Messages

1

Graphics / Re: Snake program not working.

« on: June 10, 2013, 12:40:36 pm »

I posted all the code since I had no idea where the error was occurring. I fixed the problem by using breakpoints - that was a really helpful method!

If someone was wondering, there were several problems in the moveSnake() method and the eatCircle() method. Here is the changes i made: http://pastebin.com/abdxsKMG

Have a great day everybody, and thanks for the help

2

Graphics / Re: Snake program not working.

« on: June 09, 2013, 10:28:09 pm »

Hmm. I just can't seem to get it working... When I pickup another piece, I'm trying to get something that's out of bounds of my vector. I can't seem to get the logic down. Here is the code: http://pastebin.com/Fw9CgdUd.

I'm going to bed now. Thanks a bunch in advance! I don't want you to code it for me, just give me a pointer as wto what should be done differently

3

Graphics / Re: Snake program not working.

« on: June 09, 2013, 07:43:51 pm »

Thanks for the additional comments

If you mean global as being instantiated in another class, then yes. It's not globally available though.

4

Graphics / Re: Snake program not working.

« on: June 09, 2013, 06:46:25 pm »

Aaaaand it's working. Didn't realize that was happening. I just setup a timer to fix that problem

Thanks a bunch! Will report back if I get stuck ^^

5

Graphics / Re: Snake program not working.

« on: June 09, 2013, 06:01:34 pm »

Still nothing... Not even if I call the setupSegmunts() method at the bottom of the Game() method.

6

Graphics / Re: Snake program not working.

« on: June 09, 2013, 05:09:58 pm »

I can't for the love of god find out why this isn't working. I implemented the way The Hatchet did it (kinda). Going to make it into for loops and make it able to obtain more peices that you pick up. That part shouldn't be so hard I guess. However in the first place, the code that I have at the moment is not working as intended - the snake is not being printed on the screen at all. I removed some of the methods that wasn't related to the problem:

Header file:

#include <SFML/Graphics.hpp>
#include <SFML/Window.hpp>
#include <SFML/System.hpp>
#include <iostream>
#include <vector>

class Game {
private:
        sf::RenderWindow mainWindow;
        sf::Texture snakeTexture;
        sf::Texture tailTexture;
        sf::Sprite snakeSprite;
        sf::Sprite tail;

        std::vector<sf::Sprite> snakeSegments;
       
        int oldX;
        int oldY;
        enum direction {Up, Down, Right, Left} Direction;

        void handleEvents();
        void moveSnake();
        void setupSegments();

        //void checkForCollisionWithWall();
        //bool collisionWithTail();
               
        void createMainWindow();

public:
        void run();
        Game();
};

Implementation file:

#include "Game.h"

void Game::createMainWindow() {
        mainWindow.create(sf::VideoMode(800,600), "Snake", sf::Style::Titlebar | sf::Style::Close);
        mainWindow.setMouseCursorVisible(false);
}

void Game::handleEvents() {
         sf::Event event;
        while (mainWindow.pollEvent(event))
        {
                        switch(event.type)
                        {
                        case sf::Event::Closed:
                                mainWindow.close();
                                break;
                        }

                        switch (event.key.code)
                        {
                        case sf::Keyboard::Up:
                                if (Direction != Down) {
                                        Direction = Up;
                                } break;
                        case sf::Keyboard::Down:
                                if (Direction != Up) {
                                        Direction = Down;
                                } break;
                        case sf::Keyboard::Right:
                                if (Direction != Left) {
                                        Direction = Right;
                                } break;
                        case sf::Keyboard::Left:
                                if (Direction != Right) {
                                        Direction = Left;
                                } break;
                        }
        }
}

void Game::moveSnake() {
                oldX = snakeSegments.at(0).getPosition().x;
        oldY = snakeSegments.at(0).getPosition().y;

