import_obj.py

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#
#  This program is free software; you can redistribute it and/or
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#  as published by the Free Software Foundation; either version 2
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# ##### END GPL LICENSE BLOCK #####

# <pep8 compliant>

# Script copyright (C) Campbell Barton
# Contributors: Campbell Barton, Jiri Hnidek, Paolo Ciccone

"""
This script imports a Wavefront OBJ files to Blender.

Usage:
Run this script from "File->Import" menu and then load the desired OBJ file.
Note, This loads mesh objects and materials only, nurbs and curves are not supported.

http://wiki.blender.org/index.php/Scripts/Manual/Import/wavefront_obj
"""

import array
import os
import time
import bpy
import mathutils

from bpy_extras.io_utils import unpack_list
from bpy_extras.image_utils import load_image
from bpy_extras.wm_utils.progress_report import ProgressReport


def line_value(line_split):
    """
    Returns 1 string representing the value for this line
    None will be returned if there's only 1 word
    """
    length = len(line_split)
    if length == 1:
        return None

    elif length == 2:
        return line_split[1]

    elif length > 2:
        return b' '.join(line_split[1:])


def obj_image_load(context_imagepath_map, line, DIR, recursive, relpath):
    """
    Mainly uses comprehensiveImageLoad
    But we try all space-separated items from current line when file is not found with last one
    (users keep generating/using image files with spaces in a format that does not support them, sigh...)
    Also tries to replace '_' with ' ' for Max's exporter replaces spaces with underscores.
    """
    filepath_parts = line.split(b' ')
    image = None
    for i in range(-1, -len(filepath_parts), -1):
        imagepath = os.fsdecode(b" ".join(filepath_parts[i:]))
        image = context_imagepath_map.get(imagepath, ...)
        if image is ...:
            image = load_image(imagepath, DIR, recursive=recursive, relpath=relpath)
            if image is None and "_" in imagepath:
                image = load_image(imagepath.replace("_", " "), DIR, recursive=recursive, relpath=relpath)
            if image is not None:
                context_imagepath_map[imagepath] = image
                break;

    if image is None:
        imagepath = os.fsdecode(filepath_parts[-1])
        image = load_image(imagepath, DIR, recursive=recursive, place_holder=True, relpath=relpath)
        context_imagepath_map[imagepath] = image

    return image


def create_materials(filepath, relpath,
                     material_libs, unique_materials,
                     use_image_search, float_func):
    """
    Create all the used materials in this obj,
    assign colors and images to the materials from all referenced material libs
    """
    from math import sqrt
    from bpy_extras import node_shader_utils

    DIR = os.path.dirname(filepath)
    context_material_vars = set()

    # Don't load the same image multiple times
    context_imagepath_map = {}

    nodal_material_wrap_map = {}

    def load_material_image(blender_material, mat_wrap, context_material_name, img_data, line, type):
        """
        Set textures defined in .mtl file.
        """
        map_options = {}

        curr_token = []
        for token in img_data[:-1]:
            if token.startswith(b'-') and token[1:].isalpha():
                if curr_token:
                    map_options[curr_token[0]] = curr_token[1:]
                curr_token[:] = []
            curr_token.append(token)
        if curr_token:
            map_options[curr_token[0]] = curr_token[1:]

        # Absolute path - c:\.. etc would work here
        image = obj_image_load(context_imagepath_map, line, DIR, use_image_search, relpath)

        map_offset = map_options.get(b'-o')
        map_scale = map_options.get(b'-s')

        def _generic_tex_set(nodetex, image, texcoords, translation, scale):
            nodetex.image = image
            nodetex.texcoords = texcoords
            if translation is not None:
                nodetex.translation = translation
            if scale is not None:
                nodetex.scale = scale

        # Adds textures for materials (rendering)
        if type == 'Kd':
            _generic_tex_set(mat_wrap.base_color_texture, image, 'UV', map_offset, map_scale)

        elif type == 'Ka':
            # XXX Not supported?
            print("WARNING, currently unsupported ambient texture, skipped.")

        elif type == 'Ks':
            _generic_tex_set(mat_wrap.specular_texture, image, 'UV', map_offset, map_scale)

        elif type == 'Ke':
            # XXX Not supported?
            print("WARNING, currently unsupported emit texture, skipped.")

        elif type == 'Bump':
            bump_mult = map_options.get(b'-bm')
            bump_mult = float(bump_mult[0]) if (bump_mult and len(bump_mult[0]) > 1) else 1.0
            mat_wrap.normalmap_strength_set(bump_mult)

