Move half-edge assembler to separate .c file
This commit is contained in:
parent
dfd978f714
commit
cd864fa1ba
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@ -2,7 +2,7 @@ include ../common.mk
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TARGET = drow-engine
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HEADERS = err.h common.h print.h filereader.h gl_draw.h vector.h half_edge.h
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OBJECTS = print.o filereader.o gl_draw.o vector.o half_edge.o
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OBJECTS = print.o filereader.o gl_draw.o vector.o half_edge.o half_edge_AS.o
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INCS = -I.
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CFLAGS += $(shell $(PKG_CONFIG) --cflags gl glu glib-2.0)
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465
src/half_edge.c
465
src/half_edge.c
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@ -34,7 +34,6 @@
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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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@ -56,24 +55,7 @@
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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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static void assemble_HE_stage1(VERTICES obj_v,
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HE_vert *vertices,
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int32_t *vc);
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static void assemble_HE_stage2(FACES obj_f,
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HE_vert *vertices,
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HE_face *faces,
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HE_edge *edges,
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int32_t *fc,
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int32_t *ec);
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static void assemble_HE_stage3(HE_edge *edges,
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int32_t *ec,
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int32_t *dec);
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/**
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* Get all edges that emanate from vertice and return a pointer
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@ -116,376 +98,6 @@ static bool get_all_emanating_edges(HE_vert const * const vert,
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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(uint32_t*) * (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(uint32_t**) * (i + 1));
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arr[lc][i - 1] = atoi(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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* First stage of assembling the half-edge data structure.
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* Here we allocate vertices and fill their coordinates
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* with the information we have from parsing the obj file.
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* All other yet unknown members such as edge are set to
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* NULL. This function isn't really modular, but makes
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* reading parse_obj() a bit less painful.
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*
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* @param obj_v the vertices in the raw form after they are
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* parsed from the obj file
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* @param vertices pointer the actual half-edge vertices
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* @param vc pointer to the vertice count
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*/
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static void assemble_HE_stage1(VERTICES obj_v,
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HE_vert *vertices,
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int32_t *vc)
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{
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uint8_t const xpos = 1;
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uint8_t const ypos = 2;
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uint8_t const zpos = 3;
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int8_t const default_col = -1;
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*vc = 0;
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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][xpos];
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tmp_vec->y = obj_v[*vc][ypos];
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tmp_vec->z = obj_v[*vc][zpos];
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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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vertices[*vc].dc = 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 = default_col;
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vertices[*vc].col->green = default_col;
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vertices[*vc].col->blue = default_col;
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(*vc)++;
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}
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}
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/**
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* Second stage of assembling the half-edge data structure.
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* Here we start creating the HE_edges and HE_faces and also
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* fill some missing information to the HE_verts along with it.
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* The edge pairs are still unknown, as well as some other
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* acceleration-structure related members like vertice->dummys.
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* This function isn't really modular, but makes
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* reading parse_obj() a bit less painful.
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*
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* @param obj_f the raw faces as they are after parsing the obj file
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* @param vertices the half-edge vertices
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* @param faces the half-edge faces
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* @param edges the half-edge edges
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* @param fc the count of half-edge faces
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* @param ec the count of half-edge edges
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*/
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static void assemble_HE_stage2(FACES obj_f,
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HE_vert *vertices,
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HE_face *faces,
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HE_edge *edges,
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int32_t *fc,
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int32_t *ec)
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{
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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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vertices[fv_arr_id].dummys = NULL; /* preliminary */
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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]);
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/* Acceleration struct:
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* add previous edge to edge_array of current vertice */
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REALLOC(edges[*ec].vert->edge_array,
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sizeof(HE_edge*) * (*eac + 1));
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edges[*ec].vert->edge_array[*eac] = &(edges[*ec - 1]);
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(*eac)++;
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if (obj_f_pos == (uint32_t)obj_f[i][0]) { /* no vertice left */
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uint32_t *eac;
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/* connect last edge to first edge */
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edges[*ec].next = &(edges[*ec - j]);
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eac = &(edges[*ec].next->vert->eac);
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/* Acceleration struct:
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* add last edge to edge_array element of first vertice */
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REALLOC(edges[*ec].next->vert->edge_array,
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sizeof(HE_edge*) * (*eac + 1));
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edges[*ec].next->vert->edge_array[*eac] = &(edges[*ec]);
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(*eac)++;
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}
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}
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(*ec)++;
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}
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faces[i].edge = &(edges[*ec - 1]); /* "last" edge */
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}
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}
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/**
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* Third stage of assembling the half-edge data structure.
