Topics

1

General / Help with Collision

« on: October 30, 2013, 02:28:59 am »

Hi, I am having problems with my collisions. I know how 2 check if a collision has happened but having trouble with the sprite repositioning. I some minimal code  to show what I have. Right now the code is working for side collisions but for the top it is not. I know why the commented code isn't working, one the first 2 conditions will be true. Is there something simple that I am not seeing or do I need a lot more code to get this done. I have searched for answers but what I found is way different than what I have.

#include <SFML/Graphics.hpp>

int main()
{
        sf::RenderWindow window(sf::VideoMode(800,600), "SFML");
        window.setFramerateLimit(60);
        sf::Clock frameTime;

        sf::RectangleShape square(sf::Vector2f(40.f,40.f));
        square.setFillColor(sf::Color::Red);
        square.setPosition(200.f,500.f);

        sf::RectangleShape square2(sf::Vector2f(40.f,100.f));
        square2.setFillColor(sf::Color::Green);;
        square2.setPosition(275.f,275.f);
       
        sf::Vector2f speed(150.f,150.f);

        while(window.isOpen())
        {
                float dt =  frameTime.restart().asSeconds();
               
                sf::Event event;

                while(window.pollEvent(event))
                {
                        if(event.type == sf::Event::Closed)
                                window.close();
                }

                if(sf::Keyboard::isKeyPressed(sf::Keyboard::Right))
                        square.move(speed.x * dt,0.f);
            if(sf::Keyboard::isKeyPressed(sf::Keyboard::Left))
                        square.move(-speed.x * dt,0.f);
                if(sf::Keyboard::isKeyPressed(sf::Keyboard::Down))
                        square.move(0.f,speed.y * dt);
        if(sf::Keyboard::isKeyPressed(sf::Keyboard::Up))
                        square.move(0.f,-speed.y * dt);
               

                if(square.getPosition().x + square.getSize().x > square2.getPosition().x &&
                        square.getPosition().x < square2.getPosition().x + square2.getSize().x &&
                        square.getPosition().y + square.getSize().y > square2.getPosition().y &&
                        square.getPosition().y < square2.getPosition().y + square2.getSize().y)
                {        
                        //left side of square 2 collision
                        if(square.getPosition().x < square2.getPosition().x )
                                square.setPosition(square2.getPosition().x - square2.getSize().x,square.getPosition().y);
                        //right side of square2 collision
                        if(square.getPosition().x > square2.getPosition().x)
                                square.setPosition(square2.getPosition().x + square2.getSize().x,square.getPosition().y);
                        //top of square2 collision
                        //if(square.getPosition().y + square.getSize().y > square2.getPosition().y)
                                //square.setPosition(square.getPosition().x,square2.getPosition().y - square.getSize().y);
                       
                }

                window.clear();
                window.draw(square);
                window.draw(square2);
                window.display();
        }

        return 0;
}
 

2

General discussions / SFML + Box2D

« on: April 06, 2013, 02:49:04 am »

I was just wondering how may people in the forum use Box2D for physics? I have been learning C++ , Allegro for about 1 1/2 years and sfml 2 for about 6 months. Just wanted some kind of idea on weather I should learn to code my own or use an existing engine like Box2D? Any pointers will be appreciated.

3

General discussions / What physics engine to use?

« on: April 05, 2013, 03:54:27 pm »

Hi,I was wondering what physics engine do you recommend using with SFML 2? I have been learning SFML 2 and Allegro 5 for a while now and would like to start using a physics engine. I do not have any experience with any engine but would like to start.

4

Graphics / Getting Sprite to Jump

« on: January 15, 2012, 07:28:17 pm »

I am having a problem with getting my sprite to jump. I can move the sprite fine but I cant get it to jump. If I use Sprite.move instead of SetPosition it will move across the screen by a greater distance every time I press space
but not vertical.I know i probably dont have the falling part right either but I need to get jumping right first.

Code: [Select]



float velocity = 0;  
float gravity = 0;
float uprate = 0;
bool jumping = false;
bool falling = false;

