import numpy as np
import cv2 as cv
import glob

def draw_gizmo(img, corners, imgpts):
	corner = tuple(corners[0].ravel().astype("int32"))
	imgpts = imgpts.astype("int32")
	img = cv.line(img, corner, tuple(imgpts[0].ravel()), (255,0,0), 5)
	img = cv.line(img, corner, tuple(imgpts[1].ravel()), (0,255,0), 5)
	img = cv.line(img, corner, tuple(imgpts[2].ravel()), (0,0,255), 5)
	return img


def draw_cube(img, corners, imgpts):
	imgpts = np.int32(imgpts).reshape(-1, 2)

	# draw ground floor in green
	img = cv.drawContours(img, [imgpts[:4]], -1, (0, 255, 0), -3)

	# draw pillars in blue color
	for i, j in zip(range(4), range(4, 8)):
		img = cv.line(img, tuple(imgpts[i]), tuple(imgpts[j]), (255), 3)

	# draw top layer in red color
	img = cv.drawContours(img, [imgpts[4:]], -1, (0, 0, 255), 3)

	return img


def main():
	process_video()

def process_video():
	with np.load('results/cam.npz') as X:
		mtx, dist, _, _ = [X[i] for i in ('mtx', 'dist', 'rvecs', 'tvecs')]

	criteria = (cv.TERM_CRITERIA_EPS + cv.TERM_CRITERIA_MAX_ITER, 30, 0.001)
	objp = np.zeros((6 * 7, 3), np.float32)
	objp[:, :2] = np.mgrid[0:7, 0:6].T.reshape(-1, 2)

	axis = np.float32([[3, 0, 0], [0, 3, 0], [0, 0, -3]]).reshape(-1, 3)

	# Open camera
	video = cv.VideoCapture(0)
	if not video.isOpened():
		print("Cannot open camera")
		exit()

	while True:
		# Read a new frame
		ok, img = video.read()
		if not ok:
			return
		process_img(img, criteria, objp, axis, mtx, dist)
		k = cv.waitKey(1) & 0xFF
		if k == ord('q'):
			break

def process_still():
	with np.load('results/cam.npz') as X:
		mtx, dist, _, _ = [X[i] for i in ('mtx', 'dist', 'rvecs', 'tvecs')]

	criteria = (cv.TERM_CRITERIA_EPS + cv.TERM_CRITERIA_MAX_ITER, 30, 0.001)
	objp = np.zeros((6 * 7, 3), np.float32)
	objp[:, :2] = np.mgrid[0:7, 0:6].T.reshape(-1, 2)

	axis = np.float32([[3, 0, 0], [0, 3, 0], [0, 0, -3]]).reshape(-1, 3)

	for fname in glob.glob('check*.jpg'):
		img = cv.imread(fname)
		process_img(img, criteria, objp, axis, mtx, dist)
		k = cv.waitKey(1) & 0xFF
		if k == ord('q'):
			break


def process_img(img, criteria, objp, axis, mtx, dist):	# Load previously saved data
	pattern_size = (7, 6)
	gray = cv.cvtColor(img, cv.COLOR_BGR2GRAY)
	ret, corners = cv.findChessboardCorners(gray, pattern_size, corners=None, flags=cv.CALIB_CB_ADAPTIVE_THRESH+cv.CALIB_CB_NORMALIZE_IMAGE+cv.CALIB_CB_FAST_CHECK)
	cv.drawChessboardCorners(img, corners=corners, patternSize=pattern_size, patternWasFound=ret)

	if ret:
		corners2 = cv.cornerSubPix(gray, corners, (11, 11), (-1, -1), criteria)

		# Find the rotation and translation vectors.
		ret, rvecs, tvecs = cv.solvePnP(objp, corners2, mtx, dist)

		# project 3D points to image plane
		imgpts, jac = cv.projectPoints(axis, rvecs, tvecs, mtx, dist)

		img = draw_gizmo(img, corners2, imgpts)

	cv.imshow('img', img)


if __name__ == '__main__':
	main()
	cv.destroyAllWindows()