The Question: Can ArcGIS SDK for iOS in Objective C find this solution with precision utilizing Lat/Long coordinates for ABCD to find E? if so! HOW?
How do you input for the coordinates for lineAB? This would be two sets of coordinates. I have not dealt with ArcGIS SDK for iOS yet. Can you explain for me?
Actually - you should get back a line when intersecting 2 lines. My first answer above is incorrect, I will remove it for clarity.
Code should look something like this:
<SPAN class="operator token">-</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="keyword token">void</SPAN><SPAN class="punctuation token">)</SPAN>lineIntersection<SPAN class="punctuation token">{</SPAN> AGSPolyline <SPAN class="operator token">*</SPAN>lineAB <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">[</SPAN>AGSPolyline polylineWithPoints<SPAN class="punctuation token">:</SPAN>@<SPAN class="punctuation token">[</SPAN><SPAN class="token function">AGSPointMakeWGS84</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="number token">0</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">0</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="token function">AGSPointMakeWGS84</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="number token">10</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">10</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">;</SPAN> AGSPolyline <SPAN class="operator token">*</SPAN>lineCD <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">[</SPAN>AGSPolyline polylineWithPoints<SPAN class="punctuation token">:</SPAN>@<SPAN class="punctuation token">[</SPAN><SPAN class="token function">AGSPointMakeWGS84</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="number token">0</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">10</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="token function">AGSPointMakeWGS84</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="number token">10</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">0</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="token function">AGSPointMakeWGS84</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="number token">5</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">10</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="token function">AGSPointMakeWGS84</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="number token">0</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">0</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="token function">AGSPointMakeWGS84</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="number token">10</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">10</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">;</SPAN> AGSPolyline <SPAN class="operator token">*</SPAN>lineE <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">(</SPAN>AGSPolyline<SPAN class="operator token">*</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">[</SPAN>AGSGeometryEngine intersectionOfGeometry1<SPAN class="punctuation token">:</SPAN>lineAB geometry2<SPAN class="punctuation token">:</SPAN>lineCD<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">;</SPAN> <SPAN class="token function">NSLog</SPAN><SPAN class="punctuation token">(</SPAN>@<SPAN class="string token">"lineE: %@"</SPAN><SPAN class="punctuation token">,</SPAN> lineE<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN> <SPAN class="punctuation token">}</SPAN><SPAN class="line-numbers-rows"><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN></SPAN>
Hello,I got NSLog reply of: lineE: AGSPolyline: [], sr: 4326How do I get the lat/long from lineE?
Wouldn't the AGSGeometry returned by the Geometry Engine be a point, not a polyline?
Brett,
Nick Furness pointed out to me that you need to actually union the lines together first to get what you are looking for.
Here is objective-c code to do what you need:
@interface AGSPolyline <SPAN class="punctuation token">(</SPAN>intersects<SPAN class="punctuation token">)</SPAN> <SPAN class="operator token">-</SPAN><SPAN class="punctuation token">(</SPAN>NSArray<SPAN class="operator token"><</SPAN>AGSPoint<SPAN class="operator token">*</SPAN><SPAN class="operator token">></SPAN><SPAN class="operator token">*</SPAN><SPAN class="punctuation token">)</SPAN>intersectionWithLine<SPAN class="punctuation token">:</SPAN><SPAN class="punctuation token">(</SPAN>AGSPolyline<SPAN class="operator token">*</SPAN><SPAN class="punctuation token">)</SPAN>line2<SPAN class="punctuation token">;</SPAN> @end @implementation AGSPolyline <SPAN class="punctuation token">(</SPAN>intersects<SPAN class="punctuation token">)</SPAN> <SPAN class="operator token">-</SPAN><SPAN class="punctuation token">(</SPAN>NSArray<SPAN class="operator token"><</SPAN>AGSPoint<SPAN class="operator token">*</SPAN><SPAN class="operator token">></SPAN><SPAN class="operator token">*</SPAN><SPAN class="punctuation token">)</SPAN>intersectionWithLine<SPAN class="punctuation token">:</SPAN><SPAN class="punctuation token">(</SPAN>AGSPolyline<SPAN class="operator token">*</SPAN><SPAN class="punctuation token">)</SPAN>line2<SPAN class="punctuation token">{</SPAN> NSMutableArray <SPAN class="operator token">*</SPAN>points <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">[</SPAN>NSMutableArray array<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">;</SPAN> <SPAN class="comment token">// first union the lines together</SPAN> AGSPolyline <SPAN class="operator