Find closest point on path forwards - ios

Given a path say 1000 meters long from start to goal consisting of a finite number of CLLocation points (guesstimate around 100). Assuming the user is somewhere on the path and a CLLocation coming from iOS location services, what would be the best way to calculate the nearest point forwards along the route?
Finding the nearest point is easy enough using -[CLLocation distanceFromLocation:], but as the user passes a point and moves towards the next, the previous point will still be the nearest until he passes the midway between the previous and next point.

You could keep a array consisting of the sorted (start to the end of the path) CLLocation points (hypothetical 100) and evaluate only those poins to find the nearest one that will be visited. To find a visited point you keep the starting position and mesure the distance from the start to the current location of the user(d1). If d1 > distance from start to the next point in the sorted array and the current location is nearby (10 - 100 m) the next point in sorted array then remove the point else user did not visit / passed by that location so you keep it in the sorted array.

Related

Work out world coordinates relative to position and rotation of an object in lua

I am trying to make a new tool for the tabletop simulator community based on my "pack up bag". The Packup Bag is a tool that remembers world position and rotation of objects you place inside it, so you can then place them back in the same positions and rotations they came from when "unpacking the bag".
I have been trying to modify this so it spits things out in a relative position and rotation to the bag, instead of using hardcoded world coordinates. The idea here is that players can sit at any location at the table, pick the faction bag they wish to play.. drop it on a known spot marked for them and press the place and it will populate contents of the bag relative to its location.
Now I have gotten some of this worked out... I am able to get the bag to place relative in some ways .. but I am finding it beyond my maths skills to work out the modifications of the transforms.
Basically I have this part working..
The mod understands relative position to the bag
The mod understands relative rotation to the bag
BUT.. the mod dose not understand relative position AND rotation at the same time.... I need someway to modify the position data relative to the rotational data... but can not work out how.
See this video....
https://screencast-o-matic.com/watch/cFiOeYFsyi
As you can see as I move the bag around the object is placed relative to it.... but if I rotate the bag, the object has the correct rotation but I need math to work out the correct position IF it is rotated. You can see it is just getting placed in the same position it was as if there was no rotation... as I haven't worked out how to code it to do this.
Now I have heard of something called "matrix math" but I couldn't understand it. I'm a self taught programmer of only a few months after I started modding TTS.
You can kinda understand what I mean I hope.. In the video example, when I rotate the bag, the object should be placed with the correct rotation but the world position needs to be changed.
See this Example to see relative rotation ....
https://screencast-o-matic.com/watch/cFiOeZFsyq
My code dose this by remembering the self.getPostion() of the bag and the obj.Position() of the object getting packed up.. it then dose a self - obj and stores that value for the X and Y position. It also remembers if it is negative or position and then when placing it uses the self.postion() and adds or subtracts the adjustment value. Same for rotation.
Still I do not know what ot go from here.. I have been kinda hurting my head on this and thought maybe some of you math guys might have a better idea on how to do this.
: TL;DR :
So I have
bag.getPosition() and obj.getRotation()
bag.getRotation(0 and obj.getRotation()
These return (x,y,z}
What math can I use to find the relative position and rotation of the objects to the bag so if I rotate the bag. The objects come out of it in a relative way...
Preferably in LUA.. thank you!
I'd hope you've found the answer by now, but for anyone else finding this page:
The problem is much simpler than what you're suggesting - it's basic right triangle trigonometry.
Refer to this diagram. You have a right triangle with points A, B, and C, where C is the right angle. (For brevity, I'll use abbreviations opp, adj, and hyp.) The bag is at point A, you want the object at point B. You have the angle and distance (angle A and the length of the hyp, respectively), but you need the x,y coordinates of point B relative to point A.
The x coord is the length of adj, and y coord is the length of opp. As shown, the formulas to calculate these are:
cos(angle A) = adj/hyp
sin(angle A) = opp/hyp
solving for the unknowns:
adj = hyp * cos(angle A)
opp = hyp * sin(angle A)
For your specific use, and taking into account the shift in coordinate system x,y,z => x,z,y:
obj_x_offset = distance * math.cos(bag.getRotation().y)
obj_z_offset = distance * math.sin(bag.getRotation().y)
obj_x_position = bag.getPosition().x + obj_x_offset
obj_z_position = bag.getPosition().z + obj_z_offset
Diagram source:
https://www.khanacademy.org/math/geometry/hs-geo-trig/hs-geo-modeling-with-right-triangles/a/right-triangle-trigonometry-review

