1/*
2 This file is part of the KDE project
3 SPDX-FileCopyrightText: 2003 Dominik Seichter <domseichter@web.de>
4 SPDX-FileCopyrightText: 2004 Ignacio Castaño <castano@ludicon.com>
5 SPDX-FileCopyrightText: 2010 Troy Unrau <troy@kde.org>
6 SPDX-FileCopyrightText: 2023 Mirco Miranda <mircomir@outlook.com>
7
8 SPDX-License-Identifier: LGPL-2.0-or-later
9*/
10
11#include "ras_p.h"
12#include "util_p.h"
13
14#include <QDataStream>
15#include <QDebug>
16#include <QImage>
17
18namespace // Private.
19{
20// format info from http://www.fileformat.info/format/sunraster/egff.htm
21
22// Header format of saved files.
23quint32 rasMagicBigEndian = 0x59a66a95;
24// quint32 rasMagicLittleEndian = 0x956aa659; # used to support wrong encoded files
25
26enum RASType {
27 RAS_TYPE_OLD = 0x0,
28 RAS_TYPE_STANDARD = 0x1,
29 RAS_TYPE_BYTE_ENCODED = 0x2,
30 RAS_TYPE_RGB_FORMAT = 0x3,
31 RAS_TYPE_TIFF_FORMAT = 0x4,
32 RAS_TYPE_IFF_FORMAT = 0x5,
33 RAS_TYPE_EXPERIMENTAL = 0xFFFF,
34};
35
36enum RASColorMapType {
37 RAS_COLOR_MAP_TYPE_NONE = 0x0,
38 RAS_COLOR_MAP_TYPE_RGB = 0x1,
39 RAS_COLOR_MAP_TYPE_RAW = 0x2,
40};
41
42struct RasHeader {
43 quint32 MagicNumber = 0;
44 quint32 Width = 0;
45 quint32 Height = 0;
46 quint32 Depth = 0;
47 quint32 Length = 0;
48 quint32 Type = 0;
49 quint32 ColorMapType = 0;
50 quint32 ColorMapLength = 0;
51 enum {
52 SIZE = 32,
53 }; // 8 fields of four bytes each
54};
55
56static QDataStream &operator>>(QDataStream &s, RasHeader &head)
57{
58 s >> head.MagicNumber;
59 s >> head.Width;
60 s >> head.Height;
61 s >> head.Depth;
62 s >> head.Length;
63 s >> head.Type;
64 s >> head.ColorMapType;
65 s >> head.ColorMapLength;
66 /*qDebug() << "MagicNumber: " << head.MagicNumber
67 << "Width: " << head.Width
68 << "Height: " << head.Height
69 << "Depth: " << head.Depth
70 << "Length: " << head.Length
71 << "Type: " << head.Type
72 << "ColorMapType: " << head.ColorMapType
73 << "ColorMapLength: " << head.ColorMapLength;*/
74 return s;
75}
76
77static bool IsSupported(const RasHeader &head)
78{
79 // check magic number
80 if (head.MagicNumber != rasMagicBigEndian) {
81 return false;
82 }
83 // check for an appropriate depth
84 if (head.Depth != 1 && head.Depth != 8 && head.Depth != 24 && head.Depth != 32) {
85 return false;
86 }
87 if (head.Width == 0 || head.Height == 0) {
88 return false;
89 }
90 // the Type field adds support for RLE(BGR), RGB and other encodings
91 // we support Type 1: Normal(BGR), Type 2: RLE(BGR) and Type 3: Normal(RGB) ONLY!
92 // TODO: add support for Type 4,5: TIFF/IFF
93 if (!(head.Type == RAS_TYPE_STANDARD || head.Type == RAS_TYPE_RGB_FORMAT || head.Type == RAS_TYPE_BYTE_ENCODED)) {
94 return false;
95 }
96 return true;
97}
98
99static QImage::Format imageFormat(const RasHeader &header)
100{
101 if (header.ColorMapType == RAS_COLOR_MAP_TYPE_RGB) {
102 return QImage::Format_Indexed8;
103 }
104 if (header.Depth == 8 && header.ColorMapType == RAS_COLOR_MAP_TYPE_NONE) {
105 return QImage::Format_Grayscale8;
106 }
107 if (header.Depth == 1) {
108 return QImage::Format_Mono;
109 }
110 return QImage::Format_RGB32;
111}
112
113class LineDecoder
114{
115public:
116 LineDecoder(QIODevice *d, const RasHeader &ras)
117 : device(d)
118 , header(ras)
119 {
120 }
121
122 QByteArray readLine(qint64 size)
123 {
124 /* *** uncompressed
125 */
126 if (header.Type != RAS_TYPE_BYTE_ENCODED) {
127 return device->read(maxlen: size);
128 }
129
130 /* *** rle compressed
131 * The Run-length encoding (RLE) scheme optionally used in Sun Raster
132 * files (Type = 0002h) is used to encode bytes of image data
133 * separately. RLE encoding may be found in any Sun Raster file
134 * regardless of the type of image data it contains.