                switch(Direction)
                {
                case Up:
                        snakeSegments.at(0).setPosition(oldX, oldY-20);
            snakeSegments.at(2).setPosition(snakeSegments.at(1).getPosition().x, snakeSegments.at(1).getPosition().y);
            snakeSegments.at(1).setPosition(oldX, oldY);
                        break;
                case Down:
                        snakeSegments.at(0).setPosition(oldX, oldY+20);
            snakeSegments.at(2).setPosition(snakeSegments.at(1).getPosition().x, snakeSegments.at(1).getPosition().y);
            snakeSegments.at(1).setPosition(oldX, oldY);
                        break;
                case Right:
                        snakeSegments.at(0).setPosition(oldX+20, oldY);
            snakeSegments.at(2).setPosition(snakeSegments.at(1).getPosition().x, snakeSegments.at(1).getPosition().y);
            snakeSegments.at(1).setPosition(oldX, oldY);       
                        break;
                case Left:
                        snakeSegments.at(0).setPosition(oldX-20, oldY);
            snakeSegments.at(2).setPosition(snakeSegments.at(1).getPosition().x, snakeSegments.at(1).getPosition().y);
            snakeSegments.at(1).setPosition(oldX, oldY);
                        break;
                }
}

void Game::setupSegments() {
        for (int i = 0; i < 3; i++) {
                snakeSegments.push_back(snakeSprite);
                snakeSegments.at(i).setPosition(100 + i*20, 100);
        }
}

void Game::run() {
    createMainWindow();

        while(mainWindow.isOpen())
        {
                handleEvents();
                moveSnake();
                               
                mainWindow.clear();

                for(std::vector<int>::size_type i = 0; i != snakeSegments.size(); i++) {
                        mainWindow.draw(snakeSegments.at(i));
                }

                mainWindow.display();
        }
}

Game::Game() {
        setupSegments();

        Direction = Down;

        snakeTexture.loadFromFile("pTexture.png");
        tailTexture.loadFromFile("tailTexture.png");

        snakeSprite.setTexture(snakeTexture);
        tail.setTexture(tailTexture);
}

Thanks in advance!

7

Graphics / Re: Snake program not working.

« on: June 09, 2013, 05:09:19 pm »

I can't for the love of god find out why this isn't working. I implemented the way The Hatchet did it (kinda). Going to make it into for loops and make it able to obtain more peices that you pick up. That part shouldn't be so hard I guess. However in the first place, the code that I have at the moment is not working as intended.
The snake is not being printed on the screen at all. I removed some of the methods that wasn't related to the problem:

Header file:

#include <SFML/Graphics.hpp>
#include <SFML/Window.hpp>
#include <SFML/System.hpp>
#include <iostream>
#include <vector>

class Game {
private:
        sf::RenderWindow mainWindow;
        sf::Texture snakeTexture;
        sf::Texture tailTexture;
        sf::Sprite snakeSprite;
        sf::Sprite tail;

        std::vector<sf::Sprite> snakeSegments;
       
        int oldX;
        int oldY;
        enum direction {Up, Down, Right, Left} Direction;

        void handleEvents();
        void moveSnake();
        void setupSegments();

        //void checkForCollisionWithWall();
        //bool collisionWithTail();
               
        void createMainWindow();

public:
        void run();
        Game();
};

Implementation file:

#include "Game.h"

void Game::createMainWindow() {
        mainWindow.create(sf::VideoMode(800,600), "Snake", sf::Style::Titlebar | sf::Style::Close);
        mainWindow.setMouseCursorVisible(false);
}

void Game::handleEvents() {
         sf::Event event;
        while (mainWindow.pollEvent(event))
        {
                        switch(event.type)
                        {
                        case sf::Event::Closed:
                                mainWindow.close();
                                break;
                        }

                        switch (event.key.code)
                        {
                        case sf::Keyboard::Up:
                                if (Direction != Down) {
                                        Direction = Up;
                                } break;
                        case sf::Keyboard::Down:
                                if (Direction != Up) {
                                        Direction = Down;
                                } break;
                        case sf::Keyboard::Right:
                                if (Direction != Left) {
                                        Direction = Right;
                                } break;
                        case sf::Keyboard::Left:
                                if (Direction != Right) {
                                        Direction = Left;
                                } break;
                        }
        }
}

void Game::moveSnake() {
                oldX = snakeSegments.at(0).getPosition().x;
        oldY = snakeSegments.at(0).getPosition().y;

