Messages

1

Graphics / Re: Sprite-Object lost (Probably a scoping-problem)

« on: January 12, 2015, 06:00:25 pm »

Okay, solved it. I'm so stupid. I thought the whole time that ballSprite was the problem, never even thinking about me forgetting to pass an actual sf::RenderTarget to the Entity. Great.

Thanks for all of your help =)

2

Graphics / Re: Sprite-Object lost (Probably a scoping-problem)

« on: January 11, 2015, 11:20:49 pm »

Okay, it's 100% sure now that the problem isn't my Loader/ResourceManager - But I still can't locate the origin of it. I tried making a minimal version of my code - And suddenly, it works. Weird is, that I just removed everything that hasn't to do with the rendering; And I don't really believe that those removed functions and members could influence that ballSprite Pointer. I just don't get it.

Here is my minimal example:

Code: [Select]

class Entity{
    public:
        Entity(sf::RenderTarget*target);
        virtual ~Entity() = 0;
        virtual void render()=0;
    protected:
        sf::RenderTarget*target;
};
Entity::Entity(sf::RenderTarget*target){
    this->target = target;
}
inline Entity::~Entity() { }

class BEntity : public Entity {
public:
BEntity(sf::RenderTarget* target);
~BEntity();
void render();
private:
sf::Sprite * ballSprite;
};
BEntity::BEntity(sf::RenderTarget* target) : Entity(target) {
this->ballSprite = Assets::instance().spriteManager->request(Assets::SPRITE__BALL);
this->target = target;
}
BEntity::~BEntity(){}
void BEntity::render(){
ballSprite->setPosition(200, 200);
ballSprite->setRotation(40);
target->draw(*ballSprite);
}
class World{
private:
std::vector<BEntity*> entities;
sf::RenderTarget * target;
public:
World(sf::RenderTarget * target);
void createBall();
void render();
};
World::World(sf::RenderTarget * target){
this->target = target;
}
void World::render(){
for (BEntity* e : entities){
e->render();
}
}
void World::createBall(){
entities.push_back(new BEntity(this->target));
}

int main()
{
Assets::instance().spriteManager->load(Assets::SPRITE__BALL, "ball.png");
World world(&window);
world.createBall();
sf::Clock clock;
while (window.isOpen()){
sf::Event event;
while (window.pollEvent(event)){
if (event.type == sf::Event::Closed)
window.close();
}
sf::Time delta = clock.restart();
window.clear();
world.render();
window.display();
}
return 0;
}

And then there is my longer example (Didn't omit anything but the header guards)

Entity .h&.cpp

Code: [Select]

class World;
class Entity {
public:
Entity(World * world, sf::RenderTarget* target);
virtual ~Entity() = 0;
Body* getPhysicsBody();
World* getWorld();
virtual Body* createBody() = 0;
virtual void render() = 0;
virtual void update(float delta) = 0;
virtual unsigned short int getType() = 0;
protected:
sf::RenderTarget* target;
Body * body;
World * parent;
};
inline Entity::~Entity() { }

Entity::Entity(World * world, sf::RenderTarget* target){
this->target = target;
this->parent = world;
}
Body * Entity::getPhysicsBody(){
return body;
}
World * Entity::getWorld(){
return parent;
}
BallEntity .h&.cpp

Code: [Select]

class BallEntity : public Entity {
public:
BallEntity(World * world, sf::RenderTarget* target, int radius);
~BallEntity();
Body* createBody();
void render();
void update(float delta);
unsigned short int getType();
private:
int radius;
sf::Sprite * ballSprite;
};