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* Here we find the pairs of edges and also account for the
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* possibility of border-edges, where we have to set up
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* dummy edges and connect them properly.
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*
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* @param edges the half-edge edges
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* @param ec the half-edge edges count
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* @param dec the dummy edges count
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*/
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static void assemble_HE_stage3(HE_edge *edges,
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int32_t *ec,
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int32_t *dec)
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{
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/* find pairs */
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for (uint32_t i = 0; i < (uint32_t)(*ec); i++) { /* for all edges */
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uint32_t eac = edges[i].vert->eac;
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bool pair_found = false;
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for (uint32_t j = 0; j < eac; j++) { /* for all potential pairs */
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if (edges[i].vert->edge_array[j] &&
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(edges[i].next->vert ==
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edges[i].vert->edge_array[j]->vert)) {
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edges[i].pair = edges[i].vert->edge_array[j];
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edges[i].vert->edge_array[j] = NULL;
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pair_found = true;
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break;
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}
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}
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/* create dummy pair edge if we have a border edge */
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if (!pair_found) {
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uint32_t *vert_dc = &(edges[i].next->vert->dc);
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REALLOC(edges[i].next->vert->dummys,
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sizeof(HE_edge*) * (*vert_dc + 1));
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/* NULL-face indicates border-edge */
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edges[*ec + *dec].face = NULL;
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/* we don't know this one yet */
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edges[*ec + *dec].next = NULL;
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/* set both pairs */
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edges[*ec + *dec].pair = &(edges[i]);
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edges[i].pair = &(edges[*ec + *dec]);
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/* set vertex */
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edges[*ec + *dec].vert = edges[i].next->vert;
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/* add the dummy edge to the dummys array of the vertex */
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edges[*ec + *dec].vert->dummys[*vert_dc] = &(edges[*ec + *dec]);
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(*vert_dc)++;
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(*dec)++;
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}
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}
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/* now we have to connect the dummy edges together */
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for (uint32_t i = 0; i < (uint32_t) (*dec); i++) { /* for all dummy edges */
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/* vertex the dummy edge points to */
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HE_vert *vert = edges[*ec + i].pair->vert;
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/* iterate over the dummy array */
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for (uint32_t j = 0; j < vert->dc; j++) {
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if (vert == vert->dummys[j]->vert)
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edges[*ec + i].next = vert->dummys[j];
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j++;
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}
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}
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}
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/**
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* Calculate the normal of a face that corresponds
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@ -651,81 +263,6 @@ bool normalize_object(HE_obj *obj)
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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, NULL
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* on failure
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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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dec = 0; /* dummy 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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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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vertices = malloc(sizeof(HE_vert) *
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get_row_count((int32_t const**)obj_v) + 1);
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CHECK_PTR_VAL(vertices);
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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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assemble_HE_stage1(obj_v, vertices, &vc);
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assemble_HE_stage2(obj_f, vertices, faces, edges, &fc, &ec);
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||||
assemble_HE_stage3(edges, &ec, &dec);
|
||||
|
||||
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;
|
||||
|
||||
/* cleanup */
|
||||
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(vertices[i].dummys);
|
||||
free(vertices[i].edge_array);
|
||||
free(obj_v[i]);
|
||||
}
|
||||
free(obj_v);
|
||||
free(string);
|
||||
|
||||
return obj;
|
||||
}
|
||||
|
||||
/**
|
||||
* Free the inner structures of an object.
