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/*************************************************************************
** 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;
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
throw VFException("undefined VF command (opcode " + std::to_string(opcode) + ")");
}
}
}
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
auto dvi = readBytes(pl); // DVI subroutine
_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
auto dvi = readBytes(pl); // DVI subroutine
_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);
}
}
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