token">*</SPAN>lineUnion <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">(</SPAN>AGSPolyline<SPAN class="operator token">*</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">[</SPAN>AGSGeometryEngine unionOfGeometry1<SPAN class="punctuation token">:</SPAN>self geometry2<SPAN class="punctuation token">:</SPAN>line2<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">;</SPAN> <SPAN class="comment token">// now get the intersecting line of union'ed line and self</SPAN> AGSPolyline <SPAN class="operator token">*</SPAN>line3 <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">(</SPAN>AGSPolyline<SPAN class="operator token">*</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">[</SPAN>AGSGeometryEngine intersectionOfGeometry1<SPAN class="punctuation token">:</SPAN>self geometry2<SPAN class="punctuation token">:</SPAN>lineUnion<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">;</SPAN> <SPAN class="keyword token">double</SPAN> tolerance <SPAN class="operator token">=</SPAN> <SPAN class="number token">1e-10</SPAN><SPAN class="punctuation token">;</SPAN> <SPAN class="keyword token">for</SPAN> <SPAN class="punctuation token">(</SPAN>AGSPart <SPAN class="operator token">*</SPAN>part in line3<SPAN class="punctuation token">.</SPAN>parts<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">{</SPAN> <SPAN class="keyword token">for</SPAN> <SPAN class="punctuation token">(</SPAN>AGSPoint <SPAN class="operator token">*</SPAN>point in part<SPAN class="punctuation token">.</SPAN>points<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">{</SPAN> <SPAN class="keyword token">double</SPAN> distance <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">[</SPAN>AGSGeometryEngine distanceBetweenGeometry1<SPAN class="punctuation token">:</SPAN>point geometry2<SPAN class="punctuation token">:</SPAN>line2<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">;</SPAN> <SPAN class="comment token">// if the point is on the passed-in line then add it to the return value</SPAN> <SPAN class="keyword token">if</SPAN> <SPAN class="punctuation token">(</SPAN>distance <SPAN class="operator token"><</SPAN> tolerance<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">{</SPAN> <SPAN class="punctuation token">[</SPAN>points addObject<SPAN class="punctuation token">:</SPAN>point<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">;</SPAN> <SPAN class="punctuation token">}</SPAN> <SPAN class="punctuation token">}</SPAN> <SPAN class="punctuation token">}</SPAN> <SPAN class="keyword token">return</SPAN> <SPAN class="punctuation token">[</SPAN>points copy<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">;</SPAN> <SPAN class="punctuation token">}</SPAN> @end <SPAN class="operator token">-</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="keyword token">void</SPAN><SPAN class="punctuation token">)</SPAN>testLineIntersection<SPAN class="punctuation token">{</SPAN> AGSPolyline <SPAN class="operator token">*</SPAN>lineAB <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">[</SPAN>AGSPolyline polylineWithPoints<SPAN class="punctuation token">:</SPAN>@<SPAN class="punctuation token">[</SPAN><SPAN class="token function">AGSPointMakeWGS84</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="number token">0</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">0</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="token function">AGSPointMakeWGS84</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="number token">10</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">10</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">;</SPAN> AGSPolyline <SPAN class="operator token">*</SPAN>lineCD <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">[</SPAN>AGSPolyline polylineWithPoints<SPAN class="punctuation token">:</SPAN>@<SPAN class="punctuation token">[</SPAN><SPAN class="token function">AGSPointMakeWGS84</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="number token">0</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">10</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="token function">AGSPointMakeWGS84</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="number token">10</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="number token">0</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">;</SPAN> NSArray <SPAN class="operator token">*</SPAN>pointsE <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">[</SPAN>lineAB intersectionWithLine<SPAN class="punctuation token">:</SPAN>lineCD<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">;</SPAN> <SPAN class="token function">NSLog</SPAN><SPAN class="punctuation token">(</SPAN>@<SPAN class="string token">"intersection points: %@"</SPAN><SPAN class="punctuation token">,</SPAN> pointsE<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN> <SPAN class="punctuation token">}</SPAN> <SPAN class="line-numbers-rows"><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN><SPAN></SPAN></SPAN>
Thanks to Nick Furness for pointing this out. He also provided the swift code, which I converted to objective-c.
Thanks for posting that, Ryan Olson.
For reference, here's a Gist with the Swift code: Runtime Line Intersection Points · GitHub
The Gist also discusses a potential edge-case worth being aware of, depending on how your input data is generated.
Thank you sir I will try as soon as I get time. I currently have 42 warnings from the install of the SDK, trying to work them out..