BallEntity::BallEntity(World * world, sf::RenderTarget* target, int radius) : Entity(world, target) {
this->radius = radius;
this->ballSprite = Assets::instance().spriteManager->request(Assets::SPRITE__BALL);
this->body = createBody();
}
BallEntity::~BallEntity(){}
void BallEntity::update(float delta){}
void BallEntity::render(){
ballSprite->setPosition(200, 200);
ballSprite->setRotation(40);
target->draw(*ballSprite); //VIOLATION ERROR
}
Body * BallEntity::createBody(){
b2BodyDef bodyDef;
bodyDef.type = b2_dynamicBody;
bodyDef.position.Set(0, 0);
b2Body* b2Body = getWorld()->physicsWorld.CreateBody(&bodyDef);
b2CircleShape dynamicBox;
dynamicBox.m_radius = 0.5f;
dynamicBox.m_p.Set(0, 0);
b2FixtureDef fixtureDef;
fixtureDef.shape = &dynamicBox;
fixtureDef.density = 1.0f;
fixtureDef.friction = 0.3f;
b2Body->CreateFixture(&fixtureDef);
Body * body = new Body_Box2d(this, b2Body, &getWorld()->physicsWorld);
return body;
}
unsigned short int BallEntity::getType(){
return 0;
}

World .h&.cpp

Code: [Select]

class Entity;
class World : public b2ContactListener {
private:
std::vector<Entity*> entities;
sf::RenderTarget * target;
public:
b2World physicsWorld;
World();
void deleteEntity(Entity * entityToRemove);
void createBall();
void moveEntity(float delta, sf::Vector2f velocity, Entity * entity);
void update(sf::Time delta);
void render();
void BeginContact(b2Contact* contact);
void EndContact(b2Contact* contact);
};

World::World() : physicsWorld(b2Vec2(0, 10)){
physicsWorld.SetContactListener(this);
this->entities.push_back(new WallEntity(this, 2, Assets::RESOLUTION_H*Assets::PIXELS_TO_METERS, 0, 0));
this->entities.push_back(new WallEntity(this, 2, Assets::RESOLUTION_H*Assets::PIXELS_TO_METERS, Assets::RESOLUTION_W*Assets::PIXELS_TO_METERS, 0));
}
void World::deleteEntity(Entity * entityToRemove){
entityToRemove->getPhysicsBody()->remove();
this->entities.erase(std::remove(entities.begin(), entities.end(), entityToRemove));
}
void World::createBall(){
BallEntity * be = new BallEntity(this, this->target, 0.5f);
this->entities.push_back(be);
be->getPhysicsBody()->setPositionY(0)->setPositionX(fmod(rand(), Assets::RESOLUTION_W*Assets::PIXELS_TO_METERS));
//TODO: APPLY FORCE
}
void World::moveEntity(float delta, sf::Vector2f velocity, Entity * entity){}
void World::render(){
for(Entity* e : entities){
e->render();
}
}
void World::update(sf::Time delta){
this->physicsWorld.Step(delta.asSeconds(), 8, 6);
std::vector<Entity*>::iterator iterator = entities.begin();
while (iterator != entities.end()){
if ((*iterator)->getPhysicsBody()->getPositionY() < Assets::RESOLUTION_H*Assets::PIXELS_TO_METERS){
delete *iterator;
iterator = entities.erase(iterator);
//TODO: SEND ENTITY DESTROY EVENT
(*iterator)->getPhysicsBody()->remove();
}else{
++iterator;
}
}

}
void World::BeginContact(b2Contact * contact){
Entity* e1 = (Entity*)contact->GetFixtureA()->GetBody()->GetUserData();
Entity* e2 = (Entity*)contact->GetFixtureB()->GetBody()->GetUserData();
if(e1->getType() == 0 && e2->getType() == 0){
//TODO: SEND BALL COLLIDE EVENT
}
if((e1->getType() == 0 && e2->getType() == 2) || e1->getType() == 2 && e2->getType() == 0){
//TODO:: SEND BALL COLLIDE PLATFORM EVENT
}
}
void World::EndContact(b2Contact * contact){

}

main()

Code: [Select]

World gameWorld;
int main()
{
Assets::instance().spriteManager->load(Assets::SPRITE__BALL, "ball.png");
gameWorld.createBall();

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

sf::Time delta = clock.restart();

gameWorld.update(delta);

window.clear();
gameWorld.render();
window.display();
}
return 0;
}
Minimal Example: Everything works fine.
"Real code": Violation Error.

