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authorNorbert Preining <norbert@preining.info>2019-09-02 13:46:59 +0900
committerNorbert Preining <norbert@preining.info>2019-09-02 13:46:59 +0900
commite0c6872cf40896c7be36b11dcc744620f10adf1d (patch)
tree60335e10d2f4354b0674ec22d7b53f0f8abee672 /dviware/dvisvgm/src/BasicDVIReader.cpp
Initial commit
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diff --git a/dviware/dvisvgm/src/BasicDVIReader.cpp b/dviware/dvisvgm/src/BasicDVIReader.cpp
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+/*************************************************************************
+** BasicDVIReader.cpp **
+** **
+** This file is part of dvisvgm -- a fast DVI to SVG converter **
+** Copyright (C) 2005-2019 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 <algorithm>
+#include <sstream>
+#include "BasicDVIReader.hpp"
+
+using namespace std;
+
+
+BasicDVIReader::BasicDVIReader (std::istream &is) : StreamReader(is), _dviVersion(DVI_NONE)
+{
+}
+
+
+/** Evaluates the next DVI command, and computes the corresponding handler.
+ * @param[out] handler handler for current DVI command
+ * @param[out] param the handler must be called with this parameter
+ * @return opcode of current DVI command */
+int BasicDVIReader::evalCommand (CommandHandler &handler, int &param) {
+ struct DVICommand {
+ CommandHandler handler;
+ int length; // number of parameter bytes
+ };
+
+ /* Each cmdFOO command reads the necessary number of bytes from the stream, so executeCommand
+ doesn't need to know the exact DVI command format. Some cmdFOO methods are used for multiple
+ DVI commands because they only differ in length of their parameters. */
+ static const DVICommand commands[] = {
+ {&BasicDVIReader::cmdSetChar, 1}, {&BasicDVIReader::cmdSetChar, 2}, // 128-129
+ {&BasicDVIReader::cmdSetChar, 3}, {&BasicDVIReader::cmdSetChar, 4}, // 130-131
+ {&BasicDVIReader::cmdSetRule, 8}, // 132
+ {&BasicDVIReader::cmdPutChar, 1}, {&BasicDVIReader::cmdPutChar, 2}, // 133-134
+ {&BasicDVIReader::cmdPutChar, 3}, {&BasicDVIReader::cmdPutChar, 4}, // 135-136
+ {&BasicDVIReader::cmdPutRule, 8}, // 137
+ {&BasicDVIReader::cmdNop, 0}, // 138
+ {&BasicDVIReader::cmdBop, 44}, {&BasicDVIReader::cmdEop, 0}, // 139-140
+ {&BasicDVIReader::cmdPush, 0}, {&BasicDVIReader::cmdPop, 0}, // 141-142
+ {&BasicDVIReader::cmdRight, 1}, {&BasicDVIReader::cmdRight, 2}, // 143-144
+ {&BasicDVIReader::cmdRight, 3}, {&BasicDVIReader::cmdRight, 4}, // 145-146
+ {&BasicDVIReader::cmdW0, 0}, // 147
+ {&BasicDVIReader::cmdW, 1}, {&BasicDVIReader::cmdW, 2}, // 148-149
+ {&BasicDVIReader::cmdW, 3}, {&BasicDVIReader::cmdW, 4}, // 150-151
+ {&BasicDVIReader::cmdX0, 0}, // 152
+ {&BasicDVIReader::cmdX, 1}, {&BasicDVIReader::cmdX, 2}, // 153-154
+ {&BasicDVIReader::cmdX, 3}, {&BasicDVIReader::cmdX, 4}, // 155-156
+ {&BasicDVIReader::cmdDown, 1}, {&BasicDVIReader::cmdDown, 2}, // 157-158
+ {&BasicDVIReader::cmdDown, 3}, {&BasicDVIReader::cmdDown, 4}, // 159-160
+ {&BasicDVIReader::cmdY0, 0}, // 161
+ {&BasicDVIReader::cmdY, 1}, {&BasicDVIReader::cmdY, 2}, // 162-163
