# Copyright 2016 Bhautik J Joshi
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
# http://www.apache.org/licenses/LICENSE-2.0
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from .AbstractProjection import AbstractProjection
import math
class SideBySideFisheyeProjection(AbstractProjection):
def __init__(self):
AbstractProjection.__init__(self)
def set_angular_resolution(self):
self.angular_resolution = math.pi/self.imsize[1]
def _pixel_value(self, angle):
theta = angle[0]
phi = angle[1]
if theta is None or phi is None:
return (0,0,0)
r = math.cos(phi)
# z is elevation in this case
sphere_pnt = self.point_on_sphere(theta, phi)
# sphere_pnt.x: [-1..1]
u = 0.5+(sphere_pnt[0]*-0.5)
if theta>=0:
u = u*0.5 + 0.5
else:
u = (1.0-u)*0.5
#sphere_pnt.z: -1..1 -> v: 0..1
v = 0.5+(sphere_pnt[2]*0.5)
return self.get_pixel_from_uv(u,v, self.image)
@staticmethod
def angular_position(texcoord):
up = texcoord[0]
v = texcoord[1]
# correct for hemisphere
if up>=0.5:
u = 2.0*(up-0.5)
else:
u = 2.0*up
# ignore points outside of circles
if ((u-0.5)*(u-0.5) + (v-0.5)*(v-0.5))>0.25:
return None, None
# v: 0..1-> vp: -1..1
phi = math.asin(2.0*(v-0.5))
# u = math.cos(phi)*math.cos(theta)
# u: 0..1 -> upp: -1..1
u = 1.0-u
theta = math.acos( 2.0*(u-0.5) / math.cos(phi) )
if up<0.5:
theta = theta-math.pi
return (theta,phi)