I don't get it

3

Graphics / Re: Sprite-Object lost (Probably a scoping-problem)

« on: January 11, 2015, 08:47:39 pm »

Okay, so this is really weird.

When creating my BallEntity Object directly in the main-function and rendering it, everything works fine: So it isn't even a problem of my *ballSprite Variable or ResourceManager - But when it is created by my world class (Which just instantiates it and puts it in an array that is looped through to call the render function of every entity), I get the access violation error... Going to post the code soon, just have to do that minimal example.

4

Graphics / Re: Sprite-Object lost (Probably a scoping-problem)

« on: January 11, 2015, 06:43:42 pm »

@Jesper Juhl
Going to take a look at it, thanks.

@Ixrec
Oh, okay. If the problem isn't solved (I think I have a hunch of how I might solve it right now), I'll post that version of my code here =)

@eXpl0it3r
Actually, I thought that the pointer WILL persist, since it IS a pointer and you have to manage its lifetime manually: Thats why I choose a pointer for the "Texture", and not only a Texture-Object itself. And I don't really think that the problem lies in that method, since the Texture/Sprite still exists when I request it from my BallEntity class (= Doesn't get destroyed after loading), but it just somehow gets destroyed before I can render it. It's weird, in my opinion. But after all, I'm new to C++... I'll take a look at RAII but I don't really like it since the syntax just looks so.. complicated, for something that should make your life easier. I dunno, it's just a feeling I get.

Besides...

May I ask where do I copy it? I mean, I thought that what I was doing was exactly the contrary, not copying it, since I work with pointers instead of the object itself?

Man, I really hope I'll understand this C++ stuff with pointers sometimes

5

Graphics / Re: Sprite-Object lost (Probably a scoping-problem)

« on: January 11, 2015, 03:04:14 pm »

Sorry, I thought it would be easier to understand the problem if only some simple pseudo-code was posted. Here is the whole code (Omitted unimportant parts like Header-Guards, includes, etc):

Assets.h

Code: [Select]

class Assets {
public:
static Assets& instance();
static const unsigned short int
SPRITE__BALL = 0;
ResourceManager<sf::Sprite> * spriteManager;
protected:
Assets();
static Assets * _instance;

};
Assets.cpp

Code: [Select]

Assets* Assets::_instance = NULL;
Assets::Assets(){
spriteManager = new ResourceManager<sf::Sprite>(new Loader<sf::Sprite>());
}
Assets& Assets::instance(){
if (_instance == NULL) _instance = new Assets();
return *_instance;
}
ResourceManager.h

Code: [Select]

template<class Res> class ResourceManager {
protected:
std::map<int, Res*> resourceList;
Loader<Res> * loader;
public:
~ResourceManager();
ResourceManager(Loader<Res> * loader);
void load(int key, std::string filePath);
Res* request(int key);
void unload(int key);
void dispose();
};
template<class Res> inline ResourceManager<Res>::~ResourceManager(){
this->dispose();
}

template<class Res> inline ResourceManager<Res>::ResourceManager(Loader<Res> * loader){
this->loader = loader;
}

template<class Res> inline void ResourceManager<Res>::load(int key, std::string filePath){
unload(key);
this->resourceList[key] = this->loader->loadFromFile(filePath);
}

template<class Res> inline Res* ResourceManager<Res>::request(int key){
assert(resourceList.find(key) != resourceList.end() && "Resource could not be found. Make sure to load it before requesting it.");
return this->resourceList[key];
}

template<class Res> inline void ResourceManager<Res>::unload(int key){
if (this->resourceList.find(key) != this->resourceList.end()){
delete this->resourceList[key];
this->resourceList.erase(key);
}
}

template<class Res> inline void ResourceManager<Res>::dispose(){
delete loader;
for (std::pair<int, Res*> kv : resourceList){
delete kv.second;
}
resourceList.clear();
}
Loader.h & Loader.cpp

