summaryrefslogtreecommitdiff
path: root/dviware/dvisvgm/src/VFReader.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'dviware/dvisvgm/src/VFReader.cpp')
-rw-r--r--dviware/dvisvgm/src/VFReader.cpp178
1 files changed, 178 insertions, 0 deletions
diff --git a/dviware/dvisvgm/src/VFReader.cpp b/dviware/dvisvgm/src/VFReader.cpp
new file mode 100644
index 0000000000..a618f96ef7
--- /dev/null
+++ b/dviware/dvisvgm/src/VFReader.cpp
@@ -0,0 +1,178 @@
+/*************************************************************************
+** VFReader.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 <sstream>
+#include "FixWord.hpp"
+#include "Font.hpp"
+#include "Length.hpp"
+#include "VFActions.hpp"
+#include "VFReader.hpp"
+
+using namespace std;
+
+
+VFReader::VFReader (istream &is) : StreamReader(is)
+{
+}
+
+
+VFActions* VFReader::replaceActions (VFActions *a) {
+ VFActions *ret = _actions;
+ _actions = a;
+ return ret;
+}
+
+
+/** Reads a single VF command from the current position of the input stream and calls the
+ * corresponding cmdFOO method. The execution can be influenced by a function of type ApproveOpcode.
+ * It takes an opcode and returns true if the command is supposed to be executed.
+ * @param[in] approve function to approve invocation of the action assigned to command
+ * @return opcode of the executed command */
+int VFReader::executeCommand (ApproveAction approve) {
+ int opcode = readByte();
+ if (!isStreamValid() || opcode < 0) // at end of file?
+ throw VFException("invalid VF file");
+
+ bool approved = !approve || approve(opcode);
+ VFActions *actions = _actions;
+ if (!approved)
+ replaceActions(nullptr); // disable actions
+
+ if (opcode <= 241) // short character definition?
+ cmdShortChar(opcode);
+ else if (opcode >= 243 && opcode <= 246) // font definition?
+ cmdFontDef(opcode-243+1);
+ else {
+ switch (opcode) {
+ case 242: cmdLongChar(); break; // long character definition
+ case 247: cmdPre(); break; // preamble
+ case 248: cmdPost(); break; // postamble
+ default : { // invalid opcode
+ replaceActions(actions); // reenable actions
+ ostringstream oss;
+ oss << "undefined VF command (opcode " << opcode << ')';
+ throw VFException(oss.str());
+ }
+ }
+ }
+ replaceActions(actions); // reenable actions
+ return opcode;
+}
+
+
+bool VFReader::executeAll () {
+ clearStream(); // reset all status bits
+ if (!isStreamValid())
+ return false;
+ seek(0); // move file pointer to first byte of the input stream
+ while (!eof() && executeCommand() != 248); // stop reading after post (248)
+ return true;
+}
+
+
+bool VFReader::executePreambleAndFontDefs () {
+ clearStream();
+ if (!isStreamValid())
+ return false;
+ seek(0); // move file pointer to first byte of the input stream
+ auto is_pre_or_fontdef = [](int op) {return op > 242;};
+ while (!eof() && executeCommand(is_pre_or_fontdef) > 242); // stop reading after last font definition
+ return true;
+}
+
+
+bool VFReader::executeCharDefs () {
+ clearStream();
+ if (!isStreamValid())
+ return false;
+ seek(0);
+ auto is_chardef = [](int op) {return op < 243;};
+ while (!eof() && executeCommand(is_chardef) < 243); // stop reading after last char definition
+ return true;
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+/** Reads and executes DVI preamble command. */
+void VFReader::cmdPre () {
+ uint32_t i = readUnsigned(1); // identification number (should be 2)
+ uint32_t k = readUnsigned(1); // length of following comment
+ string cmt = readString(k); // comment
+ uint32_t cs = readUnsigned(4); // check sum to be compared with TFM cecksum
+ int32_t ds = readUnsigned(4); // design size (same as TFM design size) (fix_word)
+ _designSize = double(FixWord(ds))*Length::pt2bp;
+ if (i != 202)
+ throw VFException("invalid identification value in preamble");
+ if (_actions)
+ _actions->vfPreamble(cmt, cs, ds);
+}
+
+
+void VFReader::cmdPost () {
+ while ((readUnsigned(1)) == 248); // skip fill bytes
+ if (_actions)
+ _actions->vfPostamble();
+}
+
+
+void VFReader::cmdLongChar () {
+ uint32_t pl = readUnsigned(4); // packet length (length of DVI subroutine)
+ if (!_actions)
+ seek(8+pl, ios::cur); // skip remaining char definition bytes
+ else {
+ uint32_t cc = readUnsigned(4); // character code
+ readUnsigned(4); // equals character width from corresponding TFM file
+ vector<uint8_t> dvi(pl); // DVI subroutine
+ readBytes(pl, dvi);
+ _actions->defineVFChar(cc, std::move(dvi)); // call template method for user actions
+ }
+}
+
+
+/** Reads and executes short_char_x command.
+ * @param[in] pl packet length (length of DVI subroutine) */
+void VFReader::cmdShortChar (int pl) {
+ if (!_actions)
+ seek(4+pl, ios::cur); // skip char definition bytes
+ else {
+ uint32_t cc = readUnsigned(1); // character code
+ readUnsigned(3); // character width from corresponding TFM file
+ vector<uint8_t> dvi(pl); // DVI subroutine
+ readBytes(pl, dvi);
+ _actions->defineVFChar(cc, std::move(dvi)); // call template method for user actions
+ }
+}
+
+
+void VFReader::cmdFontDef (int len) {
+ uint32_t fontnum = readUnsigned(len); // font number
+ uint32_t checksum = readUnsigned(4); // font checksum (to be compared with corresponding TFM checksum)
+ uint32_t ssize = readUnsigned(4); // scaled size of font relative to design size (fix_word)
+ uint32_t dsize = readUnsigned(4); // design size of font (same as TFM design size) (fix_word)
+ uint32_t pathlen = readUnsigned(1); // length of font path
+ uint32_t namelen = readUnsigned(1); // length of font name
+ string fontpath = readString(pathlen);
+ string fontname = readString(namelen);
+ if (_actions) {
+ double ss = double(FixWord(ssize))*Length::pt2bp;
+ double ds = double(FixWord(dsize))*Length::pt2bp;
+ _actions->defineVFFont(fontnum, fontpath, fontname, checksum, ds, ss*_designSize);
+ }
+}