Crafter.Graphics/interfaces/Crafter.Graphics-Transform2D.cppm

/*
Crafter®.Graphics
Copyright (C) 2026 Catcrafts®
catcrafts.net

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License version 3.0 as published by the Free Software Foundation;

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
*/

export module Crafter.Graphics:Transform2D;
import std;
import :Types;
import :ForwardDeclarations;

export namespace Crafter {
    struct Anchor2D {
        float x;
        float y;
        float width;
        float height;
        float offsetX;
        float offsetY;
        std::uint8_t z;
        bool maintainAspectRatio;
        Anchor2D() = default;
        Anchor2D(float x, float y, float width, float height, float offsetX, float offsetY, std::uint8_t z, bool maintainAspectRatio = false);
    };

    struct Transform2D {
        Anchor2D anchor;
        ScaleData2D scaled;
        std::vector<Transform2D*> children;
        Transform2D() = default;
        Transform2D(Anchor2D anchor) : anchor(anchor) {

        }
        Transform2D(Transform2D&) = delete;
        Transform2D(Transform2D&&) = delete;
        Transform2D& operator=(Transform2D&) = delete;
        virtual ~Transform2D() = default;

        virtual void UpdatePosition(RendertargetBase& window, Transform2D& parent) {
            ScaleElement(parent);
            for(Transform2D* child : children) {
                child->UpdatePosition(window, *this);
            }
        }

        void ScaleElement(Transform2D& parent) {
            if(anchor.maintainAspectRatio) {
                if(parent.scaled.size.x > parent.scaled.size.y) {
                    scaled.size.x = anchor.width * parent.scaled.size.y;
                    scaled.size.y = anchor.height * parent.scaled.size.y;
                } else {
                    scaled.size.x = anchor.width * parent.scaled.size.x;
                    scaled.size.y = anchor.height * parent.scaled.size.x;
                }
            } else {
                scaled.size.x = anchor.width * parent.scaled.size.x;
                scaled.size.y = anchor.height * parent.scaled.size.y;
            }

            scaled.position.x = parent.scaled.position.x + (anchor.x * parent.scaled.size.x - anchor.offsetX *  scaled.size.x);
            scaled.position.y = parent.scaled.position.y + (anchor.y * parent.scaled.size.y - anchor.offsetY *  scaled.size.y);
        }
    };
}