cl-ewkb

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  <h1>cl-ewkb</h1>
  <p>
    <a href="https://github.com/filonenko-mikhail/cl-ewkb.git">https://github.com/filonenko-mikhail/cl-ewkb.git</a>
  </p>

  
    <code class="clone">
    git clone 'https://github.com/filonenko-mikhail/cl-ewkb.git'
      <br>
      <br>
(ql:quickload :cl-ewkb)
    </code>
  

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    <span class="starlabel">&#9733;</span><span class="stars">5</span>
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    <p>cl-ewkb is a geospatial library, based on cl-wkb, that implements the OGC Well-Known Binary geographic geometry data model with PostGIS 3d, 4d extensions, and provides WKB and EWKB encoding and decoding functionality. cl-wkb author is J.P. Larocue.
Library also provide module cl-wkb, which has CLOS-based API like http://enroutesystems.com/software/cl-wkb/ with PostGIS extensions.</p>

<p>Depends on:
 ieee-floats
 flexi-streams</p>

<p>PostGIS extension WKB is described in postgis-1.5/doc/ZMSgeoms.txt
All extensions are supported: 3dz, 3dm, 4d, embedded SRID.</p>

<p>Exported structs</p>

<p>point-primitive x y
pointz-primitive x y z
pointm-primitive x y m
pointzm-primitive x y z m
point-primtive structs contain coordinates (2d, 3d, 4d)</p>

<p>linear-ring points-primitive
linear-ring struct contains array of point-primitive</p>

<p>geometry type srid
geometry parent struct for other types and also contains &ldquo;GEOMETRYCOLLECTION&rdquo;</p>

<p>point type srid point-primitive
line-string type srid points-primitive
polygon type srid linear-rings
multi-point type srid points
multi-line-string type srid line-strings
multi-polygon type srid polygons
geometry-collection type srid geometries</p>

<p>Exported functions</p>

<p>(decode octets)
Decode from wkb sequence
(decode-from stream)
Decode from wkb stream</p>

<p>Functions for encoding:</p>

<p>(encode object endianness)
Encode object to vector</p>

<p>(encode-to object stream endianness)
Encode object to stream with endianness</p>

<p>Example:</p>

<p>Getting data from postgresql and decode it:</p>

<p>(decode (caar (postmodern:query (:select (:ST_AsEWKB &ldquo;SRID=4326;LINESTRING(0 0 1 2, 1 1 2 3, 2 2 3 4)&rdquo;)))))</p>

<p>Result:</p>

<h1>(CL-EWKB::GISGEOMETRY 3758096386 4326</h1>

<p>#(CL-EWKB::LINEAR-RING
    #(#(CL-EWKB::POINT-PRIMITIVE 0.0d0 0.0d0 CL-EWKB::POINTZ-PRIMITIVE 1.0d0
        CL-EWKB::POINTZM-PRIMITIVE 2.0d0)
      #(CL-EWKB::POINT-PRIMITIVE 1.0d0 1.0d0 CL-EWKB::POINTZ-PRIMITIVE 2.0d0
        CL-EWKB::POINTZM-PRIMITIVE 3.0d0)
      #(CL-EWKB::POINT-PRIMITIVE 2.0d0 2.0d0 CL-EWKB::POINTZ-PRIMITIVE 3.0d0
        CL-EWKB::POINTZM-PRIMITIVE 4.0d0)))
  CL-EWKB::LINESTRING)</p>

<p>Drawing data with opengl (using cl-opengl):</p>

<p>Draw pointXX-primitive</p>

<p>(defun draw-point-primitive (point)
    (cond
        ((point-primitive-p point)
            (gl:vertex
                (point-primitive-x point)
                (point-primitive-y point)))
        ((pointz-primitive-p point)
            (gl:vertex
                (point-primitive-x point)
                (point-primitive-y point)
                (pointz-primitive-z point)))
        ((pointm-primitive-p point)
            (gl:vertex
                (point-primitive-x point)
                (point-primitive-y point)
                0.0
                (pointm-primitive-m point)))
        ((pointzm-primitive-p point)
            (gl:vertex
                (point-primitive-x point)
                (point-primitive-y point)
                (pointz-primitive-z point)
                (pointzm-primitive-m point)))))</p>

<p>Drawing objects</p>

<p>(defun draw-point (point)
    (gl:with-primitives :points
        (draw-point-primitive (point-primitive point))))</p>

<p>(defun draw-points (line-string)
    (gl:with-primitives :line-strip
        (map &apos;nil (lambda (point) (draw-point-primitive point))
             (line-string-points-primitive line-string))))</p>

<p>General drawing function</p>

<p>(defun draw-gisobject (object)
    (cond
        ((point-p object) (draw-point object))
        ((line-string-p object) (draw-points object))))</p>

  
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