Draw TTF font at partial pixel coordinates

Using SDL_RenderCopyF() or SDL_RenderCopyExF(), which take float coordinates, to render your textures should achieve that, so long as you specify a suitable blend mode and scaling quality.

The floating-point rendering functions have been available since SDL 2.0.10 but are seemingly still not mentioned in the main SDL 2.0 documentation. I have expressed my annoyance at this before!