vibe2_modules/source/modules/physics.cppm

export module vibe2.physics;

import vibe2.core;

// Declaraciones forward en lugar de includes pesados
struct SDL_FRect;

export namespace vibe2::physics {

    // Entidad física básica
    class PhysicsEntity {
    private:
        float x_, y_, w_, h_;          // Posición y tamaño
        float vx_, vy_;               // Velocidad
        float gravity_force_;         // Gravedad
        bool on_floor_;               // En el suelo
        bool stopped_;                // Detenido
        float bounce_loss_;           // Pérdida de rebote

    public:
        PhysicsEntity(float x, float y, float w, float h, float vx = 0.0f, float vy = 0.0f)
            : x_(x), y_(y), w_(w), h_(h),
              vx_(vx * vibe2::physics::CONVERSION_FACTOR),
              vy_(vy * vibe2::physics::CONVERSION_FACTOR),
              gravity_force_(vibe2::GRAVITY_FORCE * vibe2::physics::CONVERSION_FACTOR * vibe2::physics::CONVERSION_FACTOR),
              on_floor_(false), stopped_(false), bounce_loss_(0.7f) {}

        void update(float deltaTime) {
            if (stopped_) return;

            // Aplicar gravedad
            if (!on_floor_) {
                vy_ += gravity_force_ * deltaTime;
            }

            // Actualizar posición
            x_ += vx_ * deltaTime;
            if (!on_floor_) {
                y_ += vy_ * deltaTime;
            } else {
                y_ = vibe2::SCREEN_HEIGHT - h_;
            }

            handleCollisions();
        }

        void handleCollisions() {
            // Colisiones laterales
            if (x_ < 0) {
                x_ = 0;
                vx_ = -vx_;
            }
            if (x_ + w_ > vibe2::SCREEN_WIDTH) {
                x_ = vibe2::SCREEN_WIDTH - w_;
                vx_ = -vx_;
            }

            // Colisión superior
            if (y_ < 0) {
                y_ = 0;
                vy_ = -vy_;
            }

            // Colisión inferior (suelo)
            if (y_ + h_ > vibe2::SCREEN_HEIGHT) {
                y_ = vibe2::SCREEN_HEIGHT - h_;
                vy_ = -vy_ * bounce_loss_;

                if (vy_ > -vibe2::physics::VELOCITY_THRESHOLD && vy_ < vibe2::physics::VELOCITY_THRESHOLD) {
                    vy_ = 0.0f;
                    on_floor_ = true;
                }
            }

            // Fricción en el suelo
            if (on_floor_) {
                float friction = 1.0f - (1.0f - vibe2::physics::FRICTION_FACTOR) * deltaTime * 60.0f;
                vx_ *= friction;

                if (vx_ > -vibe2::physics::VELOCITY_THRESHOLD && vx_ < vibe2::physics::VELOCITY_THRESHOLD) {
                    vx_ = 0.0f;
                    stopped_ = true;
                }
            }
        }

        // Modificar velocidad
        void addVelocity(float vx, float vy) {
            if (stopped_) {
                vx_ += vx * vibe2::physics::CONVERSION_FACTOR;
            }
            vy_ += vy * vibe2::physics::CONVERSION_FACTOR;
            on_floor_ = false;
            stopped_ = false;
        }

        // Cambiar gravedad
        void toggleGravity() {
            gravity_force_ = (gravity_force_ == 0.0f) ?
                (vibe2::GRAVITY_FORCE * vibe2::physics::CONVERSION_FACTOR * vibe2::physics::CONVERSION_FACTOR) : 0.0f;
        }

        // Getters
        float getX() const { return x_; }
        float getY() const { return y_; }
        float getW() const { return w_; }
        float getH() const { return h_; }
        float getVX() const { return vx_; }
        float getVY() const { return vy_; }
        float getGravityForce() const { return gravity_force_; }
        bool isOnFloor() const { return on_floor_; }
        bool isStopped() const { return stopped_; }

        void setPosition(float x, float y) {
            x_ = x;
            y_ = y;
        }

    private:
        float deltaTime = 0.016f; // Para cálculos internos
    };
}