postgresql - Where Can I Find the Source Code of Spatial Relationships Functions?

Question

Where can I find the source codes of spatial relationships functions such as ST_Overlaps?

Answer 1

PostGIS 的 git 镜像是https://github.com/postgis/postgis。主源在 svn 中。如果您在 Google 上搜索“postgis source”并在 postgis 站点上找到相关页面，您就会知道这一点。

ST_Overlaps在 SQL 中声明为：

CREATE OR REPLACE FUNCTION ST_Overlaps(geom1 geometry, geom2 geometry)
    RETURNS boolean
    AS 'SELECT $1 && $2 AND _ST_Overlaps($1,$2)'

这又指：

CREATE OR REPLACE FUNCTION _ST_Overlaps(geom1 geometry, geom2 geometry)
        RETURNS boolean
        AS 'MODULE_PATHNAME','overlaps'
        LANGUAGE 'c' IMMUTABLE STRICT
        COST 100;

所以 C 实现是一个名为 的函数overlaps，它定义在postgis/lwgeom_geos.c（找到ctags -R用于构建源索引，然后vim -t overlaps，但您可以使用任何您喜欢的 C 搜索工具，或者只是 grep）。