651 lines
15 KiB
C
651 lines
15 KiB
C
/*
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* Copyright 2011-2014 hasufell
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*
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* This file is part of a hasufell project.
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation version 2 of the License only.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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/**
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* @file half_edge.c
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* This file provides operations on half-edge data structures
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* which are defined in half_edge.h, as well as assembling
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* such a struct.
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* @brief operations on half-edge data structs
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*/
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#include "common.h"
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#include "err.h"
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#include "filereader.h"
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#include "half_edge.h"
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#include "print.c"
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#include "vector.h"
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#include <stdbool.h>
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#include <stdint.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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/**
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* Fault intolerant macro. Will abort the program if the called
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* function failed.
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*/
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#define GET_ALL_EMANATING_EDGES(...) \
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{ \
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if (!get_all_emanating_edges(__VA_ARGS__)) { \
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fprintf(stderr, "Failure in get_all_emanating_edges()!\n"); \
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abort(); \
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} \
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}
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/*
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* static declarations
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*/
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static bool get_all_emanating_edges(HE_vert const * const vert,
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HE_edge ***edge_array_out,
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uint32_t *ec_out);
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static int32_t get_row_count(int32_t const **array);
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static int32_t get_face_count(FACES const faces);
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static int32_t get_edge_count(FACES const faces);
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static double **parse_2d_array(char const * const obj_string,
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char *item);
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static FACES parse_face_array(char const * const obj_string);
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/**
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* Get all edges that emanate from vertice and return a pointer
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* to that array with the size of ec_out.
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*
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* @param vert the vertice to get the emanating edges of
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* @param edge_array_out address of the 2d edge array to save
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* the result in [out]
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* @param ec_out the edge counter is saved here [out]
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* @return true/false for success/failure
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*/
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static bool get_all_emanating_edges(HE_vert const * const vert,
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HE_edge ***edge_array_out,
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uint32_t *ec_out)
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{
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uint32_t ec = 0; /* edge count */
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HE_edge **edge_array = NULL;
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if (!edge_array_out || !vert || !ec_out)
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return false;
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HE_edge *edge = vert->edge;
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/* build an array of emanating edges */
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do {
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REALLOC(edge_array,
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sizeof(HE_edge*) * (ec + 1));
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edge_array[ec] = edge;
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edge = edge->pair->next;
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ec++;
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} while (edge && edge != vert->edge);
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/* set out-pointers */
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*edge_array_out = edge_array;
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*ec_out = ec; /* this is the real size, not the x[ec] value */
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return true;
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}
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/**
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* Get the row count of the 2d array.
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*
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* @param array the 2 dimensional array
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* @return the row count
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*/
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static int32_t get_row_count(int32_t const **array)
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{
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uint32_t rc = 0;
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if (!array)
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return -1;
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while (array[rc])
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rc++;
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return rc;
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}
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/**
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* Get the amount of faces as they are in the
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* .obj file.
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*
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* @param faces the faces array
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* @return the count of faces, -1 on failure
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*/
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static int32_t get_face_count(FACES const faces)
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{
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if (!faces)
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return 0;
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return get_row_count((int32_t const**)faces);
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}
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/**
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* Get the amount of edges.
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*
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* @param faces the faces array which will be used
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* to calculate the amount of edges
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* @return the count of edges, -1 on failure
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*/
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static int32_t get_edge_count(FACES const faces)
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{
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uint32_t ec = 0;
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uint32_t fc;
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if (!faces)
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return -1;
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fc = get_face_count(faces);
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for (uint32_t i = 0; i < fc; i++)
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ec += faces[i][0];
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return ec;
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}
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/**
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* Parse a string which supposedly is a 2-dimensional
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* array in the .obj file, describing all faces, all vertices
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* and such. The parsing depends on the item string, such as "f"
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* or "v".
