General aviation Flight Instructor with student reported a NMAC with another aircraft at HMP non-towered airport in the traffic pattern. The instructor took evasive action to avoid a collision.

Narrative

While in the traffic pattern at Atlanta Speedway; runway 24 was in use. While on downwind to base Aircraft Y cutoff traffic (a student and I) on an 'extended base' entry with no radio calls or intentions known to traffic in the area. Evasive action was taken as a dive to the right was required to avoid a midair collision; I then tried to contact the aircraft via CTAF to which their response was nonchalant. Traffic pattern operations at a non-towered field are already dangerous but entering a full pattern without adhering to common practice is dangerous for everyone involved.Traffic Pattern Operations continued thereafter. After a few more laps in the pattern; the same Aircraft Y made a line up and wait call while our aircraft was on base turn to final. The aircraft proceeded to roll onto the runway while we were on short final. As a textbook runway incursion occurred; a side step to the right was executed as well as a go around in order to avoid another midair with the same aircraft. The aircraft made no further call and departed the area. Aircraft Y; was remarkably dangerous with both occurrences within the hour.