gdal集成kml库的做法

太过爱你忘了你带给我的痛 2022-08-03 11:40 177阅读 0赞

作者：朱金灿

来源：[http://blog.csdn.net/clever101][http_blog.csdn.net_clever101]

最近要读取kml文件，具体就是把kml文件当作一个矢量文件来读取。我发现gdal是支持集成kml库的。不过集成这个kml库的地方有点复杂。下面作一个详细的说明。

首先要libkml和expat这两个库，具体是修改gdal源码根目录下的nmake.opt，将EXPAT\_DIR放在LIBKML\_DIR的前面（为了确保EXPAT\_LIB能被LIBKML\_LIBS识别），具体修改如下：

# Uncomment for Expat support (required for KML, GPX and GeoRSS read support).
    EXPAT_DIR = $(THIRD_PARTY)/expat_2_1_0_vc9
    EXPAT_INCLUDE = -I$(EXPAT_DIR)/include
    !IFDEF DEBUG
    EXPAT_LIB = $(THIRD_PARTY)/expat_2_1_0_vc9/lib/libexpatD.lib
    !ELSE
    EXPAT_LIB = $(THIRD_PARTY)/expat_2_1_0_vc9/lib/libexpat.lib
    !ENDIF

LIBKML\_DIR的设置修改如下：

# Uncomment out the following lines to enable LibKML support.
    LIBKML_DIR = $(THIRD_PARTY)/libkml_1_3_0_vc9
    LIBKML_INCLUDE = -I$(LIBKML_DIR)/include -I$(THIRD_PARTY)/boost_1_42_vc9/include
    LIBKML_LIBRARY = $(LIBKML_DIR)/lib
    LIBKML_LIBS =	$(LIBKML_LIBRARY)/libkmlbase.lib \
    		$(LIBKML_LIBRARY)/libkmlconvenience.lib \
    		$(LIBKML_LIBRARY)/libkmldom.lib \
    		$(LIBKML_LIBRARY)/libkmlengine.lib \
    		$(LIBKML_LIBRARY)/libkmlregionator.lib \
    		$(LIBKML_LIBRARY)/libkmlxsd.lib \
    		$(THIRD_PARTY)/minizip_vc9/lib/minizip_static.lib \
    		$(EXPAT_LIB) \
    		$(THIRD_PARTY)/uriparser_0_7_5_vc9/lib/uriparser.lib \
    #		$(LIBKML_DIR)/third_party\zlib-1.2.3.win32/lib/minizip.lib \
    		$(THIRD_PARTY)/zlib_1_2_3_vc9/lib/libzlib_vc9_1_2_3.lib

可以除了kml本身的库外，还要添加minizip库、expat库、boost库和zip库。

这样就能将kml库集成进来。还有一点需要注意的是，我发现kml并不支持传统的shp文件的矢量类型，因此要重载kml图层类的GetGeomType接口（将kml类型转换为传统的shp的矢量类型），这个接口的实现代码如下：

OGRwkbGeometryType OGRLIBKMLLayer::GetGeomType()
    {
    	OGRwkbGeometryType eType = wkbUnknown;
    	OGRFeature* pFeature = NULL;
    	ResetReading();
    	pFeature = GetNextFeature();
    	if (pFeature != NULL)
    	{
    		OGRGeometry* pGeometry = pFeature->GetGeometryRef();
    		if (pGeometry != NULL)
    		{
    			eType = pGeometry->getGeometryType();
    		}
    	}
    	m_poOgrFeatureDefn->SetGeomType(eType);
    	return eType;
    }

[http_blog.csdn.net_clever101]: http://blog.csdn.net/clever101