axmol/core/3d/ObjLoader.h

/****************************************************************************
 Copyright (c) 2017-2018 Xiamen Yaji Software Co., Ltd.

 https://axmol.dev/

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 of this software and associated documentation files (the "Software"), to deal
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#ifndef _TINY_OBJ_LOADER_H
#define _TINY_OBJ_LOADER_H

#include <string>
#include <vector>
#include <map>
#include "base/hlookup.h"

namespace tinyobj
{

typedef struct
{
    std::string name;

    float ambient[3];
    float diffuse[3];
    float specular[3];
    float transmittance[3];
    float emission[3];
    float shininess;
    float ior;       // index of refraction
    float dissolve;  // 1 == opaque; 0 == fully transparent
    // illumination model (see http://www.fileformat.info/format/material/)
    int illum;

    std::string ambient_texname;
    std::string diffuse_texname;
    std::string specular_texname;
    std::string normal_texname;
    std::map<std::string, std::string> unknown_parameter;
} material_t;

typedef struct
{
    std::vector<float> positions;
    std::vector<float> normals;
    std::vector<float> texcoords;
    std::vector<unsigned short> indices;
    std::vector<int> material_ids;  // per-mesh material ID
} mesh_t;

typedef struct
{
    std::string name;
    mesh_t mesh;
} shape_t;

class MaterialReader
{
public:
    MaterialReader() {}
    virtual ~MaterialReader() {}

    virtual std::string operator()(std::string_view matId,
                                   std::vector<material_t>& materials,
                                   hlookup::string_map<int>& matMap) = 0;
};

class MaterialFileReader : public MaterialReader
{
public:
    MaterialFileReader(std::string_view mtl_basepath) : m_mtlBasePath(mtl_basepath) {}
    virtual ~MaterialFileReader() {}
    virtual std::string operator()(std::string_view matId,
                                   std::vector<material_t>& materials,
                                   hlookup::string_map<int>& matMap);

private:
    std::string m_mtlBasePath;
};

/// Loads .obj from a file.
/// 'shapes' will be filled with parsed shape data
/// The function returns error string.
/// Returns empty string when loading .obj success.
/// 'mtl_basepath' is optional, and used for base path for .mtl file.
std::string LoadObj(std::vector<shape_t>& shapes,        // [output]
                    std::vector<material_t>& materials,  // [output]
                    const char* filename,
                    const char* mtl_basepath = NULL);

/// Loads object from a std::istream, uses GetMtlIStreamFn to retrieve
/// std::istream for materials.
/// Returns empty string when loading .obj success.
std::string LoadObj(std::vector<shape_t>& shapes,        // [output]
                    std::vector<material_t>& materials,  // [output]
                    std::istream& inStream,
                    MaterialReader& readMatFn);

/// Loads materials into std::map
/// Returns an empty string if successful
std::string LoadMtl(hlookup::string_map<int>& material_map,
                    std::vector<material_t>& materials,
                    std::istream& inStream);
}  // namespace tinyobj

#endif  // _TINY_OBJ_LOADER_H