|
||||
*
|
||||
|
|
|
|||
|
|
@ -18,10 +18,11 @@
|
|||
|
||||
/**
|
||||
* @file half_edge.h
|
||||
* Header for the external API of half_edge.c,
|
||||
* Header for the external API of half_edge.c
|
||||
* and half_edge_AS.c,
|
||||
* primarily holding the common half-edge data
|
||||
* structures.
|
||||
* @brief header of half_edge.c
|
||||
* @brief header of half_edge related functions
|
||||
*/
|
||||
|
||||
#ifndef _DROW_ENGINE_HE_OPERATIONS_H
|
||||
|
|
|
|||
|
|
@ -0,0 +1,501 @@
|
|||
/*
|
||||
* Copyright 2011-2014 hasufell
|
||||
*
|
||||
* This file is part of a hasufell project.
|
||||
*
|
||||
* This program is free software: you can redistribute it and/or modify
|
||||
* it under the terms of the GNU General Public License as published by
|
||||
* the Free Software Foundation version 2 of the License only.
|
||||
*
|
||||
* This program 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 General Public License for more details.
|
||||
*
|
||||
* You should have received a copy of the GNU General Public License
|
||||
* along with this program. If not, see <http://www.gnu.org/licenses/>.
|
||||
*/
|
||||
|
||||
/**
|
||||
* @file half_edge.c
|
||||
* This files only purpose is to assemble the half-edge
|
||||
* data structure from an obj string.
|
||||
* @brief half-edge assembler
|
||||
*/
|
||||
|
||||
#include "common.h"
|
||||
#include "err.h"
|
||||
#include "filereader.h"
|
||||
|
||||
#include <stdbool.h>
|
||||
#include <stdint.h>
|
||||
#include <stdio.h>
|
||||
#include <stdlib.h>
|
||||
#include <string.h>
|
||||
|
||||
|
||||
static int32_t get_row_count(int32_t const **array);
|
||||
static int32_t get_face_count(FACES const faces);
|
||||
static int32_t get_edge_count(FACES const faces);
|
||||
static double **parse_2d_array(char const * const obj_string,
|
||||
char *item);
|
||||
static FACES parse_face_array(char const * const obj_string);
|
||||
static void assemble_HE_stage1(VERTICES obj_v,
|
||||
HE_vert *vertices,
|
||||
int32_t *vc);
|
||||
static void assemble_HE_stage2(FACES obj_f,
|
||||
HE_vert *vertices,
|
||||
HE_face *faces,
|
||||
HE_edge *edges,
|
||||
int32_t *fc,
|
||||
int32_t *ec);
|
||||
static void assemble_HE_stage3(HE_edge *edges,
|
||||
int32_t *ec,
|
||||
int32_t *dec);
|
||||
|
||||
|
||||
/**
|
||||
* Get the row count of the 2d array.
|
||||
*
|
||||
* @param array the 2 dimensional array
|
||||
* @return the row count
|
||||
*/
|
||||
static int32_t get_row_count(int32_t const **array)
|
||||
{
|
||||
uint32_t rc = 0;
|
||||
|
||||
if (!array)
|
||||
return -1;
|
||||
|
||||
while (array[rc])
|
||||
rc++;
|
||||
|
||||
return rc;
|
||||
|
||||
}
|
||||
|
||||
/**
|
||||
* Get the amount of faces as they are in the
|
||||
* .obj file.
|
||||
*
|
||||
* @param faces the faces array
|
||||
* @return the count of faces, -1 on failure
|
||||
*/
|
||||
static int32_t get_face_count(FACES const faces)
|
||||
{
|
||||
if (!faces)
|
||||
return 0;
|
||||
|
||||
return get_row_count((int32_t const**)faces);
|
||||
}
|
||||
|
||||
/**
|
||||
* Get the amount of edges.