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*
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* @param obj_string the string that is in obj format
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* @param item the item to look for, such as "f" or "v"
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* @return a newly allocated 2-dimensional array, NULL on failure
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*/
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static double **parse_2d_array(char const * const obj_string,
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char *item)
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{
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uint32_t lc = 0;
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char *string,
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*str_ptr_space = NULL, /* for strtok */
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*str_ptr_newline = NULL, /* for strtok */
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*str_tmp_ptr = NULL; /* for strtok */
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double **arr = NULL;
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if (!obj_string || !item)
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return NULL;
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string = malloc(sizeof(char) * strlen(obj_string) + 1);
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strcpy(string, obj_string);
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str_tmp_ptr = strtok_r(string, "\n", &str_ptr_newline);
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while (str_tmp_ptr && *str_tmp_ptr) {
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str_tmp_ptr = strtok_r(str_tmp_ptr, " ", &str_ptr_space);
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if (!strcmp(str_tmp_ptr, item)) {
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char *myint = NULL;
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uint8_t i = 1;
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REALLOC(arr, sizeof(double*) * (lc + 2));
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arr[lc] = NULL;
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while ((myint = strtok_r(NULL, " ", &str_ptr_space))) {
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i++;
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REALLOC(arr[lc],
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sizeof(double**) * (i + 1));
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arr[lc][i - 1] = atof(myint);
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}
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arr[lc][0] = i - 1; /* save length at first position */
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lc++;
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arr[lc] = NULL; /* trailing NULL pointer */
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}
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str_tmp_ptr = strtok_r(NULL, "\n", &str_ptr_newline);
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}
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free(string);
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return arr;
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}
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/**
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* Parses the face arrays. Since these contain slashes, such as
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* "f 1/4/3 8/4/4 9/8/3" we cannot use parse_2d_array() since
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* we need extra logic.
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*
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* @param obj_string the string that is in obj format
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* @return a newly allocated FACES array, NULL on failure
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*/
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static FACES parse_face_array(char const * const obj_string)
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{
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uint32_t lc = 0;
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char *string,
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*str_ptr_space = NULL, /* for strtok */
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*str_ptr_newline = NULL, /* for strtok */
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*str_tmp_ptr = NULL; /* for strtok */
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FACES arr = NULL;
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if (!obj_string)
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return NULL;
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string = malloc(sizeof(char) * strlen(obj_string) + 1);
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strcpy(string, obj_string);
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str_tmp_ptr = strtok_r(string, "\n", &str_ptr_newline);
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while (str_tmp_ptr && *str_tmp_ptr) {
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str_tmp_ptr = strtok_r(str_tmp_ptr, " ", &str_ptr_space);
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if (!strcmp(str_tmp_ptr, "f")) {
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char *myint = NULL;
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uint8_t i = 1;
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REALLOC(arr, sizeof(double*) * (lc + 2));
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arr[lc] = NULL;
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while ((myint = strtok_r(NULL, " ", &str_ptr_space))) {
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i++;
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REALLOC(arr[lc],
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sizeof(double**) * (i + 1));
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arr[lc][i - 1] = atof(myint);
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}
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arr[lc][0] = i - 1; /* save length at first position */
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lc++;
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arr[lc] = NULL; /* trailing NULL pointer */
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}
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str_tmp_ptr = strtok_r(NULL, "\n", &str_ptr_newline);
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}
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free(string);
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return arr;
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}
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/**
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* Calculate the normal of a face that corresponds
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* to edge.
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*
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* @param edge to align the normalization
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* @param vec the vector to store the result in [out]
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* @return true/false for success/failure
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*/
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bool face_normal(HE_edge const * const edge,
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vector *vec)
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{
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vector he_vec1,
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he_vec2,
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he_base;
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if (!edge || !vec)
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return false;
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COPY_VECTOR(edge->next->vert->vec, &he_base);
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/* calculate vectors between the vertices */
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SUB_VECTORS(edge->next->next->vert->vec, &he_base, &he_vec1);
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SUB_VECTORS(edge->vert->vec, &he_base, &he_vec2);
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VECTOR_PRODUCT(&he_vec1, &he_vec2, vec);
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NORMALIZE_VECTOR(vec, vec);
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return true;
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}
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/**
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* Calculate the approximated normal of a vertex.