Code: [Select]

template<class T> class Loader {
public:
T* loadFromFile(const std::string& filePath);
~Loader() {}
};
template<>
sf::Texture* Loader<sf::Texture>::loadFromFile(const std::string& path) {
sf::Texture* texture = new sf::Texture();
texture->loadFromFile(path);
return texture;
}

template<>
sf::Sprite* Loader<sf::Sprite>::loadFromFile(const std::string& path){
sf::Texture* texture = new sf::Texture;
texture->loadFromFile(path);
return new sf::Sprite(*texture);
}

And finally the problematic class, "BallEntity":

Code: [Select]

class BallEntity : public Entity {
public:
BallEntity(World * world, sf::RenderTarget* target, int radius);
        ... //Unnecessary functions omitted, fE getType(), update(),
void render();
private:
int radius;
sf::Sprite * ballSprite;
};
BallEntity::BallEntity(World * world, sf::RenderTarget* target, int radius) : Entity(world, target) {
this->radius = radius;
this->ballSprite = Assets::instance().spriteManager->request(Assets::SPRITE__BALL);
}

void BallEntity::render(){
ballSprite->setPosition(...);
ballSprite->setRotation(...);
target->draw(*ballSprite); // ACCESS VIOLATION!!!
}

I hope I did not forget any file, but I don't think so .

6

Graphics / Sprite-Object lost (Probably a scoping-problem) SOLVED

« on: January 11, 2015, 02:17:19 pm »

Hey!

I just wrote a little ResourceManager and a singleton to access these resource managers everyhwere (I know that Singletons are bad but no idea how to do it otherwise).
I also have some sort of an Entity, which uses those Managers to assign a Sprite* in the constructor and then uses the local reference in the render-function. When assigning in the constructor, everything is still "there": For example, I'm able to output the size of the texture the sprite is using. But in my render-function, suddenly, the pointer is null! I'm pretty sure it has something to do with the variable scope, but no idea what the exact problem is. Here some pseudo-code to visualize the problem:

Code: [Select]

class Entity {

public:
    Entity(){
        mySprite = Assets::instance()->spriteManager->request(spriteID); //If I debug fE texture size of mySprite, it outputs "good" results.
    }
    void render(){
        somewindow.draw(*mySprite); //ACCESS VIOLATION: Pointer is null
    }
private:
    sf::Sprite * mySprite;

}

Could anyone please help me ^^?

Kind regards

7

Graphics / Re: Sprite batching in SFML?

« on: October 30, 2014, 05:24:35 pm »

Thanks for your answers.

Thing is - I don't know how to do it. I rarely had to do with stuff that is a little bit low-level, so this is all new to me. And I have no idea how I can learn this (without needing years).

8

Graphics / Re: Sprite batching in SFML?

« on: October 30, 2014, 04:05:13 pm »

So you can't batch all of your draw calls at once if you have different textures? Isn't that heavily affecting performance?

9

Graphics / Sprite batching in SFML?

« on: October 30, 2014, 03:56:25 pm »

Hello!

I'm currently trying to learn C++ (I programmed in Java before), and wanted to use SFML to create some simple graphical programs. To help me get comfortable with the language, I thought about creating some simple, tiny games, one of them being a game where objects are falling down from the top of the screen and you have to "catch" them. So, while writing the code, I noticed one thing: Apparently you have to make a draw call everytime you want a texture rendered. In my opinion this could be quite a heavy task for the computer, so my question is: Is there something like a SpriteBatch in SFML? (In Java I used a library called LibGDX where you had to use a class called "SpriteBatch". On every render-call, you would use the SpriteBatch#begin() method, make your draw calls, and then call SpriteBatch#end(). Is there something similar in SFML?)

Kind regards