//总体来说这个过程就是构建数据源->构建层->构建要素->构建形状->关闭数据源。
//要包含的GDAL头文件
#include <gdal_priv.h>
#include <ogrsf_frmts.h>
#include <iostream>
using namespace std;
#pragma comment(lib,"gdal_i.lib")
bool Creatshape(const char* pszFileName ,int line,int row);
#include <tchar.h> //_TCHAR* 类型在该头文件里
int _tmain(int argc, _TCHAR* argv[])
{
const char *pszFileName="C:\Users\Public\Pictures\Sample Pictures\srtm_51_03.tif";
Creatshape(pszFileName,7,9);
system("pause");
return 0;
}
/************************************************************************/
/*创建过程：构建数据源->构建层->构建要素->构建形状->关闭数据源
/* 参数pszFileName 为输入的文件名
参数linenum为划分的行数
参数rows为划分的列数*/
/************************************************************************/
bool Creatshape(const char* pszFileName ,int linenum,int rows)
{
//获取影像信息
GDALDataset *poDataSet;
GDALAllRegister();
CPLSetConfigOption("GDAL_FILENAME_IS_UTF8","NO");
poDataSet=(GDALDataset*)GDALOpen(pszFileName,GA_ReadOnly); //打开数据集
if (poDataSet==NULL)
{
"Failed to open this dataset!"; //代开失败的话则给出提示并退出
exit(1);
}
double Trans[6];//坐标转换参数数组,作为GetGeoTransform()函数的参数
int width,height; //影像的像行列数;
width=poDataSet->GetRasterXSize(); //获取影像列数，为后续划分网格做准备
height=poDataSet->GetRasterYSize();//获取影像行数，为后续划分网格做准备
poDataSet->GetGeoTransform(Trans);
for (int i=0;i<6;i++)
{
cout<<Trans[i]<<endl; //循环输出仿射变换参数;
}
//注册shape文件驱动
const char* pszDriverName="ESRI Shapefile";
OGRSFDriver *poDriver;
OGRRegisterAll();
poDriver=OGRSFDriverRegistrar::GetRegistrar()->GetDriverByName(pszDriverName);
if (poDriver==NULL)
{
printf("%s driver is not available!",pszDriverName);
exit(1);
}
//创建shape文件;
OGRDataSource *poDS;
//创建一个叫myshapefile的目录，存放生成的文件;
//如果名字有.shp后缀，则直接在当前目录下生成文件;
poDS=poDriver->CreateDataSource("myshapefile.shp",NULL);
if (poDS==NULL)
{
printf("Create my shape file failed!");
exit(1);
}
//创建输出图层;
OGRLayer *poLayer;;
const char *prj=poDataSet->GetProjectionRef(); //获取栅格影像的空间参考信息
cout<<"栅格数据空间参考信息为:
"<<prj<<endl<<endl;
OGRSpatialReference oSRS;
oSRS.SetFromUserInput(prj); //将获得的空间参考信息字符串做为文本一次性赋给矢量数据的OGRSpatialReference对象;
poLayer=poDS->CreateLayer(pszFileName,&oSRS, wkbUnknown, NULL);
if (poLayer==NULL)
{
printf("Creat layer failed!");
exit(1);
}
//创建层数据的属性fields;
OGRFieldDefn oField("Point",OFTString);
oField.SetWidth(10);
if (poLayer->CreateField(&oField)!=OGRERR_NONE)
{
printf("Create Point Field Failed!");
exit(1);
}
//创建features，写入feature到磁盘;
OGRFeature *poFeature;
poFeature=OGRFeature::CreateFeature(poLayer->GetLayerDefn());
//绘制外边框
OGRLineString Line;
OGRPoint Point1(Trans[0],Trans[3]);
OGRPoint Point2(Trans[0]+width*Trans[1],Trans[3]);
OGRPoint Point3(Trans[0]+width*Trans[1],Trans[3]+width*Trans[4]+height*Trans[5]);
OGRPoint Point4(Trans[0],Trans[3]+width*Trans[4]+height*Trans[5]);//四个角点的地理坐标，通过行列号计算地理坐标，是通过六参数得到的;
Line.addPoint(&Point1);
Line.addPoint(&Point2);
Line.addPoint(&Point3);
Line.addPoint(&Point4);
Line.addPoint(&Point1);
//水平方向加线;
OGRLineString SubHline[50];
OGRPoint PointLeft[50],PointRight[50];
for (int i=1;i<linenum;i++)
{
PointLeft[i].setX(Trans[0]); //设置左边框上要加线的起点X坐标
PointLeft[i].setY((Point4.getY()-Trans[3])/linenum*i+Trans[3]);//设置左边框上要加线的起点Y坐标
PointRight[i].setX(Point2.getX());//设置右边框上要加线的起点X坐标
PointRight[i].setY((Point4.getY()-Trans[3])/linenum*i+Trans[3]);//设置右边框上要加线的起点Y坐标
}
for (int i=1;i<linenum;i++)
{
SubHline[i].addPoint(&PointLeft[i]); //左边框上加点;
SubHline[i].addPoint(&PointRight[i]);//右边框上加点;
if (i<linenum-1)
{
SubHline[i].addPoint(&PointRight[i+1]); //从右边框的上一点转到下一点，避免交叉斜线的出现;
}
Line.addSubLineString(&SubHline[i]);//将SubHline数组中的每一个线做为子线段添加到Line对象中;
}
Line.addPoint(&Point2);
//垂直方向加线
OGRLineString SubVline[50];
OGRPoint PointUp[50],PointDown[50];
for (int j=1;j<rows;j++)
{
//添加上边框上的点;
PointUp[j].setX((Point2.getX()-Trans[0])/rows*j+Trans[0]);
PointUp[j].setY(Trans[3]);
//添加下边框上的点;
PointDown[j].setX((Point2.getX()-Trans[0])/rows*j+Trans[0]);
PointDown[j].setY(Point4.getY());
}
for (int j=1;j<rows;j++)
{
SubVline[j].addPoint(&PointUp[j]);
SubVline[j].addPoint(&PointDown[j]);
if (j<rows-1)
{
SubVline[j].addPoint(&PointDown[j+1]); //从下边框的前一点转到后一点，避免交叉斜线的出现;
}
Line.addSubLineString(&SubVline[j]);
}
//poFeature->SetGeometryDirectly(&Line);//问题出在这啊！！用SetGeometryDirectly报错，要用SetGeometry
poFeature->SetGeometry(&Line);
if (poLayer->CreateFeature(poFeature)!=OGRERR_NONE)
{
printf("Failed create feature in shapefile！");
exit(1);
}
OGRFeature::DestroyFeature(poFeature);
OGRDataSource::DestroyDataSource(poDS);
printf("创建矢量数据成功！
");
system("pause");
return TRUE;
}
用ENVI打开生成的shp文件：
注意：在计算四个角点的坐标时，用到了六参数，参考博客：http://blog.csdn.net/ivanljf/article/details/9226463