|
||||
*
|
||||
* @param faces the faces array which will be used
|
||||
* to calculate the amount of edges
|
||||
* @return the count of edges, -1 on failure
|
||||
*/
|
||||
static int32_t get_edge_count(FACES const faces)
|
||||
{
|
||||
uint32_t ec = 0;
|
||||
uint32_t fc;
|
||||
|
||||
if (!faces)
|
||||
return -1;
|
||||
|
||||
fc = get_face_count(faces);
|
||||
|
||||
for (uint32_t i = 0; i < fc; i++)
|
||||
ec += faces[i][0];
|
||||
|
||||
return ec;
|
||||
}
|
||||
|
||||
/**
|
||||
* Parse a string which supposedly is a 2-dimensional
|
||||
* array in the .obj file, describing all faces, all vertices
|
||||
* and such. The parsing depends on the item string, such as "f"
|
||||
* or "v".
|
||||
*
|
||||
* @param obj_string the string that is in obj format
|
||||
* @param item the item to look for, such as "f" or "v"
|
||||
* @return a newly allocated 2-dimensional array, NULL on failure
|
||||
*/
|
||||
static double **parse_2d_array(char const * const obj_string,
|
||||
char *item)
|
||||
{
|
||||
uint32_t lc = 0;
|
||||
char *string,
|
||||
*str_ptr_space = NULL, /* for strtok */
|
||||
*str_ptr_newline = NULL, /* for strtok */
|
||||
*str_tmp_ptr = NULL; /* for strtok */
|
||||
double **arr = NULL;
|
||||
|
||||
if (!obj_string || !item)
|
||||
return NULL;
|
||||
|
||||
string = malloc(sizeof(char) * strlen(obj_string) + 1);
|
||||
strcpy(string, obj_string);
|
||||
|
||||
str_tmp_ptr = strtok_r(string, "\n", &str_ptr_newline);
|
||||
while (str_tmp_ptr && *str_tmp_ptr) {
|
||||
|
||||
str_tmp_ptr = strtok_r(str_tmp_ptr, " ", &str_ptr_space);
|
||||
|
||||
if (!strcmp(str_tmp_ptr, item)) {
|
||||
char *myint = NULL;
|
||||
uint8_t i = 1;
|
||||
|
||||
REALLOC(arr, sizeof(double*) * (lc + 2));
|
||||
arr[lc] = NULL;
|
||||
while ((myint = strtok_r(NULL, " ", &str_ptr_space))) {
|
||||
i++;
|
||||
|
||||
REALLOC(arr[lc],
|
||||
sizeof(double**) * (i + 1));
|
||||
arr[lc][i - 1] = atof(myint);
|
||||
}
|
||||
arr[lc][0] = i - 1; /* save length at first position */
|
||||
lc++;
|
||||
arr[lc] = NULL; /* trailing NULL pointer */
|
||||
}
|
||||
|
||||
str_tmp_ptr = strtok_r(NULL, "\n", &str_ptr_newline);
|
||||
}
|
||||
|
||||
free(string);
|
||||
|
||||
return arr;
|
||||
}
|
||||
|
||||
/**
|
||||
* Parses the face arrays. Since these contain slashes, such as
|
||||
* "f 1/4/3 8/4/4 9/8/3" we cannot use parse_2d_array() since
|
||||
* we need extra logic.
