lib3ds_mesh.c

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/*
    Copyright (C) 1996-2008 by Jan Eric Kyprianidis <www.kyprianidis.com>
    All rights reserved.
    
    This program is free  software: you can redistribute it and/or modify 
    it under the terms of the GNU Lesser General Public License as published 
    by the Free Software Foundation, either version 2.1 of the License, or 
    (at your option) any later version.

    Thisprogram  is  distributed in the hope that it will be useful, 
    but WITHOUT ANY WARRANTY; without even the implied warranty of 
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 
    GNU Lesser General Public License for more details.
    
    You should  have received a copy of the GNU Lesser General Public License
    along with  this program; If not, see <http://www.gnu.org/licenses/>. 
*/
#include "lib3ds_impl.h"


Lib3dsMesh*
lib3ds_mesh_new(const char *name) {
    Lib3dsMesh *mesh;

    assert(name);
    assert(strlen(name) < 64);

    mesh = (Lib3dsMesh*) calloc(sizeof(Lib3dsMesh), 1);
    if (!mesh) {
        return (0);
    }
    strcpy(mesh->name, name);
    lib3ds_matrix_identity(mesh->matrix);
    mesh->map_type = LIB3DS_MAP_NONE;
    return (mesh);
}


void
lib3ds_mesh_free(Lib3dsMesh *mesh) {
    lib3ds_mesh_resize_vertices(mesh, 0, 0, 0);
    lib3ds_mesh_resize_faces(mesh, 0);
    memset(mesh, 0, sizeof(Lib3dsMesh));
    free(mesh);
}


void
lib3ds_mesh_resize_vertices(Lib3dsMesh *mesh, int nvertices, int use_texcos, int use_flags) {
    assert(mesh);
    mesh->vertices = lib3ds_util_realloc_array(mesh->vertices, mesh->nvertices, nvertices, 3 * sizeof(float));
    mesh->texcos = lib3ds_util_realloc_array(
        mesh->texcos, 
        mesh->texcos? mesh->nvertices : 0, 
        use_texcos? nvertices : 0, 
        2 * sizeof(float)
    );
    mesh->vflags = lib3ds_util_realloc_array(
        mesh->vflags, 
        mesh->vflags? mesh->nvertices : 0, 
        use_flags? nvertices : 0, 
        2 * sizeof(float)
    );
    mesh->nvertices = nvertices;
}


void 
lib3ds_mesh_resize_faces(Lib3dsMesh *mesh, int nfaces) {
    int i;
    assert(mesh);
    mesh->faces = lib3ds_util_realloc_array(mesh->faces, mesh->nfaces, nfaces, sizeof(Lib3dsFace));
    for (i = mesh->nfaces; i < nfaces; ++i) {
        mesh->faces[i].material = -1;
    }
    mesh->nfaces = nfaces;
}


void
lib3ds_mesh_bounding_box(Lib3dsMesh *mesh, float bmin[3], float bmax[3]) {
    int i;
    bmin[0] = bmin[1] = bmin[2] = FLT_MAX;
    bmax[0] = bmax[1] = bmax[2] = -FLT_MAX;

    for (i = 0; i < mesh->nvertices; ++i) {
        lib3ds_vector_min(bmin, mesh->vertices[i]);
        lib3ds_vector_max(bmax, mesh->vertices[i]);
    }
}


void
lib3ds_mesh_calculate_face_normals(Lib3dsMesh *mesh, float (*face_normals)[3]) {
    int i;

    if (!mesh->nfaces) {
        return;
    }
    for (i = 0; i < mesh->nfaces; ++i) {
        lib3ds_vector_normal(
            face_normals[i],
            mesh->vertices[mesh->faces[i].index[0]],
            mesh->vertices[mesh->faces[i].index[1]],
            mesh->vertices[mesh->faces[i].index[2]]
        );
    }
}


typedef struct Lib3dsFaces {
    struct Lib3dsFaces *next;
    int index;
    float normal[3];
} Lib3dsFaces;


void
lib3ds_mesh_calculate_vertex_normals(Lib3dsMesh *mesh, float (*normals)[3]) {
    Lib3dsFaces **fl;
    Lib3dsFaces *fa;
    int i, j;

    if (!mesh->nfaces) {
        return;
    }

    fl = calloc(sizeof(Lib3dsFaces*), mesh->nvertices);
    fa = malloc(sizeof(Lib3dsFaces) * 3 * mesh->nfaces);