Input data is generated, by manual input on:
<SPAN class="" style="color: #2b91af; border: 0px;">CGPoint</SPAN><SPAN class="" style="color: #303336; border: 0px;"> p1 </SPAN><SPAN class="" style="color: #303336; border: 0px;">=</SPAN><SPAN class="" style="color: #303336; border: 0px;"> </SPAN><SPAN class="" style="color: #2b91af; border: 0px;">CGPointMake</SPAN><SPAN class="" style="color: #303336; border: 0px;">(</SPAN><SPAN class="" style="color: #7d2727; border: 0px;">32.734444</SPAN><SPAN class="" style="color: #303336; border: 0px;">,</SPAN><SPAN class="" style="color: #303336; border: 0px;"> </SPAN><SPAN class="" style="color: #303336; border: 0px;">-</SPAN><SPAN class="" style="color: #7d2727; border: 0px;">116.577499</SPAN><SPAN class="" style="color: #303336; border: 0px;">);</SPAN><SPAN class="" style="color: #303336; border: 0px;"></SPAN><SPAN class="" style="color: #2b91af; border: 0px;">CGPoint</SPAN><SPAN class="" style="color: #303336; border: 0px;"> p2 </SPAN><SPAN class="" style="color: #303336; border: 0px;">=</SPAN><SPAN class="" style="color: #303336; border: 0px;"> </SPAN><SPAN class="" style="color: #2b91af; border: 0px;">CGPointMake</SPAN><SPAN class="" style="color: #303336; border: 0px;">(</SPAN><SPAN class="" style="color: #7d2727; border: 0px;">32.7337</SPAN><SPAN class="" style="color: #303336; border: 0px;">,</SPAN><SPAN class="" style="color: #303336; border: 0px;"> </SPAN><SPAN class="" style="color: #303336; border: 0px;">-</SPAN><SPAN class="" style="color: #7d2727; border: 0px;">117.008</SPAN><SPAN class="" style="color: #303336; border: 0px;">);</SPAN><SPAN class="" style="color: #303336; border: 0px;"></SPAN><SPAN class="" style="color: #2b91af; border: 0px;">CGPoint</SPAN><SPAN class="" style="color: #303336; border: 0px;"> p3 </SPAN><SPAN class="" style="color: #303336; border: 0px;">=</SPAN><SPAN class="" style="color: #303336; border: 0px;"> </SPAN><SPAN class="" style="color: #2b91af; border: 0px;">CGPointMake</SPAN><SPAN class="" style="color: #303336; border: 0px;">(</SPAN><SPAN class="" style="color: #7d2727; border: 0px;">33.363609</SPAN><SPAN class="" style="color: #303336; border: 0px;">,</SPAN><SPAN class="" style="color: #303336; border: 0px;"> </SPAN><SPAN class="" style="color: #303336; border: 0px;">-</SPAN><SPAN class="" style="color: #7d2727; border: 0px;">116.836388</SPAN><SPAN class="" style="color: #303336; border: 0px;">);</SPAN><SPAN class="" style="color: #303336; border: 0px;"></SPAN><SPAN class="" style="color: #2b91af; border: 0px;">CGPoint</SPAN><SPAN class="" style="color: #303336; border: 0px;"> p4 </SPAN><SPAN class="" style="color: #303336; border: 0px;">=</SPAN><SPAN class="" style="color: #303336; border: 0px;"> </SPAN><SPAN class="" style="color: #2b91af; border: 0px;">CGPointMake</SPAN><SPAN class="" style="color: #303336; border: 0px;">(</SPAN><SPAN class="" style="color: #7d2727; border: 0px;">32.64</SPAN><SPAN class="" style="color: #303336; border: 0px;">,</SPAN><SPAN class="" style="color: #303336; border: 0px;"> </SPAN><SPAN class="" style="color: #303336; border: 0px;">-</SPAN><SPAN class="" style="color: #7d2727; border: 0px;">116.836</SPAN><SPAN class="" style="color: #303336; border: 0px;">);</SPAN>
-(void)lineIntersection{ AGSPolyline *lineAB = [AGSPolyline polylineWithPoints:@[AGSPointMakeWGS84(p1), AGSPointMakeWGS84(p2)]]; AGSPolyline *lineCD = [AGSPolyline polylineWithPoints:@[AGSPointMakeWGS84(p3), AGSPointMakeWGS84(p4)]]; NSArray *pointsE = [lineAB intersectionWithLine:lineCD]; NSLog(@intersection points: %@", pointsE);}
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