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*
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* @param vert the vertex
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* @param vec the vector to store the result in [out]
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* @return true/false for success/failure
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*/
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bool vec_normal(HE_vert const * const vert, vector *vec)
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{
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HE_edge **edge_array = NULL;
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uint32_t ec;
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vector he_base;
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if (!vert || !vec)
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return false;
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GET_ALL_EMANATING_EDGES(vert, &edge_array, &ec);
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COPY_VECTOR(edge_array[0]->vert->vec, &he_base);
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SET_NULL_VECTOR(vec); /* set to null for later summation */
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/* iterate over all edges, get the normalized
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* face vector and add those up */
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for (uint32_t i = 0; i < ec; i++) {
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vector new_vec;
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FACE_NORMAL(edge_array[i], &new_vec);
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ADD_VECTORS(vec, &new_vec, vec);
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}
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/* normalize the result */
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NORMALIZE_VECTOR(vec, vec);
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free(edge_array);
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return true;
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}
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/**
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* Find the center of an object and store the coordinates
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* in a HE_vert struct.
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*
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* @param obj the object we want to find the center of
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* @param vec the vector to store the result in [out]
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* @return true/false for success/failure
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*/
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bool find_center(HE_obj const * const obj, vector *vec)
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{
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float x = 0,
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y = 0,
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z = 0;
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uint32_t i;
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if (!obj || !vec)
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return false;
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for (i = 0; i < obj->vc; i++) {
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x += obj->vertices[i].vec->x;
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y += obj->vertices[i].vec->y;
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z += obj->vertices[i].vec->z;
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}
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vec->x = x / i;
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vec->y = y / i;
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vec->z = z / i;
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return true;
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}
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/**
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* Calculates the factor that can be used to scale down the object
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* to the size of 1.
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*
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* @param obj the object we want to scale
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* @return the corresponding scale factor, -1 on error
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*/
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float get_normalized_scale_factor(HE_obj const * const obj)
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{
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float max;
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float min;
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uint32_t i;
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if (!obj)
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return -1;
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max = obj->vertices[0].vec->x +
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obj->vertices[0].vec->y + obj->vertices[0].vec->z;
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min = obj->vertices[0].vec->x +
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obj->vertices[0].vec->y + obj->vertices[0].vec->z;
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for (i = 0; i < obj->vc; i++) {
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if ((obj->vertices[i].vec->x +
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obj->vertices[i].vec->y +
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obj->vertices[i].vec->z) > max)
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max = obj->vertices[i].vec->x +
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obj->vertices[i].vec->y +
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obj->vertices[i].vec->z;
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else if ((obj->vertices[i].vec->x +
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obj->vertices[i].vec->y +
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obj->vertices[i].vec->z) < min)
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min = obj->vertices[i].vec->x +
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obj->vertices[i].vec->y +
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obj->vertices[i].vec->z;
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}
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return 1 / (max - min);
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}
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/**
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* Scales down the object to the size of 1. The parameter
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* is modified!
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*
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* @param obj the object we want to scale [mod]
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*/
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bool normalize_object(HE_obj *obj)
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{
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float scale_factor;
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if (!obj)
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return false;
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scale_factor = get_normalized_scale_factor(obj);
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for (uint32_t i = 0; i < obj->vc; i++) {
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obj->vertices[i].vec->x = obj->vertices[i].vec->x * scale_factor;
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obj->vertices[i].vec->y = obj->vertices[i].vec->y * scale_factor;
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obj->vertices[i].vec->z = obj->vertices[i].vec->z * scale_factor;
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}
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return true;
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}
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/**
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* Parse an .obj string and return a HE_obj
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* that represents the whole object.