    for (i = 0; i < mesh->nfaces; ++i) {
        for (j = 0; j < 3; ++j) {
            Lib3dsFaces* l = &fa[3*i+j];
            float p[3], q[3], n[3];
            float len, weight;

            l->index = i;
            l->next = fl[mesh->faces[i].index[j]];
            fl[mesh->faces[i].index[j]] = l;

            lib3ds_vector_sub(p, mesh->vertices[mesh->faces[i].index[j<2? j + 1 : 0]], mesh->vertices[mesh->faces[i].index[j]]);
            lib3ds_vector_sub(q, mesh->vertices[mesh->faces[i].index[j>0? j - 1 : 2]], mesh->vertices[mesh->faces[i].index[j]]);
            lib3ds_vector_cross(n, p, q);
            len = lib3ds_vector_length(n);
            if (len > 0) {       
                weight = (float)atan2(len, lib3ds_vector_dot(p, q));
                lib3ds_vector_scalar_mul(l->normal, n, weight / len);
            } else {
                lib3ds_vector_zero(l->normal);
            }
        }
    }

    for (i = 0; i < mesh->nfaces; ++i) {
        Lib3dsFace *f = &mesh->faces[i];
        for (j = 0; j < 3; ++j) {
            float n[3];
            Lib3dsFaces *p;
            Lib3dsFace *pf;

            assert(mesh->faces[i].index[j] < mesh->nvertices);

            if (f->smoothing_group) {
                unsigned smoothing_group = f->smoothing_group;

                lib3ds_vector_zero(n);
                for (p = fl[mesh->faces[i].index[j]]; p; p = p->next) {
                    pf = &mesh->faces[p->index];
                    if (pf->smoothing_group & f->smoothing_group)
                        smoothing_group |= pf->smoothing_group;
                }

                for (p = fl[mesh->faces[i].index[j]]; p; p = p->next) {
                    pf = &mesh->faces[p->index];                
                    if (smoothing_group & pf->smoothing_group) {
                        lib3ds_vector_add(n, n, p->normal);
                    }
                }
            } else {
                lib3ds_vector_copy(n, fa[3*i+j].normal);
            }

            lib3ds_vector_normalize(n);
            lib3ds_vector_copy(normals[3*i+j], n);
        }
    }

    free(fa);
    free(fl);
}


static void
face_array_read(Lib3dsFile *file, Lib3dsMesh *mesh, Lib3dsIo *io) {
    Lib3dsChunk c;
    uint16_t chunk;
    int i;
    uint16_t nfaces;

    lib3ds_chunk_read_start(&c, CHK_FACE_ARRAY, io);

    lib3ds_mesh_resize_faces(mesh, 0);
    nfaces = lib3ds_io_read_word(io);
    if (nfaces) {
        lib3ds_mesh_resize_faces(mesh, nfaces);
        for (i = 0; i < nfaces; ++i) {
            mesh->faces[i].index[0] = lib3ds_io_read_word(io);
            mesh->faces[i].index[1] = lib3ds_io_read_word(io);
            mesh->faces[i].index[2] = lib3ds_io_read_word(io);
            mesh->faces[i].flags = lib3ds_io_read_word(io);
        }
        lib3ds_chunk_read_tell(&c, io);

        while ((chunk = lib3ds_chunk_read_next(&c, io)) != 0) {
            switch (chunk) {
                case CHK_MSH_MAT_GROUP: {
                    char name[64];
                    unsigned n;
                    unsigned i;
                    int index;
                    int material;

                    lib3ds_io_read_string(io, name, 64);
                    material = lib3ds_file_material_by_name(file, name);

                    n = lib3ds_io_read_word(io);
                    for (i = 0; i < n; ++i) {
                        index = lib3ds_io_read_word(io);
                        if (index < mesh->nfaces) {
                            mesh->faces[index].material = material;
                        } else {
                            // TODO warning
                        }
                    }
                    break;
                }

                case CHK_SMOOTH_GROUP: {
                    int i;
                    for (i = 0; i < mesh->nfaces; ++i) {
                        mesh->faces[i].smoothing_group = lib3ds_io_read_dword(io);
                    }
                    break;
                }

                case CHK_MSH_BOXMAP: {
                    lib3ds_io_read_string(io, mesh->box_front, 64);
                    lib3ds_io_read_string(io, mesh->box_back, 64);
                    lib3ds_io_read_string(io, mesh->box_left, 64);
                    lib3ds_io_read_string(io, mesh->box_right, 64);
                    lib3ds_io_read_string(io, mesh->box_top, 64);
                    lib3ds_io_read_string(io, mesh->box_bottom, 64);
                    break;
                }

                default:
                    lib3ds_chunk_unknown(chunk,io);
            }
        }