if(Event.Key.Code == sf::Keyboard::Right)
Sprite2.Move(sprite2Speed * Window.GetFrameTime() /1000.f, 0.f);
if(Event.Key.Code == sf::Keyboard::Left)
Sprite2.Move(-sprite2Speed * Window.GetFrameTime() / 1000.f, 0.f);
if(Event.Key.Code == sf::Keyboard::Up)
Sprite2.Move(0.f, -sprite2Speed * Window.GetFrameTime() / 1000.f);
if(Event.Key.Code == sf::Keyboard::Down)
Sprite2.Move(0.f, sprite2Speed * Window.GetFrameTime() / 1000.f);
if(Event.Key.Code == sf::Keyboard::Space && jumping == false && falling == false)
{
velocity = 50.0f;
gravity = 0;
jumping = true;
}
if(jumping)
{
velocity = velocity - uprate;
Sprite2.SetPosition(Sprite2.GetPosition().x,Sprite2.GetPosition().y - (velocity));
if(velocity == -50.0f)
{
jumping = false;
falling = true;
gravity = 2;
}
if(falling)
velocity = velocity + gravity;
Sprite2.SetPosition(Sprite2.GetPosition().x,Sprite2.GetPosition().y+(velocity));
if(Sprite2.GetPosition().y + Sprite2.GetSize().y > Ground.GetPosition().y)
{
falling = false;
velocity =0;
gravity = 0;
}
}


5

General discussions / sf::input for sfml2

« on: January 12, 2012, 02:32:08 am »

I have been following the Game From Scratch tutorial and it is coded in 1.6.
I think I have everything right except the code for sf::Input I looked at the documentation and cant seem to figure it out.Here is the code, if anyone can give some info i would greatly appreciate it.

 

Code: [Select]


const sf::Input& Game::GetInput()
{
return _mainWindow.GetInput();
}



I already know that it should be keyPressed and Keyboard

Code: [Select]


void PlayerPaddle::Update(float elapsedTime)
{

if(Game::GetInput().IsKeyDown(sf::Key::Left))
{
this->_velocity-= 5.0f;
}
if(Game::GetInput().IsKeyDown(sf::Key::Right))
{
this->_velocity+= 5.0f;
}

if(Game::GetInput().IsKeyDown(sf::Key::Down))
{
this->_velocity= 0.0f;
}

if(_velocity > _maxVelocity)
this->_velocity = _maxVelocity;

if(_velocity < -_maxVelocity)
this->_velocity = -_maxVelocity;


sf::Vector2f pos = this->GetPosition();

if(pos.x  < GetSprite().GetSize().x/2
|| pos.x > (Game::SCREEN_WIDTH - GetSprite().GetSize().x/2))
{
_velocity = -_velocity; // Bounce by current velocity in opposite direction
}

GetSprite().Move(_velocity * elapsedTime, 0);
}


6

General / Sprite movement

« on: November 13, 2011, 09:53:39 pm »

I am having a problem with sprite movement.If I run this code the only key that works is left.Nothing happens with the other keys.Another problems is the sprite moves right off the screen when I press left.Is there something simple I can do or do I need to write the code a different way?

Code: [Select]

float ElapsedTime = Window.GetFrameTime() ;
       
        // Move the sprite
        switch(Event.Type)
        {
        case sf::Event::KeyPressed:
            switch(Event.Key.Code)
            case sf::Keyboard::Left:
                Sprite.Move(-100 * ElapsedTime, 0);
                break;
            case sf::Keyboard::Right:
                Sprite.Move( 100 * ElapsedTime, 0);
                break;
            case sf::Keyboard::Up:
                Sprite.Move(0, -100 * ElapsedTime);
                break;
            case sf::Keyboard::Down:
                Sprite.Move(0,  100 * ElapsedTime);
                break;
            default:
                break;


        }

7

General / Key events on sfml2

« on: November 13, 2011, 04:24:35 pm »

in this switch statement it does not matter whitch key i press it says f was pressed what am i doing wrong?

 case sf::Event::KeyPressed:
                switch (Event.KeyPressed)
                {
                case sf::Keyboard::Back:
                    std::cout << "Backspace was pressed." << std:: endl;
                    break;
                case sf::Keyboard::F:
                    std::cout << "f was pressed." << std:: endl;
                    break;
                default:
                    break;
                }

8

General / sfml vs sfml 2.0 key events

« on: November 12, 2011, 09:54:01 pm »

I m following the tutorials on 1.6 .The one on opengl. When I try to compile it give me errors on the key events.

this is the line giving the errors:

if ((Event.Type == sf::Event::KeyPressed) && (Event.Key.Code == sf::Key::Escape))
                App.Close();

I have read that you use keyboard instead of key but what would the line of code be?

Is there a code sheet showing the differences and how to write them?

9

General / opengl codeblocks

« on: November 12, 2011, 08:13:05 pm »

I am getting a error when trying to compile code with opengl

error: 'glClearDepth' was not declared in this scope|

I am using sfml2, do i need to link the opengl libraries and how?[/img][/code]

10

General / code completion code blocks

« on: November 12, 2011, 02:17:39 am »

Hey everyone I am new to SFML, I set up code blocks and can run a program fine but not all of my code completion works. Like when I type
sf::VideoMode it does not give me other options this would greatly help my learning. Any help with this will be appriciated.