void DvisvgmSpecialHandler::processImg (InputReader &ir, SpecialActions &actions) {
try {
Length w = read_length(ir);
Length h = read_length(ir);
string f = ir.getString();
update_bbox(w, h, Length(0), false, actions);
auto img = util::make_unique<XMLElement>("image");
img->addAttribute("x", actions.getX());
img->addAttribute("y", actions.getY());
img->addAttribute("width", w.bp());
img->addAttribute("height", h.bp());
img->addAttribute("xlink:href", f);
if (!actions.getMatrix().isIdentity())
img->addAttribute("transform", actions.getMatrix().toSVG());
actions.svgTree().appendToPage(std::move(img));
}
catch (const UnitException &e) {
throw SpecialException(string("dvisvgm:img: ") + e.what());
}
}
/** 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 PS point units
* @param[in] h height of the rectangle in PS point units
* @param[in] d depth of the rectangle in PS point units
* @param[in] transform if true, apply the current transformation matrix to the rectangle
* @param[in] actions object providing the actions that can be performed by the SpecialHandler */
static void update_bbox (Length w, Length h, Length d, bool transform, SpecialActions &actions) {
double x = actions.getX();
double y = actions.getY();
BoundingBox bbox1(x, y, x+w.bp(), y-h.bp());
BoundingBox bbox2(x, y, x+w.bp(), y+d.bp());
if (transform) {
bbox1.transform(actions.getMatrix());
bbox2.transform(actions.getMatrix());
}
actions.embed(bbox1);
actions.embed(bbox2);
}
/** Evaluates the special dvisvgm:bbox.
* variant 1: dvisvgm:bbox [r[el]] <width> <height> [<depth>] [transform]
* variant 2: dvisvgm:bbox a[bs] <x1> <y1> <x2> <y2> [transform]
* variant 3: dvisvgm:bbox f[ix] <x1> <y1> <x2> <y2> [transform]
* variant 4: dvisvgm:bbox n[ew] <name>
* variant 5: dvisvgm:bbox lock | unlock */
void DvisvgmSpecialHandler::processBBox (InputReader &ir, SpecialActions &actions) {
ir.skipSpace();
if (ir.check("lock"))
actions.bbox().lock();
else if (ir.check("unlock"))
actions.bbox().unlock();
else {
int c = ir.peek();
try {
if (!isalpha(c))
c = 'r'; // no mode specifier => relative box parameters
else {
while (!isspace(ir.peek())) // skip trailing characters
ir.get();
if (c == 'n') { // "new": create new local bounding box
ir.skipSpace();
string name;
while (isalnum(ir.peek()))
name += char(ir.get());
ir.skipSpace();
if (!name.empty() && ir.eof())
actions.bbox(name, true); // create new user box
}
else if (c == 'a' || c == 'f') { // "abs" or "fix"
Length lengths[4];
for (Length &len : lengths)
len = read_length(ir);
BoundingBox b(lengths[0], lengths[1], lengths[2], lengths[3]);
ir.skipSpace();
if (ir.check("transform"))
b.transform(actions.getMatrix());
if (c == 'a')
actions.embed(b);
else {
actions.bbox() = b;
actions.bbox().lock();
}
}
}
if (c == 'r') {
Length w = read_length(ir);
Length h = read_length(ir);
Length d = read_length(ir);
ir.skipSpace();
update_bbox(w, h, d, ir.check("transform"), actions);
}
}
catch (const UnitException &e) {
throw SpecialException(string("dvisvgm:bbox: ") + e.what());
}
}
}
/** 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) {
bool repl_bbox = true;
while (repl_bbox) {
size_t pos = str.find("{?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;
}
}
struct Constant {
const char *name;
string val;
};
const array<Constant, 5> constants {{
{"x", XMLString(actions.getX())},
{"y", XMLString(actions.getY())},
{"color", actions.getColor().svgColorString()},
{"matrix", actions.getMatrix().toSVG()},
{"nl", "\n"},
}};
for (const Constant &constant : constants) {
const string pattern = string("{?")+constant.name+"}";
size_t pos = str.find(pattern);
while (pos != string::npos) {
str.replace(pos, strlen(constant.name)+3, constant.val);
pos = str.find(pattern, pos+constant.val.length()); // look for further matches
}
}
}