How To Detect A User Is Within Range Of An Annotation

So I am working on a project that includes many uses placing annotations all around a map. The annotation, (which is a custom image with a much larger circular range) appears on the screen and, ideally, I would like for a user to be:
Notified if they are within the range of a annotation
and
Not be allowed to place another annotation within the range of another one if the circular pins overlap by, say, more than 25%
I think this is a pretty unique question and should be fun for somebody to help out with, so have fun! Thanks everybody!
You can check the distance from each annotation using
- (CLLocationDistance)distanceFromLocation:(const CLLocation *)location
This method measures the distance between the two locations by tracing
a line between them that follows the curvature of the Earth. The
resulting arc is a smooth curve and does not take into account
specific altitude changes between the two locations.
For more details refer Link
Try this:
let location = CLLocation(latitude: 1, longitude: 1)//Or user's location
let distance = location.distance(from: anotherLocation)
Edit:
As mentioned in the comments, you wanted to create an equidistant point. I suggest manually doing that:
Subtract the annotation's location from he user's location. Then add your distance back to the original one. For example:
The user's location = (1, 1)
The annotation's location = (3, 2)
Vertical difference would be 2
Horizontal difference would be 1
Then:
(3 + 2, 2 + 1)
Your result: (5, 3)
Now you would have two points (the one you just created and the user's location) at each end with a center point (original annotation)

Algolia: Search multiple geos simultaneously?

Is there any way to search for items within distance of a lat/long for multiple lat/longs simultaneously? E.g., to say "give me all results within 10 miles of 14.2342,-13.234234 AND 1.3234,4.56775"?
I currently only see the ability to search one set of coordinates at a time.
In its current version, the API only allows to pass one lat/long value at a time.
Nevertheless, it allows to pass multiple bounding boxes at the same time. That means that you could easily calculate the bounding boxe coordinates (see How to calculate the bounding box for a given lat/lng location?), and pass those to the search parameters.
You can find here https://www.algolia.com/doc/tutorials/geo-search a guide (+ sample code) showing how Geoloc search works. And more detail about the boundingBox parameters at https://www.algolia.com/doc/rest#param-insideBoundingBox

Delivery radius for a restaurant in Apple Maps

I'm trying to develop a delivery system for a restaurant, but I'm not sure how to approach this problem. The restaurant has five locations; four of them are in one state and the other is in a different state.
They only do deliveries for each location depending on how far it is; they also have setup certain limitations for each location.
My idea will be:
Fetch user's location on iOS (Accomplished)
Check if user location is inside of any Restaurant delivery radius. If so, set that location as the store, if not, just show a message that we don't delivery in their area.
Where I'm stuck
How can I define in Apple Maps the limits of Location 1, 2, 3, etc. (meaning what area will they be doing delivery to)?
Try setting the deliverable radius around the location of the restaurant. You can even draw an MKCircle to be fancy.
CLLocation * _storeLocation = [[CLLocation alloc] initWithLatitude:30.270135 longitude:-97.731270];
double deliverableRadius = 3 * 1609.34; // 3 miles (or the area they will deliver to)
MKCircle * circle = [MKCircle circleWithCenterCoordinate:storeLocation.coordinate radius:deliverableRadius];
[_mapView addOverlay:circle];
Once you have established the deliverable area, you can check to see if the see if the users location is within this area.
So I think a simple approach might be to simply check if the user is within a certain distance of a restaurant (ie "If I am less than 25 miles from a restaurant, then they will deliver to me").
First convert the address of the restaurant locations into gps coordinates. See Converting Place Names Into Coordinates for more info.
Next, calculate the distance between the user's location and the location of each restaurant and check if that distance less than the maximum delivery distance.
A formula for calcualating the distance between two points can be found here.

Find places within the boundaries of given locations

in my maps app i have to find the places (bank,ATM,cafe,bar..) inside bound of selected locations.Actually i have to get the places which are centre to the given locations.
for example i have 4 places a,b,c,d i have to get all banks inside bounds of these 4 places and have show them on map.
i can get nearest places for each location individually by using GooglePlaces API.but i need show places which are centre(approximately) to these 4 places.
please give me any suggestions how to do this or any example code or any other tutorials or links....
Thanks
Raki.
Your solution would be to take the average lat/lon of your points and then hit your Google API to get locations in that area. This average will be in the middle of however many coordinates you have. Example:
double totalLat = 0;
double totalLon = 0;
for(CLLocationCoordinate2D coordinate in coordinateArray)
{
totalLat += coordinate.latitude;
totalLon += coordinate.longitude;
}
// Use this average coordinate (which is the center of your points) to hit your Google API
CLLocationCoordinate2D averageCoordinate = CLLocationCoordinate2DMake(totalLat / coordinateArray.count, totalLon / coordinateArray.count);
Note: I haven't actually tested this, so don't just copy/paste, but it's the general idea.
You can always use the radius parameter defined in the Places API to get this information.
Please follow this Stack Overflow answer for more details.

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