text_shaper_char.hpp

// Copyright Take Vos 2022.
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt or copy at https://www.boost.org/LICENSE_1_0.txt)
 
#pragma once
 
#include "text_style.hpp"
#include "glyph_ids.hpp"
#include "glyph_metrics.hpp"
#include "font.hpp"
#include "../unicode/unicode_description.hpp"
#include "../unicode/grapheme.hpp"
#include "../geometry/point.hpp"
#include "../geometry/axis_aligned_rectangle.hpp"
 
namespace hi::inline v1 {
class font_book;
 
class text_shaper_char {
public:
    hi::grapheme grapheme;
 
    hi::text_style style;
 
    float dpi_scale = 1.0f;
 
    hi::glyph_ids glyph;
 
    hi::glyph_metrics metrics;
 
    size_t line_nr;
 
    size_t column_nr;
 
    point2 position;
 
    aarectangle rectangle;
 
    unicode_description const *description;
 
    unicode_bidi_class direction;
 
    unicode_script script;
 
    float scale = 1.0f;
 
    float width = 0.0f;
 
    bool is_trailing_white_space = false;
 
    bool glyph_is_initial = false;
 
    [[nodiscard]] text_shaper_char(hi::grapheme const &grapheme, text_style const &style, float dpi_scale) noexcept;
 
    void initialize_glyph(hi::font_book &font_book, hi::font const &font) noexcept;
 
    void initialize_glyph(hi::font_book &font_book) noexcept;
 
    void replace_glyph(char32_t code_point) noexcept;
 
    [[nodiscard]] hi::font_metrics font_metrics() const noexcept
    {
        return scale * glyph.font().metrics;
    }
 
    [[nodiscard]] vector2 get_kerning(text_shaper_char const &next) const noexcept
    {
        if (&(glyph.font()) != &(next.glyph.font()) or scale != next.scale or not glyph.has_num_glyphs<1>() or
            not next.glyph.has_num_glyphs<1>()) {
            return vector2{};
        } else {
            hilet kerning = glyph.font().get_kerning(glyph.get_single(), next.glyph.get_single());
            return scale * kerning;
        }
    }
 
    [[nodiscard]] friend bool operator==(text_shaper_char const &lhs, char32_t const &rhs) noexcept
    {
        return lhs.grapheme == rhs;
    }
 
    [[nodiscard]] friend bool operator==(text_shaper_char const &lhs, char const &rhs) noexcept
    {
        return lhs.grapheme == rhs;
    }
 
private:
    void set_glyph(hi::glyph_ids &&new_glyph) noexcept;
};
 
} // namespace hi::inline v1