boost::string 例题1
如果有一个语法正确的shader源文件,其包括若干关于uniform变量的定义。请写一个程序从某个shader源文件里提取其全部定义的uniform变量。要求记录其名称、数据类型和初始值(如果有定义)。而且能够设计一个函数能够改动某个uniform变量的值。
例如以下表所看到的。程序须要提取出一共6个uniform变量,并存放如某种数据结构中,当中3个有初始值。3个没有初始值,而且用户能够改动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: 仅仅处理了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;
}