SFML2 PNG difference

[Groogy]

I just noticed a thing when I tried to render a PNG image. What I expected was this image:

But what I got was this:


Don't mind the red background, just me trying something out.
Anyway I don't understand why the transparency doesn't work and why the edges are cut off? Is it something I've done wrong?

I noticed this when I for the first time tried rendering something trough my game engine. The code for my test class looks like this:

Code: [Select]

class ImageEntity : public GraphicalEntity
{
public:
static ImageEntity *New()
{
ImageEntity *object = new ImageEntity();
object->Init();
return object;
}

protected:
void Init()
{
GraphicalEntity::Init();
myImage.LoadFromFile("data/test.png");
mySprite.SetImage(myImage);
}

void InitReceiver()
{
myReceiver = new ImageReceiver(*this);
}

void Render(sf::RenderTarget &target, sf::Renderer &renderer) const
{
target.Draw(mySprite);
}

sf::Image myImage;
sf::Sprite mySprite;
};

There's a lot of more code involved but the engine is getting quite huge and has a asynchronous design so it's kinda hard to show all the relevant code.

[Laurent]

Well, if it's just loading a PNG and displaying it with a sprite, it shouldn't be hard to write a minimal code that reproduces this problem.

[Groogy]

Aight okay, this code rendered exactly what it should produce.

Code: [Select]

int main()
{
sf::RenderWindow window(sf::VideoMode(800, 600), "Test");
sf::Image image;
sf::Sprite sprite;
image.LoadFromFile("data/test.png");
sprite.SetImage(image);
window.Clear(sf::Color(255, 0, 0));
window.Draw(sprite);
window.Display();
sf::Sleep(5);
return 0;
}

Could the error come from that a GraphicalEntity inherits from sf::Drawable?
*EDIT*
Tried but still worked like it should...


*REVELATION*
AAAAAH I'm so damn stupid.... The artifact comes from the fact that I do not clear every frame.... So the alpha transparency just stacks up for each frame and eventually reaches 255 making it totally opaque. And the cutoffs is not seen with the transparency but becomes visible when it turns opaque. Oooh damn what a huge mistake by me. I did the part managing the window so long ago that I forgot that it only cleared when the Rendering thread was created. So there actually is no error, just me that forgot