game/player.cpp

#include <cmath>

#include "player.hpp"
#include "vec2util.hpp"

namespace Proto4 {
    Player::Player() : sf::CircleShape(30, 3) {
        setFillColor(sf::Color(50, 150, 150));
        setOrigin(30, 30);
    }

    void Player::update(sf::Time timeStep, sf::Vector2f mousePos) {
        updateRotation(timeStep.asSeconds(), mousePos);
        updateSpeed(timeStep.asSeconds(), keyboard2Acceleration());
    }

    void Player::reset() {
        speed = sf::Vector2f{0, 0};
        setRotation(0.f);
    }

    sf::Vector2f Player::keyboard2Acceleration() {
        sf::Vector2f acceleration = sf::Vector2f(0, 0);

        if (
            sf::Keyboard::isKeyPressed(sf::Keyboard::Left) ||
            sf::Keyboard::isKeyPressed(sf::Keyboard::A)
        ) acceleration.x -= 100.f;
        if (
            sf::Keyboard::isKeyPressed(sf::Keyboard::Right) ||
            sf::Keyboard::isKeyPressed(sf::Keyboard::D)
        ) acceleration.x += 100.f;
        if (
            sf::Keyboard::isKeyPressed(sf::Keyboard::Up) ||
            sf::Keyboard::isKeyPressed(sf::Keyboard::W)
        ) acceleration.y -= 100.f;
        if (
            sf::Keyboard::isKeyPressed(sf::Keyboard::Down) ||
            sf::Keyboard::isKeyPressed(sf::Keyboard::S)
        ) acceleration.y += 100.f;

        return normalized(acceleration);
    }

    void Player::updateSpeed(float timeStep, sf::Vector2f accel) {
        accel *= acceleration * timeStep;
        float decel = 1 - deceleration * timeStep;

        // x / y accelerate & decelerate separately
        // to allow for exponential deceleration
        if (accel.y == 0.f) speed.y *= decel;
        else speed.y += accel.y;

        if (accel.x == 0.f) speed.x *= decel;
        else speed.x += accel.x;

        // normalize with speed limit * timeStep
        float currentSpeed = magnitude(speed);
        if (currentSpeed > maxSpeed)
            speed *= maxSpeed / currentSpeed;

        move(speed * timeStep);
    }

    void Player::updateRotation(float timeStep, sf::Vector2f mousePos) {
        sf::Vector2f playerPos = getPosition();
        if (playerPos == mousePos) return;

        //calc mouse<>player angle
        float targetRotation = -180 - atan2(mousePos.x - playerPos.x, mousePos.y - playerPos.y) * 180 / PI;
        float rot = getRotation();
        float rotationDiff = std::remainder(targetRotation - rot + 180, 360);

        //limit rotationspeed
        if (rotationDiff > maxRotationSpeed * timeStep)
            rot -= maxRotationSpeed * timeStep;
        else if (rotationDiff < -maxRotationSpeed * timeStep)
            rot += maxRotationSpeed * timeStep;
        else
            rot = targetRotation;

        //bring the value back down into the interval [0, 360]
        if (rot < 0) rot += 360;
        else if (rot > 360) rot -= 360;

        setRotation(rot);
    }
}