summaryrefslogtreecommitdiff
path: root/Build/source/texk/dvisvgm/dvisvgm-1.0.9/src/GFReader.cpp
blob: b47c175f048139eaba5035c58f1b86b0a70c3bee (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
/*************************************************************************
** GFReader.cpp                                                         **
**                                                                      **
** This file is part of dvisvgm -- the DVI to SVG converter             **
** Copyright (C) 2005-2011 Martin Gieseking <martin.gieseking@uos.de>   **
**                                                                      **
** This program is free software; you can redistribute it and/or        **
** modify it under the terms of the GNU General Public License as       **
** published by the Free Software Foundation; either version 3 of       **
** the License, or (at your option) any later version.                  **
**                                                                      **
** This program is distributed in the hope that it will be useful, but  **
** WITHOUT ANY WARRANTY; without even the implied warranty of           **
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the         **
** GNU General Public License for more details.                         **
**                                                                      **
** You should have received a copy of the GNU General Public License    **
** along with this program; if not, see <http://www.gnu.org/licenses/>. **
*************************************************************************/

#include <iostream>
#include <sstream>
#include "GFReader.h"
#include "macros.h"
#include "SignalHandler.h"

using namespace std;

struct GFCommand
{
	void (GFReader::*method)(int);
	int numBytes;
};


static inline double fix2double (Int32 fix) {
	return double(fix)/(1 << 20);
}


static inline double scaled2double (Int32 scaled) {
	return double(scaled)/(1 << 16);
}


GFReader::GFReader (istream &is) : _in(is)
{
	_minX = _maxX = _minY = _maxY = _x = _y = 0;
}


UInt32 GFReader::readUnsigned (int bytes) {
	UInt32 ret = 0;
	for (int i=bytes-1; i >= 0 && !_in.eof(); i--) {
		UInt32 b = _in.get();
		ret |= b << (8*i);
	}
	return ret;
}


Int32 GFReader::readSigned (int bytes) {
	Int32 ret = _in.get();
	if (ret & 128)        // negative value?
		ret |= 0xffffff00;
	for (int i=bytes-2; i >= 0 && !_in.eof(); i--)
		ret = (ret << 8) | _in.get();
	return ret;
}


string GFReader::readString (int bytes) {
	vector<char> buf(bytes+1);
	if (bytes > 0)
		_in.get(&buf[0], bytes+1);  // reads 'bytes' bytes (pos. bytes+1 is set to 0)
	else
		buf[0] = 0;
	return &buf[0];
}


/** Reads a single GF command from the current position of the input stream and calls the
 *  corresponding cmdFOO method.
 *  @return opcode of the executed command */
int GFReader::executeCommand () {
	SignalHandler::instance().check();
   /* Each cmdFOO command reads the necessary number of bytes from the stream so executeCommand
   doesn't need to know the exact GF command format. Some cmdFOO methods are used for multiple
	GF commands because they only differ in the size of their parameters. */
	static const GFCommand commands[] = {
		{&GFReader::cmdPaint, 1}, {&GFReader::cmdPaint, 2}, {&GFReader::cmdPaint, 3},                        // 64-66
		{&GFReader::cmdBoc, 0},   {&GFReader::cmdBoc1, 0},                                                   // 67-68
		{&GFReader::cmdEoc, 0},                                                                              // 69
		{&GFReader::cmdSkip, 0},  {&GFReader::cmdSkip, 1},  {&GFReader::cmdSkip, 2},{&GFReader::cmdSkip, 3}, // 70-73
		{&GFReader::cmdXXX, 1},   {&GFReader::cmdXXX, 2},   {&GFReader::cmdXXX, 3}, {&GFReader::cmdXXX, 4},  // 239-242
		{&GFReader::cmdYYY, 0},                                                                              // 243
		{&GFReader::cmdNop, 0},                                                                              // 244
		{&GFReader::cmdCharLoc, 0}, {&GFReader::cmdCharLoc0, 0},                                             // 245-246
		{&GFReader::cmdPre, 0},     {&GFReader::cmdPost, 0}, {&GFReader::cmdPostPost, 0}                     // 247-249
	};

