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/*************************************************************************
** DvisvgmSpecialHandler.cpp **
** **
** This file is part of dvisvgm -- the DVI to SVG converter **
** Copyright (C) 2005-2012 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 <cstring>
#include "DvisvgmSpecialHandler.h"
#include "InputBuffer.h"
#include "InputReader.h"
#include "SpecialActions.h"
#include "XMLNode.h"
#include "XMLString.h"
using namespace std;
/** Replaces constants of the form {?name} by their corresponding value.
* @param[in,out] str text to expand
* @param[in] actions interfcae to the world outside the special handler */
static void expand_constants (string &str, SpecialActions *actions) {
struct Constant {
const char *name;
string val;
}
constants[] = {
{"x", XMLString(actions->getX())},
{"y", XMLString(actions->getY())},
{"color", actions->getColor().rgbString()},
{"nl", "\n"},
{0, ""}
};
bool repl_bbox = true;
while (repl_bbox) {
size_t pos = str.find(string("{?bbox "));
if (pos == string::npos)
repl_bbox = false;
else {
size_t endpos = pos+7;
while (endpos < str.length() && isalnum(str[endpos]))
++endpos;
if (str[endpos] == '}') {
BoundingBox &box=actions->bbox(str.substr(pos+7, endpos-pos-7));
str.replace(pos, endpos-pos+1, box.toSVGViewBox());
}
else
repl_bbox = false;
}
}
for (const Constant *p=constants; p->name; p++) {
const string pattern = string("{?")+p->name+"}";
size_t pos = str.find(pattern);
while (pos != string::npos) {
str.replace(pos, strlen(p->name)+3, p->val);
pos = str.find(pattern, pos+p->val.length()); // look for further matches
}
}
}
/** Embeds the virtual rectangle (x, y ,w , h) into the current bounding box,
* where (x,y) is the lower left vertex composed of the current DVI position.
* @param[in] w width of the rectangle in TeX point units
* @param[in] h height of the rectangle in TeX point units
* @param[in] d depth of the rectangle in TeX point units */
static void update_bbox (double w, double h, double d, SpecialActions *actions) {
double x = actions->getX();
double y = actions->getY();
actions->embed(BoundingBox(x, y, x+w, y-h));
actions->embed(BoundingBox(x, y, x+w, y+d));
}
/** Inserts raw text into the SVG tree.
* @param[in,out] in the raw text is read from this input buffer
* @param[in] actions interfcae to the world outside the special handler
* @param[in] group true if the text should be wrapped by a group element */
static void raw (InputReader &in, SpecialActions *actions, bool group=false) {
string str;
while (!in.eof()) {
int c = in.get();
if (isprint(c))
str += char(c);
}
expand_constants(str, actions);
if (!str.empty()) {
XMLNode *node = new XMLTextNode(str);
if (group) {
XMLElementNode *g = new XMLElementNode("g");
g->addAttribute("x", actions->getX());
g->addAttribute("y", actions->getY());
if (actions->getColor() != Color::BLACK)
g->addAttribute("fill", actions->getColor().rgbString());
g->append(node);
node = g;
}
actions->appendToPage(node);
}
}
/** Evaluates the special dvisvgm:bbox.
* variant 1: dvisvgm:bbox [r[el]] <width> <height> [<depth>]
* variant 2: dvisvgm:bbox a[bs] <x1> <y1> <x2> <y2>
* variant 3: dvisvgm:bbox f[ix] <x1> <y1> <x2> <y2>
* variant 4: dvisvgm:bbox n[ew] <name> */
static void bbox (InputReader &in, SpecialActions *actions) {
in.skipSpace();
int c = in.peek();
if (isalpha(c)) {
while (!isspace(in.peek())) // skip trailing characters
in.get();
if (c == 'n') {
in.skipSpace();
string name;
while (isalnum(in.peek()))
name += char(in.get());
in.skipSpace();
if (!name.empty() && in.eof())
actions->bbox(name, true); // create new user box
}
else if (c == 'a' || c == 'f') {
double p[4];
for (int i=0; i < 4; i++)
p[i] = in.getDouble();
BoundingBox b(p[0], p[1], p[2], p[3]);
if (c == 'a')
actions->embed(b);
else {
actions->bbox() = b;
actions->bbox().lock();
}
}
}
else
c = 'r'; // no mode specifier => relative box parameters
if (c == 'r') {
double w = in.getDouble();
double h = in.getDouble();
double d = in.getDouble();
update_bbox(w, h, d, actions);
}
}
static void img (InputReader &in, SpecialActions *actions) {
double w = in.getDouble();
double h = in.getDouble();
string f = in.getString();
update_bbox(w, h, 0, actions);
XMLElementNode *img = new XMLElementNode("image");
img->addAttribute("x", actions->getX());
img->addAttribute("y", actions->getY());
img->addAttribute("width", w);
img->addAttribute("height", h);
img->addAttribute("xlink:href", f);
if (actions && !actions->getMatrix().isIdentity())
img->addAttribute("transform", actions->getMatrix().getSVG());
actions->appendToPage(img);
}
/** Evaluates and executes a dvisvgm special statement.
* @param[in] prefix special prefix read by the SpecialManager
* @param[in] is the special statement is read from this stream
* @param[in,out] in the raw text is read from this input buffer */
bool DvisvgmSpecialHandler::process (const char *prefix, istream &is, SpecialActions *actions) {
if (actions) {
StreamInputBuffer ib(is);
BufferInputReader in(ib);
string cmd = in.getWord();
if (cmd == "raw") // raw <text>
raw(in, actions);
else if (cmd == "bbox") // bbox [r] <width> <height> <depth> or bbox a <x1> <y1> <x2> <y2>
bbox(in, actions);
else if (cmd == "img") { // img <width> <height> <file>
img(in, actions);
}
}
return true;
}
const char** DvisvgmSpecialHandler::prefixes () const {
static const char *pfx[] = {"dvisvgm:", 0};
return pfx;
}
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