            _generic_tex_set(mat_wrap.normalmap_texture, image, 'UV', map_offset, map_scale)

        elif type == 'D':
            _generic_tex_set(mat_wrap.transmission_texture, image, 'UV', map_offset, map_scale)

        elif type == 'disp':
            # XXX Not supported?
            print("WARNING, currently unsupported displacement texture, skipped.")
            # ~ mat_wrap.bump_image_set(image)
            # ~ mat_wrap.bump_mapping_set(coords='UV', translation=map_offset, scale=map_scale)

        elif type == 'refl':
            map_type = map_options.get(b'-type')
            if map_type and map_type != [b'sphere']:
                print("WARNING, unsupported reflection type '%s', defaulting to 'sphere'"
                      "" % ' '.join(i.decode() for i in map_type))

            _generic_tex_set(mat_wrap.base_color_texture, image, 'Reflection', map_offset, map_scale)
            mat_wrap.base_color_texture.projection = 'SPHERE'

        else:
            raise Exception("invalid type %r" % type)

    def finalize_material(context_material, context_material_vars, spec_colors, emit_colors,
                          do_highlight, do_reflection, do_transparency, do_glass):
        # Finalize previous mat, if any.
        if context_material:
            if "specular" in context_material_vars:
                # XXX This is highly approximated, not sure whether we can do better...
                # TODO: Find a way to guesstimate best value from diffuse color...
                # IDEA: Use standard deviation of both spec and diff colors (i.e. how far away they are
                #       from some grey), and apply the the proportion between those two as tint factor?
                spec = sum(spec_colors) / 3.0
                # ~ spec_var = math.sqrt(sum((c - spec) ** 2 for c in spec_color) / 3.0)
                # ~ diff = sum(context_mat_wrap.base_color) / 3.0
                # ~ diff_var = math.sqrt(sum((c - diff) ** 2 for c in context_mat_wrap.base_color) / 3.0)
                # ~ tint = min(1.0, spec_var / diff_var)
                context_mat_wrap.specular = spec
                context_mat_wrap.specular_tint = 0.0
                if "roughness" not in context_material_vars:
                    context_mat_wrap.roughness = 0.0


            emit_value = sum(emit_colors) / 3.0
            if emit_value > 1e-6:
                print("WARNING, emit value unsupported by Principled BSDF shader, skipped.")
                # We have to adapt it to diffuse color too...
                emit_value /= sum(context_material.diffuse_color) / 3.0
            # ~ context_material.emit = emit_value

            # FIXME, how else to use this?
            if do_highlight:
                if "specular" not in context_material_vars:
                    context_mat_wrap.specular = 1.0
                if "roughness" not in context_material_vars:
                    context_mat_wrap.roughness = 0.0
            else:
                if "specular" not in context_material_vars:
                    context_mat_wrap.specular = 0.0
                if "roughness" not in context_material_vars:
                    context_mat_wrap.roughness = 1.0

            if do_reflection:
                if "metallic" not in context_material_vars:
                    context_mat_wrap.metallic = 1.0
            else:
                # since we are (ab)using ambient term for metallic (which can be non-zero)
                context_mat_wrap.metallic = 0.0

            if do_transparency:
                if "ior" not in context_material_vars:
                    context_mat_wrap.ior = 1.0
                if "transmission" not in context_material_vars:
                    context_mat_wrap.transmission = 1.0
                # EEVEE only
                context_material.blend_method = 'BLEND'

            if do_glass:
                if "ior" not in context_material_vars:
                    context_mat_wrap.ior = 1.5

    # Try to find a MTL with the same name as the OBJ if no MTLs are specified.
    temp_mtl = os.path.splitext((os.path.basename(filepath)))[0] + ".mtl"
    if os.path.exists(os.path.join(DIR, temp_mtl)):
        material_libs.add(temp_mtl)
    del temp_mtl

    # Create new materials
    for name in unique_materials:  # .keys()
        ma_name = "Default OBJ" if name is None else name.decode('utf-8', "replace")
        ma = unique_materials[name] = bpy.data.materials.new(ma_name)
        ma_wrap = node_shader_utils.PrincipledBSDFWrapper(ma, is_readonly=False)
        nodal_material_wrap_map[ma] = ma_wrap
        ma_wrap.use_nodes = True

    for libname in sorted(material_libs):
        # print(libname)
        mtlpath = os.path.join(DIR, libname)
        if not os.path.exists(mtlpath):
            print("\tMaterial not found MTL: %r" % mtlpath)
        else:
            # Note: with modern Principled BSDF shader, things like ambient, raytrace or fresnel are always 'ON'
            # (i.e. automatically controlled by other parameters).
            do_highlight = False
            do_reflection = False
            do_transparency = False
            do_glass = False
            spec_colors = [0.0, 0.0, 0.0]
            emit_colors = [0.0, 0.0, 0.0]

