Determining if a point lies on the interior of a polygon Written by Paul Bourke  November 1987 Solution 1 (2D) The following is a simple solution to the problem often encountered in computer graphics, determining whether or not a point (x,y) lies ins…

A General Polygon Clipping Library Version 2.32    http://www.cs.man.ac.uk/~toby/alan/software/gpc.html Alan Murta Advanced Interfaces Group Department of Computer Science University of Manchester Manchester M13 9PL, UK Abstract: This document descri…

管理操作函数 AddGeometryColumn - Adds a geometry column to an existing table of attributes. By default uses type modifier to define rather than constraints. Pass in false for use_typmod to get old check constraint based behavior DropGeometryColumn - Remove…

Linux TCP Performance Tuning News Linux Performance Tuning Recommended Books Recommended Links Linux performance bottlenecks Kernel parameters tuning on Linux Performance Monitoring tcpdump iptraf netstat ntop nfsstat lsof vmstat Disk subsystem tunin…

simplestyle-spec A simple specification for styling GeoJSON data. Versions 1.1.0 Adds properties to permit styling of Polygon and LineString types. 1.0.0 Initial release: this defines only three keys and an example encoding. Implementations Authors T…

参考:Function and Operator Reference Name Description ABS() Return the absolute value ACOS() Return the arc cosine ADDDATE() Add time values (intervals) to a date value ADDTIME() Add time AES_DECRYPT() Decrypt using AES AES_ENCRYPT() Encrypt using AES…

在OpenGL ES 中,仅有一种表面网格表示方式,那就是三角形. 三角形的三个顶点,可以组几个面?有答 1 的没有?有!那就是还不懂OpenGL ES 的我. 事实上,一张纸是有正反面的,那么一个三角形也应该有两个面,那么在空间中,如何区分呢?那就是正反面. 那具体哪个是正面,哪个是反面呢,据说是默认逆时针是正面,顺时针是反面,不过到现在还没搞清楚,这个顺和逆是个怎么看法,我们只知道在两个轴组成的二维平面坐标系中的顺和逆. 有知道的朋友不妨给予指出,谢谢. 不过,从下面的官方资料中,不难看出,…

原文 GDI+ Tutorial for Beginners GDI+ is next evolution of GDI. Using GDI objects in earlier versions of Visual Studio was a pain. In Visual Studio .NET, Microsoft has taken care of most of the GDI problems and have made it easy to use. GDI+ resides in…

http://dev.mysql.com/worklog/task/?spm=5176.100239.blogcont4270.8.j3asa7&id=6609 前文: 这两天因为项目原因看了一下MySQL的空间索引,发现网上的资料不多,查了一下官方文档,为了强化记忆做了一个简单的翻译.基本上理解了mysql空间索引的要点.谨以此纪. Extensions for Spatial Data Open Geospatial Consortium (OGC) 是一个由超过两百五十个公司,机构,大学组…

Name Description ABS() Return the absolute value ACOS() Return the arc cosine ADDDATE() Add time values (intervals) to a date value ADDTIME() Add time AES_DECRYPT() Decrypt using AES AES_ENCRYPT() Encrypt using AES AND, && Logical AND ANY_VALUE()…