135 *
136 * The RLE packets are typically three bytes in size:
137 * - The first byte is a Flag Value indicating the type of RLE packet.
138 * - The second byte is the Run Count.
139 * - The third byte is the Run Value.
140 *
141 * A Flag Value of 80h is followed by a Run Count in the range of 01h
142 * to FFh. The Run Value follows the Run count and is in the range of
143 * 00h to FFh. The pixel run is the Run Value repeated Run Count times.
144 * There are two exceptions to this algorithm. First, if the Run Count
145 * following the Flag Value is 00h, this is an indication that the run
146 * is a single byte in length and has a value of 80h. And second, if
147 * the Flag Value is not 80h, then it is assumed that the data is
148 * unencoded pixel data and is written directly to the output stream.
149 *
150 * source: http://www.fileformat.info/format/sunraster/egff.htm
151 */
152 for (qsizetype psz = 0, ptr = 0; uncBuffer.size() < size;) {
153 rleBuffer.append(a: device->read(maxlen: std::min(a: qint64(32768), b: size)));
154 qsizetype sz = rleBuffer.size();
155 if (psz == sz) {
156 break; // avoid infinite loop (data corrupted?!)
157 }
158 auto data = reinterpret_cast<uchar *>(rleBuffer.data());
159 for (; ptr < sz;) {
160 auto flag = data[ptr++];
161 if (flag == 0x80) {
162 if (ptr >= sz) {
163 ptr -= 1;
164 break;
165 }
166 auto cnt = data[ptr++];
167 if (cnt == 0) {
168 uncBuffer.append(c: char(0x80));
169 continue;
170 } else if (ptr >= sz) {
171 ptr -= 2;
172 break;
173 }
174 auto val = data[ptr++];
175 uncBuffer.append(a: QByteArray(1 + cnt, char(val)));
176 } else {
177 uncBuffer.append(c: char(flag));
178 }
179 }
180 if (ptr) { // remove consumed data
181 rleBuffer.remove(index: 0, len: ptr);
182 ptr = 0;
183 }
184 psz = rleBuffer.size();
185 }
186 if (uncBuffer.size() < size) {
187 return QByteArray(); // something wrong
188 }
189 auto line = uncBuffer.mid(index: 0, len: size);
190 uncBuffer.remove(index: 0, len: line.size()); // remove consumed data
191 return line;
192 }
193
194private:
195 QIODevice *device;
196 RasHeader header;
197
198 // RLE decoding buffers
199 QByteArray rleBuffer;
200 QByteArray uncBuffer;
201};
202
203static bool LoadRAS(QDataStream &s, const RasHeader &ras, QImage &img)
204{
205 // The width of a scan line is always a multiple of 16 bits, padded when necessary.
206 auto rasLineSize = (qint64(ras.Width) * ras.Depth + 7) / 8;
207 if (rasLineSize & 1)
208 ++rasLineSize;
209 if (rasLineSize > kMaxQVectorSize) {
210 qWarning() << "LoadRAS() unsupported line size" << rasLineSize;
211 return false;
212 }
213
214 // Allocate image
215 img = imageAlloc(width: ras.Width, height: ras.Height, format: imageFormat(header: ras));
216 if (img.isNull()) {
217 return false;
218 }
219
220 // Read palette if needed.