    }
    lib3ds_chunk_read_end(&c, io);
}


void
lib3ds_mesh_read(Lib3dsFile *file, Lib3dsMesh *mesh, Lib3dsIo *io) {
    Lib3dsChunk c;
    uint16_t chunk;

    lib3ds_chunk_read_start(&c, CHK_N_TRI_OBJECT, io);

    while ((chunk = lib3ds_chunk_read_next(&c, io)) != 0) {
        switch (chunk) {
            case CHK_MESH_MATRIX: {
                int i, j;

                lib3ds_matrix_identity(mesh->matrix);
                for (i = 0; i < 4; i++) {
                    for (j = 0; j < 3; j++) {
                        mesh->matrix[i][j] = lib3ds_io_read_float(io);
                    }
                }
                break;
            }

            case CHK_MESH_COLOR: {
                mesh->color = lib3ds_io_read_byte(io);
                break;
            }

            case CHK_POINT_ARRAY: {
                int i;
                uint16_t nvertices = lib3ds_io_read_word(io);
                lib3ds_mesh_resize_vertices(mesh, nvertices, mesh->texcos != NULL, mesh->vflags != NULL);
                for (i = 0; i < mesh->nvertices; ++i) {
                    lib3ds_io_read_vector(io, mesh->vertices[i]);
                }
                break;
            }

            case CHK_POINT_FLAG_ARRAY: {
                int i;
                uint16_t nflags = lib3ds_io_read_word(io);
                uint16_t nvertices = (mesh->nvertices >= nflags)? mesh->nvertices : nflags;
                lib3ds_mesh_resize_vertices(mesh, nvertices, mesh->texcos != NULL, 1);
                for (i = 0; i < nflags; ++i) {
                    mesh->vflags[i] = lib3ds_io_read_word(io);
                }
                break;
            }

            case CHK_FACE_ARRAY: {
                lib3ds_chunk_read_reset(&c, io);
                face_array_read(file, mesh, io);
                break;
            }

            case CHK_MESH_TEXTURE_INFO: {
                int i, j;

                //FIXME: mesh->map_type = lib3ds_io_read_word(io);

                for (i = 0; i < 2; ++i) {
                    mesh->map_tile[i] = lib3ds_io_read_float(io);
                }
                for (i = 0; i < 3; ++i) {
                    mesh->map_pos[i] = lib3ds_io_read_float(io);
                }
                mesh->map_scale = lib3ds_io_read_float(io);

                lib3ds_matrix_identity(mesh->map_matrix);
                for (i = 0; i < 4; i++) {
                    for (j = 0; j < 3; j++) {
                        mesh->map_matrix[i][j] = lib3ds_io_read_float(io);
                    }
                }
                for (i = 0; i < 2; ++i) {
                    mesh->map_planar_size[i] = lib3ds_io_read_float(io);
                }
                mesh->map_cylinder_height = lib3ds_io_read_float(io);
                break;
            }

            case CHK_TEX_VERTS: {
                int i;
                uint16_t ntexcos = lib3ds_io_read_word(io);
                uint16_t nvertices = (mesh->nvertices >= ntexcos)? mesh->nvertices : ntexcos;;
                if (!mesh->texcos) {
                    lib3ds_mesh_resize_vertices(mesh, nvertices, 1, mesh->vflags != NULL);
                }
                for (i = 0; i < ntexcos; ++i) {
                    mesh->texcos[i][0] = lib3ds_io_read_float(io);
                    mesh->texcos[i][1] = lib3ds_io_read_float(io);
                }
                break;
            }

            default:
                lib3ds_chunk_unknown(chunk, io);
        }
    }

    if (lib3ds_matrix_det(mesh->matrix) < 0.0) {
        /* Flip X coordinate of vertices if mesh matrix
           has negative determinant */
        float inv_matrix[4][4], M[4][4];
        float tmp[3];
        int i;

        lib3ds_matrix_copy(inv_matrix, mesh->matrix);
        lib3ds_matrix_inv(inv_matrix);

        lib3ds_matrix_copy(M, mesh->matrix);
        lib3ds_matrix_scale(M, -1.0f, 1.0f, 1.0f);
        lib3ds_matrix_mult(M, M, inv_matrix);