            # print('\t\tloading mtl: %e' % mtlpath)
            context_material = None
            context_mat_wrap = None
            mtl = open(mtlpath, 'rb')
            for line in mtl:  # .readlines():
                line = line.strip()
                if not line or line.startswith(b'#'):
                    continue

                line_split = line.split()
                line_id = line_split[0].lower()

                if line_id == b'newmtl':
                    # Finalize previous mat, if any.
                    finalize_material(context_material, context_material_vars, spec_colors, emit_colors,
                                      do_highlight, do_reflection, do_transparency, do_glass)

                    context_material_name = line_value(line_split)
                    context_material = unique_materials.get(context_material_name)
                    if context_material is not None:
                        context_mat_wrap = nodal_material_wrap_map[context_material]
                    context_material_vars.clear()

                    spec_colors = [0.0, 0.0, 0.0]
                    emit_colors[:] = [0.0, 0.0, 0.0]
                    do_highlight = False
                    do_reflection = False
                    do_transparency = False
                    do_glass = False


                elif context_material:
                    # we need to make a material to assign properties to it.
                    if line_id == b'ka':
                        refl = (float_func(line_split[1]) + float_func(line_split[2]) + float_func(line_split[3])) / 3.0
                        context_mat_wrap.metallic = refl
                        context_material_vars.add("metallic")
                    elif line_id == b'kd':
                        col = (float_func(line_split[1]), float_func(line_split[2]), float_func(line_split[3]))
                        context_mat_wrap.base_color = col
                    elif line_id == b'ks':
                        spec_colors[:] = [
                            float_func(line_split[1]), float_func(line_split[2]), float_func(line_split[3])]
                        context_material_vars.add("specular")
                    elif line_id == b'ke':
                        # We cannot set context_material.emit right now, we need final diffuse color as well for this.
                        # XXX Unsupported currently
                        emit_colors[:] = [
                            float_func(line_split[1]), float_func(line_split[2]), float_func(line_split[3])]
                    elif line_id == b'ns':
                        # XXX Totally empirical conversion, trying to adapt it
                        #     (from 0.0 - 900.0 OBJ specular exponent range to 1.0 - 0.0 Principled BSDF range)...
                        context_mat_wrap.roughness = 1.0 - (sqrt(float_func(line_split[1])) / 30)
                        context_material_vars.add("roughness")
                    elif line_id == b'ni':  # Refraction index (between 0.001 and 10).
                        context_mat_wrap.ior = float_func(line_split[1])
                        context_material_vars.add("ior")
                    elif line_id == b'd':  # dissolve (transparency)
                        context_mat_wrap.transmission = 1.0 - float_func(line_split[1])
                        context_material_vars.add("transmission")
                    elif line_id == b'tr':  # translucency
                        print("WARNING, currently unsupported 'tr' translucency option, skipped.")
                    elif line_id == b'tf':
                        # rgb, filter color, blender has no support for this.
                        print("WARNING, currently unsupported 'tf' filter color option, skipped.")
                    elif line_id == b'illum':
                        illum = get_int(line_split[1])

                        # inline comments are from the spec, v4.2
                        if illum == 0:
                            # Color on and Ambient off
                            print("WARNING, Principled BSDF shader does not support illumination 0 mode "
                                  "(colors with no ambient), skipped.")
                        elif illum == 1:
                            # Color on and Ambient on
                            pass
                        elif illum == 2:
                            # Highlight on
                            do_highlight = True
                        elif illum == 3:
                            # Reflection on and Ray trace on
                            do_reflection = True
                        elif illum == 4:
                            # Transparency: Glass on
                            # Reflection: Ray trace on
                            do_transparency = True
                            do_reflection = True
                            do_glass = True
                        elif illum == 5:
                            # Reflection: Fresnel on and Ray trace on
                            do_reflection = True
                        elif illum == 6:
                            # Transparency: Refraction on
                            # Reflection: Fresnel off and Ray trace on
                            do_transparency = True
                            do_reflection = True
                        elif illum == 7:
                            # Transparency: Refraction on
                            # Reflection: Fresnel on and Ray trace on
                            do_transparency = True
                            do_reflection = True
                        elif illum == 8:
                            # Reflection on and Ray trace off
                            do_reflection = True
                        elif illum == 9:
                            # Transparency: Glass on
                            # Reflection: Ray trace off
                            do_transparency = True
                            do_reflection = False
                            do_glass = True
                        elif illum == 10:
                            # Casts shadows onto invisible surfaces
                            print("WARNING, Principled BSDF shader does not support illumination 10 mode "
                                  "(cast shadows on invisible surfaces), skipped.")
                            pass

