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# $Id: lookat.py,v 1.2 2005/07/21 15:07:11 mbaas Exp $

## \file lookat.py
## Contains the LookAt component.

"""This module contains the LookAt component which has a position
slot (pos) and a target slot (target) which are both of type vec3.
The output (output) is a mat3 that contains a rotation so that when positioned
at pos the z axis points to target."""

from component import createFunctionComponent
from cgtypes import *
from sl import radians
import scene

def _lookat(pos=vec3(0), target=vec3(0), up=vec3(0,0,1), roll=0.0):
    try:
        M = mat4().lookAt(pos, target, up)
    except:
        M = mat4(1)

    return M.getMat3()*mat3().rotation(radians(roll), vec3(0,0,1))

LookAt = createFunctionComponent(_lookat) # "mat3 (vec3 pos, vec3 target, vec3 up, double roll)")