        for (i = 0; i < mesh->nvertices; ++i) {
            lib3ds_vector_transform(tmp, M, mesh->vertices[i]);
            lib3ds_vector_copy(mesh->vertices[i], tmp);
        }
    }

    lib3ds_chunk_read_end(&c, io);
}


static void
point_array_write(Lib3dsMesh *mesh, Lib3dsIo *io) {
    Lib3dsChunk c;
    int i;

    c.chunk = CHK_POINT_ARRAY;
    c.size = 8 + 12 * mesh->nvertices;
    lib3ds_chunk_write(&c, io);

    lib3ds_io_write_word(io, (uint16_t) mesh->nvertices);

    if (lib3ds_matrix_det(mesh->matrix) >= 0.0f) {
        for (i = 0; i < mesh->nvertices; ++i) {
            lib3ds_io_write_vector(io, mesh->vertices[i]);
        }
    } else {
        /* Flip X coordinate of vertices if mesh matrix
           has negative determinant */
        float inv_matrix[4][4], M[4][4];
        float tmp[3];

        lib3ds_matrix_copy(inv_matrix, mesh->matrix);
        lib3ds_matrix_inv(inv_matrix);
        lib3ds_matrix_copy(M, mesh->matrix);
        lib3ds_matrix_scale(M, -1.0f, 1.0f, 1.0f);
        lib3ds_matrix_mult(M, M, inv_matrix);

        for (i = 0; i < mesh->nvertices; ++i) {
            lib3ds_vector_transform(tmp, M, mesh->vertices[i]);
            lib3ds_io_write_vector(io, tmp);
        }
    }
}


static void
flag_array_write(Lib3dsMesh *mesh, Lib3dsIo *io) {
    Lib3dsChunk c;
    int i;

    if (!mesh->vflags) {
        return;
    }

    c.chunk = CHK_POINT_FLAG_ARRAY;
    c.size = 8 + 2 * mesh->nvertices;
    lib3ds_chunk_write(&c, io);

    lib3ds_io_write_word(io, (uint16_t) mesh->nvertices);
    for (i = 0; i < mesh->nvertices; ++i) {
        lib3ds_io_write_word(io, mesh->vflags[i]);
    }
}


static void
face_array_write(Lib3dsFile *file, Lib3dsMesh *mesh, Lib3dsIo *io) {
    Lib3dsChunk c;

    if (mesh->nfaces == 0) {
        return;
    }
    c.chunk = CHK_FACE_ARRAY;
    lib3ds_chunk_write_start(&c, io);

    {
        int i;

        lib3ds_io_write_word(io, (uint16_t) mesh->nfaces);
        for (i = 0; i < mesh->nfaces; ++i) {
            lib3ds_io_write_word(io, mesh->faces[i].index[0]);
            lib3ds_io_write_word(io, mesh->faces[i].index[1]);
            lib3ds_io_write_word(io, mesh->faces[i].index[2]);
            lib3ds_io_write_word(io, mesh->faces[i].flags);
        }
    }

    {
        /*---- MSH_CHK_MAT_GROUP ----*/
        Lib3dsChunk c;
        int i, j;
        uint16_t num;
        char *matf = ((Lib3dsIoImpl*)io->impl)->tmp_mem = calloc(sizeof(char), mesh->nfaces);
        assert(matf);

        for (i = 0; i < mesh->nfaces; ++i) {
            if (!matf[i] && (mesh->faces[i].material >= 0) && (mesh->faces[i].material < file->nmaterials)) {
                matf[i] = 1;
                num = 1;

                for (j = i + 1; j < mesh->nfaces; ++j) {
                    if (mesh->faces[i].material == mesh->faces[j].material) ++num;
                }

                c.chunk = CHK_MSH_MAT_GROUP;
                c.size = 6 + (uint32_t)strlen(file->materials[mesh->faces[i].material]->name) + 1 + 2 + 2 * num;
                lib3ds_chunk_write(&c, io);
                lib3ds_io_write_string(io, file->materials[mesh->faces[i].material]->name);
                lib3ds_io_write_word(io, num);
                lib3ds_io_write_word(io, (uint16_t) i);

                for (j = i + 1; j < mesh->nfaces; ++j) {
                    if (mesh->faces[i].material == mesh->faces[j].material) {
                        lib3ds_io_write_word(io, (uint16_t) j);
                        matf[j] = 1;
                    }
                }
            }
        }
        ((Lib3dsIoImpl*)io->impl)->tmp_mem = NULL;
        free(matf);
    }

