kanjivg-tools/Libraries/Kanimaji/Source/SVG.cpp

#include "SVG.hpp"

#include <format>

namespace Kanimaji::SVG
{
    struct Vec2
    {
        double x;
        double y;

        friend Vec2 operator+(const Vec2& u, const Vec2& v)
        {
            return Vec2 {
                .x = u.x + v.x,
                .y = u.y + v.y,
            };
        }
    };

    class Path::Element
    {
    public:
        virtual ~Element() = default;

        virtual double Length(Vec2 origin) const = 0;
        virtual Vec2 Endpoint(Vec2 origin) const = 0;
    };

    namespace
    {
        class ParseError : public Error
        {
        public:
            ParseError(std::size_t current, std::string_view message)
                : Error(std::format("[At: {}] {}", current, message))
            {}
        };

        class Move : public Path::Element
        {
        public:
            Move(bool relative, Vec2 move)
                : mRelative(relative), mMove(move)
            {}

            double Length(Vec2 origin) const override
            {
                return 0;
            }

            Vec2 Endpoint(Vec2 origin) const override
            {
                return mRelative ? origin + mMove : mMove;
            }
        private:
            bool mRelative; // 7B padding, oof
            Vec2 mMove;
        };

        class CubicBezier : public Path::Element
        {
        public:
            CubicBezier(bool relative, Vec2 control1, Vec2 control2, Vec2 end)
                : mRelative(relative), mControl1(control1), mControl2(control2), mEnd(end)
            {}

            double Length(Vec2 origin) const override
            {
                throw Error("not implemented");
            }

            Vec2 Endpoint(Vec2 origin) const override
            {
                return mEnd;
            }
        private:
            bool mRelative; // 7B padding, oof
            Vec2 mControl1;
            Vec2 mControl2;
            Vec2 mEnd;
        };

        using ElementPtr = std::unique_ptr<Path::Element>;
        void Parse(std::string_view definition, std::vector<ElementPtr>& elements)
        {
            std::size_t current = 0;

            while (current < definition.size()) {
                switch (definition[current]) {
                case 'M': [[fallthrough]];
                case 'm':
                    // ParseMove
                    break;
                case 'C': [[fallthrough]];
                case 'c':
                    // ParseCubicBezier
                    break;
                default:
                    throw ParseError(current, "Unrecognized character");
                }
            }
        }
    }

    Path::Path(std::string_view definition)
    {
        Parse(definition, mSegments);
    }

    Path::~Path() = default;

    double Path::Length() const
    {
        return 0;
    }
}