#!BPY
 
"""
Name: 'Game Engine Path Baker'
Blender: 242
Group: 'Misc'
Tooltip: 'Bake a path animation to and object's Ipo'
"""

__author__= "Timothy Wakeham"
__url__= ["blender.org", "blenderartists.org"]
__version__= "1.0"

__bpydoc__= """\
This script bakes a path animation to an object's Ipo, for use in the game engine

Usage:
Modify the User variables as fits your application, and run from text window.
"""

# User edit stuff here ##################################

#number of steps between each controlpoint
res = 25

#object to make follow path
bake_ob = 'Camera'

#number of frames each step takes
step_time = 1

#start frame
start = 0

# End user edit stuff ###################################

import Blender

def coeff(p0, p1, p2, p3):
	co = []
	for x in range(3):
		cx = 3 * (p1[x] - p0[x])
		bx = 3 * (p2[x] - p1[x]) - cx
		ax = p3[x] - p0[x] - cx - bx
		co.append([ax, bx, cx])
	return co

def eval_curve(o, co, t):
	p = []
	t2 = t*t
	for x in range(3):
		val = co[x][0] * t2 * t + co[x][1] * t2 + co[x][2] * t + o[x]
		p.append(val)
	return p

obj = Blender.Object.GetSelected()[0]
if obj.getType() <> 'Curve':
	Blender.Draw.PupMenu('Please select path to bake%t|Ok')
	raise
curve = obj.getData()
points = curve[0]
num_points = len(points)

frame = start
step = 1.0 / res

obj = Blender.Object.Get(bake_ob)
ipo = Blender.Ipo.New('Object', 'Path')
lx = ipo.addCurve('LocX')
ly = ipo.addCurve('LocY')
lz = ipo.addCurve('LocZ')

for idx in range(num_points - 1):
	b0 = points[idx].getTriple()
	b1 = points[idx + 1].getTriple()
	p0 = b0[1]
	p1 = b0[2]
	p2 = b1[0]
	p3 = b1[1]
	
	co = coeff(p0, p1, p2, p3)
	
	for t in range(res):
		p = eval_curve(p0, co, step * t)
		lx[frame] = p[0]
		ly[frame] = p[1]
		lz[frame] = p[2]
		
		frame += step_time
		
obj.setIpo(ipo)