psemek/libs/fonts/source/monospace_font.cpp

90 lines
2.6 KiB
C++

#include <psemek/fonts/monospace_font.hpp>
#include <psemek/util/unicode.hpp>
#include <psemek/util/exception.hpp>
namespace psemek::fonts
{
monospace_font::monospace_font(character_range range, std::string_view name, geom::vector<int, 2> size, gfx::texture_2d atlas, std::vector<geom::box<float, 2>> texcoords)
: range_{range}
, name_{name}
, size_{size}
, atlas_{std::move(atlas)}
, texcoords_{std::move(texcoords)}
{
if (range_.end - range_.begin != texcoords_.size())
throw util::exception("Wrong number of texture coordinates");
if (!supports_character('?'))
throw util::exception("Monospace font must support '?' character");
}
static geom::vector<float, 2> advance_dir(shape_options::direction_t direction)
{
switch (direction)
{
case shape_options::left_to_right: return {1.f, 0.f};
case shape_options::right_to_left: return {-1.f, 0.f};
case shape_options::top_to_bottom: return {0.f, 1.f};
case shape_options::bottom_to_top: return {0.f, -1.f};
}
return {1.f, 0.f};
}
bool monospace_font::supports_character(char32_t c) const
{
return std::isspace(c) || (c >= range_.begin && c < range_.end);
}
std::vector<glyph> monospace_font::shape(std::string_view str, shape_options const & options, geom::point<float, 2> & pen) const
{
return shape_impl(util::utf8_range(str), options, pen);
}
std::vector<glyph> monospace_font::shape(std::u32string_view str, shape_options const & options, geom::point<float, 2> & pen) const
{
return shape_impl(str, options, pen);
}
template <typename String>
std::vector<glyph> monospace_font::shape_impl(String const & str, shape_options const & options, geom::point<float, 2> & pen) const
{
char32_t const unknown = supports_character(options.unknown_character) ? options.unknown_character : '?';
geom::vector<float, 2> const size = geom::cast<float>(this->size()) * options.scale;
geom::vector<float, 2> const advance = geom::pointwise_mult(advance_dir(options.direction), size);
std::vector<glyph> result;
for (char32_t c : str)
{
glyph g;
if (std::isspace(c))
{
g.character = c;
g.position = {{{pen[0], pen[0]}, {pen[1], pen[1]}}};
}
else
{
g.character = supports_character(c) ? c : unknown;
g.position = {{{pen[0], pen[0] + size[0]}, {pen[1], pen[1] + size[1]}}};
}
result.push_back(g);
pen += advance;
}
return result;
}
std::optional<geom::box<float, 2>> monospace_font::texcoords(char32_t c) const
{
if (!supports_character(c)) return std::nullopt;
if (std::isspace(c))
return texcoords_[' ' - range_.begin];
return texcoords_[c - range_.begin];
}
}