Use CSI @ instead of emitting lots of spaces

This greatly reduces the amount of data written for a redraw especially
on big terminals where most of the data is trailing blanks
This commit is contained in:
Maxime Coste 2020-03-28 19:55:17 +11:00
parent 8e1b79b1b7
commit 484cfae9d1

View File

@ -49,19 +49,36 @@ struct TerminalUI::Window::Line
struct Atom
{
String text;
ColumnCount skip = 0;
Face face;
friend bool operator==(const Atom& lhs, const Atom& rhs) { return lhs.text == rhs.text and lhs.face == rhs.face; }
ColumnCount length() const { return text.column_length() + skip; }
void resize(ColumnCount size)
{
auto text_len = text.column_length();
if (size < text_len)
{
text.resize(text.byte_count_to(size), 0);
skip = 0;
}
else
skip = size - text_len;
}
friend bool operator==(const Atom& lhs, const Atom& rhs) { return lhs.text == rhs.text and lhs.skip == rhs.skip and lhs.face == rhs.face; }
friend bool operator!=(const Atom& lhs, const Atom& rhs) { return not (lhs == rhs); }
friend size_t hash_value(const Atom& atom) { return hash_values(atom.text, atom.face); }
friend size_t hash_value(const Atom& atom) { return hash_values(atom.text, atom.skip, atom.face); }
};
void append(String text, Face face)
void append(String text, ColumnCount skip, Face face)
{
if (not atoms.empty() and atoms.back().face == face)
if (not atoms.empty() and atoms.back().face == face and (atoms.back().skip == 0 or text.empty()))
{
atoms.back().text += text;
atoms.back().skip += skip;
}
else
atoms.push_back({std::move(text), face});
atoms.push_back({std::move(text), skip, face});
}
void resize(ColumnCount width)
@ -69,52 +86,55 @@ struct TerminalUI::Window::Line
auto it = atoms.begin();
ColumnCount column = 0;
for (; it != atoms.end() and column < width; ++it)
column += it->text.column_length();
column += it->length();
if (column < width)
append(String{' ', width - column}, atoms.empty() ? Face{} : atoms.back().face);
append({}, width - column, atoms.empty() ? Face{} : atoms.back().face);
else
{
atoms.erase(it, atoms.end());
if (column > width)
{
auto& text = atoms.back().text;
auto new_length = text.column_length() - (column - width);
text.resize(text.byte_count_to(new_length), 0);
}
atoms.back().resize(atoms.back().length() - (column - width));
}
}
Vector<Atom>::iterator erase_range(ColumnCount pos, ColumnCount len)
{
struct Pos{ Vector<Atom>::iterator it; ByteCount byte; };
struct Pos{ Vector<Atom>::iterator it; ColumnCount column; };
auto find_col = [pos=0_col, it=atoms.begin(), end=atoms.end()](ColumnCount col) mutable {
for (; it != end; ++it)
{
auto atom_len = it->text.column_length();
auto atom_len = it->length();
if (pos + atom_len >= col)
return Pos{it, it->text.byte_count_to(col - pos)};
return Pos{it, col - pos};
pos += atom_len;
}
return Pos{it, 0_byte};
return Pos{it, 0_col};
};
Pos begin = find_col(pos);
Pos end = find_col(pos+len);
auto make_tail = [](const Atom& atom, ColumnCount from) {
if (atom.text.column_length() > from)
return Atom{atom.text.substr(atom.text.byte_count_to(from)).str(), atom.skip, atom.face};
else
return Atom{{}, atom.length() - from, atom.face};
};
if (begin.it == end.it)
{
auto end_text = begin.it->text.substr(end.byte).str();
begin.it->text.resize(begin.byte, 0);
return end_text.empty() ? begin.it+1 : atoms.insert(begin.it+1, {std::move(end_text), begin.it->face});
Atom tail = make_tail(*begin.it, end.column);
begin.it->resize(begin.column);
return (tail.text.empty() and tail.skip == 0) ? begin.it+1 : atoms.insert(begin.it+1, tail);
}
begin.it->text.resize(begin.byte, 0);
if (end.byte > 0)
begin.it->resize(begin.column);
if (end.column > 0)
{
if (end.byte == end.it->text.length())
if (end.column == end.it->length())
++end.it;
else
end.it->text = end.it->text.substr(end.byte).str();
*end.it = make_tail(*end.it, end.column);
}
return atoms.erase(begin.it+1, end.it);
}
@ -149,17 +169,14 @@ void TerminalUI::Window::draw(DisplayCoord pos,
auto face = merge_faces(default_face, atom.face);
if (content.back() == '\n')
{
lines[(int)pos.line].append(content.substr(0, content.length()-1).str(), face);
lines[(int)pos.line].append(" ", face);
}
lines[(int)pos.line].append(content.substr(0, content.length()-1).str(), 1, face);
else
lines[(int)pos.line].append(content.str(), face);
lines[(int)pos.line].append(content.str(), 0, face);
pos.column += content.column_length();
}
if (pos.column < size.column)
lines[(int)pos.line].append(String(' ', size.column - pos.column), default_face);
lines[(int)pos.line].append({}, size.column - pos.column, default_face);
}
void TerminalUI::Screen::output(bool force)
@ -229,14 +246,30 @@ void TerminalUI::Screen::output(bool force)
else
printf("\033[%dH", line + 1);
ColumnCount pending_move = 0;
for (auto& atom : lines[line++].atoms)
{
if (pending_move != 0)
{
printf("\033[%dC", (int)pending_move);
pending_move = 0;
}
fputs("\033[", stdout);
set_attributes(atom.face.attributes);
set_color(true, atom.face.fg);
set_color(false, atom.face.bg);
fputs("m", stdout);
fputs(atom.text.c_str(), stdout);
if (atom.skip > 0)
{
if (atom.skip > 4 and atom.face.attributes == Attribute{})
{
printf("\033[%d@", (int)atom.skip);
pending_move = atom.skip;
}
else for (ColumnCount c = 0; c < atom.skip; ++c)
fputs(" ", stdout);
}
}
}
}