Obj.h

Types

typedef float ilG_obj_vertex[4];
typedef float ilG_obj_texcoord[3];
typedef float ilG_obj_normal[3];
typedef float ilG_obj_color[3];

typedef struct ilG_obj_face {
    struct ilG_obj_face *next;
    ilG_obj_vertex vertices[4];
    ilG_obj_texcoord texcoords[4];
    ilG_obj_normal normals[4];
    int vertices_index[4], texcoords_index[4], normals_index[4];
    int num;
} ilG_obj_face;

Represents a face, that is, a set of planar coordinates. This structure supports up to quad primitives.

typedef struct ilG_obj_mtl {
    const char *name;
    ilG_obj_color ambient, diffuse, specular;
    float specular_co, transparency;
    int illumination;
} ilG_obj_mtl;

Represents common parameters of a .mtl file, used for lighting.

typedef struct ilG_obj_mesh {
    struct ilG_obj_mesh *next;
    ilG_obj_face *first_face;
    ilG_obj_mtl mtl;
    const char *name, *group;
    int smoothing;
} ilG_obj_mesh;

Represents a single named/grouped set of faces in a .obj file.

typedef struct ilG_obj_file {
    ilG_obj_mesh * first_mesh;
    const char *name;
} ilG_obj_file;

Represents the entire contents of a Wavefront OBJ file.

typedef const char* (*ilG_obj_reader)(const char *name);

Callback used for reading included files (for example, an mtllib command in an obj file)

enum ilG_obj_vertextype {
    OBJ_NOVERTICES = 0,
    OBJ_X = 1,
    OBJ_Y = 2,
    OBJ_Z = 4,
    OBJ_W = 8,
    OBJ_XYZ = OBJ_X|OBJ_Y|OBJ_Z,
    OBJ_XYZW = OBJ_XYZ|OBJ_W
};

enum ilG_obj_texcoordtype {
    OBJ_NOTEXCOORDS = 0,
    OBJ_U = 1,
    OBJ_V = 2,
    // OBJ_W (already defined)
    OBJ_UV = OBJ_U|OBJ_V,
    OBJ_UVW = OBJ_UV|OBJ_W
};

enum ilG_obj_normaltype {
    OBJ_NONORMALS = 0,
    OBJ_NORMALS = 1
};

enum ilG_obj_facetype {
    OBJ_TRIANGLES,
    OBJ_QUADS
};

enum ilG_obj_vbolayout {
    OBJ_INTERLEAVED,
    OBJ_TIGHT
};

These enumerations are used for configuring the output of the OBJ -> VBO converter.

Functions

const char* ilG_obj_stdio_reader(const char *filename);

A default reader function which uses stdio. Use this if you don't care about how files are read when calling readstring().

ilG_obj_file ilG_obj_readstring(const char * data, ilG_obj_reader inc, const char *filename);

Reads a string and parses it as an OBJ file.

ilG_obj_file ilG_obj_readfile(const char *filename);

Readstring helper.

GLfloat *ilG_obj_to_vbo(ilG_obj_mesh *mesh, enum ilG_obj_vertextype vertex, enum ilG_obj_texcoordtype texcoord, enum ilG_obj_normaltype normal, enum ilG_obj_facetype face, enum ilG_obj_vbolayout layout, size_t *size);

A function for converting an OBJ file into a VBO-friendly array of floats.

GLuint ilG_obj_to_gl(ilG_obj_mesh *mesh, GLint *count);

A function for uploading the output of obj_to_vbo into OpenGL. Takes a mesh to convert and a pointer to a variable that will be filled with the number of polygons to draw. Always outputs GL_TRIANGLES.

void ilG_obj_bindmtl(ilG_obj_mtl mtl, GLuint program, const char *ambient, const char *diffuse, const char *specular, const char *specular_co, const char *transparency);

Binds an MTL file as uniform variables in a GLSL program.