Refactor parse_obj() and move some subroutines to new functions
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parent
0ecd0d8e9f
commit
dfd978f714
316
src/half_edge.c
316
src/half_edge.c
@ -62,7 +62,18 @@ 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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@ -274,8 +285,28 @@ static FACES parse_face_array(char const * const obj_string)
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return arr;
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}
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static void fill_vertices(VERTICES obj_v, HE_vert *vertices, int32_t *vc)
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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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@ -288,9 +319,9 @@ static void fill_vertices(VERTICES obj_v, HE_vert *vertices, int32_t *vc)
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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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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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@ -302,14 +333,160 @@ static void fill_vertices(VERTICES obj_v, HE_vert *vertices, int32_t *vc)
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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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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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* to edge.
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@ -507,137 +684,26 @@ HE_obj *parse_obj(char const * const obj_string)
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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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int32_t count = get_row_count((int32_t const**)obj_v);
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vertices = malloc(sizeof(HE_vert) *
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count + 1);
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printf("row count %d\n", get_row_count((int32_t const**)obj_v));
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/* fill the vertices */
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fill_vertices(obj_v, vertices, &vc);
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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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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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/* 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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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);
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obj = (HE_obj*) malloc(sizeof(HE_obj));
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CHECK_PTR_VAL(obj);
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obj->edges = edges;
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obj->vertices = vertices;
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obj->faces = faces;
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@ -93,7 +93,7 @@ void print_faces(HE_obj *obj)
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* Print all plain unconverted faces
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* as they are saved in the .obj file.
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*
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* @param face the plain face struct
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* @param faces the plain faces
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* @param fc the count of faces
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*/
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void print_plain_faces(FACES faces, uint32_t fc)
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