Rename smoc_area to area and make it return steradians

Author: df7cb

doc/functions.sgm

@@ -15,7 +15,7 @@
               The <function>area</function> function returns the area of a
               spherical object in square radians. Supported data types are:
               <type>scircle</type>, <type>spolygon</type> (if the polygon
-	      is convex), and <type>sbox</type>.
+              is convex), <type>sbox</type>, and <type>smoc</type>.
             </para>
             <example>
               <title>Area of a spherical circle as a multiple of &pgr;</title>
@@ -24,6 +24,11 @@
 <![CDATA[ area]]>
 <![CDATA[------]]>
 <![CDATA[ 1]]>
+<![CDATA[(1 row)]]>
+<![CDATA[sql> SELECT area(smoc '0/1-3');]]>
+<![CDATA[       area]]>
+<![CDATA[-------------------]]>
+<![CDATA[ 3.141592653589793]]>
 <![CDATA[(1 row)]]>
               </programlisting>
             </example>
@@ -592,16 +597,6 @@
             </programlisting>
           </example>
 
-          <funcsynopsis>
-            <funcprototype>
-              <funcdef><function>smoc_area</function></funcdef>
-                <paramdef>smoc</paramdef>
-            </funcprototype>
-          </funcsynopsis>
-          <para>
-            Returns the size of an smoc in order 29 pixels.
-          </para>
-
           <funcsynopsis>
             <funcprototype>
               <funcdef><function>smoc_degrade</function></funcdef>
@@ -631,7 +626,7 @@
           </funcsynopsis>
           <para>
             <type>smoc</type> union and intersection are available as aggregate functions
-            that compute the aggretated area over a given column.
+            that compute the aggretated coverage over a given column.
           </para>
           <example>
             <title>Computing the overall coverage of a catalog</title>

expected/moc.out

@@ -1,5 +1,5 @@
 SET client_min_messages = 'notice';
--- SET client_min_messages = 'warning';
+SET extra_float_digits = 0; -- make results compatible with 9.6 .. 11
 SELECT smoc('');            -- expected: '0/'
  smoc 
 ------
@@ -42,6 +42,30 @@ SELECT smoc_info('0/1-2'::smoc);
  version: 0, order: 0, depth: 1, first: 288230376151711744, last: 864691128455135232, area: 576460752303423488, tree_begin: 48, data_begin: 72
 (1 row)
 
+SELECT area('0/'::smoc);
+ area 
+------
+    0
+(1 row)
+
+SELECT area('29/1'::smoc);
+         area         
+----------------------
+ 3.63319635209232e-18
+(1 row)
+
+SELECT area('0/1-3'::smoc);
+       area       
+------------------
+ 3.14159265358979
+(1 row)
+
+SELECT area('0/0-11'::smoc);
+       area       
+------------------
+ 12.5663706143592
+(1 row)
+
 SELECT '(0.78, 0.81)'::spoint <@ '7/123-456,10000-20000'::smoc;
  ?column? 
 ----------

moc.c

@@ -418,7 +418,7 @@ smoc_area(PG_FUNCTION_ARGS)
 	/* get just the MOC header: */
 	Smoc *moc = (Smoc *) PG_DETOAST_DATUM_SLICE(PG_GETARG_DATUM(0), 0,
 															MOC_HEADER_VARSIZE);
-	PG_RETURN_INT64(moc->area);
+	PG_RETURN_FLOAT8(moc->area * 4.0 * M_PI / MOC_AREA_ALL_SKY);
 }
 
 Datum

pgs_moc_ops.sql.in

@@ -8,9 +8,9 @@ CREATE FUNCTION smoc_info (smoc)
 	IMMUTABLE
 	STRICT;
 
-CREATE FUNCTION smoc_area (smoc)
-	RETURNS bigint
-	AS 'MODULE_PATHNAME'
+CREATE FUNCTION area (smoc)
+	RETURNS double precision
+	AS 'MODULE_PATHNAME', 'smoc_area'
 	LANGUAGE C
 	PARALLEL SAFE
 	IMMUTABLE

sql/moc.sql

@@ -1,5 +1,5 @@
 SET client_min_messages = 'notice';
--- SET client_min_messages = 'warning';
+SET extra_float_digits = 0; -- make results compatible with 9.6 .. 11
 
 SELECT smoc('');            -- expected: '0/'
 SELECT '0/'::smoc;          -- expected: '0/'
@@ -10,6 +10,11 @@ SELECT '0/0,1,2,3,7'::smoc; -- expected: '0/0-3,7'
 SELECT smoc_info('0/'::smoc);
 SELECT smoc_info('0/1-2'::smoc);
 
+SELECT area('0/'::smoc);
+SELECT area('29/1'::smoc);
+SELECT area('0/1-3'::smoc);
+SELECT area('0/0-11'::smoc);
+
 SELECT '(0.78, 0.81)'::spoint <@ '7/123-456,10000-20000'::smoc;
 SELECT '(0.78, 0.81)'::spoint <@ '7/123-456,1000-2000'::smoc;