|
||||
*
|
||||
* @param obj_string the string that is in obj format
|
||||
* @return a newly allocated FACES array, NULL on failure
|
||||
*/
|
||||
static FACES parse_face_array(char const * const obj_string)
|
||||
{
|
||||
uint32_t lc = 0;
|
||||
char *string,
|
||||
*str_ptr_space = NULL, /* for strtok */
|
||||
*str_ptr_newline = NULL, /* for strtok */
|
||||
*str_tmp_ptr = NULL; /* for strtok */
|
||||
FACES arr = NULL;
|
||||
|
||||
if (!obj_string)
|
||||
return NULL;
|
||||
|
||||
string = malloc(sizeof(char) * strlen(obj_string) + 1);
|
||||
strcpy(string, obj_string);
|
||||
|
||||
str_tmp_ptr = strtok_r(string, "\n", &str_ptr_newline);
|
||||
while (str_tmp_ptr && *str_tmp_ptr) {
|
||||
|
||||
str_tmp_ptr = strtok_r(str_tmp_ptr, " ", &str_ptr_space);
|
||||
|
||||
if (!strcmp(str_tmp_ptr, "f")) {
|
||||
char *myint = NULL;
|
||||
uint8_t i = 1;
|
||||
|
||||
REALLOC(arr, sizeof(uint32_t*) * (lc + 2));
|
||||
arr[lc] = NULL;
|
||||
while ((myint = strtok_r(NULL, " ", &str_ptr_space))) {
|
||||
i++;
|
||||
|
||||
REALLOC(arr[lc],
|
||||
sizeof(uint32_t**) * (i + 1));
|
||||
arr[lc][i - 1] = atoi(myint);
|
||||
}
|
||||
arr[lc][0] = i - 1; /* save length at first position */
|
||||
lc++;
|
||||
arr[lc] = NULL; /* trailing NULL pointer */
|
||||
}
|
||||
|
||||
str_tmp_ptr = strtok_r(NULL, "\n", &str_ptr_newline);
|
||||
}
|
||||
|
||||
free(string);
|
||||
|
||||
return arr;
|
||||
}
|
||||
|
||||
/**
|
||||
* First stage of assembling the half-edge data structure.
|
||||
* Here we allocate vertices and fill their coordinates
|
||||
* with the information we have from parsing the obj file.
|
||||
* All other yet unknown members such as edge are set to
|
||||
* NULL. This function isn't really modular, but makes
|
||||
* reading parse_obj() a bit less painful.
|
||||
*
|
||||
* @param obj_v the vertices in the raw form after they are
|
||||
* parsed from the obj file
|
||||
* @param vertices pointer the actual half-edge vertices
|
||||
* @param vc pointer to the vertice count
|
||||
*/
|
||||
static void assemble_HE_stage1(VERTICES obj_v,
|
||||
HE_vert *vertices,
|
||||
int32_t *vc)
|
||||
{
|
||||
uint8_t const xpos = 1;
|
||||
uint8_t const ypos = 2;
|
||||
uint8_t const zpos = 3;
|
||||
int8_t const default_col = -1;
|
||||
|
||||
*vc = 0;
|
||||
|
||||
while (obj_v[*vc]) {
|
||||
vector *tmp_vec;
|
||||
|
||||
if (obj_v[*vc][0] > 3)
|
||||
ABORT("Failure in parse_obj(),\n"
|
||||
"malformed vertice, exceeds 3 dimensions!\n");
|
||||
|
||||
tmp_vec = malloc(sizeof(vector));
|
||||
CHECK_PTR_VAL(tmp_vec);
|
||||
|
||||
tmp_vec->x = obj_v[*vc][xpos];
|
||||
tmp_vec->y = obj_v[*vc][ypos];
|
||||
tmp_vec->z = obj_v[*vc][zpos];
|
||||
|
||||
vertices[*vc].vec = tmp_vec;
|
||||
|
||||
/* set unused/unknown values to NULL */
|
||||
vertices[*vc].edge = NULL;
|
||||
vertices[*vc].edge_array = NULL;
|
||||
vertices[*vc].eac = 0;
|
||||
vertices[*vc].dc = 0;
|
||||
|
||||
/* allocate color struct and set preliminary colors */
|
||||
vertices[*vc].col = malloc(sizeof(color));
|
||||
vertices[*vc].col->red = default_col;
|
||||
vertices[*vc].col->green = default_col;
|
||||
vertices[*vc].col->blue = default_col;
|
||||
|
||||
(*vc)++;
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Second stage of assembling the half-edge data structure.