                switch(Direction)
                {
                case Up:
                        snakeSegments.at(0).setPosition(oldX, oldY-20);
            snakeSegments.at(2).setPosition(snakeSegments.at(1).getPosition().x, snakeSegments.at(1).getPosition().y);
            snakeSegments.at(1).setPosition(oldX, oldY);
                        break;
                case Down:
                        snakeSegments.at(0).setPosition(oldX, oldY+20);
            snakeSegments.at(2).setPosition(snakeSegments.at(1).getPosition().x, snakeSegments.at(1).getPosition().y);
            snakeSegments.at(1).setPosition(oldX, oldY);
                        break;
                case Right:
                        snakeSegments.at(0).setPosition(oldX+20, oldY);
            snakeSegments.at(2).setPosition(snakeSegments.at(1).getPosition().x, snakeSegments.at(1).getPosition().y);
            snakeSegments.at(1).setPosition(oldX, oldY);       
                        break;
                case Left:
                        snakeSegments.at(0).setPosition(oldX-20, oldY);
            snakeSegments.at(2).setPosition(snakeSegments.at(1).getPosition().x, snakeSegments.at(1).getPosition().y);
            snakeSegments.at(1).setPosition(oldX, oldY);
                        break;
                }
}

void Game::setupSegments() {
        for (int i = 0; i < 3; i++) {
                snakeSegments.push_back(snakeSprite);
                snakeSegments.at(i).setPosition(100 + i*20, 100);
        }
}

void Game::run() {
    createMainWindow();

        while(mainWindow.isOpen())
        {
                handleEvents();
                moveSnake();
                               
                mainWindow.clear();

                for(std::vector<int>::size_type i = 0; i != snakeSegments.size(); i++) {
                        mainWindow.draw(snakeSegments.at(i));
                }

                mainWindow.display();
        }
}

Game::Game() {
        setupSegments();

        Direction = Down;

        snakeTexture.loadFromFile("pTexture.png");
        tailTexture.loadFromFile("tailTexture.png");

        snakeSprite.setTexture(snakeTexture);
        tail.setTexture(tailTexture);
}

Thanks in advance!

8

Graphics / Re: Snake program not working.

« on: June 09, 2013, 03:22:45 pm »

Kudos for learning to program, but I'm going to say the best thing you could probably do would be to find a c++ snake game tutorial online, there are lots if you google it.

I'd say that would probably be the worst thing.

You'll certainly find a lots that use plain old arrays, or worse new[] and delete[], or even worse self-built data structures. Global variables, reinvented wheels, and general bad style is unfortunately very common in C++ tutorials on the internet, especially in those on YouTube. By learning from internet tutorials, you get used to a lot of bad habits that are difficult to get rid of. Of course there are exceptions.

Anyway, wizh, you're doing it far too complicated. In order to draw a snake, it is enough to store a list of segments, for example in the STL container std::deque. One possibility is to have a pure logical class called Segment that stores the position (tile indices, not world units) of the segment, and possibly its type.

struct Segment
{
    enum Type { Head, Body, Tail };

    Type type;
    sf::Vector2i gridPosition;
};

class Game
{
    ...
    private:
        std::deque<Segment> segments;
};

In each step, you remove the last segment with pop_back() and insert a new one with push_front(). If you use different segment types, you have to adapt the front one before inserting the new head.

Of course you can also iterate through all segments and just update their positions, that requires less memory allocations. In this case, you could also use std::vector (in fact, for such tiny sizes the container choice is almost irrelevant, so you choose the one that's easiest to handle). There are many possibilities, but it's important to have a clear view of the parts of your game. This is where classes help a lot.

To render, you can just loop through all segments, create a sprite for each segment on the fly, and draw it. This won't be a performance issue. Otherwise you could still store the sprite in the segment, but it's usually cleaner to keep graphics and logics separated.

Also, don't mix event handling with game logics. Upon user inputs, you just set a variable such as the direction, but you don't change the snake directly. The snake (describing the gameplay) is modified during the update step of your game, which usually happens in regular intervals.