	int opcode = _in.get();
	if (opcode < 0)  // at end of file?
		throw GFException("unexpected end of file");

	if (opcode >= 0 && opcode <= 63)
		cmdPaint0(opcode);
	else if (opcode >= 74 && opcode <= 238)
		cmdNewRow(opcode-74);
	else if (opcode >= 250) {
		ostringstream oss;
		oss << "undefined GF command (opcode " << opcode << ")";
		throw GFException(oss.str());
	}
	else {
		int offset = opcode <= 73 ? 64 : 239-(73-64+1);
		const GFCommand &cmd = commands[opcode-offset];
		if (cmd.method)
			(this->*cmd.method)(cmd.numBytes);
	}
	return opcode;
}


bool GFReader::executeChar (UInt8 c) {
	_in.clear();
	if (_charInfoMap.empty())
		executePostamble();          // read character info
	_in.clear();
	Iterator it = _charInfoMap.find(c);
	if (_in && it != _charInfoMap.end()) {
		_in.seekg(it->second.location, ios_base::beg);
		while (executeCommand() != 69);  // execute all commands until eoc is reached
		return true;
	}
	return false;
}


bool GFReader::executeAllChars () {
	_in.clear();
	if (_charInfoMap.empty())
		executePostamble();   // read character info
	_in.clear();
	if (_in) {
		_in.seekg(0);
		while (executeCommand() != 248); // execute all commands until postamble is reached
		return true;
	}
	return false;
}


bool GFReader::executePostamble () {
	_in.clear();
	if (!_in)
		return false;
	_in.seekg(-1, ios_base::end);
	while (_in.peek() == 223)         // skip fill bytes
		_in.seekg(-1, ios_base::cur);
	_in.seekg(-4, ios_base::cur);
	UInt32 q = readUnsigned(4);      // pointer to begin of postamble
	_in.seekg(q, ios_base::beg);      // now on begin of postamble
	while (executeCommand() != 249); // execute all commands until postpost is reached
	return true;
}


/** Returns the design size of this font int TeX point units. */
double GFReader::getDesignSize () const {
	return fix2double(_designSize);
}

/** Returns the number of horizontal pixels per point. */
double GFReader::getHPixelsPerPoint () const {
	return scaled2double(_hppp);
}

/** Returns the number of vertical pixels per point. */
double GFReader::getVPixelsPerPoint () const {
	return scaled2double(_vppp);
}

/** Returns the width of character c in TeX point units */
double GFReader::getCharWidth (UInt32 c) const {
	ConstIterator it = _charInfoMap.find(c%256);
	return it == _charInfoMap.end() ? 0 : it->second.width*getDesignSize()/(1<<24);
}

///////////////////////


/** Reads the preamble. */
void GFReader::cmdPre (int) {
	UInt32 i = readUnsigned(1);
	if (i == 131) {
		UInt32 k = readUnsigned(1);
		string s = readString(k);
		preamble(s);
	}
	else
		throw GFException("invalid identification number in GF preamble");
}


/** Reads the postamble. */
void GFReader::cmdPost (int) {
	readUnsigned(4);               // pointer to byte after final eoc
	_designSize = readUnsigned(4);  // design size of font in points
	_checksum   = readUnsigned(4);  // checksum
	_hppp       = readUnsigned(4);  // horizontal pixels per point (scaled int)
	_vppp       = readUnsigned(4);  // vertical pixels per point (scaled int)
	_in.seekg(16, ios_base::cur);   // skip x and y bounds
	postamble();
}


/** Reads trailing bytes at end of stream. */
void GFReader::cmdPostPost (int) {
	readUnsigned(4);   // pointer to begin of postamble
	UInt32 i = readUnsigned(1);
	if (i == 131)
		while (readUnsigned(1) == 223); // skip fill bytes
	else
		throw GFException("invalid identification number in GF preamble");
}


