Procedures in c++ w/ SFML don't work properly, movement algorithm

Question

In main loop while( win.isOpen() ) i have 4 if's:

#include<SFML/Graphics.hpp>
using namespace sf;
int main()
{
    RenderWindow win( VideoMode( 1280, 1024, 32 ), "abc" );
    View view( FloatRect( 0, 0, 320, 256 ) );
    Sprite player;
    Texture player_t;
    Image player_i;
    player_i.loadFromFile( "sprite1.png" );
    player_t.loadFromImage( player_i );

    player.setTexture( player_t );
    win.setView( view );

    float speed = 80.f;
    Clock frameClock;
    while( win.isOpen() )
    {
        Event event;
        while( win.pollEvent( event ) )
        {
            if( event.type == Event::Closed )
                win.close();
        }
        Time frameTime = frameClock.restart();

        Vector2f movement( 0.f, 0.f ), viewMovement( 0.f, 0.f );
        if( Keyboard::isKeyPressed( Keyboard::Up ) )
        {
            if( player.getPosition().y >= 0)
                movement.y -= speed;
            if( player.getPosition().y + 25 <= view.getCenter().y - 50 && view.getCenter().y - 128 >= 0 )
                viewMovement.y -= speed;
        }
        if( Keyboard::isKeyPressed( Keyboard::Down ) )
        {
            if( player.getPosition().y + 100 <= 1024 )
                movement.y += speed;
            if( player.getPosition().y + 25 >= view.getCenter().y + 50 && view.getCenter().y + 128 <= 1024 )
                viewMovement.y += speed;
        }
        if( Keyboard::isKeyPressed( Keyboard::Left ) )
        {
            if( player.getPosition().x >= 0)
                movement.x -= speed;
            if( player.getPosition().x + 15 <= view.getCenter().x - 82 && view.getCenter().x - 160 >= 0 )
                viewMovement.x -= speed;
        }
        if( Keyboard::isKeyPressed( Keyboard::Right ) )
        {
            if( player.getPosition().x + 100 <= 1280)
                movement.x += speed;
            if( player.getPosition().x + 15 >= view.getCenter().x + 82 && view.getCenter().x + 160 <= 1280 )
                viewMovement.x += speed;
        }
        player.move( movement * frameTime.asSeconds() );
        view.move( viewMovement * frameTime.asSeconds() );
        win.setView( view );

        win.clear();
        win.draw( player );
        win.display();
    }

}

If they are in int main() they work fine, but I'd like to put them in a procedure out of int main(), but when i do that no error comes up during compilation, but the sprite does not move when i press Up, Down, Left and Right keys. What seems to be the problem?

Here's code after making procedures:

#include<SFML/Graphics.hpp>
using namespace sf;
RenderWindow win( VideoMode( 1280, 1024, 32 ), "abc" );
View view( FloatRect( 0, 0, 320, 256 ) );
Sprite player;
Vector2f movement( 0.f, 0.f ), viewMovement( 0.f, 0.f );
float speed = 80.f;
void movementOfPlayer()
{
    if( Keyboard::isKeyPressed( Keyboard::Up ) )
        {
            if( player.getPosition().y >= 0)
                movement.y -= speed;
            if( player.getPosition().y + 25 <= view.getCenter().y - 50 &&     view.getCenter().y - 128 >= 0 )
                viewMovement.y -= speed;
    }
    if( Keyboard::isKeyPressed( Keyboard::Down ) )
    {
            if( player.getPosition().y + 100 <= 1024 )
                movement.y += speed;
            if( player.getPosition().y + 25 >= view.getCenter().y + 50 && view.getCenter().y + 128 <= 1024 )
                viewMovement.y += speed;
    }
    if( Keyboard::isKeyPressed( Keyboard::Left ) )
    {
            if( player.getPosition().x >= 0)
                movement.x -= speed;
            if( player.getPosition().x + 15 <= view.getCenter().x - 82 && view.getCenter().x - 160 >= 0 )
                viewMovement.x -= speed;
    }
    if( Keyboard::isKeyPressed( Keyboard::Right ) )
    {
            if( player.getPosition().x + 100 <= 1280)
                movement.x += speed;
            if( player.getPosition().x + 15 >= view.getCenter().x + 82 && view.getCenter().x + 160 <= 1280 )
                viewMovement.x += speed;
    }
}
int main()
{
    Texture player_t;
    Image player_i;
    player_i.loadFromFile( "sprite1.png" );
    player_t.loadFromImage( player_i );

    player.setTexture( player_t );
    win.setView( view );

    Clock frameClock;
    while( win.isOpen() )
    {
        Event event;
        while( win.pollEvent( event ) )
        {
            if( event.type == Event::Closed )
                win.close();
        }
    Time frameTime = frameClock.restart();

    Vector2f movement( 0.f, 0.f ), viewMovement( 0.f, 0.f );
    movementOfPlayer();
    player.move( movement * frameTime.asSeconds() );
    view.move( viewMovement * frameTime.asSeconds() );
    win.setView( view );
    win.clear();
    win.draw( player );
    win.display();
}

}

Did you link the object file generated from the separate file? — Technohacker, Feb 18 '18 at 12:55
Can you please post the skeleton of your main or engine run? — Martin Sand, Feb 18 '18 at 13:10
I made some changes to the question it simplifies the problem. What i noticed is that Vector2f movement and viewMovement change INSIDE the procedure but when procedure ends they turn back to 0. (When i put if's in voids i make variables global and write them before voids, since as is said in the question voids will be outside int main() ). — Running_Sloth, Feb 18 '18 at 13:53

score 1 · Answer 1 · answered Feb 18 '18 at 14:21

Ok, i found the problem by myself while reading my own question.

Vector2f movement( 0.f, 0.f ), viewMovement( 0.f, 0.f );

This ( in while( win.isOpen() ) ) is wrong since i already wrote it, before int main();

movement = Vector2f( 0.f, 0.f );
viewMovement = Vector2f( 0.f, 0.f );

With this ^ it works.

Thanks for everyone who was even thinking about it to answer me.

Procedures in c++ w/ SFML don't work properly, movement algorithm

1 Answers1