C++ CompString::substr方法代码示例

/*
 * Get the first "argument" in the given string, trimmed
 * and move source string pointer after the end of the argument.
 * For instance in string " foo, bar" this function will return "foo".
 *
 * This function returns NULL if no argument found
 * or a malloc'ed string that will have to be freed later.
 */
CompString
FragmentParser::getFirstArgument (const CompString &line,
				  size_t &pos)
{
    CompString arg;
    CompString string;
    size_t next, temp, orig;
    int length;
    CompString retArg;

    if (pos >= line.size ())
	return CompString ("");

    /* Left trim */
    string = FragmentParser::ltrim (line.substr (pos));

    orig = pos;
    pos = 0;

    /* Find next comma or semicolon (which isn't that useful since we
     * are working on tokens delimited by semicolons) */
    if ((next = string.find (",", pos)) != std::string::npos ||
	(next = string.find (";", pos)) != std::string::npos)
    {
	length = next - pos;
	if (!length)
	{
	    pos = orig + 1;
	    return getFirstArgument (line, pos);
	}
	if ((temp = string.find ("{", pos) != std::string::npos) && temp < next &&
	    (temp = string.find ("}", pos) != std::string::npos) && temp > next)
	{
	    if ((next = string.find (",", temp)) != std::string::npos ||
		(next = string.find (";", temp)) != std::string::npos)
		length = next - pos;
	    else
		length = string.substr (pos).size ();
	}
    }
    else
	length = string.substr (pos).size ();

    /* Allocate, copy and end string */
    arg = string.substr (pos, length);

    /* Increment source pointer */
    if ((orig + arg.size () + 1) <= line.size ())
	pos += orig + arg.size () + 1;
    else
	pos = std::string::npos;

    return arg;
}

bool
SvgScreen::fileToImage (CompString &path,
			CompSize   &size,
			int        &stride,
			void       *&data)
{
    CompString fileName = path;
    bool       status = false;
    int        len = fileName.length ();

    if (len < 4 || fileName.substr (len - 4, 4) != ".svg")
	fileName += ".svg";

    status = readSvgToImage (fileName.c_str (), size, data);

    if (status)
    {
	stride = size.width () * 4;
	return true;
    }

    status = screen->fileToImage (path, size, stride, data);

    return status;
}

CompString
PngScreen::fileNameWithExtension (CompString &path)
{
    unsigned int len = path.length ();

    if (len > 4 && path.substr (len - 4, 4) == ".png")
	return path;

    return path + ".png";
}

/*
 * Left trimming function
 */
CompString
FragmentParser::ltrim (const CompString &string)
{
    size_t pos = 0;
    while (!(pos >= string.size ()))
    {
	if (isspace (string.at (pos)))
	    pos++;
	else
	    break;
    }

    return string.substr (pos);
}

/*
 * Add a new fragment offset to the offsets stack from an ADD op string
 */
FragmentParser::FragmentOffset *
FragmentParser::programAddOffsetFromAddOp (const CompString &source)
{
    FragmentOffset  offset;
    CompString  op;
    size_t	    pos = 0;
    CompString	    name;
    CompString	    offsetString;
    CompString	    temp;
    std::list <FragmentOffset>::iterator it = offsets.begin ();

    if (source.size () < 5)
	return NULL;

    op = source;
    pos += 3;
    name = getFirstArgument (op, pos);
    if (name.empty ())
	return NULL;

    temp = getFirstArgument (op, pos);

    /* If an offset with the same name is
     * already registered, skip this one */
    if ((!offsets.empty () &&
	 !programFindOffset (it, name).empty ()) ||
	 temp.empty ())
	return &(*it);

    /* Just use the end of the op as the offset */
    pos += 1;
    offsetString = ltrim (op.substr (pos));
    if (offsetString.empty ())
	return NULL;

    offset.name =  name;
    offset.offset = offsetString;

    offsets.push_back (offset);

    return &(offsets.back ());
}

/*
 * Parse the source buffer op by op and add each op to function data
 *
 * FIXME : I am more than 200 lines long, I feel so heavy!
 */
void
FragmentParser::programParseSource (GLFragment::FunctionData *data,
		    		    int target, CompString &source)
{
    CompString line, next;
    CompString current;
    CompString strtok;
    size_t     pos = 0, strippos = 0;
    int   length, oplength, type;

    CompString arg1, arg2, temp;

    /* Find the header, skip it, and start parsing from there */

    pos = source.find ("!!ARBfp1.0", pos);
    if (pos != std::string::npos)
    {
	pos += 9;
    }

    /* Strip comments */
    while ((strippos = source.find ("#", strippos)) != std::string::npos)
    {
	size_t carriagepos = source.find ("\n", strippos);

	if (carriagepos != std::string::npos)
	{
	    source.erase (strippos, carriagepos - strippos);
	    strippos = 0;
	}
	else
	    source = source.substr (0, strippos);
    }

    strippos = 0;

    /* Strip linefeeds */
    while ((strippos = source.find ("\n", strippos)) != std::string::npos)
	source[strippos] = ' ';

    /* Parse each instruction */
    while (!(pos >= (source.size () - 1)))
    {
	size_t nPos = source.find (";", pos + 1);
	line = source.substr (pos + 1, nPos - pos);
	CompString origcurrent = current = ltrim (line);
	/* Find instruction type */
	type = NoOp;

	/* Data ops */
	if (current.substr (0, 3) == "END")
	    type = NoOp;
	else if (current.substr (0, 3) == "ABS" ||
		 current.substr (0, 3) == "CMP" ||
		 current.substr (0, 3) == "COS" ||
		 current.substr (0, 3) == "DP3" ||
		 current.substr (0, 3) == "DP4" ||
		 current.substr (0, 3) == "EX2" ||
		 current.substr (0, 3) == "FLR" ||
		 current.substr (0, 3) == "FRC" ||
		 current.substr (0, 3) == "KIL" ||
		 current.substr (0, 3) == "LG2" ||
		 current.substr (0, 3) == "LIT" ||
		 current.substr (0, 3) == "LRP" ||
		 current.substr (0, 3) == "MAD" ||
		 current.substr (0, 3) == "MAX" ||
		 current.substr (0, 3) == "MIN" ||
		 current.substr (0, 3) == "POW" ||
		 current.substr (0, 3) == "RCP" ||
		 current.substr (0, 3) == "RSQ" ||
		 current.substr (0, 3) == "SCS" ||
		 current.substr (0, 3) == "SIN" ||
		 current.substr (0, 3) == "SGE" ||
		 current.substr (0, 3) == "SLT" ||
		 current.substr (0, 3) == "SUB" ||
		 current.substr (0, 3) == "SWZ" ||
		 current.substr (0, 3) == "TXP" ||
		 current.substr (0, 3) == "TXB" ||
		 current.substr (0, 3) == "XPD")
		type = DataOp;
	else if (current.substr (0, 4) == "TEMP")
	    type = TempOp;
	else if (current.substr (0, 5) == "PARAM")
	    type = ParamOp;
	else if (current.substr (0, 6) == "ATTRIB")
	    type = AttribOp;
	else if (current.substr (0, 3) == "TEX")
	    type = FetchOp;
	else if (current.substr (0, 3) == "ADD")
	{
	    if (current.find ("fragment.texcoord", 0) != std::string::npos)
		programAddOffsetFromAddOp (current.c_str ());
	    else
		type = DataOp;
	}
//.........这里部分代码省略.........