assimp/code/AssetLib/Obj/ObjTools.h

/*
Open Asset Import Library (assimp)
----------------------------------------------------------------------

Copyright (c) 2006-2022, assimp team

All rights reserved.

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with or without modification, are permitted provided that the
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* Redistributions of source code must retain the above
  copyright notice, this list of conditions and the
  following disclaimer.

* Redistributions in binary form must reproduce the above
  copyright notice, this list of conditions and the
  following disclaimer in the documentation and/or other
  materials provided with the distribution.

* Neither the name of the assimp team, nor the names of its
  contributors may be used to endorse or promote products
  derived from this software without specific prior
  written permission of the assimp team.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

----------------------------------------------------------------------
*/

/** @file   ObjTools.h
 *  @brief  Some helpful templates for text parsing
 */
#ifndef OBJ_TOOLS_H_INC
#define OBJ_TOOLS_H_INC

#include <assimp/ParsingUtils.h>
#include <assimp/fast_atof.h>
#include <vector>

namespace Assimp {

/** 
 *  @brief  Returns true, if the last entry of the buffer is reached.
 *  @param[in] it   Iterator of current position.
 *  @param[in] end  Iterator with end of buffer.
 *  @return true, if the end of the buffer is reached.
 */
template <class char_t>
inline bool isEndOfBuffer(char_t it, char_t end) {
    if (it == end) {
        return true;
    }
    --end;

    return (it == end);
}

/** 
 *  @brief  Returns next word separated by a space
 *  @param[in] pBuffer  Pointer to data buffer
 *  @param[in] pEnd     Pointer to end of buffer
 *  @return Pointer to next space
 */
template <class Char_T>
inline Char_T getNextWord(Char_T pBuffer, Char_T pEnd) {
    while (!isEndOfBuffer(pBuffer, pEnd)) {
        if (!IsSpaceOrNewLine(*pBuffer) || IsLineEnd(*pBuffer)) {
            break;
        }
        ++pBuffer;
    }

    return pBuffer;
}

/** 
 *  @brief  Returns pointer a next token
 *  @param[in] pBuffer  Pointer to data buffer
 *  @param[in] pEnd     Pointer to end of buffer
 *  @return Pointer to next token
 */
template <class Char_T>
inline Char_T getNextToken(Char_T pBuffer, Char_T pEnd) {
    while (!isEndOfBuffer(pBuffer, pEnd)) {
        if (IsSpaceOrNewLine(*pBuffer)) {
            break;
        }
        ++pBuffer;
    }
    return getNextWord(pBuffer, pEnd);
}

/** 
 *  @brief  Skips a line
 *  @param[in]  it      Iterator set to current position
 *  @param[in]  end     Iterator set to end of scratch buffer for readout
 *  @param[out] uiLine  Current line number in format
 *  @return Current-iterator with new position
 */
template <class char_t>
inline char_t skipLine(char_t it, char_t end, unsigned int &uiLine) {
    if (it >= end) {
        return it;
    }

    while (!isEndOfBuffer(it, end) && !IsLineEnd(*it)) {
        ++it;
    }

    if (it != end) {
        ++it;
        ++uiLine;
    }
    // fix .. from time to time there are spaces at the beginning of a material line
    while (it != end && (*it == '\t' || *it == ' ')) {
        ++it;
    }

    return it;
}

/** 
 *  @brief  Get a name from the current line. Preserve space in the middle,
 *          but trim it at the end.
 *  @param[in]  it      set to current position
 *  @param[in]  end     set to end of scratch buffer for readout
 *  @param[out] name    Separated name
 *  @return Current-iterator with new position
 */
template <class char_t>
inline char_t getName(char_t it, char_t end, std::string &name) {
    name = "";
    if (isEndOfBuffer(it, end)) {
        return end;
    }

    char *pStart = &(*it);
    while (!isEndOfBuffer(it, end) && !IsLineEnd(*it)) {
        ++it;
    }

    while (IsSpace(*it)) {
        --it;
    }
    // Get name
    // if there is no name, and the previous char is a separator, come back to start
    while (&(*it) < pStart) {
        ++it;
    }
    std::string strName(pStart, &(*it));
    if (!strName.empty()) {
        name = strName;
    } 
    

    return it;
}

/** 
 *  @brief  Get a name from the current line. Do not preserve space
 *    in the middle, but trim it at the end.
 *  @param  it      set to current position
 *  @param  end     set to end of scratch buffer for readout
 *  @param  name    Separated name
 *  @return Current-iterator with new position
 */
template <class char_t>
inline char_t getNameNoSpace(char_t it, char_t end, std::string &name) {
    name = "";
    if (isEndOfBuffer(it, end)) {
        return end;
    }

    char *pStart = &(*it);
    while (!isEndOfBuffer(it, end) && !IsLineEnd(*it) && !IsSpaceOrNewLine(*it)) {
        ++it;
    }

    while (isEndOfBuffer(it, end) || IsLineEnd(*it) || IsSpaceOrNewLine(*it)) {
        --it;
    }
    ++it;

    // Get name
    // if there is no name, and the previous char is a separator, come back to start
    while (&(*it) < pStart) {
        ++it;
    }
    std::string strName(pStart, &(*it));
    if (!strName.empty()) {
        name = strName;
    }
        
    return it;
}

/** 
 *  @brief  Get next word from given line
 *  @param[in] it      set to current position
 *  @param[in] end     set to end of scratch buffer for readout
 *  @param[in] pBuffer Buffer for next word
 *  @param[in] length  Buffer length
 *  @return Current-iterator with new position
 */
template <class char_t>
inline char_t CopyNextWord(char_t it, char_t end, char *pBuffer, size_t length) {
    size_t index = 0;
    it = getNextWord<char_t>(it, end);
    while (!IsSpaceOrNewLine(*it) && !isEndOfBuffer(it, end)) {
        pBuffer[index] = *it;
        ++index;
        if (index == length - 1) {
            break;
        }
        ++it;
    }
    pBuffer[index] = '\0';
    return it;
}

/** 
 *  @brief  Get next float from given line
 *  @param[in]  it      set to current position
 *  @param[in]  end     set to end of scratch buffer for readout
 *  @param[out] value   Separated float value.
 *  @return Current-iterator with new position
 */
template <class char_t>
inline char_t getFloat(char_t it, char_t end, ai_real &value) {
    static const size_t BUFFERSIZE = 1024;
    char buffer[BUFFERSIZE] = {};
    it = CopyNextWord<char_t>(it, end, buffer, BUFFERSIZE);
    value = (ai_real)fast_atof(buffer);

    return it;
}

/**
 *  @brief  Will remove white-spaces for a string.
 *  @param[in] str  The string to clean
 *  @return The trimmed string.
 */
template <class string_type>
inline string_type trim_whitespaces(string_type str) {
    while (!str.empty() && IsSpace(str[0])) {
        str.erase(0);
    }
    while (!str.empty() && IsSpace(str[str.length() - 1])) {
        str.erase(str.length() - 1);
    }
    return str;
}

/**
 *  @brief  Checks for a line-end.
 *  @param[in] it   Current iterator in string.
 *  @param[in] end  End of the string.
 *  @return The trimmed string.
 */
template <class T>
bool hasLineEnd(T it, T end) {
    bool hasLineEnd = false;
    while (!isEndOfBuffer(it, end)) {
        ++it;
        if (IsLineEnd(it)) {
            hasLineEnd = true;
            break;
        }
    }

    return hasLineEnd;
}

} // Namespace Assimp

#endif // OBJ_TOOLS_H_INC