    {
        /*---- SMOOTH_GROUP ----*/
        Lib3dsChunk c;
        int i;

        c.chunk = CHK_SMOOTH_GROUP;
        c.size = 6 + 4 * mesh->nfaces;
        lib3ds_chunk_write(&c, io);

        for (i = 0; i < mesh->nfaces; ++i) {
            lib3ds_io_write_dword(io, mesh->faces[i].smoothing_group);
        }
    }

    {
        /*---- MSH_BOXMAP ----*/
        Lib3dsChunk c;

        if (strlen(mesh->box_front) ||
            strlen(mesh->box_back) ||
            strlen(mesh->box_left) ||
            strlen(mesh->box_right) ||
            strlen(mesh->box_top) ||
            strlen(mesh->box_bottom)) {

            c.chunk = CHK_MSH_BOXMAP;
            lib3ds_chunk_write_start(&c, io);

            lib3ds_io_write_string(io, mesh->box_front);
            lib3ds_io_write_string(io, mesh->box_back);
            lib3ds_io_write_string(io, mesh->box_left);
            lib3ds_io_write_string(io, mesh->box_right);
            lib3ds_io_write_string(io, mesh->box_top);
            lib3ds_io_write_string(io, mesh->box_bottom);

            lib3ds_chunk_write_end(&c, io);
        }
    }

    lib3ds_chunk_write_end(&c, io);
}


static void
texco_array_write(Lib3dsMesh *mesh, Lib3dsIo *io) {
    Lib3dsChunk c;
    int i;

    if (!mesh->texcos) {
        return;
    }
     
    c.chunk = CHK_TEX_VERTS;
    c.size = 8 + 8 * mesh->nvertices;
    lib3ds_chunk_write(&c, io);

    lib3ds_io_write_word(io, mesh->nvertices);
    for (i = 0; i < mesh->nvertices; ++i) {
        lib3ds_io_write_float(io, mesh->texcos[i][0]);
        lib3ds_io_write_float(io, mesh->texcos[i][1]);
    }
}


void
lib3ds_mesh_write(Lib3dsFile *file, Lib3dsMesh *mesh, Lib3dsIo *io) {
    Lib3dsChunk c;

    c.chunk = CHK_N_TRI_OBJECT;
    lib3ds_chunk_write_start(&c, io);

    point_array_write(mesh, io);
    texco_array_write(mesh, io);

    if (mesh->map_type != LIB3DS_MAP_NONE) {   /*---- LIB3DS_MESH_TEXTURE_INFO ----*/
        Lib3dsChunk c;
        int i, j;

        c.chunk = CHK_MESH_TEXTURE_INFO;
        c.size = 92;
        lib3ds_chunk_write(&c, io);

        lib3ds_io_write_word(io, mesh->map_type);

        for (i = 0; i < 2; ++i) {
            lib3ds_io_write_float(io, mesh->map_tile[i]);
        }
        lib3ds_io_write_vector(io, mesh->map_pos);
        lib3ds_io_write_float(io, mesh->map_scale);

        for (i = 0; i < 4; i++) {
            for (j = 0; j < 3; j++) {
                lib3ds_io_write_float(io, mesh->map_matrix[i][j]);
            }
        }
        for (i = 0; i < 2; ++i) {
            lib3ds_io_write_float(io, mesh->map_planar_size[i]);
        }
        lib3ds_io_write_float(io, mesh->map_cylinder_height);
    }

    flag_array_write(mesh, io);

    {
        /*---- LIB3DS_MESH_MATRIX ----*/
        Lib3dsChunk c;
        int i, j;

        c.chunk = CHK_MESH_MATRIX;
        c.size = 54;
        lib3ds_chunk_write(&c, io);
        for (i = 0; i < 4; i++) {
            for (j = 0; j < 3; j++) {
                lib3ds_io_write_float(io, mesh->matrix[i][j]);
            }
        }
    }

    if (mesh->color) {   /*---- LIB3DS_MESH_COLOR ----*/
        Lib3dsChunk c;

        c.chunk = CHK_MESH_COLOR;
        c.size = 7;
        lib3ds_chunk_write(&c, io);
        lib3ds_io_write_byte(io, mesh->color);
    }
    
    face_array_write(file, mesh, io);

    lib3ds_chunk_write_end(&c, io);
}