/** Inverts "paint color" (black to white or vice versa) of n pixels
 *  and advances the cursor by n.
 *  @param[in] n number of pixels to be inverted */
void GFReader::cmdPaint0 (int n) {
	if (_penDown)                    // set pixels?
		_bitmap.setBits(_y, _x, n);
	_x += n;
	_penDown = !_penDown;             // inverse pen state
}


/** Inverts "paint color" (black to white or vice versa) of n pixels
 *  and advances the cursor by n. The number n of pixels is read from
 *  the input stream.
 *  @param[in] len size of n in bytes */
void GFReader::cmdPaint (int len) {
	UInt32 pixels = readUnsigned(len);
	cmdPaint0(pixels);
}


/** Beginning of character (generic format). */
void GFReader::cmdBoc (int) {
	_currentChar = readSigned(4);
	readSigned(4);  // pointer to previous boc with same c mod 256
	_minX = readSigned(4);
	_maxX = readSigned(4);
	_minY = readSigned(4);
	_maxY = readSigned(4);
	_x = _minX;
	_y = _maxY;
	_penDown = false;
	_bitmap.resize(_minX, _maxX, _minY, _maxY);
	beginChar(_currentChar);
}


/** Beginning of character (compact format). */
void GFReader::cmdBoc1 (int) {
	_currentChar = readUnsigned(1);
	UInt32 dx = readUnsigned(1);
	_maxX = readUnsigned(1);
	_minX = _maxX - dx;
	UInt32 dy = readUnsigned(1);
	_maxY = readUnsigned(1);
	_minY = _maxY - dy;
	_x = _minX;
	_y = _maxY;
	_penDown = false;
	_bitmap.resize(_minX, _maxX, _minY, _maxY);
	beginChar(_currentChar);
}


/** End of character. */
void GFReader::cmdEoc (int) {
	endChar(_currentChar);
}


/** Moves cursor to the beginning of a following row and sets
 *  paint color to white.
 *  @param[in] len if 0: move to next row, otherwise: number of bytes to read.
 *                 The read value denotes the number of rows to be skipped.  */
void GFReader::cmdSkip (int len) {
	if (len == 0)
		_y--;
	else
		_y -= readUnsigned(len)+1;
	_x = _minX;
	_penDown = false;
}


/** Moves cursor to pixel number 'col' in the next row and sets
 *  the paint color to black.
 *  @param[in] col pixel/column number */
void GFReader::cmdNewRow (int col) {
	_x = _minX + col ;
	_y--;
	_penDown = true;
}


void GFReader::cmdXXX (int len) {
	UInt32 n = readUnsigned(len);
	string str = readString(n);
	special(str);
}


void GFReader::cmdYYY (int) {
	Int32 y = readSigned(4);
	numspecial(y);
}


/** Does nothing. */
void GFReader::cmdNop (int) {
}


/** Reads character locator (part of postamble) */
void GFReader::cmdCharLoc0 (int) {
	UInt8 c  = readUnsigned(1); // character code mod 256
	UInt8 dm = readUnsigned(1); //
	Int32 w  = readSigned(4);   // (1<<24)*characterWidth/designSize
	Int32 p   = readSigned(4);  // pointer to begin of (last) character data
	Int32 dx  = 65536*dm;
	Int32 dy  = 0;
	_charInfoMap[c] = CharInfo(dx, dy, w, p);
}


/** Reads character locator (part of postamble) */
void GFReader::cmdCharLoc (int) {
	UInt32 c = readUnsigned(1); // character code mod 256
	Int32 dx = readSigned(4);   // horizontal escapement (scaled pixel units)
	Int32 dy = readSigned(4);   // vertical escapement (scaled pixel units)
	Int32 w  = readSigned(4);   // (1<<24)*characterWidth/designSize
	Int32 p  = readSigned(4);   // pointer to begin of (last) character data
	_charInfoMap[c] = CharInfo(dx, dy, w, p);
}