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| """ Snow Globe: Calibration Script for a Cheap DIY Spherical Projection Setup | |
| Copyright (c) 2011, Nirav Patel <http://eclecti.cc> | |
| Permission to use, copy, modify, and/or distribute this software for any | |
| purpose with or without fee is hereby granted, provided that the above | |
| copyright notice and this permission notice appear in all copies. | |
| THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES | |
| WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF | |
| MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR | |
| ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES | |
| WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN | |
| ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF | |
| OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. | |
| This script allows you to calibrate a Snow Globe. You use the arrow keys to | |
| line up the longitude lines correctly to arrive at the x and y position, | |
| plus and minus keys to adjust the radius size until it fits the full visible | |
| area of the sphere, and 9 and 0 to adjust the lens offset until the latitudes | |
| look properly aligned. Press s to save the calibration data to a file. | |
| usage: | |
| python calibration.py calibration.txt | |
| """ | |
| #!/usr/bin/env python | |
| import sys | |
| import math | |
| import pickle | |
| import pygame | |
| from pygame.locals import * | |
| class SnowGlobeCalibration(object): | |
| def __init__(self, fullscreen, filename): | |
| self.filename = filename | |
| self.size = (848, 480) | |
| self.clock = pygame.time.Clock() | |
| if fullscreen: | |
| self.display = pygame.display.set_mode(self.size, pygame.FULLSCREEN) | |
| else: | |
| self.display = pygame.display.set_mode(self.size, 0) | |
| self.display.fill((0,0,0)) | |
| self.r = 378 | |
| self.offset = 370.0 | |
| self.center = (431,210) | |
| self.lastrect = None | |
| if self.filename != None: | |
| self.open_calibration() | |
| self.sphere = pygame.surface.Surface((self.r*2,self.r*2)) | |
| self.generate_sphere() | |
| self.dx = 0 | |
| self.dy = 0 | |
| self.dr = 0 | |
| self.do = 0 | |
| self.going = True | |
| # An abandoned path by which I went pixel by pixel, determined the correct | |
| # theta and phi angles mapping to the hemisphere, and decided the color based | |
| # on the angle. Significantly too slow to run real time in python | |
| # def coord_color(self, theta, phi): | |
| # r = 255 | |
| # g = 255 | |
| # b = 255 | |
| # if theta < math.pi/4: | |
| # r = 0 | |
| # if phi > math.pi/2 or (phi > -math.pi/2 and phi < 0): | |
| # g = 0 | |
| # return (r, g, b) | |
| # | |
| # def cartesian_to_polar(self, x, y, d): | |
| # theta = math.acos(d/self.r) | |
| # phi = math.atan2(x-self.r,y-self.r) | |
| # return theta, phi | |
| # | |
| # def generate_sphere(self): | |
| # self.sphere = pygame.surface.Surface((self.r*2, self.r*2)) | |
| # pixels = pygame.surfarray.pixels3d(self.sphere) | |
| # for x, col in enumerate(pixels): | |
| # for y, color in enumerate(col): | |
| # d = math.sqrt((x-self.r)**2+(y-self.r)**2) | |
| # if d < self.r: | |
| # theta, phi = self.cartesian_to_polar(x, y, d) | |
| # pixels[x][y] = self.coord_color(theta, phi) | |
| ''' A whole lot of voodoo involving the law of sines to map a sphere | |
| to a hemisphere and then the hemisphere to a plane. ''' | |
| def radius_for_theta(self, theta): | |
| side_a = math.sin(theta)*self.r | |
| side_c = math.sin(math.pi/2.0-theta)*self.r | |
| # mapping the sphere angle to the hemisphere angle | |
| angle_b = math.atan2(side_a, side_c + self.offset) | |
| angle_b = min(math.pi/2,max(0.0,angle_b)) | |
| # map the hemisphere angle to the radius of the projected image in pixels | |
| # assumes the lens follows the r=2*f*sin(theta/2) mapping, but who knows | |
| rad = (float(self.r)/math.sin(math.pi/4))*math.sin(angle_b/2.0) | |
| return int(rad) | |
