Java: is it possible to check if elevation for given point exists in Surface?

MarkoTandre

Hello,

If I ask (getElevationAsync(Point point)) from surface then I get 0 if it doesn't exist. How can I check if it exists in any of the ElevationSources?

I couldn't find anything how to check it.

Method getElevationAsync(Point point) should throw exception not return 0 elevation if it doesn't exist in any ElevationSource. This is bad practice and can do much harm.

The answer is not to use some url for elevations for entire world because most of the time my use case is offline and .tif file must be used as ElevationSource.

LudoG

You can do it by checking all Envelope of each RasterElevationSource

<SPAN class="keyword token">double</SPAN> pointX <SPAN class="operator token">=</SPAN> point<SPAN class="punctuation token">.</SPAN><SPAN class="token function">getX</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN> 
<SPAN class="keyword token">double</SPAN> pointY <SPAN class="operator token">=</SPAN> point<SPAN class="punctuation token">.</SPAN><SPAN class="token function">getY</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN> 
<SPAN class="keyword token">for</SPAN><SPAN class="punctuation token">(</SPAN>ElevationSource elevationSource <SPAN class="operator token">:</SPAN> surface<SPAN class="punctuation token">.</SPAN><SPAN class="token function">getElevationSources</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">)</SPAN> 
<SPAN class="punctuation token">{</SPAN> 
 Envelope envelope <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">(</SPAN>RasterElevationSource<SPAN class="punctuation token">)</SPAN> elevationSource<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">.</SPAN><SPAN class="token function">getFullExtent</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN> 
 <SPAN class="keyword token">if</SPAN> <SPAN class="punctuation token">(</SPAN>pointX between envelope<SPAN class="punctuation token">.</SPAN><SPAN class="token function">getXMin</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN> AND envelope<SPAN class="punctuation token">.</SPAN><SPAN class="token function">getXMax</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN> AND pointY between envelope<SPAN class="punctuation token">.</SPAN><SPAN class="token function">getYMin</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN> AND envelope<SPAN class="punctuation token">.</SPAN><SPAN class="token function">getYMax</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN> <SPAN class="punctuation token">)</SPAN> 
 <SPAN class="keyword token">return</SPAN> <SPAN class="token boolean">true</SPAN><SPAN class="punctuation token">;</SPAN> 
<SPAN class="punctuation token">}</SPAN> 
<SPAN class="keyword token">return</SPAN> <SPAN class="token boolean">false</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>