UE4.26 集成Proj4

UE4.26 集成Proj4

vcpkg 编译 Proj4

1. 安装proj4
   .\vcpkg.exe install proj4:x64-windows

2. 导出proj4
.\vcpkg.exe export proj4:x64-windows --7zip

UE4 集成

proj4.build.cs

1. 设置包含头文件
2. 设置连接库
3. 设置DLL依赖拷贝
4. 设置相关资源拷贝

using System.IO;
using UnrealBuildTool;
using System.Collections.Generic;

public class PROJ : ModuleRules
{
    
    
	public PROJ(ReadOnlyTargetRules Target) : base(Target)
	{
    
    
		Type = ModuleType.External;
		bEnableExceptions = true;
		string VcPkgInstalled = "vcpkg-installed";

		if (Target.Platform == UnrealTargetPlatform.Win64)
		{
    
    
			// add include 
			PublicSystemIncludePaths.Add(Path.Combine(ModuleDirectory, VcPkgInstalled, "overlay-x64-windows", "include"));
			// add lib
			string LibPath = Path.Combine(ModuleDirectory, VcPkgInstalled, "overlay-x64-windows", "lib");
			PublicAdditionalLibraries.Add(Path.Combine(LibPath, "proj.lib"));
			PublicAdditionalLibraries.Add(Path.Combine(LibPath, "sqlite3.lib"));
			// add dll
			List<string> RuntimeModuleNames = new List<string>();
			RuntimeModuleNames.Add("jpeg62.dll");
			RuntimeModuleNames.Add("libcurl.dll");
			RuntimeModuleNames.Add("lzma.dll");
			RuntimeModuleNames.Add("proj.dll");
			RuntimeModuleNames.Add("sqlite3.dll");
			RuntimeModuleNames.Add("tiff.dll");
			RuntimeModuleNames.Add("turbojpeg.dll");
			RuntimeModuleNames.Add("zlib1.dll");
		
			string ProjRedistFolder = Path.Combine(ModuleDirectory, VcPkgInstalled, "overlay-x64-windows", "bin");
			
			foreach (string RuntimeModuleName in RuntimeModuleNames)
			{
    
    
				string ModulePath = Path.Combine(ProjRedistFolder, RuntimeModuleName);
				if (!File.Exists(ModulePath))
				{
    
    
					string Err = string.Format("proj module '{0}' not found.", ModulePath);
					System.Console.WriteLine(Err);
					throw new BuildException(Err);
				}
				RuntimeDependencies.Add("$(BinaryOutputDir)/" + RuntimeModuleName, ModulePath);
			}
			// Copy share/proj4
			// Stage Proj data files Copy
			string ProjShareFolder = Path.Combine(ModuleDirectory, VcPkgInstalled, "overlay-x64-windows", "share");
			RuntimeDependencies.Add("$(PluginDir)/Resources/PROJ/*", Path.Combine(ProjShareFolder, "proj4/*"), StagedFileType.SystemNonUFS);
		}
	}
}

Usage

1. 初始化

FString BaseDir;
	BaseDir = IPluginManager::Get().FindPlugin("XXXX")->GetBaseDir();

// Add on the relative location of the third party dll and load it
FString ProjDataPathPath;
ProjDataPathPath = FPaths::Combine(*BaseDir, TEXT("Resources/PROJ"));
PJ_CONTEXT* ProjContext=proj_context_create();
FTCHARToUTF8 Convert(*ProjDataPathPath);
const ANSICHAR* Temp = Convert.Get();
proj_context_set_search_paths(ProjContext, 1, &Temp);

2. 投影坐标转地理坐标（经纬度）

PJ* GetPROJProjection(FString SourceCRS, FString DestinationCRS)
{
    
    
	FTCHARToUTF8 ConvertSource(*SourceCRS);
	FTCHARToUTF8 ConvertDestination(*DestinationCRS);
	const ANSICHAR* Source = ConvertSource.Get();
	const ANSICHAR* Destination = ConvertDestination.Get();

	PJ* TempPJ = proj_create_crs_to_crs(ProjContext, Source, Destination, nullptr);
	if (TempPJ == nullptr)
	{
    
    
		int ErrorNumber = proj_context_errno(ProjContext);
		FString ProjError = FString(proj_errno_string(ErrorNumber));
		
		return nullptr;
	}

	/* This will ensure that the order of coordinates for the input CRS */
	/* will be longitude, latitude, whereas EPSG:4326 mandates latitude, longitude */
	PJ* P_for_GIS = proj_normalize_for_visualization(ProjContext, TempPJ);
	if (P_for_GIS == nullptr)
	{
    
    
		int ErrorNumber = proj_context_errno(ProjContext);
		FString ProjError = FString(proj_errno_string(ErrorNumber));
	}

	proj_destroy(TempPJ);
	return P_for_GIS;
}

// Projected -> Geographic
	
PJ* ProjProjectedToGeographic =GetPROJProjection("EPSG:32617", "EPSG:4326");

void ProjectedToGeographic(const FCartesianCoordinates& ProjectedCoordinates, FGeographicCoordinates& GeographicCoordinates)
{
    
    
	PJ_COORD input, output;
	input = proj_coord(ProjectedCoordinates.X, ProjectedCoordinates.Y, ProjectedCoordinates.Z, 0);

	output = proj_trans(ProjProjectedToGeographic, PJ_FWD, input);
	GeographicCoordinates.Latitude = output.lpz.phi;
	GeographicCoordinates.Longitude = output.lpz.lam;
	GeographicCoordinates.Altitude = output.lpz.z;
}

3. destroy

proj_destroy(ProjProjectedToGeographic);

参考

1. https://blog.csdn.net/mrbaolong/article/details/109424871
2. https://github.com/ue4plugins/UEGeoCoordinates