Thanks for your detailed response. About handling game logics and user input, I actually what you suggest (I think):

void Game::handleEvents() {
         sf::Event event;
        while (mainWindow.pollEvent(event))
        {
                        switch(event.type)
                        {
                        case sf::Event::Closed:
                                mainWindow.close();
                                break;
                        }

                        switch (event.key.code)
                        {
                        case sf::Keyboard::Up:
                                if (Direction != Down) {
                                        Direction = Up;
                                } break;
                        case sf::Keyboard::Down:
                                if (Direction != Up) {
                                        Direction = Down;
                                } break;
                        case sf::Keyboard::Right:
                                if (Direction != Left) {
                                        Direction = Right;
                                } break;
                        case sf::Keyboard::Left:
                                if (Direction != Right) {
                                        Direction = Left;
                                } break;
                        }
        }
}

void Game::moveSnake() {
        elapsed = gameClock.getElapsedTime();
        if (elapsed.asSeconds() >= 0.15) {
                switch(Direction)
                {
                case Up:
                        snakeSprite.setPosition(snakeSprite.getPosition().x, snakeSprite.getPosition().y - 20);
                        break;
                case Down:
                        snakeSprite.setPosition(snakeSprite.getPosition().x, snakeSprite.getPosition().y + 20);
                        break;
                case Right:
                        snakeSprite.setPosition(snakeSprite.getPosition().x + 20, snakeSprite.getPosition().y);
                        break;
                case Left:
                        snakeSprite.setPosition(snakeSprite.getPosition().x - 20, snakeSprite.getPosition().y);
                        break;
                }

                lastPosition0 = (snakeSprite.getPosition());
                gameClock.restart();
        }

}

Kudos for learning to program, but I'm going to say the best thing you could probably do would be to find a c++ snake game tutorial online, there are lots if you google it.

I'd say that would probably be the worst thing.

You'll certainly find a lots that use plain old arrays, or worse new[] and delete[], or even worse self-built data structures. Global variables, reinvented wheels, and general bad style is unfortunately very common in C++ tutorials on the internet, especially in those on YouTube. By learning from internet tutorials, you get used to a lot of bad habits that are difficult to get rid of. Of course there are exceptions.

It may not be the best but it sounded like he has no programming experience with the "Been only programming for under a week" line.  So I thought maybe seeing some examples would give him ideas.  Once he learned to get the bad ideas working we could set him on the path to good ideas.

As far as why it's not drawing, you could have loaded the texture out of order of order of when you set it to your sprite, could be not loading the texture at all.  You didn't show us where you load and set the textures only where you draw it(which seems as though it should draw it even if only on the same spot).

And yes, as Nexus said you are making this far more complicated than it needs be I think.  This is my stupid, quick and dirty 'snake' program that only consists of 3 segments.


It only moves as you press the keys, it doesn't move on its own.  That's some game logic you could work out for yourself.

Thanks for the code! My program is actually already doing that (making the snake move on it's own)

9

Graphics / Re: Snake program not working.

« on: June 09, 2013, 02:48:09 pm »

Kudos for learning to program, but I'm going to say the best thing you could probably do would be to find a c++ snake game tutorial online, there are lots if you google it.  They may not use SFML but really all you need SFML for is to draw to the screen anyways, most will probably use some other openGL library or raw openGL calls. 

Go find some basic coding tutorials since the logic of "I need to draw these first parts once at this spot then use a bool to not draw them again at that spot" is not very good logic. 

And your Else chunk is drawing the tail on the same spot 3 times.  Lets say 'lastPosition0' is at (10, 10):

tail.setPosition(lastPosition0); //sets tail to (10, 10)
            mainWindow.draw(tail); //draws the tail at (10, 10)
            lastPosition1 = tail.getPosition(); //sets lastPosition1 to (10, 10) since tail was at (10, 10)
           
            tail.setPosition(lastPosition1); //sets tail to (10, 10)
            mainWindow.draw(tail); //draws at (10, 10)
            lastPosition2 = tail.getPosition(); //sets lastPosition2 to (10, 10) since tail was still at (10, 10)

            tail.setPosition(lastPosition2); // sets tail to (10, 10)
            mainWindow.draw(tail);

Since i have nothing better to do I could try and prototype a simple snake game in the next while to give you a base example of what I would do I suppose.

I think you misunderstood my idea.

I made this little part just as a fun little sideproject to the 'real' game. I wanted to make the program myself, but I guess I could see how you'd handle it ^^

Still wondering why the sprite is not being displayed, though - even if it were 3 at the same place.