+ {&BasicDVIReader::cmdY, 3}, {&BasicDVIReader::cmdY, 4}, // 164-165
+ {&BasicDVIReader::cmdZ0, 0}, // 166
+ {&BasicDVIReader::cmdZ, 1}, {&BasicDVIReader::cmdZ, 2}, // 167-168
+ {&BasicDVIReader::cmdZ, 3}, {&BasicDVIReader::cmdZ, 4}, // 169-170
+
+ {&BasicDVIReader::cmdFontNum, 1}, {&BasicDVIReader::cmdFontNum, 2}, // 235-236
+ {&BasicDVIReader::cmdFontNum, 3}, {&BasicDVIReader::cmdFontNum, 4}, // 237-238
+ {&BasicDVIReader::cmdXXX, 1}, {&BasicDVIReader::cmdXXX, 2}, // 239-240
+ {&BasicDVIReader::cmdXXX, 3}, {&BasicDVIReader::cmdXXX, 4}, // 241-242
+ {&BasicDVIReader::cmdFontDef, 1}, {&BasicDVIReader::cmdFontDef, 2}, // 243-244
+ {&BasicDVIReader::cmdFontDef, 3}, {&BasicDVIReader::cmdFontDef, 4}, // 245-246
+ {&BasicDVIReader::cmdPre, 0}, {&BasicDVIReader::cmdPost, 0}, // 247-248
+ {&BasicDVIReader::cmdPostPost, 0}, // 249
+ };
+
+ const int opcode = readByte();
+ if (!isStreamValid() || opcode < 0) // at end of file
+ throw InvalidDVIFileException("invalid DVI file");
+
+ int num_param_bytes = 0;
+ param = -1;
+ if (opcode >= OP_SETCHAR0 && opcode <= OP_SETCHAR127) {
+ handler = &BasicDVIReader::cmdSetChar0;
+ param = opcode;
+ }
+ else if (opcode >= OP_FNTNUM0 && opcode <= OP_FNTNUM63) {
+ handler = &BasicDVIReader::cmdFontNum0;
+ param = opcode-OP_FNTNUM0;
+ }
+ else if (evalXDVOpcode(opcode, handler))
+ num_param_bytes = 0;
+ else if (_dviVersion == DVI_PTEX && opcode == OP_DIR) { // direction command set by pTeX?
+ handler = &BasicDVIReader::cmdDir;
+ num_param_bytes = 1;
+ }
+ else if (opcode > OP_POSTPOST) {
+ ostringstream oss;
+ oss << "undefined DVI command (opcode " << opcode << ')';
+ throw DVIException(oss.str());
+ }
+ else {
+ const int offset = opcode < OP_FNTNUM0 ? OP_SET1 : (OP_FNTNUM63+1)-(OP_FNTNUM0-OP_SET1);
+ handler = commands[opcode-offset].handler;
+ num_param_bytes = commands[opcode-offset].length;
+ }
+ if (param < 0)
+ param = num_param_bytes;
+ return opcode;
+}
+
+
+/** Checks if a given opcode belongs to an XDV extension.
+ * @param[in] op the opcode to check
+ * @param[out] handler corresponding command handler if opcode is valid */
+bool BasicDVIReader::evalXDVOpcode (int op, CommandHandler &handler) const {
+ static const struct {
+ int min, max; // minimal and maximal opcode in XDV section
+ } xdvranges[] = {
+ {251, 254}, // XDV5
+ {252, 253}, // XDV6
+ {252, 254}, // XDV7
+ };
+ int index = _dviVersion-DVI_XDV5;
+ if (_dviVersion < DVI_XDV5 || _dviVersion > DVI_XDV7 || op < xdvranges[index].min || op > xdvranges[index].max)
+ return false;
+
+ static const CommandHandler handlers[] = {
+ &BasicDVIReader::cmdXPic, // 251 (XDV5 only)
+ &BasicDVIReader::cmdXFontDef, // 252
+ &BasicDVIReader::cmdXGlyphArray, // 253
+ &BasicDVIReader::cmdXTextAndGlyphs, // 254 (XDV7 only)
+ &BasicDVIReader::cmdXGlyphString // 254 (XDV5 only)
+ };
+ index = op-251;
+ if (_dviVersion == DVI_XDV5 && op == 254)
+ index++;
+ handler = handlers[index];
+ return true;
+}
+
+
+/** Reads a single DVI command from the current position of the input stream and calls the
+ * corresponding cmdFOO method.
