Very bad text quality in SDL_RENDER_SOFTWARE mode


Because SDL2 still badly support video drivers on ARM platforms, at least up to 2.0.5, I have to use the software video mode.
If it’s a big problem about performances, it’s also a big problem about text rendering on transparent textures.

THis is the code I use to generated the text below:

txtSurf = TTF_RenderUTF8_Blended(police, label->attributes.texts[idxTxt].string, textColor);

SDL_Texture *text = SDL_CreateTextureFromSurface( label->widget.parent->renderer, txtSurf );

SDL_FreeSurface( txtSurf );

SDL_SetTextureBlendMode(text, SDL_BLENDMODE_BLEND);

SDL_RenderCopy( label->widget.parent->renderer, text, &src, &dest );


Below is a comparison on a laptop between software and accelerated video mode:

software accelerated

Is there a way to improve text quality in software mode ?

After test on another same model laptop, I only get this problem on Debian Stretch. Works well on Jessie.