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*
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* @param obj_string the whole string from the .obj file
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* @return the HE_face array that represents the object
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*/
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HE_obj *parse_obj(char const * const obj_string)
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{
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int32_t vc = 0, /* vertices count */
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fc = 0, /* face count */
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ec = 0; /* edge count */
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char *string = NULL;
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HE_vert *vertices = NULL;
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HE_edge *edges = NULL;
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HE_face *faces = NULL;
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HE_obj *obj = NULL;
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FACES obj_f = NULL;
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/* V_TEXTURES obj_vt = NULL; */
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VERTICES obj_v = NULL;
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if (!obj_string || !*obj_string)
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return NULL;
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string = malloc(sizeof(char) * strlen(obj_string) + 1);
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strcpy(string, obj_string);
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obj_v = parse_2d_array(string, "v");
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/* obj_vt = parse_2d_array(obj_string, "vt"); */
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obj_f = parse_face_array(string);
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vc = 0;
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vertices = malloc(sizeof(HE_vert) *
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(get_row_count((int32_t const**)obj_v) + 1));
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/* fill the vertices */
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while (obj_v[vc]) {
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vector *tmp_vec;
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if (obj_v[vc][0] > 3)
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ABORT("Failure in parse_obj(),\n"
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"malformed vertice, exceeds 3 dimensions!\n");
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tmp_vec = malloc(sizeof(vector));
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CHECK_PTR_VAL(tmp_vec);
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tmp_vec->x = obj_v[vc][1];
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tmp_vec->y = obj_v[vc][2];
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tmp_vec->z = obj_v[vc][3];
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vertices[vc].vec = tmp_vec;
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/* set unused/unknown values to NULL */
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vertices[vc].edge = NULL;
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vertices[vc].edge_array = NULL;
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vertices[vc].eac = 0;
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/* allocate color struct and set preliminary colors */
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vertices[vc].col = malloc(sizeof(color));
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vertices[vc].col->red = -1;
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vertices[vc].col->green = -1;
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vertices[vc].col->blue = -1;
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vc++;
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}
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if ((ec = get_edge_count(obj_f)) == -1)
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ABORT("Invalid edge count!\n");
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if ((fc = get_face_count(obj_f)) == -1)
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ABORT("Invalid face count!\n");
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/* print_plain_faces(obj_v, vc + 1); */
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faces = (HE_face*) malloc(sizeof(HE_face) * fc);
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CHECK_PTR_VAL(faces);
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/* hold enough space for possible dummy edges */
