How monster animations work in Q2?

[dfut]

So, i was browsing the monster code and found this:

mframe_t berserk_frames_pain2[] = {
{ai_move, 0, NULL},
{ai_move, 0, NULL},
{ai_move, 0, NULL},
{ai_move, 0, NULL},
{ai_move, 0, NULL},
{ai_move, 0, NULL},
{ai_move, 0, NULL},
{ai_move, 0, NULL},
{ai_move, 0, NULL},
{ai_move, 0, NULL},
{ai_move, 0, NULL},
{ai_move, 0, NULL},
{ai_move, 0, NULL},
{ai_move, 0, NULL},
{ai_move, 0, NULL},
{ai_move, 0, NULL},
{ai_move, 0, NULL},
{ai_move, 0, NULL},
{ai_move, 0, NULL},
{ai_move, 0, NULL}
};
How does it work? Why is the same line repeated over and over again for a pain animation?

[knightmare]

That's just part of the animation system. The animation frames themselves are in the monster models, and are listed in the header (.h) file for each monster.

The mframe_t frame pointer lists declare which functions are to be called for each animation frame and the distance moved, while the mmove_t sequence declares the start and end frames for an animation, along with the pointer list and end function. The monster's currentmove pointer is set to an mmove_t sequence, and the generic monster code (in g_monster.c) handles it from there.

In short, you won't be able to understand the monster animation/movement/AI from looking at a single file. It's distributed across multiple files to simplify adding more monsters.