|
||||
* Here we start creating the HE_edges and HE_faces and also
|
||||
* fill some missing information to the HE_verts along with it.
|
||||
* The edge pairs are still unknown, as well as some other
|
||||
* acceleration-structure related members like vertice->dummys.
|
||||
* This function isn't really modular, but makes
|
||||
* reading parse_obj() a bit less painful.
|
||||
*
|
||||
* @param obj_f the raw faces as they are after parsing the obj file
|
||||
* @param vertices the half-edge vertices
|
||||
* @param faces the half-edge faces
|
||||
* @param edges the half-edge edges
|
||||
* @param fc the count of half-edge faces
|
||||
* @param ec the count of half-edge edges
|
||||
*/
|
||||
static void assemble_HE_stage2(FACES obj_f,
|
||||
HE_vert *vertices,
|
||||
HE_face *faces,
|
||||
HE_edge *edges,
|
||||
int32_t *fc,
|
||||
int32_t *ec)
|
||||
{
|
||||
*ec = 0;
|
||||
/* create HE_edges and real HE_faces */
|
||||
for (uint32_t i = 0; i < (uint32_t)(*fc); i++) { /* for all faces */
|
||||
|
||||
/* for all vertices of the face */
|
||||
for (uint32_t j = 0; j < (uint32_t)obj_f[i][0]; j++) {
|
||||
uint32_t obj_f_pos = j + 1; /* first pos is reserved for length */
|
||||
uint32_t fv_arr_id =
|
||||
obj_f[i][obj_f_pos] - 1; /* fv_id starts at 1 */
|
||||
|
||||
edges[*ec].vert = &(vertices[fv_arr_id]);
|
||||
edges[*ec].face = &(faces[i]);
|
||||
edges[*ec].pair = NULL; /* preliminary */
|
||||
vertices[fv_arr_id].edge = &(edges[*ec]); /* last one wins */
|
||||
vertices[fv_arr_id].dummys = NULL; /* preliminary */
|
||||
|
||||
/* Skip j == 0 here, so we don't underrun the arrays,
|
||||
* since we always look one edge back. The first edge
|
||||
* element is taken care of below as well. */
|
||||
if (j > 0) {
|
||||
uint32_t *eac = &(edges[*ec].vert->eac);
|
||||
|
||||
/* connect previous edge to current edge */
|
||||
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 */
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Third stage of assembling the half-edge data structure.
|
||||
* Here we find the pairs of edges and also account for the
|
||||
* possibility of border-edges, where we have to set up
|
||||
* dummy edges and connect them properly.