221 if (ras.ColorMapType == RAS_COLOR_MAP_TYPE_RGB) {
222 // max 256 rgb elements palette is supported
223 if (ras.ColorMapLength > 768) {
224 return false;
225 }
226 QList<quint8> palette(ras.ColorMapLength);
227 for (quint32 i = 0; i < ras.ColorMapLength; ++i) {
228 s >> palette[i];
229 if (s.status() != QDataStream::Ok) {
230 return false;
231 }
232 }
233 QList<QRgb> colorTable;
234 for (quint32 i = 0, n = ras.ColorMapLength / 3; i < n; ++i) {
235 colorTable << qRgb(r: palette.at(i), g: palette.at(i: i + n), b: palette.at(i: i + 2 * n));
236 }
237 for (; colorTable.size() < 256;) {
238 colorTable << qRgb(r: 255, g: 255, b: 255);
239 }
240 img.setColorTable(colorTable);
241 }
242
243 LineDecoder dec(s.device(), ras);
244 auto bytesPerLine = std::min(a: img.bytesPerLine(), b: qsizetype(rasLineSize));
245 for (quint32 y = 0; y < ras.Height; ++y) {
246 auto rasLine = dec.readLine(size: rasLineSize);
247 if (rasLine.size() != rasLineSize) {
248 qWarning() << "LoadRAS() unable to read line" << y << ": the seems corrupted!";
249 return false;
250 }
251
252 // Grayscale 1-bit / Grayscale 8-bit (never seen)
253 if (ras.ColorMapType == RAS_COLOR_MAP_TYPE_NONE && (ras.Depth == 1 || ras.Depth == 8)) {
254 for (auto &&b : rasLine) {
255 b = ~b;
256 }
257 std::memcpy(dest: img.scanLine(y), src: rasLine.constData(), n: bytesPerLine);
258 continue;
259 }
260
261 // Image with palette
262 if (ras.ColorMapType == RAS_COLOR_MAP_TYPE_RGB && (ras.Depth == 1 || ras.Depth == 8)) {
263 std::memcpy(dest: img.scanLine(y), src: rasLine.constData(), n: bytesPerLine);
264 continue;
265 }
266
267 // BGR 24-bit
268 if (ras.ColorMapType == RAS_COLOR_MAP_TYPE_NONE && ras.Depth == 24 && (ras.Type == RAS_TYPE_STANDARD || ras.Type == RAS_TYPE_BYTE_ENCODED)) {
269 quint8 red;
270 quint8 green;
271 quint8 blue;
272 auto scanLine = reinterpret_cast<QRgb *>(img.scanLine(y));
273 for (quint32 x = 0; x < ras.Width; x++) {
274 red = rasLine.at(i: x * 3 + 2);
275 green = rasLine.at(i: x * 3 + 1);
276 blue = rasLine.at(i: x * 3);
277 *(scanLine + x) = qRgb(r: red, g: green, b: blue);
278 }
279 continue;
280 }
281
282 // RGB 24-bit
283 if (ras.ColorMapType == RAS_COLOR_MAP_TYPE_NONE && ras.Depth == 24 && ras.Type == RAS_TYPE_RGB_FORMAT) {
284 quint8 red;
285 quint8 green;
286 quint8 blue;
287 auto scanLine = reinterpret_cast<QRgb *>(img.scanLine(y));
288 for (quint32 x = 0; x < ras.Width; x++) {
289 red = rasLine.at(i: x * 3);
290 green = rasLine.at(i: x * 3 + 1);
291 blue = rasLine.at(i: x * 3 + 2);
292 *(scanLine + x) = qRgb(r: red, g: green, b: blue);
293 }
294 continue;
295 }
296
297 // BGR 32-bit (not tested: test case missing)
298 if (ras.ColorMapType == RAS_COLOR_MAP_TYPE_NONE && ras.Depth == 32 && (ras.Type == RAS_TYPE_STANDARD || ras.Type == RAS_TYPE_BYTE_ENCODED)) {
299 quint8 red;
300 quint8 green;
301 quint8 blue;
302 auto scanLine = reinterpret_cast<QRgb *>(img.scanLine(y));
303 for (quint32 x = 0; x < ras.Width; x++) {
304 red = rasLine.at(i: x * 4 + 3);
305 green = rasLine.at(i: x * 4 + 2);
306 blue = rasLine.at(i: x * 4 + 1);
307 *(scanLine + x) = qRgb(r: red, g: green, b: blue);
308 }
309
310 continue;
311 }
312
313 // RGB 32-bit (tested: test case missing due to image too large)
314 if (ras.ColorMapType == RAS_COLOR_MAP_TYPE_NONE && ras.Depth == 32 && ras.Type == RAS_TYPE_RGB_FORMAT) {
315 quint8 red;
316 quint8 green;
317 quint8 blue;
318 auto scanLine = reinterpret_cast<QRgb *>(img.scanLine(y));
319 for (quint32 x = 0; x < ras.Width; x++) {
320 red = rasLine.at(i: x * 4 + 1);
321 green = rasLine.at(i: x * 4 + 2);
322 blue = rasLine.at(i: x * 4 + 3);
323 *(scanLine + x) = qRgb(r: red, g: green, b: blue);
324 }
325 continue;
326 }
327
328 qWarning() << "LoadRAS() unsupported format!"