+ * @return opcode of the executed command */
+int BasicDVIReader::executeCommand () {
+ CommandHandler handler;
+ int param; // parameter of handler
+ int opcode = evalCommand(handler, param);
+ (this->*handler)(param);
+ return opcode;
+}
+
+
+void BasicDVIReader::executePostPost () {
+ clearStream(); // reset all status bits
+ if (!isStreamValid())
+ throw DVIException("invalid DVI file");
+
+ seek(-1, ios::end); // stream pointer to last byte
+ int count=0;
+ while (peek() == DVI_FILL) { // count trailing fill bytes
+ seek(-1, ios::cur);
+ count++;
+ }
+ if (count < 4) // the standard requires at least 4 trailing fill bytes
+ throw DVIException("missing fill bytes at end of file");
+
+ setDVIVersion((DVIVersion)readUnsigned(1));
+}
+
+
+void BasicDVIReader::executeAllPages () {
+ if (_dviVersion == DVI_NONE)
+ executePostPost(); // get version ID from post_post
+ seek(0); // go to preamble
+ while (executeCommand() != OP_POST); // execute all commands until postamble is reached
+}
+
+
+void BasicDVIReader::setDVIVersion (DVIVersion version) {
+ _dviVersion = max(_dviVersion, version);
+ switch (_dviVersion) {
+ case DVI_STANDARD:
+ case DVI_PTEX:
+ case DVI_XDV5:
+ case DVI_XDV6:
+ case DVI_XDV7:
+ break;
+ default:
+ ostringstream oss;
+ oss << "DVI version " << _dviVersion << " not supported";
+ throw DVIException(oss.str());
+ }
+}
+
+/////////////////////////////////////
+
+/** Executes preamble command.
+ * Format: pre i[1] num[4] den[4] mag[4] k[1] x[k] */
+void BasicDVIReader::cmdPre (int) {
+ setDVIVersion((DVIVersion)readUnsigned(1)); // identification number
+ seek(12, ios::cur); // skip numerator, denominator, and mag factor
+ uint32_t k = readUnsigned(1); // length of following comment
+ seek(k, ios::cur); // skip comment
+}
+
+
+/** Executes postamble command.
+ * Format: post p[4] num[4] den[4] mag[4] l[4] u[4] s[2] t[2] */
+void BasicDVIReader::cmdPost (int) {
+ seek(28, ios::cur);
+}
+
+
+/** Executes postpost command.
+ * Format: postpost q[4] i[1] 223's[>= 4] */
+void BasicDVIReader::cmdPostPost (int) {
+ seek(4, ios::cur);
+ setDVIVersion((DVIVersion)readUnsigned(1)); // identification byte
+ while (readUnsigned(1) == DVI_FILL); // skip fill bytes (223), eof bit should be set now
+}
+
+
+/** Executes bop (begin of page) command.
+ * Format: bop c0[+4] ... c9[+4] p[+4] */
+void BasicDVIReader::cmdBop (int) {seek(44, ios::cur);}
+void BasicDVIReader::cmdEop (int) {}
+void BasicDVIReader::cmdPush (int) {}
+void BasicDVIReader::cmdPop (int) {}
+void BasicDVIReader::cmdSetChar0 (int) {}
+void BasicDVIReader::cmdSetChar (int len) {seek(len, ios::cur);}
+void BasicDVIReader::cmdPutChar (int len) {seek(len, ios::cur);}
+void BasicDVIReader::cmdSetRule (int) {seek(8, ios::cur);}
+void BasicDVIReader::cmdPutRule (int) {seek(8, ios::cur);}
+void BasicDVIReader::cmdRight (int len) {seek(len, ios::cur);}
+void BasicDVIReader::cmdDown (int len) {seek(len, ios::cur);}
+void BasicDVIReader::cmdX0 (int) {}
+void BasicDVIReader::cmdY0 (int) {}
+void BasicDVIReader::cmdW0 (int) {}
+void BasicDVIReader::cmdZ0 (int) {}
+void BasicDVIReader::cmdX (int len) {seek(len, ios::cur);}
+void BasicDVIReader::cmdY (int len) {seek(len, ios::cur);}
+void BasicDVIReader::cmdW (int len) {seek(len, ios::cur);}
+void BasicDVIReader::cmdZ (int len) {seek(len, ios::cur);}
+void BasicDVIReader::cmdNop (int) {}
+void BasicDVIReader::cmdDir (int) {seek(1, ios::cur);}
+void BasicDVIReader::cmdFontNum0 (int) {}
+void BasicDVIReader::cmdFontNum (int len) {seek(len, ios::cur);}
+void BasicDVIReader::cmdXXX (int len) {seek(readUnsigned(len), ios::cur);}
+
+
+/** Executes fontdef command.
