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Hippolyzer/hippolyzer/lib/base/anim_utils.py

92 lines
3.1 KiB
Python

"""
Assorted utilities to make creating animations from scratch easier
"""
import copy
from typing import List, Union
from hippolyzer.lib.base.datatypes import Vector3, Quaternion
from hippolyzer.lib.base.llanim import PosKeyframe, RotKeyframe
def smooth_step(t: float):
t = max(0.0, min(1.0, t))
return t * t * (3 - 2 * t)
def rot_interp(r0: Quaternion, r1: Quaternion, t: float):
"""
Bad quaternion interpolation
TODO: This is definitely not correct yet seems to work ok? Implement slerp.
"""
# Ignore W
r0 = r0.data(3)
r1 = r1.data(3)
return Quaternion(*map(lambda pair: ((pair[0] * (1.0 - t)) + (pair[1] * t)), zip(r0, r1)))
def unique_frames(frames: List[Union[PosKeyframe, RotKeyframe]]):
"""Drop frames where time and coordinate are exact duplicates of another frame"""
new_frames = []
for frame in frames:
# TODO: fudge factor for float comparison instead
if frame not in new_frames:
new_frames.append(frame)
return new_frames
def shift_keyframes(frames: List[Union[PosKeyframe, RotKeyframe]], num: int):
"""
Shift keyframes around by `num` frames
Assumes keyframes occur at a set cadence, and that first and last keyframe are at the same coord.
"""
# Get rid of duplicate frames
frames = unique_frames(frames)
pop_idx = -1
insert_idx = 0
if num < 0:
insert_idx = len(frames) - 1
pop_idx = 0
num = -num
old_times = [f.time for f in frames]
new_frames = frames.copy()
# Drop last, duped frame. We'll copy the first frame to replace it later
new_frames.pop(-1)
for _ in range(num):
new_frames.insert(insert_idx, new_frames.pop(pop_idx))
# Put first frame back on the end
new_frames.append(copy.copy(new_frames[0]))
assert len(old_times) == len(new_frames)
assert new_frames[0] == new_frames[-1]
# Make the times of the shifted keyframes match up with the previous timeline
for old_time, new_frame in zip(old_times, new_frames):
new_frame.time = old_time
return new_frames
def smooth_pos(start: Vector3, end: Vector3, inter_frames: int, time: float, duration: float) -> List[PosKeyframe]:
"""Generate keyframes to smoothly interpolate between two positions"""
frames = [PosKeyframe(time=time, pos=start)]
for i in range(0, inter_frames):
t = (i + 1) / (inter_frames + 1)
smooth_t = smooth_step(t)
pos = Vector3(smooth_t, smooth_t, smooth_t).interpolate(start, end)
frames.append(PosKeyframe(time=time + (t * duration), pos=pos))
return frames + [PosKeyframe(time=time + duration, pos=end)]
def smooth_rot(start: Quaternion, end: Quaternion, inter_frames: int, time: float, duration: float)\
-> List[RotKeyframe]:
"""Generate keyframes to smoothly interpolate between two rotations"""
frames = [RotKeyframe(time=time, rot=start)]
for i in range(0, inter_frames):
t = (i + 1) / (inter_frames + 1)
smooth_t = smooth_step(t)
frames.append(RotKeyframe(time=time + (t * duration), rot=rot_interp(start, end, smooth_t)))
return frames + [RotKeyframe(time=time + duration, rot=end)]