                    elif line_id == b'map_ka':
                        img_data = line.split()[1:]
                        if img_data:
                            load_material_image(context_material, context_mat_wrap,
                                                context_material_name, img_data, line, 'Ka')
                    elif line_id == b'map_ks':
                        img_data = line.split()[1:]
                        if img_data:
                            load_material_image(context_material, context_mat_wrap,
                                                context_material_name, img_data, line, 'Ks')
                    elif line_id == b'map_kd':
                        img_data = line.split()[1:]
                        if img_data:
                            load_material_image(context_material, context_mat_wrap,
                                                context_material_name, img_data, line, 'Kd')
                    elif line_id == b'map_ke':
                        img_data = line.split()[1:]
                        if img_data:
                            load_material_image(context_material, context_mat_wrap,
                                                context_material_name, img_data, line, 'Ke')
                    elif line_id in {b'map_bump', b'bump'}:  # 'bump' is incorrect but some files use it.
                        img_data = line.split()[1:]
                        if img_data:
                            load_material_image(context_material, context_mat_wrap,
                                                context_material_name, img_data, line, 'Bump')
                    elif line_id in {b'map_d', b'map_tr'}:  # Alpha map - Dissolve
                        img_data = line.split()[1:]
                        if img_data:
                            load_material_image(context_material, context_mat_wrap,
                                                context_material_name, img_data, line, 'D')

                    elif line_id in {b'map_disp', b'disp'}:  # displacementmap
                        img_data = line.split()[1:]
                        if img_data:
                            load_material_image(context_material, context_mat_wrap,
                                                context_material_name, img_data, line, 'disp')

                    elif line_id in {b'map_refl', b'refl'}:  # reflectionmap
                        img_data = line.split()[1:]
                        if img_data:
                            load_material_image(context_material, context_mat_wrap,
                                                context_material_name, img_data, line, 'refl')
                    else:
                        print("WARNING: %r:%r (ignored)" % (filepath, line))

            # Finalize last mat, if any.
            finalize_material(context_material, context_material_vars, spec_colors, emit_colors,
                              do_highlight, do_reflection, do_transparency, do_glass)
            mtl.close()


def split_mesh(verts_loc, faces, unique_materials, filepath, SPLIT_OB_OR_GROUP):
    """
    Takes vert_loc and faces, and separates into multiple sets of
    (verts_loc, faces, unique_materials, dataname)
    """

    filename = os.path.splitext((os.path.basename(filepath)))[0]

    if not SPLIT_OB_OR_GROUP or not faces:
        use_verts_nor = any(f[1] for f in faces)
        use_verts_tex = any(f[2] for f in faces)
        # use the filename for the object name since we aren't chopping up the mesh.
        return [(verts_loc, faces, unique_materials, filename, use_verts_nor, use_verts_tex)]

    def key_to_name(key):
        # if the key is a tuple, join it to make a string
        if not key:
            return filename  # assume its a string. make sure this is true if the splitting code is changed
        else:
            return key.decode('utf-8', 'replace')

    # Return a key that makes the faces unique.
    face_split_dict = {}

    oldkey = -1  # initialize to a value that will never match the key

    for face in faces:
        (face_vert_loc_indices,
         face_vert_nor_indices,
         face_vert_tex_indices,
         context_material,
         context_smooth_group,
         context_object,
         face_invalid_blenpoly,
         ) = face
        key = context_object

        if oldkey != key:
            # Check the key has changed.
            (verts_split, faces_split, unique_materials_split, vert_remap,
             use_verts_nor, use_verts_tex) = face_split_dict.setdefault(key, ([], [], {}, {}, [], []))
            oldkey = key


        if not use_verts_nor and face_vert_nor_indices:
            use_verts_nor.append(True)

        if not use_verts_tex and face_vert_tex_indices:
            use_verts_tex.append(True)

        # Remap verts to new vert list and add where needed
        for loop_idx, vert_idx in enumerate(face_vert_loc_indices):
            map_index = vert_remap.get(vert_idx)
            if map_index is None:
                map_index = len(verts_split)
                vert_remap[vert_idx] = map_index  # set the new remapped index so we only add once and can reference next time.
                verts_split.append(verts_loc[vert_idx])  # add the vert to the local verts

            face_vert_loc_indices[loop_idx] = map_index  # remap to the local index

            if context_material not in unique_materials_split:
                unique_materials_split[context_material] = unique_materials[context_material]

        faces_split.append(face)

