attributed_glyph.hpp

// Copyright Take Vos 2020-2021.
// 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 "font_glyph_ids.hpp"
#include "attributed_grapheme.hpp"
#include "glyph_metrics.hpp"
#include "../graphic_path.hpp"
#include "../geometry/translate.hpp"
 
namespace tt {
 
struct attributed_glyph {
    font_glyph_ids glyphs;
 
    ssize_t logicalIndex;
 
    glyph_metrics metrics;
 
    point2 position;
 
    int8_t graphemeCount;
 
    unicode_general_category general_category;
 
    text_style style;
 
    attributed_glyph(
        tt::font_book const &font_book, attributed_grapheme const &attr_grapheme,
        attributed_glyph const *next_attr_glyph = nullptr) noexcept;
 
    attributed_glyph(attributed_glyph const &other) = default;
    attributed_glyph(attributed_glyph &&other) noexcept = default;
    attributed_glyph &operator=(attributed_glyph const &other) = default;
    attributed_glyph &operator=(attributed_glyph &&other) noexcept = default;
    ~attributed_glyph() = default;
 
    [[nodiscard]] bool containsLogicalIndex(ssize_t index) const noexcept {
        ttlet first = logicalIndex;
        ttlet last = first + graphemeCount;
        return index >= first && index < last;
    }
 
    [[nodiscard]] bool isLetter() const noexcept
    {
        return is_L(general_category);
    }
 
    [[nodiscard]] bool isDigit() const noexcept
    {
        return is_N(general_category);
    }
 
    [[nodiscard]] bool isIdentifier() const noexcept { return isLetter() || isDigit(); }
 
    [[nodiscard]] bool isWhiteSpace() const noexcept
    {
        return general_category == unicode_general_category::Zs || general_category == unicode_general_category::Zl;
    }
 
    [[nodiscard]] bool isParagraphSeparator() const noexcept
    {
        return general_category == unicode_general_category::Zp;
    }
    [[nodiscard]] bool isVisible() const noexcept
    {
        return is_visible(general_category);
    }
    
    [[nodiscard]] int selectionWordClusterID() const noexcept {
        if (isParagraphSeparator()) {
            return 0;
        } else if (isIdentifier()) {
            return 1;
        } else if (isVisible()) {
            return 2;
        } else {
            return 3;
        }
    }
 
    [[nodiscard]] aarectangle boundingBox(float border) const noexcept {
        return translate2{position} * expand(metrics.boundingBox, border * style.scaled_size());
    }
 
    [[nodiscard]] ssize_t relativeIndexAtCoordinate(point2 coordinate) const noexcept {
        ttlet relativePositionInGlyph = (coordinate.x() - position.x()) / metrics.advance.x();
        ttlet relativePositionPergrapheme = relativePositionInGlyph * narrow_cast<float>(graphemeCount);
        return narrow_cast<ssize_t>(std::round(relativePositionPergrapheme));
    }
 
    [[nodiscard]] graphic_path get_path() const noexcept;
};
 
}