assimp/code/AssetLib/DXF/DXFHelper.h

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

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  copyright notice, this list of conditions and the
  following disclaimer.

* Redistributions in binary form must reproduce the above
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*/

/** @file  DXFHelper.h
 *  @brief Internal utilities for the DXF loader.
 */

#ifndef INCLUDED_DXFHELPER_H
#define INCLUDED_DXFHELPER_H

#include <assimp/LineSplitter.h>
#include <assimp/TinyFormatter.h>
#include <assimp/StreamReader.h>
#include <assimp/fast_atof.h>
#include <vector>
#include <assimp/DefaultLogger.hpp>

namespace Assimp {
namespace DXF {

// read pairs of lines, parse group code and value and provide utilities
// to convert the data to the target data type.
// do NOT skip empty lines. In DXF files, they count as valid data.
class LineReader {
public:
    LineReader(StreamReaderLE& reader)
    : splitter(reader,false,true)
    , groupcode( 0 )
    , value()
    , end() {
        // empty
    }

    // -----------------------------------------
    bool Is(int gc, const char* what) const {
        return groupcode == gc && !strcmp(what,value.c_str());
    }

    // -----------------------------------------
    bool Is(int gc) const {
        return groupcode == gc;
    }

    // -----------------------------------------
    int GroupCode() const {
        return groupcode;
    }

    // -----------------------------------------
    const std::string& Value() const {
        return value;
    }

    // -----------------------------------------
    bool End() const {
        return !((bool)*this);
    }

    // -----------------------------------------
    unsigned int ValueAsUnsignedInt() const {
        return strtoul10(value.c_str());
    }

    // -----------------------------------------
    int ValueAsSignedInt() const {
        return strtol10(value.c_str());
    }

    // -----------------------------------------
    float ValueAsFloat() const {
        return fast_atof(value.c_str());
    }

    // -----------------------------------------
    /** pseudo-iterator increment to advance to the next (groupcode/value) pair */
    LineReader& operator++() {
        if (end) {
            if (end == 1) {
                ++end;
            }
            return *this;
        }

        try {
            groupcode = strtol10(splitter->c_str());
            splitter++;

            value = *splitter;
            splitter++;

            // automatically skip over {} meta blocks (these are for application use
            // and currently not relevant for Assimp).
            if (value.length() && value[0] == '{') {

                size_t cnt = 0;
                for(;splitter->length() && splitter->at(0) != '}'; splitter++, cnt++);

                splitter++;
                ASSIMP_LOG_VERBOSE_DEBUG((Formatter::format("DXF: skipped over control group ("),cnt," lines)"));
            }
        } catch(std::logic_error&) {
            ai_assert(!splitter);
        }
        if (!splitter) {
            end = 1;
        }
        return *this;
    }

    // -----------------------------------------
    LineReader& operator++(int) {
        return ++(*this);
    }


    // -----------------------------------------
    operator bool() const {
        return end <= 1;
    }

private:
    LineSplitter splitter;
    int groupcode;
    std::string value;
    int end;
};

// represents a POLYLINE or a LWPOLYLINE. or even a 3DFACE The data is converted as needed.
struct PolyLine {
    PolyLine()
    : flags() {
        // empty
    }

    std::vector<aiVector3D> positions;
    std::vector<aiColor4D>  colors;
    std::vector<unsigned int> indices;
    std::vector<unsigned int> counts;
    unsigned int flags;

    std::string layer;
    std::string desc;
};

// reference to a BLOCK. Specifies its own coordinate system.
struct InsertBlock {
    InsertBlock()
    : pos()
    , scale(1.f,1.f,1.f)
    , angle()
    , name() {
        // empty
    }

    aiVector3D pos;
    aiVector3D scale;
    float angle;

    std::string name;
};


// keeps track of all geometry in a single BLOCK.
struct Block
{
    std::vector< std::shared_ptr<PolyLine> > lines;
    std::vector<InsertBlock> insertions;

    std::string name;
    aiVector3D base;
};


struct FileData
{
    // note: the LAST block always contains the stuff from ENTITIES.
    std::vector<Block> blocks;
};

}
} // Namespace Assimp

#endif