c++ multithreading - trying to make non-const objects const - c++

Question

I have a c++, sfml program and upon trying to implement multi threading have ran into a problem. First off I have little experience with multi threading. When I go to assign the thread tasks it is throwing 22 new errors all relating to objects being const but the objects are not const. Thanks.
sorry if the title is poorly worded.
here's some code to look over
class NewKey {
public:
sf::Image Img;
sf::Texture Tex;
sf::Sprite Sprite;
sf::Vector2i Velocity;
sf::Vector2i Acceleration;
sf::Vector2i NextPos;
bool isMovingLeft() {
if (Velocity.x < 0)
return true;
else
return false;
}
bool isMovingRight() {
if (Velocity.x > 0)
return true;
else
return false;
}
void velocityCap() {
if (Velocity.x >= 130)
Velocity.x = 130;
if (Velocity.y >= 130)
Velocity.y = 130;
if (Velocity.x <= -130)
Velocity.x = -130;
if (Velocity.y <= -130)
Velocity.y = -130;
}
void loseSpeed(int x) {
if (isMovingLeft()) {
Acceleration.x += x;
}
else if (isMovingRight())
Acceleration.x -= x;;
}
void StepVelocity() {
Velocity += Acceleration;
Acceleration = sf::Vector2i(0, 0);
}
};
void foo() {
NewKey Key;
std::thread thread1;
std::unique_ptr <sf::RenderWindow> window = std::make_unique<sf::RenderWindow>(sf::VideoMode(100, 100, 32), "Main Window", sf::Style::None);
Key.NextPos = Gravity(Key, window, thread1);
thread1.join();
}
sf::Vector2i Gravity(NewKey& Key, std::unique_ptr <sf::RenderWindow>& window, std::thread& thread1) {
int windSpeed = 2;
int dropRate = 10;
thread1 = std::thread([=] {
if (Key.Velocity.x == 1)
Key.loseSpeed(1);
else
Key.loseSpeed(windSpeed);
Key.StepVelocity();
Key.velocityCap();
if (Key.Velocity.y < 10 && Key.Velocity.y > 0) {
Key.Velocity.y = 0;
}
});
sf::Vector2i Result = sf::Vector2i(window->getPosition() + Key.Velocity);
return Result;
}
int main()
{
foo();
}
the errors
Severity Code Description Project File Line Suppression State
Error (active) E1086 the object has type qualifiers that are not compatible with the member function "NewKey::loseSpeed" Error C:\Users\Jacob Krumholz\source\repos\FallingKeys\Error\Error.cpp 61
Error (active) E1086 the object has type qualifiers that are not compatible with the member function "NewKey::loseSpeed" Error C:\Users\Jacob Krumholz\source\repos\FallingKeys\Error\Error.cpp 63
Error (active) E1086 the object has type qualifiers that are not compatible with the member function "NewKey::StepVelocity" Error C:\Users\Jacob Krumholz\source\repos\FallingKeys\Error\Error.cpp 64
Error (active) E1086 the object has type qualifiers that are not compatible with the member function "NewKey::velocityCap" Error C:\Users\Jacob Krumholz\source\repos\FallingKeys\Error\Error.cpp 65
Error (active) E0137 expression must be a modifiable lvalue Error C:\Users\Jacob Krumholz\source\repos\FallingKeys\Error\Error.cpp 67
Error C3861 'Gravity': identifier not found Error C:\Users\Jacob Krumholz\source\repos\FallingKeys\Error\Error.cpp 53
Error C2662 'void NewKey::loseSpeed(int)': cannot convert 'this' pointer from 'const NewKey' to 'NewKey &' Error C:\Users\Jacob Krumholz\source\repos\FallingKeys\Error\Error.cpp 61
Error C2662 'void NewKey::loseSpeed(int)': cannot convert 'this' pointer from 'const NewKey' to 'NewKey &' Error C:\Users\Jacob Krumholz\source\repos\FallingKeys\Error\Error.cpp 63
Error C2662 'void NewKey::StepVelocity(void)': cannot convert 'this' pointer from 'const NewKey' to 'NewKey &' Error C:\Users\Jacob Krumholz\source\repos\FallingKeys\Error\Error.cpp 64
Error C2662 'void NewKey::velocityCap(void)': cannot convert 'this' pointer from 'const NewKey' to 'NewKey &' Error C:\Users\Jacob Krumholz\source\repos\FallingKeys\Error\Error.cpp 65
Error C3490 'y' cannot be modified because it is being accessed through a const object Error C:\Users\Jacob Krumholz\source\repos\FallingKeys\Error\Error.cpp 67