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boost::string 例题1

2024-07-11 18:31:48   226人阅读

假设有一个语法正确的shader源文件，其包含若干关于uniform变量的定义。请写一个程序从某个shader源文件中提取其所有定义的uniform变量，要求记录其名称、数据类型和初始值（如果有定义），并且可以设计一个函数可以修改某个uniform变量的值。

如下表所示，程序需要提取出一共6个uniform变量，并存放如某种数据结构中，其中3个有初始值，3个没有初始值，并且用户可以修改该数据结构中指定的uniform变量的值。

uniform vec3 uLightDirectionE;

uniform vec3 uMaterialAmbient = vec3(0.3, 0.3, 0.3);

uniform vec3 uMaterialDiffuse = vec3(0.9, 0.7, 0.7);

uniform vec3 uLightAmbient = vec3(0.6, 0.6, 0.6);

uniform vec3 uLightDiffuse;

uniform bool uIsFirstFrame;

 

void main()

{

}

#include <iostream>
#include <fstream>
#include <map>
#include <vector>
#include <boost/any.hpp>
#include <boost/lexical_cast.hpp>
#include <boost/algorithm/string.hpp>
#include <boost/utility/string_ref.hpp>

template<typename T>
struct any_print
{
	void operator()(boost::any &a)
	{
		try
		{
			std::cout << *boost::any_cast<T>(&a);
		}
		catch (boost::bad_any_cast& e)
		{
			std::cout << e.what() << std::endl;
		}
	}
};

//////////////////////////////////////////////////////////////////////////

template<typename T>
inline void any_print_fun(boost::any& a)
{
	any_print<T>()(a);
}

struct vec3
{
	float x;
	float y;
	float z;
	vec3(float vX = 0.0f, float vY = 0.0f, float vZ = 0.0f) : x(vX), y(vY), z(vZ) {}
	friend std::ostream& operator<<(std::ostream& os, const vec3& vData)
	{
		os << "vec3(" << vData.x << "," << vData.y << "," << vData.z << ")";
		return os;
	}
};

class CTest
{
public:
	CTest() {}
	~CTest() {}

//*********************************************************************************
//FUNCTION:
	void parseText(const char* vFileName)
	{
		std::ifstream Ifs(vFileName);
		if (!Ifs) 
		{
			std::cout << "Can not open the file " << vFileName << std::endl;
			exit(-1);
		}

		std::string TmpStr;
		while (getline(Ifs, TmpStr))
		{
			//std::cout << TmpStr  << " xxx " << std::endl;
			if (TmpStr.find("uniform") != std::string::npos)
			{
				processUniformString(TmpStr);
			}
		}
		Ifs.close();
	}

//*********************************************************************************
//FUNCTION:
	void setValue(const std::string& vValueName, const boost::any& vValue)
	{
		DataType::iterator It = m_ValueData.find(vValueName);
		if (It == m_ValueData.end())
		{
			std::cout << "can not find the value " << vValueName << std::endl;
			return;
		}

		if (It->second.second.type() != vValue.type())
		{
			std::cout << "The type is not the same" << vValueName << std::endl;
			return;
		}
		m_ValueData[vValueName] = std::make_pair(It->second.first, vValue);
	}

//*********************************************************************************
//FUNCTION:
	void printData() 
	{
		for (DataType::iterator It=m_ValueData.begin(); It != m_ValueData.end(); ++It)
		{
			std::cout << It->first << " " << It->second.first << " ";
			if (It->second.first == "bool") any_print_fun<bool>(It->second.second);
			else if (It->second.first == "int") any_print_fun<int>(It->second.second);
			else if (It->second.first == "float") any_print_fun<float>(It->second.second);
			else if (It->second.first == "vec3") any_print_fun<vec3>(It->second.second);
			std::cout << std::endl;
		}
	}

private:
	typedef boost::split_iterator<std::string::const_iterator> Split_String_Itearor;
	typedef std::map<std::string, std::pair<std::string, boost::any>> DataType;

//*********************************************************************************
//FUNCTION: 只处理了int，bool， float， vec3这几种类型
	void processUniformString(const std::string& vSorceString)
	{
		Split_String_Itearor Bgn, End;
		std::vector<std::string> StrVec;
		for (Bgn = boost::algorithm::make_split_iterator(vSorceString, boost::algorithm::token_finder(boost::is_any_of(" (,);"))); Bgn != End; ++Bgn)
		{ 
			if ((*Bgn).size()>0) StrVec.push_back(std::string((*Bgn).begin(), (*Bgn).end()));
		}

		/*for (int i=0; i<StrVec.size(); ++i)
		{
			std::cout << "[" << StrVec[i] << "]" ;
		}std::cout << std::endl;*/

		std::string ValueTeyp = StrVec[1];
		std::string Key       = StrVec[2];
		if (ValueTeyp == "bool")	
		{   
			if (StrVec.size() == 3)
				m_ValueData[Key] = std::make_pair(ValueTeyp, boost::any(bool(0)));
			else if (StrVec.size() == 5)
				m_ValueData[Key] = std::make_pair(ValueTeyp, boost::any(boost::lexical_cast<bool>(StrVec[4])));
			
		}
		else if (ValueTeyp == "int")
		{
			if (StrVec.size() == 3)
				m_ValueData[Key] = std::make_pair(ValueTeyp, boost::any(int(0)));
			else if (StrVec.size() == 5)
				m_ValueData[Key] = std::make_pair(ValueTeyp, boost::any(boost::lexical_cast<int>(StrVec[4])));
		}
		else if (ValueTeyp == "float")
		{
			if (StrVec.size() == 3)
				m_ValueData[Key] = std::make_pair(ValueTeyp, boost::any(float(0)));
			else if (StrVec.size() == 5)
				m_ValueData[Key] = std::make_pair(ValueTeyp, boost::any(boost::lexical_cast<float>(StrVec[4])));
		}
		else if (ValueTeyp == "vec3") 
		{
			if (StrVec.size() == 3)
				m_ValueData[Key] = std::make_pair(ValueTeyp, boost::any(vec3(0, 0, 0)));
			else if (StrVec.size() == 8)
			{
				float x = boost::lexical_cast<float>(StrVec[5]);
				float y = boost::lexical_cast<float>(StrVec[6]);
				float z = boost::lexical_cast<float>(StrVec[7]);
				m_ValueData[Key] = std::make_pair(ValueTeyp, boost::any(vec3(x, y, z)));
			}
		}
		else 
		{
			std::cout << "can not process the type :" << ValueTeyp 
				<< " the value may be wrong " << std::endl;
		}
	}

private:
	DataType m_ValueData;
};

int main()
{
	CTest Test;
	Test.parseText("test.txt");
	Test.printData();
	Test.setValue("uLightDiffuse", boost::any(vec3(10.0, 1.0, 1.0)));
	Test.setValue("uIsFirstFrame", boost::any(bool(1)));
	Test.printData();
	getchar();
	return 0;
}


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