    # remove one of the items and reorder
    return [(verts_split, faces_split, unique_materials_split, key_to_name(key), bool(use_vnor), bool(use_vtex))
            for key, (verts_split, faces_split, unique_materials_split, _, use_vnor, use_vtex)
            in face_split_dict.items()]


def create_mesh(new_objects,
                use_edges,
                verts_loc,
                verts_nor,
                verts_tex,
                faces,
                unique_materials,
                unique_smooth_groups,
                vertex_groups,
                dataname,
                ):
    """
    Takes all the data gathered and generates a mesh, adding the new object to new_objects
    deals with ngons, sharp edges and assigning materials
    """

    if unique_smooth_groups:
        sharp_edges = set()
        smooth_group_users = {context_smooth_group: {} for context_smooth_group in unique_smooth_groups.keys()}
        context_smooth_group_old = -1

    fgon_edges = set()  # Used for storing fgon keys when we need to tessellate/untessellate them (ngons with hole).
    edges = []
    tot_loops = 0

    context_object = None

    # reverse loop through face indices
    for f_idx in range(len(faces) - 1, -1, -1):
        (face_vert_loc_indices,
         face_vert_nor_indices,
         face_vert_tex_indices,
         context_material,
         context_smooth_group,
         context_object,
         face_invalid_blenpoly,
         ) = faces[f_idx]

        len_face_vert_loc_indices = len(face_vert_loc_indices)

        if len_face_vert_loc_indices == 1:
            faces.pop(f_idx)  # cant add single vert faces

        # Face with a single item in face_vert_nor_indices is actually a polyline!
        elif len(face_vert_nor_indices) == 1 or len_face_vert_loc_indices == 2:
            if use_edges:
                edges.extend((face_vert_loc_indices[i], face_vert_loc_indices[i + 1])
                             for i in range(len_face_vert_loc_indices - 1))
            faces.pop(f_idx)

        else:
            # Smooth Group
            if unique_smooth_groups and context_smooth_group:
                # Is a part of of a smooth group and is a face
                if context_smooth_group_old is not context_smooth_group:
                    edge_dict = smooth_group_users[context_smooth_group]
                    context_smooth_group_old = context_smooth_group

                prev_vidx = face_vert_loc_indices[-1]
                for vidx in face_vert_loc_indices:
                    edge_key = (prev_vidx, vidx) if (prev_vidx < vidx) else (vidx, prev_vidx)
                    prev_vidx = vidx
                    edge_dict[edge_key] = edge_dict.get(edge_key, 0) + 1

            # NGons into triangles
            if face_invalid_blenpoly:
                # ignore triangles with invalid indices
                if len(face_vert_loc_indices) > 3:
                    from bpy_extras.mesh_utils import ngon_tessellate
                    ngon_face_indices = ngon_tessellate(verts_loc, face_vert_loc_indices, debug_print=bpy.app.debug)
                    faces.extend([([face_vert_loc_indices[ngon[0]],
                                    face_vert_loc_indices[ngon[1]],
                                    face_vert_loc_indices[ngon[2]],
                                    ],
                                [face_vert_nor_indices[ngon[0]],
                                    face_vert_nor_indices[ngon[1]],
                                    face_vert_nor_indices[ngon[2]],
                                    ] if face_vert_nor_indices else [],
                                [face_vert_tex_indices[ngon[0]],
                                    face_vert_tex_indices[ngon[1]],
                                    face_vert_tex_indices[ngon[2]],
                                    ] if face_vert_tex_indices else [],
                                context_material,
                                context_smooth_group,
                                context_object,
                                [],
                                )
                                for ngon in ngon_face_indices]
                                )
                    tot_loops += 3 * len(ngon_face_indices)

                    # edges to make ngons
                    if len(ngon_face_indices) > 1:
                        edge_users = set()
                        for ngon in ngon_face_indices:
                            prev_vidx = face_vert_loc_indices[ngon[-1]]
                            for ngidx in ngon:
                                vidx = face_vert_loc_indices[ngidx]
                                if vidx == prev_vidx:
                                    continue  # broken OBJ... Just skip.
                                edge_key = (prev_vidx, vidx) if (prev_vidx < vidx) else (vidx, prev_vidx)
                                prev_vidx = vidx
                                if edge_key in edge_users:
                                    fgon_edges.add(edge_key)
                                else:
                                    edge_users.add(edge_key)

                faces.pop(f_idx)
            else:
                tot_loops += len_face_vert_loc_indices

