SFML 2.0 RC: sf::RenderTexture: bug or bad use?

[webshinra]

Hi there,
i start a project months ago, and it finally go far enough to build a GUI.
But after a moment and after a lot of optimisation, a visual artefact appear.

http://www.pasteall.org/pic/show.php?id=31433 (screen-shoot)

I will rapidly explain the rendering process:
voxel of the world are generated by a coherent noise generator and saved with semantic information in a octree.
After that, the 2D renderer run through the octree, adding sprite to many sf::RenderTexture to buffer a "zone" and after it, sf::RenderTexture are put on the main vue (as sprites) to show the world.
the sf::RenderTexture is cleared with sf::Color::Transparent, but, when put on each other sf::RenderTexture seam to keep (black) color from the background and when transparent sprite are on a border we can see a black/gray gradien.
( sf::Color::Transparent is a black transparent but if i use (255,255,255,0) as background color the border look white instead of black)

Maybe I made a mistake using RenderTexture but it look like a bug from the lib.

What's your point of vue?

[Laurent]

Hmm, it's hard to see what's wrong. Would you be able to write a complete and minimal app that reproduces this problem, so that I can test it?

[webshinra]

hum, i don't see how to write a 'simple' app which present this problem but I can give you access to repository and a little more explications.

https://gitorious.org/dyasb/pages/Home (wiki, for dependencies)
https://gitorious.org/dyasb/dyasbo (git repository)

the most important file is https://gitorious.org/dyasb/dyasbo/blobs/master/src/Map2dDisplay.cpp
the run() function create a array of renderTexture https://gitorious.org/dyasb/dyasbo/blobs/master/src/Map2dDisplay.cpp#line63
those rendertextures are built by "build from tree" https://gitorious.org/dyasb/dyasbo/blobs/master/src/Map2dDisplay.cpp#line217
and then displayer in the right order https://gitorious.org/dyasb/dyasbo/blobs/master/src/Map2dDisplay.cpp#line179

(if you take the time to compile the project, at the first run you will see a black screen, you should zoom back using "-" to get see the earth and then you can zoom in an navigate using the mouse)

[Laurent]

Sorry but I don't have the time to explore your project

Can't you write a very simplified version of what you do? If it's just drawing to render-textures which cause problems, then it's not hard to try that in a minimal main() with a window and a drawing loop.

[webshinra]

hum, i think it's the same problem as in this minimal app:
http://webshinra.fr/dyasbo.tar.gz

[webshinra]

up?

[Laurent]

Sorry, I didn't have the time to test it yet.