Strange color-behavoir while drawing to backbuffer after blitting texture onto it

SDL Development
1

Hello SDL-Community,

as mentioned in the title, I have a problem while drawing onto the renderers backbuffer (NULL-target).
When I blit a texture to the backbuffer (“SDL_RenderCopy()”) and destroy this texture afterwards, the texture’s contents are still in the backbuffer, which is great.
But when I (without a “RenderPresent()”) try to draw to the backbuffer (over the containing texture-data) than,
the render-draw-color-domains (for each color-channel r,g,b&a) are capped at the color-channel-values of the pixel at x,y = 0,0 from the texture blitted before to the backbuffer, even if setting higher values with “SDL_SetRenderDrawColor()”.
So if this pixel was a dark cyan, I cannot draw a white or red/purple etc.,
but only that dark cyan, a dark blue/green, black or all of what’s in between.

Is this behavoir intended or a bug?
I tried to backup the renderers backbuffer in a sub-routine, that’s why I asked.

I’m using SDL v2.0.10

Thank you for your answers and have a great weekend.

2

I’m sorry,

I did not read the thread “I think SDL_ttf is disturbing SDL_SetRenderDrawColor for me” because of the keyword “SDL_ttf” before.
This is probably the same behavoir as in my case.

And as the following post (in aforementioned thread) states:

There may be a fix to this issue in future releases.