    # Build sharp edges
    if unique_smooth_groups:
        for edge_dict in smooth_group_users.values():
            for key, users in edge_dict.items():
                if users == 1:  # This edge is on the boundary of a group
                    sharp_edges.add(key)

    # map the material names to an index
    material_mapping = {name: i for i, name in enumerate(unique_materials)}  # enumerate over unique_materials keys()

    materials = [None] * len(unique_materials)

    for name, index in material_mapping.items():
        materials[index] = unique_materials[name]

    me = bpy.data.meshes.new(dataname)

    # make sure the list isnt too big
    for material in materials:
        me.materials.append(material)

    me.vertices.add(len(verts_loc))
    me.loops.add(tot_loops)
    me.polygons.add(len(faces))

    # verts_loc is a list of (x, y, z) tuples
    me.vertices.foreach_set("co", unpack_list(verts_loc))

    loops_vert_idx = tuple(vidx for (face_vert_loc_indices, _, _, _, _, _, _) in faces for vidx in face_vert_loc_indices)
    faces_loop_start = []
    lidx = 0
    for f in faces:
        face_vert_loc_indices = f[0]
        nbr_vidx = len(face_vert_loc_indices)
        faces_loop_start.append(lidx)
        lidx += nbr_vidx
    faces_loop_total = tuple(len(face_vert_loc_indices) for (face_vert_loc_indices, _, _, _, _, _, _) in faces)

    me.loops.foreach_set("vertex_index", loops_vert_idx)
    me.polygons.foreach_set("loop_start", faces_loop_start)
    me.polygons.foreach_set("loop_total", faces_loop_total)

    faces_ma_index = tuple(material_mapping[context_material] for (_, _, _, context_material, _, _, _) in faces)
    me.polygons.foreach_set("material_index", faces_ma_index)

    faces_use_smooth = tuple(bool(context_smooth_group) for (_, _, _, _, context_smooth_group, _, _) in faces)
    me.polygons.foreach_set("use_smooth", faces_use_smooth)

    if verts_nor and me.loops:
        # Note: we store 'temp' normals in loops, since validate() may alter final mesh,
        #       we can only set custom lnors *after* calling it.
        me.create_normals_split()
        loops_nor = tuple(no for (_, face_vert_nor_indices, _, _, _, _, _) in faces for face_noidx in face_vert_nor_indices for no in verts_nor[face_noidx])
        me.loops.foreach_set("normal", loops_nor)

    if verts_tex and me.polygons:
        me.uv_layers.new()
        loops_uv = tuple(uv for (_, _, face_vert_tex_indices, _, _, _, _) in faces for face_uvidx in face_vert_tex_indices for uv in verts_tex[face_uvidx])
        me.uv_layers[0].data.foreach_set("uv", loops_uv)

    use_edges = use_edges and bool(edges)
    if use_edges:
        me.edges.add(len(edges))
        # edges should be a list of (a, b) tuples
        me.edges.foreach_set("vertices", unpack_list(edges))

    me.validate(clean_customdata=False)  # *Very* important to not remove lnors here!
    me.update(calc_edges=use_edges)

    # Un-tessellate as much as possible, in case we had to triangulate some ngons...
    if fgon_edges:
        import bmesh
        bm = bmesh.new()
        bm.from_mesh(me)
        verts = bm.verts[:]
        get = bm.edges.get
        edges = [get((verts[vidx1], verts[vidx2])) for vidx1, vidx2 in fgon_edges]
        try:
            bmesh.ops.dissolve_edges(bm, edges=edges, use_verts=False)
        except:
            # Possible dissolve fails for some edges, but don't fail silently in case this is a real bug.
            import traceback
            traceback.print_exc()

        bm.to_mesh(me)
        bm.free()

    # XXX If validate changes the geometry, this is likely to be broken...
    if unique_smooth_groups and sharp_edges:
        for e in me.edges:
            if e.key in sharp_edges:
                e.use_edge_sharp = True

    if verts_nor:
        clnors = array.array('f', [0.0] * (len(me.loops) * 3))
        me.loops.foreach_get("normal", clnors)

        if not unique_smooth_groups:
            me.polygons.foreach_set("use_smooth", [True] * len(me.polygons))

        me.normals_split_custom_set(tuple(zip(*(iter(clnors),) * 3)))
        me.use_auto_smooth = True

    ob = bpy.data.objects.new(me.name, me)
    new_objects.append(ob)