|
||||
*
|
||||
* @param edges the half-edge edges
|
||||
* @param ec the half-edge edges count
|
||||
* @param dec the dummy edges count
|
||||
*/
|
||||
static void assemble_HE_stage3(HE_edge *edges,
|
||||
int32_t *ec,
|
||||
int32_t *dec)
|
||||
{
|
||||
/* 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;
|
||||
|
||||
pair_found = true;
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
/* create dummy pair edge if we have a border edge */
|
||||
if (!pair_found) {
|
||||
uint32_t *vert_dc = &(edges[i].next->vert->dc);
|
||||
|
||||
REALLOC(edges[i].next->vert->dummys,
|
||||
sizeof(HE_edge*) * (*vert_dc + 1));
|
||||
|
||||
/* NULL-face indicates border-edge */
|
||||
edges[*ec + *dec].face = NULL;
|
||||
/* we don't know this one yet */
|
||||
edges[*ec + *dec].next = NULL;
|
||||
/* set both pairs */
|
||||
edges[*ec + *dec].pair = &(edges[i]);
|
||||
edges[i].pair = &(edges[*ec + *dec]);
|
||||
/* set vertex */
|
||||
edges[*ec + *dec].vert = edges[i].next->vert;
|
||||
/* add the dummy edge to the dummys array of the vertex */
|
||||
edges[*ec + *dec].vert->dummys[*vert_dc] = &(edges[*ec + *dec]);
|
||||
(*vert_dc)++;
|
||||
|
||||
(*dec)++;
|
||||
}
|
||||
}
|
||||
|
||||
/* now we have to connect the dummy edges together */
|
||||
for (uint32_t i = 0; i < (uint32_t) (*dec); i++) { /* for all dummy edges */
|
||||
/* vertex the dummy edge points to */
|
||||
HE_vert *vert = edges[*ec + i].pair->vert;
|
||||
|
||||
/* iterate over the dummy array */
|
||||
for (uint32_t j = 0; j < vert->dc; j++) {
|
||||
if (vert == vert->dummys[j]->vert)
|
||||
edges[*ec + i].next = vert->dummys[j];
|
||||
j++;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Parse an .obj string and return a HE_obj
|
||||
* that represents the whole object.
|
||||
*
|
||||
* @param obj_string the whole string from the .obj file
|
||||
* @return the HE_face array that represents the object, NULL
|
||||
* on failure
|
||||
*/
|
||||
HE_obj *parse_obj(char const * const obj_string)
|
||||
{
|
||||
int32_t vc = 0, /* vertices count */
|
||||
fc = 0, /* face count */
|
||||
ec = 0, /* edge count */
|
||||
dec = 0; /* dummy edge count */
|
||||
char *string = NULL;
|
||||
HE_vert *vertices = NULL;
|
||||
HE_edge *edges = NULL;
|
||||
HE_face *faces = NULL;
|
||||
HE_obj *obj = NULL;
|
||||
FACES obj_f = NULL;
|
||||
/* V_TEXTURES obj_vt = NULL; */
|
||||
VERTICES obj_v = NULL;
|
||||
|
||||
if (!obj_string || !*obj_string)
|
||||
return NULL;
|
||||
|
||||
string = malloc(sizeof(char) * strlen(obj_string) + 1);
|
||||
strcpy(string, obj_string);
|
||||
|
||||
obj_v = parse_2d_array(string, "v");
|
||||
/* obj_vt = parse_2d_array(obj_string, "vt"); */
|
||||
obj_f = parse_face_array(string);
|
||||
|
||||
if ((ec = get_edge_count(obj_f)) == -1)
|
||||
ABORT("Invalid edge count!\n");
|
||||
if ((fc = get_face_count(obj_f)) == -1)
|
||||
ABORT("Invalid face count!\n");
|
||||
|
||||
vertices = malloc(sizeof(HE_vert) *
|
||||
get_row_count((int32_t const**)obj_v) + 1);
|
||||
CHECK_PTR_VAL(vertices);
|
||||
faces = (HE_face*) malloc(sizeof(HE_face) * fc);
|
||||
CHECK_PTR_VAL(faces);
|
||||
/* hold enough space for possible dummy edges */
|
||||
edges = (HE_edge*) malloc(sizeof(HE_edge) * ec * 2);
|
||||
CHECK_PTR_VAL(edges);
|
||||
|
||||
assemble_HE_stage1(obj_v, vertices, &vc);
|
||||
assemble_HE_stage2(obj_f, vertices, faces, edges, &fc, &ec);
|
||||
assemble_HE_stage3(edges, &ec, &dec);
|
||||
|
||||
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;
|
||||
|
||||
/* cleanup */
|
||||
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(vertices[i].dummys);
|
||||
free(vertices[i].edge_array);
|
||||
free(obj_v[i]);
|
||||
}
|
||||
free(obj_v);
|
||||
free(string);
|
||||
|
||||
return obj;
|
||||
}
|
||||
Loading…
Reference in New Issue