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edges = (HE_edge*) malloc(sizeof(HE_edge) * ec * 2);
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CHECK_PTR_VAL(edges);
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ec = 0;
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/* create HE_edges and real HE_faces */
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for (uint32_t i = 0; i < (uint32_t)fc; i++) { /* for all faces */
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/* for all vertices of the face */
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for (uint32_t j = 0; j < (uint32_t)obj_f[i][0]; j++) {
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uint32_t obj_f_pos = j + 1; /* first pos is reserved for length */
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uint32_t fv_arr_id =
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obj_f[i][obj_f_pos] - 1; /* fv_id starts at 1 */
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edges[ec].vert = &(vertices[fv_arr_id]);
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edges[ec].face = &(faces[i]);
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edges[ec].pair = NULL; /* preliminary */
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vertices[fv_arr_id].edge = &(edges[ec]); /* last one wins */
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/* Skip j == 0 here, so we don't underrun the arrays,
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* since we always look one edge back. The first edge
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* element is taken care of below as well. */
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if (j > 0) {
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uint32_t *eac = &(edges[ec].vert->eac);
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/* connect previous edge to current edge */
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edges[ec - 1].next = &(edges[ec]);
|
|
|
|
/* Acceleration struct:
|
|
* add previous edge to edge_array of current vertice */
|
|
REALLOC(edges[ec].vert->edge_array,
|
|
sizeof(HE_edge*) * (*eac + 1));
|
|
edges[ec].vert->edge_array[*eac] = &(edges[ec - 1]);
|
|
(*eac)++;
|
|
|
|
if (obj_f_pos == (uint32_t)obj_f[i][0]) { /* no vertice left */
|
|
uint32_t *eac;
|
|
/* connect last edge to first edge */
|
|
edges[ec].next = &(edges[ec - j]);
|
|
eac = &(edges[ec].next->vert->eac);
|
|
|
|
/* Acceleration struct:
|
|
* add last edge to edge_array element of first vertice */
|
|
REALLOC(edges[ec].next->vert->edge_array,
|
|
sizeof(HE_edge*) * (*eac + 1));
|
|
edges[ec].next->vert->edge_array[*eac] = &(edges[ec]);
|
|
(*eac)++;
|
|
}
|
|
}
|
|
|
|
ec++;
|
|
}
|
|
|
|
faces[i].edge = &(edges[ec - 1]); /* "last" edge */
|
|
}
|
|
|
|
/* find pairs */
|
|
for (uint32_t i = 0; i < (uint32_t)ec; i++) { /* for all edges */
|
|
uint32_t eac = edges[i].vert->eac;
|
|
bool pair_found = false;
|
|
|
|
for (uint32_t j = 0; j < eac; j++) { /* for all potential pairs */
|
|
if (edges[i].vert->edge_array[j] &&
|
|
(edges[i].next->vert ==
|
|
edges[i].vert->edge_array[j]->vert)) {
|
|
edges[i].pair = edges[i].vert->edge_array[j];
|
|
edges[i].vert->edge_array[j] = NULL;
|
|
|
|
/* this is a trick to make sure the
|
|
* edge member of HE_vert is never
|
|
* a border-edge (unless there are only
|
|
* border edges), otherwise
|
|
* get_all_emanating_edges() would break
|
|
* for vertices that are at the edge
|
|
* of an open object */
|
|
edges[i].vert->edge = &(edges[i]);
|
|
|
|
pair_found = true;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (!pair_found) { /* we have a border edge */
|
|
/* add dummy edge, so get_all_emanating_edges()
|
|
* does not break */
|
|
edges[ec + i].face = NULL;
|
|
edges[ec + i].next = NULL;
|
|
edges[ec + i].pair = &(edges[i]);
|
|
edges[ec + i].vert = edges[i].next->vert;
|
|
edges[i].pair = &(edges[ec + i]);
|
|
}
|
|
}
|
|
|
|
/* don't need the edge array anymore */
|
|
for (uint32_t i = 0; i < (uint32_t)vc; i++)
|
|
free(vertices[i].edge_array);
|
|
|
|
obj = (HE_obj*) malloc(sizeof(HE_obj));
|
|
CHECK_PTR_VAL(obj);
|
|
|
|
obj->edges = edges;
|
|
obj->vertices = vertices;
|
|
obj->faces = faces;
|
|
obj->ec = ec;
|
|
obj->vc = vc;
|
|
obj->fc = fc;
|
|
|
|
for (uint32_t i = 0; i < (uint32_t)fc; i++)
|
|
free(obj_f[i]);
|
|
free(obj_f);
|
|
for (uint32_t i = 0; i < (uint32_t)vc; i++)
|
|
free(obj_v[i]);
|
|
free(obj_v);
|
|
free(string);
|
|
|
|
return obj;
|
|
}
|
|
|
|
/**
|
|
* Free the inner structures of an object.
|
|
*
|
|
* @param obj the object to free
|
|
*/
|
|
void delete_object(HE_obj *obj)
|
|
{
|
|
if (!obj)
|
|
return;
|
|
|
|
for (uint32_t i = 0; i < obj->vc; i++) {
|
|
free(obj->vertices[i].vec);
|
|
free(obj->vertices[i].col);
|
|
}
|
|
free(obj->edges);
|
|
free(obj->vertices);
|
|
free(obj->faces);
|
|
}
|