    # Create the vertex groups. No need to have the flag passed here since we test for the
    # content of the vertex_groups. If the user selects to NOT have vertex groups saved then
    # the following test will never run
    for group_name, group_indices in vertex_groups.items():
        group = ob.vertex_groups.new(name=group_name.decode('utf-8', "replace"))
        group.add(group_indices, 1.0, 'REPLACE')


def create_nurbs(context_nurbs, vert_loc, new_objects):
    """
    Add nurbs object to blender, only support one type at the moment
    """
    deg = context_nurbs.get(b'deg', (3,))
    curv_range = context_nurbs.get(b'curv_range')
    curv_idx = context_nurbs.get(b'curv_idx', [])
    parm_u = context_nurbs.get(b'parm_u', [])
    parm_v = context_nurbs.get(b'parm_v', [])
    name = context_nurbs.get(b'name', b'ObjNurb')
    cstype = context_nurbs.get(b'cstype')

    if cstype is None:
        print('\tWarning, cstype not found')
        return
    if cstype != b'bspline':
        print('\tWarning, cstype is not supported (only bspline)')
        return
    if not curv_idx:
        print('\tWarning, curv argument empty or not set')
        return
    if len(deg) > 1 or parm_v:
        print('\tWarning, surfaces not supported')
        return

    cu = bpy.data.curves.new(name.decode('utf-8', "replace"), 'CURVE')
    cu.dimensions = '3D'

    nu = cu.splines.new('NURBS')
    nu.points.add(len(curv_idx) - 1)  # a point is added to start with
    nu.points.foreach_set("co", [co_axis for vt_idx in curv_idx for co_axis in (vert_loc[vt_idx] + (1.0,))])

    nu.order_u = deg[0] + 1

    # get for endpoint flag from the weighting
    if curv_range and len(parm_u) > deg[0] + 1:
        do_endpoints = True
        for i in range(deg[0] + 1):

            if abs(parm_u[i] - curv_range[0]) > 0.0001:
                do_endpoints = False
                break

            if abs(parm_u[-(i + 1)] - curv_range[1]) > 0.0001:
                do_endpoints = False
                break

    else:
        do_endpoints = False

    if do_endpoints:
        nu.use_endpoint_u = True

    # close
    '''
    do_closed = False
    if len(parm_u) > deg[0]+1:
        for i in xrange(deg[0]+1):
            #print curv_idx[i], curv_idx[-(i+1)]

            if curv_idx[i]==curv_idx[-(i+1)]:
                do_closed = True
                break

    if do_closed:
        nu.use_cyclic_u = True
    '''

    ob = bpy.data.objects.new(name.decode('utf-8', "replace"), cu)

    new_objects.append(ob)


def strip_slash(line_split):
    if line_split[-1][-1] == 92:  # '\' char
        if len(line_split[-1]) == 1:
            line_split.pop()  # remove the \ item
        else:
            line_split[-1] = line_split[-1][:-1]  # remove the \ from the end last number
        return True
    return False


def get_float_func(filepath):
    """
    find the float function for this obj file
    - whether to replace commas or not
    """
    file = open(filepath, 'rb')
    for line in file:  # .readlines():
        line = line.lstrip()
        if line.startswith(b'v'):  # vn vt v
            if b',' in line:
                file.close()
                return lambda f: float(f.replace(b',', b'.'))
            elif b'.' in line:
                file.close()
                return float

    file.close()
    # in case all vert values were ints
    return float


def get_int(svalue):
    if b',' in svalue:
        return int(float(svalue.replace(b',', b'.')))
    return int(float(svalue))


def load(context,
         filepath,
         *,
         global_clight_size=0.0,
         use_smooth_groups=True,
         use_edges=True,
         use_split_objects=True,
         use_split_groups=True,
         use_image_search=True,
         use_groups_as_vgroups=False,
         relpath=None,
         global_matrix=None
         ):
    """
    Called by the user interface or another script.
    load_obj(path) - should give acceptable results.
    This function passes the file and sends the data off
        to be split into objects and then converted into mesh objects
    """

    def handle_vec(line_start, context_multi_line, line_split, tag, data, vec, vec_len):
        ret_context_multi_line = tag if strip_slash(line_split) else b''
        if line_start == tag:
            vec[:] = [float_func(v) for v in line_split[1:]]
        elif context_multi_line == tag:
            vec += [float_func(v) for v in line_split]
        if not ret_context_multi_line:
            data.append(tuple(vec[:vec_len]))
        return ret_context_multi_line