329 << "ColorMapType:" << ras.ColorMapType << "Type:" << ras.Type << "Depth:" << ras.Depth;
330 return false;
331 }
332
333 return true;
334}
335} // namespace
336
337class RASHandlerPrivate
338{
339public:
340 RASHandlerPrivate() {}
341 ~RASHandlerPrivate() {}
342
343 RasHeader m_header;
344};
345
346
347RASHandler::RASHandler()
348 : QImageIOHandler()
349 , d(new RASHandlerPrivate)
350{
351}
352
353bool RASHandler::canRead() const
354{
355 if (canRead(device: device())) {
356 setFormat("ras");
357 return true;
358 }
359 return false;
360}
361
362bool RASHandler::canRead(QIODevice *device)
363{
364 if (!device) {
365 qWarning(msg: "RASHandler::canRead() called with no device");
366 return false;
367 }
368
369 auto head = device->peek(maxlen: RasHeader::SIZE); // header is exactly 32 bytes, always FIXME
370 if (head.size() < RasHeader::SIZE) {
371 return false;
372 }
373
374 QDataStream stream(head);
375 stream.setByteOrder(QDataStream::BigEndian);
376 RasHeader ras;
377 stream >> ras;
378 return IsSupported(head: ras);
379}
380
381bool RASHandler::read(QImage *outImage)
382{
383 QDataStream s(device());
384 s.setByteOrder(QDataStream::BigEndian);
385
386 // Read image header.
387 auto&& ras = d->m_header;
388 s >> ras;
389
390 if (ras.ColorMapLength > kMaxQVectorSize) {
391 qWarning() << "LoadRAS() unsupported image color map length in file header" << ras.ColorMapLength;
392 return false;
393 }
394
395 // Check supported file types.
396 if (!IsSupported(head: ras)) {
397 // qDebug() << "This RAS file is not supported.";
398 return false;
399 }
400
401 QImage img;
402 if (!LoadRAS(s, ras, img)) {
403 // qDebug() << "Error loading RAS file.";
404 return false;
405 }
406
407 *outImage = img;
408 return true;
409}
410
411bool RASHandler::supportsOption(ImageOption option) const
412{
413 if (option == QImageIOHandler::Size) {
414 return true;
415 }
416 if (option == QImageIOHandler::ImageFormat) {
417 return true;
418 }
419 return false;
420}
421
422QVariant RASHandler::option(ImageOption option) const
423{
424 QVariant v;
425
426 if (option == QImageIOHandler::Size) {
427 auto&& header = d->m_header;
428 if (IsSupported(head: header)) {
429 v = QVariant::fromValue(value: QSize(header.Width, header.Height));
430 }
431 else if (auto dev = device()) {
432 QDataStream s(dev->peek(maxlen: RasHeader::SIZE));
433 s.setByteOrder(QDataStream::BigEndian);
434 s >> header;
435 if (s.status() == QDataStream::Ok && IsSupported(head: header)) {
436 v = QVariant::fromValue(value: QSize(header.Width, header.Height));
437 }
438 }
439 }
440
441 if (option == QImageIOHandler::ImageFormat) {
442 auto&& header = d->m_header;
443 if (IsSupported(head: header)) {
444 v = QVariant::fromValue(value: imageFormat(header));
445 }
446 else if (auto dev = device()) {
447 QDataStream s(dev->peek(maxlen: RasHeader::SIZE));
448 s.setByteOrder(QDataStream::BigEndian);
449 s >> header;
450 if (s.status() == QDataStream::Ok && IsSupported(head: header)) {
451 v = QVariant::fromValue(value: imageFormat(header));
452 }
453 }
454 }
455
456 return v;
457}
458
459QImageIOPlugin::Capabilities RASPlugin::capabilities(QIODevice *device, const QByteArray &format) const
460{
461 if (format == "im1" || format == "im8" || format == "im24" || format == "im32" || format == "ras" || format == "sun") {
462 return Capabilities(CanRead);
463 }
464 if (!format.isEmpty()) {
465 return {};
466 }
467 if (!device->isOpen()) {
468 return {};
469 }
470
471 Capabilities cap;
472 if (device->isReadable() && RASHandler::canRead(device)) {
473 cap |= CanRead;
474 }
475 return cap;
476}
477
478QImageIOHandler *RASPlugin::create(QIODevice *device, const QByteArray &format) const
479{
480 QImageIOHandler *handler = new RASHandler;
481 handler->setDevice(device);
482 handler->setFormat(format);
483 return handler;
484}
485
486#include "moc_ras_p.cpp"
487

source code of kimageformats/src/imageformats/ras.cpp