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256 lines
4.9 KiB
C++

#include "StdAfx.h"
#include "GetElevation.h"
// tiff文件读取
#include "gdal_priv.h"
#include "cpl_conv.h" //for CPLMalloc()
// boost-1.56:准C++标准库
#include <boost/lexical_cast.hpp>
#include <boost/format.hpp>
#include <vector>
using namespace std;
// 定义高程图像存储结构体
#pragma pack(1)
struct struDemPic
{
struDemPic()
{
pDEMData = NULL;
};
virtual ~struDemPic()
{
if (pDEMData != NULL)
{
delete[] pDEMData;
pDEMData = NULL;
}
}
signed short int *pDEMData;
string strDemName;
double adfGeoTransform[6];
int iXSize;
int iYSize;
};
#pragma pack()
// 定义类型: DEM_PIC_LIST
typedef vector<struDemPic*> DEM_PIC_LIST;
// 全局变量
DEM_PIC_LIST g_DemPicList;
// 基于经纬度 计算tif文件名称
string GetDemName( const float fLonDeg, const float fLatDeg )
{
string sLatLon; // 输出
int iLon = (int) fLonDeg;
int iLat = (int) fLatDeg;
//判断经纬度在正常范围之内
if ((fLonDeg < -180) || (fLonDeg > 180))
{
return "";
}
if ((fLatDeg < -90) || (fLatDeg > 90))
{
return "";
}
string sLat, sLon;
// 纬度 南北纬 区别对待
boost::format fmt("S%02d");
if (fLatDeg <= 0)
{
fmt % ((-iLat) + 1);
sLat = fmt.str();
}
else
{
fmt = boost::format("N%02d");
fmt % iLat;
sLat = fmt.str();
}
// 经度 东西经 区别对待
if (fLonDeg <= 0)
{
fmt = boost::format("W%03d");
fmt % ((-iLon) + 1);
sLon = fmt.str();
}
else
{
fmt = boost::format("E%03d");
fmt % iLon;
sLon = fmt.str();
}
sLatLon = "ASTGTM_" + sLat + sLon + "_dem.tif";
return sLatLon;
}
// 搜寻文件路径是否已经存在
int FindDemDataSet( const string strDemName )
{
for ( unsigned int i = 0; i < g_DemPicList.size(); i++ )
{
if ( g_DemPicList[i]->strDemName == strDemName )
{
return i;
}
}
return -1;
}
bool GetDem( float& fElevator, const float fLonDeg, const float fLatDeg, struDemPic* pDemPic )
{
// 空值判断
if (pDemPic == NULL)
{
return false;
}
// 分辨率 判断
if (pDemPic->adfGeoTransform[1] <= 0 || pDemPic->adfGeoTransform[5] >= 0)
{
return false;
}
// 计算像素坐标
float px = float(( fLonDeg - pDemPic->adfGeoTransform[0] ) / pDemPic->adfGeoTransform[1]);
float py = float(( pDemPic->adfGeoTransform[3] - fLatDeg ) / fabs(pDemPic->adfGeoTransform[5]));
//防止越界
if ((px < 0) || (px > pDemPic->iXSize - 1) ||
(py < 0) || ( py > pDemPic->iYSize - 1))
{
return false;
}
// 规则:双线性内插 计算高程值
int yt = 0, yb = 0; // y 上下
int xl = 0, xr = 0; // x 左右
yt = int(py);
yb = yt + 1;
xl = int(px);
xr = xl + 1;
if ((xl < 0) || (xl > pDemPic->iXSize - 1) ||
(xr < 0) || (xr > pDemPic->iYSize - 1))
{
return false;
}
if ((yt < 0) || (yt > pDemPic->iXSize - 1) ||
(yb < 0) || (yb > pDemPic->iYSize - 1))
{
return false;
}
// 相邻四个像素的值
signed short int DNlt = *(pDemPic->pDEMData + yt * pDemPic->iXSize + xl);
signed short int DNrt = *(pDemPic->pDEMData + yt * pDemPic->iXSize + xr);
signed short int DNlb = *(pDemPic->pDEMData + yb * pDemPic->iXSize + xl);
signed short int DNrb = *(pDemPic->pDEMData + yb * pDemPic->iXSize + xr);
// 间距
float h, v;
h = py - yt;
v = px - xl;
fElevator = DNlt * (1 - h) * (1 - v) + DNlb * h * (1 - v)+ DNrt * (1 - h) * v + DNrb * h * v;
return true;
}
// 获取高程
bool GetDem( float& fElevator, float fLonDeg, float fLatDeg, string sDir)
{
// tif文件 名称
string strName = GetDemName(fLonDeg, fLatDeg);
if (strName == "")
{
return false;
}
// tif文件 路径名称
string strPathName;
if (sDir != "")
{
strPathName = sDir + "\\" + strName;
}
else
{
return false;
}
// 是否能在记录中找到
int idx = FindDemDataSet(strPathName);
if (idx >= 0)
{
return GetDem(fElevator, fLonDeg, fLatDeg, g_DemPicList[idx]);;
}
//如果在数据集数组中找不到 读取文件并添加到数据集
// 注册
GDALAllRegister();
CPLSetConfigOption("GDAL_FILENAME_IS_UTF8", "NO");
GDALDataset* tempdata = NULL;
tempdata = (GDALDataset*) GDALOpen(strPathName.c_str(), GA_ReadOnly);
if ( tempdata != NULL )
{
GDALDataType dataType = tempdata->GetRasterBand(1)->GetRasterDataType();
int iXSzie = tempdata->GetRasterBand(1)->GetXSize();
int iYSzie = tempdata->GetRasterBand(1)->GetYSize();
struDemPic* temp = new struDemPic;
temp->iXSize = iXSzie;
temp->iYSize = iYSzie;
tempdata->GetGeoTransform(temp->adfGeoTransform);
temp->pDEMData = new signed short int[iXSzie * iYSzie];
memset((void*) temp->pDEMData, 0, iXSzie * iYSzie * sizeof(signed short int));
tempdata->GetRasterBand(1)->RasterIO( GF_Read, 0, 0, iXSzie, iYSzie, temp->pDEMData, iXSzie, iYSzie, GDT_Int16, 0, 0 );
GDALClose(tempdata);
// 入队 存储
temp->strDemName = strPathName;
g_DemPicList.push_back(temp);
return GetDem(fElevator, fLonDeg, fLatDeg, g_DemPicList[g_DemPicList.size() - 1]);;
}
return false;
}
//功能:释放资源
void ReleaseDemMemory()
{
// 高程数集
for (unsigned int i = 0; i < g_DemPicList.size(); i++ )
{
if ( g_DemPicList[i] != NULL )
{
delete g_DemPicList[i];
}
}
g_DemPicList.clear();
}