+ * Format: fontdef k[len] c[4] s[4] d[4] a[1] l[1] n[a+l]
+ * @param[in] len size of font number variable (in bytes) */
+void BasicDVIReader::cmdFontDef (int len) {
+ seek(len+12, ios::cur); // skip font number
+ uint32_t pathlen = readUnsigned(1); // length of font path
+ uint32_t namelen = readUnsigned(1); // length of font name
+ seek(pathlen+namelen, ios::cur);
+}
+
+
+/** XDV extension: include image or pdf file.
+ * parameters: box[1] matrix[4][6] p[2] len[2] path[l] */
+void BasicDVIReader::cmdXPic (int) {
+ seek(1+24+2, ios::cur);
+ uint16_t len = readUnsigned(2);
+ seek(len, ios::cur);
+}
+
+
+void BasicDVIReader::cmdXFontDef (int) {
+ seek(4+4, ios::cur);
+ uint16_t flags = readUnsigned(2);
+ uint8_t len = readUnsigned(1);
+ if (_dviVersion == DVI_XDV5)
+ len += readUnsigned(1)+readUnsigned(1);
+ seek(len, ios::cur);
+ if (_dviVersion >= DVI_XDV6)
+ seek(4, ios::cur); // skip subfont index
+ if (flags & 0x0200) // colored?
+ seek(4, ios::cur);
+ if (flags & 0x1000) // extend?
+ seek(4, ios::cur);
+ if (flags & 0x2000) // slant?
+ seek(4, ios::cur);
+ if (flags & 0x4000) // embolden?
+ seek(4, ios::cur);
+ if ((flags & 0x0800) && (_dviVersion == DVI_XDV5)) { // variations?
+ uint16_t num_variations = readSigned(2);
+ seek(4*num_variations, ios::cur);
+ }
+}
+
+
+/** XDV extension: prints an array of characters where each character
+ * can take independent x and y coordinates.
+ * parameters: w[4] n[2] xy[(4+4)n] g[2n] */
+void BasicDVIReader::cmdXGlyphArray (int) {
+ seek(4, ios::cur);
+ uint16_t num_glyphs = readUnsigned(2);
+ seek(10*num_glyphs, ios::cur);
+}
+
+
+/** XDV extension: prints an array/string of characters where each character
+ * can take independent x coordinates whereas all share a single y coordinate.
+ * parameters: w[4] n[2] x[4n] y[4] g[2n] */
+void BasicDVIReader::cmdXGlyphString (int) {
+ seek(4, ios::cur);
+ uint16_t num_glyphs = readUnsigned(2);
+ seek(6*num_glyphs, ios::cur);
+}
+
+
+/** XDV extension: Same as cmdXGlyphArray plus a leading array of UTF-16 characters
+ * that specify the "actual text" represented by the glyphs to be printed. It usually
+ * contains the text with special characters (like ligatures) expanded so that it
+ * can be used for text search, plain text copy & paste etc. This XDV command was
+ * introduced with XeTeX 0.99995 and can be triggered by <tt>\\XeTeXgenerateactualtext1</tt>.
+ * parameters: l[2] t[2l] w[4] n[2] xy[8n] g[2n] */
+void BasicDVIReader::cmdXTextAndGlyphs (int) {
+ uint16_t l = readUnsigned(2);
+ seek(2*l, ios::cur);
+ cmdXGlyphArray(0);
+}