| def generate_sphere(self): | |
| self.sphere = pygame.surface.Surface((self.r*2, self.r*2)) | |
| # latitude colored regions | |
| pygame.draw.circle(self.sphere, (255,0,64), (self.r, self.r), self.radius_for_theta(math.pi)) | |
| pygame.draw.circle(self.sphere, (192,0,128), (self.r, self.r), self.radius_for_theta(math.pi*3.0/4.0)) | |
| pygame.draw.circle(self.sphere, (128,0,192), (self.r, self.r), self.radius_for_theta(math.pi/2.0)) | |
| pygame.draw.circle(self.sphere, (64,0,255), (self.r, self.r), self.radius_for_theta(math.pi/4.0)) | |
| # longitude grid lines | |
| pygame.draw.line(self.sphere, (128,255,128), (self.r, self.r), (0, 0), 5) | |
| pygame.draw.line(self.sphere, (128,255,128), (self.r, self.r), (self.r, 0), 5) | |
| pygame.draw.line(self.sphere, (128,255,128), (self.r, self.r), (self.r*2, 0), 5) | |
| pygame.draw.line(self.sphere, (128,255,128), (self.r, self.r), (self.r*2, self.r), 5) | |
| pygame.draw.line(self.sphere, (128,255,128), (self.r, self.r), (self.r*2, self.r*2), 5) | |
| pygame.draw.line(self.sphere, (128,255,128), (self.r, self.r), (self.r, self.r*2), 5) | |
| pygame.draw.line(self.sphere, (128,255,128), (self.r, self.r), (0, self.r*2), 5) | |
| pygame.draw.line(self.sphere, (128,255,128), (self.r, self.r), (0, self.r), 5) | |
| def composite(self): | |
| self.display.fill((0,0,0),self.lastrect) | |
| rect = self.display.blit(self.sphere, (self.center[0]-self.r, self.center[1]-self.r)) | |
| pygame.display.update([rect,self.lastrect]) | |
| self.lastrect = rect | |
| def move(self): | |
| self.center = (self.center[0] + self.dx, self.center[1] + self.dy) | |
| if self.dr != 0 or self.do != 0: | |
| self.r += self.dr | |
| if self.offset < self.r or self.do == -1: | |
| self.offset += self.do | |
| elif self.offset > self.r: | |
| self.offset = self.r | |
| self.generate_sphere() | |
| def open_calibration(self): | |
| try: | |
| f = open(self.filename, 'r') | |
| except IOError: | |
| print "Failed to open %s." % self.filename | |
| else: | |
| properties = pickle.load(f) | |
| try: | |
| self.r = properties["radius"] | |
| self.offset = properties["offset"] | |
| self.center = properties["center"] | |
| except KeyError: | |
| print "%s missing properties." % self.filename | |
| f.close() | |
| def save_calibration(self): | |
| with open(self.filename, 'w') as f: | |
| properties = dict(radius=self.r,offset=self.offset,center=self.center) | |
| pickle.dump(properties,f) | |
| def check_input(self): | |
| events = pygame.event.get() | |
| for e in events: | |
| if e.type == QUIT or (e.type == KEYDOWN and e.key == K_ESCAPE): | |
| self.going = False | |
| elif e.type == KEYDOWN: | |
| if e.key == K_LEFT: | |
| self.dx = -1 | |
| elif e.key == K_RIGHT: | |
| self.dx = 1 | |
| elif e.key == K_UP: | |
| self.dy = -1 | |
| elif e.key == K_DOWN: | |
| self.dy = 1 | |
| elif e.key == K_MINUS: | |
| self.dr = -1 | |
| elif e.key == K_EQUALS: | |
| self.dr = 1 | |
| elif e.key == K_9: | |
| self.do = -1 | |
| elif e.key == K_0: | |
| self.do = 1 | |
| elif e.key == K_s: | |
| if self.filename != None: | |
| self.save_calibration() | |
| elif e.type == KEYUP: | |
| if (e.key == K_LEFT and self.dx == -1) or (e.key == K_RIGHT and self.dx == 1): | |
| self.dx = 0 | |
| elif (e.key == K_UP and self.dy == -1) or (e.key == K_DOWN and self.dy == 1): | |
| self.dy = 0 | |
| elif (e.key == K_MINUS and self.dr == -1) or (e.key == K_EQUALS and self.dr == 1): | |
| self.dr = 0 | |
| elif (e.key == K_9 and self.do == -1) or (e.key == K_0 and self.do == 1): | |
| self.do = 0 | |
| def main(self): | |
| while self.going: | |
| self.check_input() | |
| self.move() | |
| self.composite() | |
| self.clock.tick(60) | |
| print (self.r, self.offset, self.center) | |
| if __name__ == '__main__': | |
| pygame.init() | |
| filename = None | |
| if len(sys.argv) > 1: | |
| filename = sys.argv[1] | |
| snowglobe = SnowGlobeCalibration(True, filename) | |
| snowglobe.main() | |