    def create_face(context_material, context_smooth_group, context_object):
        face_vert_loc_indices = []
        face_vert_nor_indices = []
        face_vert_tex_indices = []
        return (
            face_vert_loc_indices,
            face_vert_nor_indices,
            face_vert_tex_indices,
            context_material,
            context_smooth_group,
            context_object,
            [],  # If non-empty, that face is a Blender-invalid ngon (holes...), need a mutable object for that...
        )

    with ProgressReport(context.window_manager) as progress:
        progress.enter_substeps(1, "Importing OBJ %r..." % filepath)

        if global_matrix is None:
            global_matrix = mathutils.Matrix()

        if use_split_objects or use_split_groups:
            use_groups_as_vgroups = False

        time_main = time.time()

        verts_loc = []
        verts_nor = []
        verts_tex = []
        faces = []  # tuples of the faces
        material_libs = set()  # filenames to material libs this OBJ uses
        vertex_groups = {}  # when use_groups_as_vgroups is true

        # Get the string to float conversion func for this file- is 'float' for almost all files.
        float_func = get_float_func(filepath)

        # Context variables
        context_material = None
        context_smooth_group = None
        context_object = None
        context_vgroup = None

        # Nurbs
        context_nurbs = {}
        nurbs = []
        context_parm = b''  # used by nurbs too but could be used elsewhere

        # Until we can use sets
        use_default_material = False
        unique_materials = {}
        unique_smooth_groups = {}
        # unique_obects= {} - no use for this variable since the objects are stored in the face.

        # when there are faces that end with \
        # it means they are multiline-
        # since we use xreadline we cant skip to the next line
        # so we need to know whether
        context_multi_line = b''

        # Per-face handling data.
        face_vert_loc_indices = None
        face_vert_nor_indices = None
        face_vert_tex_indices = None
        face_vert_nor_valid = face_vert_tex_valid = False
        verts_loc_len = verts_nor_len = verts_tex_len = 0
        face_items_usage = set()
        face_invalid_blenpoly = None
        prev_vidx = None
        face = None
        vec = []

        quick_vert_failures = 0
        skip_quick_vert = False

        progress.enter_substeps(3, "Parsing OBJ file...")
        with open(filepath, 'rb') as f:
            for line in f:
                line_split = line.split()

                if not line_split:
                    continue

                line_start = line_split[0]  # we compare with this a _lot_

                # Handling vertex data are pretty similar, factorize that.
                # Also, most OBJ files store all those on a single line, so try fast parsing for that first,
                # and only fallback to full multi-line parsing when needed, this gives significant speed-up
                # (~40% on affected code).
                if line_start == b'v':
                    vdata, vdata_len, do_quick_vert = (verts_loc, 3, not skip_quick_vert)
                elif line_start == b'vn':
                    vdata, vdata_len, do_quick_vert = (verts_nor, 3, not skip_quick_vert)
                elif line_start == b'vt':
                    vdata, vdata_len, do_quick_vert = verts_tex, 2, not skip_quick_vert
                elif context_multi_line == b'v':
                    vdata, vdata_len, do_quick_vert = verts_loc, 3, False
                elif context_multi_line == b'vn':
                    vdata, vdata_len, do_quick_vert = verts_nor, 3, False
                elif context_multi_line == b'vt':
                    vdata, vdata_len, do_quick_vert = verts_tex, 2, False
                else:
                    vdata_len = 0

                if vdata_len:
                    if do_quick_vert:
                        try:
                            vdata.append(tuple(map(float_func, line_split[1:vdata_len + 1])))
                        except:
                            do_quick_vert = False
                            # In case we get too many failures on quick parsing, force fallback to full multi-line one.
                            # Exception handling can become costly...
                            quick_vert_failures += 1
                            if quick_vert_failures > 10000:
                                skip_quick_vert = True
                    if not do_quick_vert:
                        context_multi_line = handle_vec(line_start, context_multi_line, line_split, b'v', vdata, vec, vdata_len)

                elif line_start == b'f' or context_multi_line == b'f':
                    if not context_multi_line:
                        line_split = line_split[1:]
                        # Instantiate a face
                        face = create_face(context_material, context_smooth_group, context_object)
                        (face_vert_loc_indices, face_vert_nor_indices, face_vert_tex_indices,
                         _1, _2, _3, face_invalid_blenpoly) = face
                        faces.append(face)
                        face_items_usage.clear()
                        verts_loc_len = len(verts_loc)
                        verts_nor_len = len(verts_nor)
                        verts_tex_len = len(verts_tex)
                        if context_material is None:
                            use_default_material = True
                    # Else, use face_vert_loc_indices and face_vert_tex_indices previously defined and used the obj_face