10

Graphics / Re: Snake program not working.

« on: June 09, 2013, 01:43:24 pm »

Hmm, sorry - I thought I had provided enough information.

The problem is that the tail isn't drawn to the screen at all. My logic was that the invidual pieces for the tail would have to replace the previous one.

The 'first' bool just makes it so that the initial 3 parts only get's drawn once. It get's set as false when the program executes: i.e. before anything happens.

The lastPosition0 (the head's position) get's set when the snake moves:

void Game::moveSnake() {
        elapsed = gameClock.getElapsedTime();
        if (elapsed.asSeconds() >= 0.15) {
                switch(Direction)
                {
                case Up:
                        snakeSprite.setPosition(snakeSprite.getPosition().x, snakeSprite.getPosition().y - 20);
                        break;
                case Down:
                        snakeSprite.setPosition(snakeSprite.getPosition().x, snakeSprite.getPosition().y + 20);
                        break;
                case Right:
                        snakeSprite.setPosition(snakeSprite.getPosition().x + 20, snakeSprite.getPosition().y);
                        break;
                case Left:
                        snakeSprite.setPosition(snakeSprite.getPosition().x - 20, snakeSprite.getPosition().y);
                        break;
                }

                lastPosition0 = (snakeSprite.getPosition());
                gameClock.restart();
        }

}
 

The different positions for the tail is all respectively set to their previous position, thus different positions.

I've been programming for less than a week so bare with me

All constructive criticism is welcomed.

11

Graphics / Snake program not working.

« on: June 09, 2013, 12:56:12 pm »

I was going to make a snake game, and wanted to do a quick "prototype" with just 3 pieces in the tail. However, this isn't working, and I just can't seem to figure out what it is that I'm doing wrong.

while(mainWindow.isOpen())
        {
                handleEvents();
                moveSnake();

                checkForCollisionWithWall();
                               
                mainWindow.clear();

                if(!first) {
               
                        tail.setPosition(snakeSprite.getPosition().x + 3, snakeSprite.getPosition().y - 20);
                        mainWindow.draw(tail);

                        lastPosition1 = tail.getPosition();
                               
                        tail.setPosition(snakeSprite.getPosition().x + 3, snakeSprite.getPosition().y - 40);
                        mainWindow.draw(tail);

                        lastPosition2 = tail.getPosition();
       
                        tail.setPosition(snakeSprite.getPosition().x + 3, snakeSprite.getPosition().y - 60);
                        mainWindow.draw(tail);

                        first = true;
               
                } else {

                        tail.setPosition(lastPosition0);
                        mainWindow.draw(tail);
                        lastPosition1 = tail.getPosition();
                       
                        tail.setPosition(lastPosition1);
                        mainWindow.draw(tail);
                        lastPosition2 = tail.getPosition();

                        tail.setPosition(lastPosition2);
                        mainWindow.draw(tail);
                }
               
                mainWindow.draw(snakeSprite);
                mainWindow.display();
         }
}
 

By using std::cout I figured that my positions were getting set correctly, the sprites are just not showing up.

Thanks in advance

12

Graphics / Re: Style question.

« on: June 09, 2013, 12:26:39 pm »

I see, thanks.

13

SFML projects / Re: Just another Tower Defense

« on: June 08, 2013, 08:36:22 pm »

Could you share the sourcecode?

14

Graphics / Style question.

« on: June 08, 2013, 07:06:04 pm »

I read in another thread that you should never make textures local temporary objects. So I was wondering, is this the correct way to handle drawing a sprite from another method?

#include <SFML/Graphics.hpp>

void drawSprite(sf::RenderWindow &window, sf::Texture texture) {

        sf::Sprite sprite;
        sprite.setTexture(texture);
    window.draw(sprite);
}


int main()
{
    sf::RenderWindow window(sf::VideoMode(200, 200), "SFML works!");

        sf::Texture texture;
        texture.loadFromFile("pTexture.png");

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

        window.clear();
                drawSprite(window, texture);
        window.display();
    }

    return 0;
}

15

General / Re: Program exits when I hover mouse over window.

« on: June 05, 2013, 09:56:45 pm »

Facepalm.