Ept summary bounds (#3172)

* Limit EPT summary bounds to match the behavior of point count when a spatial query is passed. Update docs.

* Remove dangling link from doc.

* Remove curl comment in EPT doc.

doc/stages/readers.ept.rst

@@ -17,7 +17,7 @@ with `Potree`_ or `Plasio`_.
 Example
 --------------------------------------------------------------------------------
 
-This example downloads a small area around the the Statue of Liberty from the New York City data set (4.7 billion points) which can be viewed in its entirety in `Potree`_ or `Plasio`_.
+This example downloads a small area around the the Statue of Liberty from the New York City data set (4.7 billion points) which can be viewed in its entirety in `Potree`_.
 
 .. code-block:: json
 
@@ -53,7 +53,7 @@ Options
 --------------------------------------------------------------------------------
 
 filename
-    EPT resource from which to read.  Because EPT resources do not have a file extension, to specify an EPT resource as a string, it must be prefixed with ``ept://``.  For example, ``pdal translate ept://http://na.entwine.io/autzen autzen.laz``. [Required]
+    Path to the EPT resource from which to read, ending with ``ept.json``.  For example, ``/Users/connor/entwine/autzen/ept.json`` or ``http://na.entwine.io/autzen/ept.json``. [Required]
 
 spatialreference
     Spatial reference to apply to the data.  Overrides any SRS in the input
@@ -94,11 +94,18 @@ origin
     dimension, which can be determined from  the file's position in EPT
     metadata file ``entwine-files.json``.
 
+.. note::
+
+    When using ``pdal info --summary``, using the ``origin`` option will cause the resulting bounds to be clipped to those of the selected origin, and the resulting number of points to be an upper bound for this selection.
+
 polygon
   The clipping polygon, expressed in a well-known text string,
   eg: "POLYGON((0 0, 5000 10000, 10000 0, 0 0))".  This option can be
   specified more than once by placing values in an array.
 
+.. note::
+
+    When using ``pdal info --summary``, using the ``polygon`` option will cause the resulting bounds to be clipped to the maximal extents of all provided polygons, and the resulting number of points to be an upper bound for this polygon selection.
 
 threads
     Number of worker threads used to download and process EPT data.  A
@@ -107,7 +114,6 @@ threads
 .. _Entwine Point Tile: https://entwine.io/entwine-point-tile.html
 .. _Entwine: https://entwine.io/
 .. _Potree: http://potree.entwine.io/data/nyc.html
-.. _Plasio: http://speck.ly/?s=http%3A%2F%2Fc%5B0-7%5D.greyhound.io&r=ept%3A%2F%2Fna.entwine.io%2Fnyc&ca=-0&ce=49.06&ct=-8239196%2C4958509.308%2C337&cd=42640.943&cmd=125978.13&ps=2&pa=0.1&ze=1&c0s=remote%3A%2F%2Fimagery%3Furl%3Dhttp%3A%2F%2Fserver.arcgisonline.com%2FArcGIS%2Frest%2Fservices%2FWorld_Imagery%2FMapServer%2Ftile%2F%7B%7Bz%7D%7D%2F%7B%7By%7D%7D%2F%7B%7Bx%7D%7D.jpg
 .. _Schema: https://entwine.io/entwine-point-tile.html#schema
 
 header

io/EptReader.cpp

@@ -349,8 +349,9 @@ QuickInfo EptReader::inspect()
     for (auto& el : m_info->dims())
         qi.m_dimNames.push_back(el.first);
 
-    // If we've passed a spatial query, determine an upper bound on the
-    // point count.
+    // If there is a spatial query from an explicit --bounds, an origin query,
+    // or polygons, then we'll limit our number of points to be an upper bound,
+    // and clip our bounds to the selected region.
     if (!m_queryBounds.contains(qi.m_bounds) || m_args->m_polys.size())
     {
         log()->get(LogLevel::Debug) <<
@@ -359,9 +360,25 @@ QuickInfo EptReader::inspect()
         m_hierarchy.reset(new Hierarchy);
         overlaps();
 
+        // If we've passed a spatial query, determine an upper bound on the
+        // point count based on the hierarchy.
         qi.m_pointCount = 0;
         for (const Overlap& overlap : *m_hierarchy)
             qi.m_pointCount += overlap.m_count;
+
+        // Also clip the resulting bounds to the intersection of:
+        //  - the query bounds (from an explicit bounds or an origin query)
+        //  - the extents of the polygon selection
+        qi.m_bounds.clip(m_queryBounds);
+        if (m_args->m_polys.size())
+        {
+            BOX3D b;
+            for (const auto& poly : m_args->m_polys)
+            {
+                b.grow(poly.bounds());
+            }
+            qi.m_bounds.clip(b);
+        }
     }
     qi.m_valid = true;