I wrote this simple custom BlendState.
Without a RenderTarget everything works fine.
However, when I’m drawing to a RenderTarget. Things go wrong.
The problem is that the SpriteBatch class is using AlphaBlend by default and thus it alters the final image.
Just use renderstate.alphablend when beginning the spritebatch there. It’s a possible parameter.
More sure you call “clear” on the render target and choose a transparent background.
Oh I see you don’t want it. Nevertheless blendstate is a parameter for spritebatch calls.
This is how i doing currently. As i said the problem is that when i draw the final RenderTarget the SpriteBatch is going to modify the image. I need an another custom BlendState to prevent that but i don’t have any idea about how to do it.
Try clearing the backbuffer after the render to texture
I would clear the second back buffer to black. I would use BlendState.AlphaBlend for both SpriteBatch.Begin() calls. Not sure why additive is being used unless you’re doing something a bit out of the ordinary.
Since that, I found the solution :D. Anybody who is interested in the result here’s the library where I contributed NuklearDotNet