytes >= buflen -1)
return false;
// limit xbm headers to the first 4k in the file to prevent
// excessive reads on non-xbm files
totalReadBytes += readBytes;
if (totalReadBytes >= maxlen)
return false;
}
auto parseDefine = [] (const char *buf, int len) -> int {
auto checkChar = [] (char ch) -> bool {
return isAsciiLetterOrNumber(ch)
|| ch == '_' || ch == '.';
};
auto isAsciiSpace = [] (char ch) -> bool {
return ch == ' ' || ch == '\t';
};
const char define[] = "#define";
constexpr size_t defineLen = sizeof(define) - 1;
if (strncmp(buf, define, defineLen) != 0)
return 0;
int index = defineLen;
while (buf[index] && isAsciiSpace(buf[index]))
++index;
while (buf[index] && checkChar(buf[index]))
++index;
while (buf[index] && isAsciiSpace(buf[index]))
++index;
return QByteArray(buf + index, len - index).toInt();
};
// "#define .._width <num>"
w = parseDefine(buf, readBytes - 1);
readBytes = device->readLine(buf, buflen);
// "#define .._height <num>"
h = parseDefine(buf, readBytes - 1);
// format error
if (w <= 0 || w > 32767 || h <= 0 || h > 32767)
return false;
return true;
}
static bool read_xbm_body(QIODevice *device, int w, int h, QImage *outImage)
{
const int buflen = 300;
char buf[buflen + 1];
qint64 readBytes = 0;
char *p;
// scan for database
do {
if ((readBytes = device->readLine(buf, buflen)) <= 0) {
// end of file
return false;
}
buf[readBytes] = '\0';
p = strstr(buf, "0x");
} while (!p);
if (!QImageIOHandler::allocateImage(QSize(w, h), QImage::Format_MonoLSB, outImage))
return false;
outImage->fill(Qt::color0); // in case the image data does not cover the full image
outImage->setColorCount(2);
outImage->setColor(0, qRgb(255,255,255)); // white
outImage->setColor(1, qRgb(0,0,0)); // black
int x = 0, y = 0;
uchar *b = outImage->scanLine(0);
w = (w+7)/8; // byte width
while (y < h) { // for all encoded bytes...
if (p && p < (buf + readBytes - 3)) { // p = "0x.."
const int byte = hex2byte(p + 2);
if (byte < 0) // non-hex char encountered
return false;
*b++ = byte;
p += 2;
if (++x == w && ++y < h) {
b = outImage->scanLine(y);
x = 0;
}
p = strstr(p, "0x");
} else { // read another line
if ((readBytes = device->readLine(buf,buflen)) <= 0) // EOF ==> truncated image
break;
buf[readBytes] = '\0';
p = strstr(buf, "0x");
}
}
return true;
}
static bool read_xbm_image(QIODevice *device, QImage *outImage)
{
int w = 0, h = 0;
if (!read_xbm_header(device, w, h))
return false;
return read_xbm_body(device, w, h, outImage);
}
static bool write_xbm_image(const QImage &sourceImage, QIODevice *device, const QString &fileName)
{
QImage image = sourceImage;
int w = image.width();
int h = image.height();
int i;
const QByteArray s = fileName.toUtf8(); // get file base name
const auto msize = s.size() + 100;
char *buf = new char[msize];
qsnprintf(buf, msize, "#define %s_width %d\n", s.data(), w);
device->write(buf, qstrlen(buf));
qsnprintf(buf, msize, "#define %s_height %d\n", s.data(), h);
device->write(buf, qstrlen(buf));
qsnprintf(buf, msize, "static char %s_bits[] = {\n ", s.data());
device->write(buf, qstrlen(buf));
if (image.format() != QImage::Format_MonoLSB)
image = image.convertToFormat(QImage::Format_MonoLSB);
bool invert = qGray(image.color(0)) < qGray(image.color(1));
char hexrep[16];
for (i=0; i<10; i++)
hexrep[i] = '0' + i;
for (i=10; i<16; i++)
hexrep[i] = 'a' -10 + i;
if (invert) {
char t;
for (i=0; i<8; i++) {
t = hexrep[15-i];
hexrep[15-i] = hexrep[i];
hexrep[i] = t;
}
}
int bcnt = 0;
char *p = buf;
int bpl = (w+7)/8;
for (int y = 0; y < h; ++y) {
const uchar *b = image.constScanLine(y);
for (i = 0; i < bpl; ++i) {
*p++ = '0'; *p++ = 'x';
*p++ = hexrep[*b >> 4];
*p++ = hexrep[*b++ & 0xf];
if (i < bpl - 1 || y < h - 1) {
*p++ = ',';
if (++bcnt > 14) {
*p++ = '\n';
*p++ = ' ';
*p = '\0';
if ((int)qstrlen(buf) != device->write(buf, qstrlen(buf))) {
delete [] buf;
return false;
}
p = buf;
bcnt = 0;
}
}
}
}
#ifdef Q_CC_MSVC
strcpy_s(p, sizeof(" };\n"), " };\n");
#else
strcpy(p, " };\n");
#endif
if ((int)qstrlen(buf) != device->write(buf, qstrlen(buf))) {
delete [] buf;
return false;
}
delete [] buf;
return true;
}
QXbmHandler::QXbmHandler()
: state(Ready)
{
}
bool QXbmHandler::readHeader()
{
state = Error;
if (!read_xbm_header(device(), width, height))
return false;
state = ReadHeader;
return true;
}
bool QXbmHandler::canRead() const
{
if (state == Ready && !canRead(device()))
return false;
if (state != Error) {
setFormat("xbm");
return true;
}
return false;
}
bool QXbmHandler::canRead(QIODevice *device)
{
if (!device) {
qCWarning(lcImageIo, "QXbmHandler::canRead() called with no device");
return false;
}
// it's impossible to tell whether we can load an XBM or not when
// it's from a sequential device, as the only way to do it is to
// attempt to parse the whole image.
if (device->isSequential())
return false;
QImage image;
qint64 oldPos = device->pos();
bool success = read_xbm_image(device, &image);
device->seek(oldPos);
return success;
}
bool QXbmHandler::read(QImage *image)
{
if (state == Error)
return false;
if (state == Ready && !readHeader()) {
state = Error;
return false;
}
if (!read_xbm_body(device(), width, height, image)) {
state = Error;
return false;
}
state = Ready;
return true;
}
bool QXbmHandler::write(const QImage &image)
{
return write_xbm_image(image, device(), fileName);
}
bool QXbmHandler::supportsOption(ImageOption option) const
{
return option == Name
|| option == Size
|| option == ImageFormat;
}
QVariant QXbmHandler::option(ImageOption option) const
{
if (option == Name) {
return fileName;
} else if (option == Size) {
if (state == Error)
return QVariant();
if (state == Ready && !const_cast<QXbmHandler*>(this)->readHeader())
return QVariant();
return QSize(width, height);
} else if (option == ImageFormat) {
return QImage::Format_MonoLSB;
}
return QVariant();
}
void QXbmHandler::setOption(ImageOption option, const QVariant &value)
{
if (option == Name)
fileName = value.toString();
}
QT_END_NAMESPACE
#endif // QT_NO_IMAGEFORMAT_XBM