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/*************************************************************************
** VFReader.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 <sstream>
#include "Font.h"
#include "VFActions.h"
#include "VFReader.h"
#include "macros.h"
using namespace std;
/** Converts a TFM fix point value to double. */
inline static double fix2double (FixWord fix) {
return double(fix)/(1 << 20);
}
VFReader::VFReader (istream &is)
: StreamReader(is), actions(0) {
}
VFReader::~VFReader () {
}
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 = in().get();
if (!in() || opcode < 0) // at end of file
throw VFException("invalid file");
bool approved = !approve || approve(opcode);
VFActions *act = actions;
if (!approved)
replaceActions(0); // 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(act); // reenable actions
ostringstream oss;
oss << "undefined VF command (opcode " << opcode << ')';
throw VFException(oss.str());
}
}
}
replaceActions(act); // reenable actions
return opcode;
}
bool VFReader::executeAll () {
in().clear(); // reset all status bits
if (!in())
return false;
in().seekg(0); // move file pointer to first byte of the input stream
while (!in().eof() && executeCommand() != 248); // stop reading after post (248)
return true;
}
/// Returns true if op indicates the preamble or a font definition
static bool is_pre_or_fontdef (int op) {return op > 242;}
static bool is_chardef (int op) {return op < 243;}
bool VFReader::executePreambleAndFontDefs () {
in().clear();
if (!in())
return false;
in().seekg(0); // move file pointer to first byte of the input stream
while (!in().eof() && executeCommand(is_pre_or_fontdef) > 242); // stop reading after last font definition
return true;
}
bool VFReader::executeCharDefs () {
in().clear();
if (!in())
return false;
in().seekg(0);
while (!in().eof() && executeCommand(is_chardef) < 243); // stop reading after last char definition
return true;
}
//////////////////////////////////////////////////////////////////////////////
/** Reads and executes DVI preamble command. */
void VFReader::cmdPre () {
UInt32 i = readUnsigned(1); // identification number (should be 2)
UInt32 k = readUnsigned(1); // length of following comment
string cmt = readString(k); // comment
UInt32 cs = readUnsigned(4); // check sum to be compared with TFM cecksum
UInt32 ds = readUnsigned(4); // design size (same as TFM design size) (fix_word)
designSize = fix2double(ds);
if (i != 202)
throw VFException("invalid identification value in preamble");
if (actions)
actions->preamble(cmt, cs, ds);
}
void VFReader::cmdPost () {
while ((readUnsigned(1)) == 248); // skip fill bytes
if (actions)
actions->postamble();
}
void VFReader::cmdLongChar () {
UInt32 pl = readUnsigned(4); // packet length (length of DVI subroutine)
if (actions) {
UInt32 cc = readUnsigned(4); // character code
readUnsigned(4); // character width from corresponding TFM file
vector<UInt8> *dvi = new vector<UInt8>(pl); // DVI subroutine
readBytes(pl, *dvi);
actions->defineVFChar(cc, dvi); // call template method for user actions
}
else
in().seekg(8+pl, ios::cur); // skip remaining char definition bytes
}
/** Reads and executes short_char_x command.
* @param[in] pl packet length (length of DVI subroutine) */
void VFReader::cmdShortChar (int pl) {
if (actions) {
UInt32 cc = readUnsigned(1); // character code
readUnsigned(3); // character width from corresponding TFM file
vector<UInt8> *dvi = new vector<UInt8>(pl); // DVI subroutine
readBytes(pl, *dvi);
actions->defineVFChar(cc, dvi); // call template method for user actions
}
else
in().seekg(4+pl, ios::cur); // skip char definition bytes
}
void VFReader::cmdFontDef (int len) {
UInt32 fontnum = readUnsigned(len); // font number
UInt32 checksum = readUnsigned(4); // font checksum (to be compared with corresponding TFM checksum)
UInt32 ssize = readUnsigned(4); // scaled size of font relative to design size (fix_word)
UInt32 dsize = readUnsigned(4); // design size of font (same as TFM design size) (fix_word)
UInt32 pathlen = readUnsigned(1); // length of font path
UInt32 namelen = readUnsigned(1); // length of font name
string fontpath = readString(pathlen);
string fontname = readString(namelen);
if (actions) {
double ss = fix2double(ssize);
double ds = fix2double(dsize);
actions->defineVFFont(fontnum, fontpath, fontname, checksum, ds, ss*designSize);
}
}
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