kml_com.m

//
//  kml_com.c
//  KMLViewer
//
//  Created by Mojtaba Cazi on 2/27/18.
//

#include "kml_com.h"

// Convert a KML coordinate list string to a C array of CLLocationCoordinate2Ds.
// KML coordinate lists are longitude,latitude[,altitude] tuples specified by whitespace.
void strToCoords(NSString *str, CLLocationCoordinate2D **coordsOut, NSUInteger *coordsLenOut) {
    NSUInteger read = 0, space = 10;
    CLLocationCoordinate2D *coords = malloc(sizeof(CLLocationCoordinate2D) * space);
    
    NSArray *tuples = [str componentsSeparatedByCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
    for (NSString *tuple in tuples) {
        if (read == space) {
            space *= 2;
            coords = realloc(coords, sizeof(CLLocationCoordinate2D) * space);
        }
        
        double lat, lon;
        NSScanner *scanner = [[NSScanner alloc] initWithString:tuple];
        [scanner setCharactersToBeSkipped:[NSCharacterSet characterSetWithCharactersInString:@","]];
        BOOL success = [scanner scanDouble:&lon];
        if (success)
            success = [scanner scanDouble:&lat];
        if (success) {
            CLLocationCoordinate2D c = CLLocationCoordinate2DMake(lat, lon);
            if (CLLocationCoordinate2DIsValid(c))
                coords[read++] = c;
        }
    }
    
    *coordsOut = coords;
    *coordsLenOut = read;
}