I noticed that render a portion of the texture, it affects is border values with the proximity of the outside remaining parts of the texture.

This is a problem when those 2 portions are 2 different frames: basically it is interpolating the border with the outside of the texture when need rescaling.

This causes frame/sprite artifacts.

Consider a texture atlas with multiple frames next to each other. Copying one frame is resulting having the border interpolated with another frame and this most likely is creating an artifact.

Is there any way to strictly render a portion of texture making SDL Renderer ignoring whatever else is outside the rect?

Simply copy and rescale only the rect given?

e.g:
The 2 frames:

1st frame on the bottom is altered by the values of the 2nd frame

2nd frame on the top is altered by the values of the 1st frame

This issue doesn’t happen if adding 1 pixel pad among the 2 frames or using 1 texture per frame. I am wondering is there any SDL2 settings to avoid this unwanted (subpixels?) interpolation?

Please also note that all the operations are performed with exact integers, so don’t understand really from where that “noise” could come from.
Could it be from some Video drivers settings?