obj.c

#include "obj.h"
#include "data/format/scanner/scanner.h"
#include "files/helpers.h"

void push_idx(mesh *m, int trig){
    chunk_array_push(m->segments, &trig);
}

int handle_trig(mesh *mesh, string_slice sl){
    char *s1 = (char*)seek_to(sl.data, '/');
    int segment = (parse_int64(sl.data,s1-sl.data-1) & 0xFFFFFFFF) - 1;
    push_idx(mesh, segment);
    //TODO: extra trig data
    return segment;
}

void handle_obj_line(void *ctx, string_slice line){
    mesh *m = (mesh *)ctx;
    Scanner s = scanner_make(line.data, line.length);
    char first = scan_next(&s);
    if (first == 'v'){
        if (scan_next(&s) != ' ') return;//TODO: other options
        vector3 vector = {};
        string_slice v1 = scan_to(&s, ' ');
        if (!v1.length) return;
        vector.x = parse_float(v1.data, v1.length-1);
        string_slice v2 = scan_to(&s, ' ');
        if (!v2.length) return;
        vector.y = parse_float(v2.data, v2.length-1);
        string_slice v3 = scan_to(&s, ' ');
        if (!v3.length) return;
        vector.z = parse_float(v3.data, v3.length);
        chunk_array_push(m->vertices, &vector);
    }
    if (first == 'f'){
        if (scan_next(&s) != ' ') return;
        int first_s = -1;
        int last_s = -1;
        for (int i = 0; !scan_eof(&s); i++){
            string_slice sl = scan_to(&s, ' ');
            if (sl.length == 0) break;
            if (i > 2){
                push_idx(m, first_s);
                push_idx(m, last_s);
            }
            int seg = handle_trig(m, sl);
            if (i == 0) first_s = seg;
            last_s = seg;
        };
    }
}

mesh parse_obj(void* obj, size_t size, primitives prim_type){
    mesh m = {};
    m.vertices = chunk_array_create(sizeof(vector3), 1000);
    m.segments = chunk_array_create(sizeof(int), 1000);
    m.primitive_type = prim_type;
    read_lines(obj, &m, handle_obj_line);
    return m;
}