size_t _FindMainFunction( eastl::string& str )//找到主函数段
{
size_t start_pos = 0;
do
{
start_pos = str.find("main", start_pos);
if( start_pos != eastl::string::npos )
{
size_t i = -1;
bool istype = false;
do
{
istype = ! Utility::NotVariablePart( str[ start_pos + i-- ] );
} while ( !istype );
if ( 'd' == str[start_pos + ++i] )
{
start_pos = str.find("{", start_pos);
return start_pos + 1;
}
}
start_pos++;
} while ( start_pos != eastl::string::npos );
return eastl::string::npos;
}
bool _VariableModifier_Type( eastl::string& str, const eastl::string& vname, const char* modifier, eastl::string& type )//是否为某种修饰类型的变量
{
size_t start_pos = 0;
do
{
start_pos = str.find( vname, start_pos );
if ( start_pos != eastl::string::npos )
{
size_t trunk = str.find_last_of( ';', start_pos );
trunk = trunk != eastl::string::npos ? trunk : 0;
string substr = str.substr( trunk, start_pos - trunk );
size_t istype = substr.find( modifier );
if ( istype != eastl::string::npos )
{
type = substr.substr( substr.find_first_of(' ') );
return true;
}
start_pos += vname.size();
}
} while ( start_pos != eastl::string::npos );
return false;
}
// Parses the entire shader string buffer to match instances of the program meta flag
// Format of the shader usage flags: "!!>:(Flag Type, <Values, sep. by comma>)"
// Flag Type can be either Usage or Permute
void UProgramPermutor::ParseProgramMetaFlags(const eastl::string& inShaderBufferString, eastl::vector<SShaderMetaFlagInstance>& outMetaFlagInstances)
{
// Find all occurrences of shader meta flag string
size_t currentFindIndex = inShaderBufferString.find(s_shaderMetaFlagString, 0);
outMetaFlagInstances.clear();
while (currentFindIndex != eastl::string::npos)
{
eastl::string metaFlagInstanceString;
currentFindIndex += UProgramPermutor::s_shaderMetaFlagString.length();
while (inShaderBufferString[currentFindIndex] != ')')
{
metaFlagInstanceString += inShaderBufferString[currentFindIndex];
++currentFindIndex;
}
++currentFindIndex; // Skip past the ending parentheses
if (metaFlagInstanceString.empty())
{
LOG(LogProgramPermutor, Warning, "Warning: Shader usage instance #%d has an empty description pair!", outMetaFlagInstances.size());
return;
}
eastl::vector<eastl::string> metaFlagSubstrings;
SShaderMetaFlagInstance currentMetaFlagInstance;
// Split the meta flag string by coma
size_t currentCommaIndex = 0;
size_t nextCommaIndex = metaFlagInstanceString.find(',', currentCommaIndex);
while (nextCommaIndex != eastl::string::npos)
{
eastl::string flagValueString = metaFlagInstanceString.substr(currentCommaIndex, (nextCommaIndex - currentCommaIndex));
metaFlagSubstrings.emplace_back(flagValueString);
currentCommaIndex = nextCommaIndex + 1;
nextCommaIndex = metaFlagInstanceString.find(',', currentCommaIndex);
if (nextCommaIndex == eastl::string::npos)
{
eastl::string lastFlagValueString = metaFlagInstanceString.substr(currentCommaIndex, (nextCommaIndex - currentCommaIndex));
// On the last iteration, we need to add the last string
metaFlagSubstrings.emplace_back(lastFlagValueString);
}
}
// Flag string count sanity check
if (metaFlagSubstrings.size() == 0)
{
LOG(LogProgramPermutor, Warning, "Warning: Shader usage instance #%d has more than one separation commas!", outMetaFlagInstances.size());
return;
}
// First substring is the flag type
currentMetaFlagInstance.MetaFlagType = ConvertStringToFlagType(metaFlagSubstrings.front());
if (currentMetaFlagInstance.MetaFlagType == EMetaFlagType::EMetaFlagType_Invalid)
{
LOG(LogProgramPermutor, Warning, "Warning: Shader usage instance #%d has an invalid meta flag type!", outMetaFlagInstances.size());
return;
}
// Rest of the substrings are the parameter values (if applicable)
for (size_t i = 1; i < metaFlagSubstrings.size(); ++i)
{
currentMetaFlagInstance.MetaFlagValues.emplace_back(metaFlagSubstrings[i]);
}
outMetaFlagInstances.emplace_back(currentMetaFlagInstance);
currentFindIndex = inShaderBufferString.find(UProgramPermutor::s_shaderMetaFlagString, currentFindIndex);
}
}