10 enum ValueType { VAL_NUM, VAL_VEC, VAL_STR };
19 typedef bool (*Func)(ParserState*);
35 std::stack<Value> val;
36 std::map<std::string, Value> var;
37 std::map<std::string, FuncDesc> func;
39 std::map<std::string, Gear*> gears;
40 std::stack<Gear*> cur_gear;
46 static bool machine(ParserState *ps);
47 static bool expect(ParserState *ps, char c);
48 static bool statement(ParserState *ps);
49 static bool expression(ParserState *ps);
50 static bool term(ParserState *ps);
51 static bool vector(ParserState *ps);
52 static bool function(ParserState *ps, const char *name);
54 static char *get_ident(ParserState *ps, char *buf, int bsz);
55 static bool get_number(ParserState *ps, float *num);
56 static char *get_string(ParserState *ps, char *buf, int bsz);
58 static bool nextchar(ParserState *ps);
59 static void putback(ParserState *ps, char c);
61 static void errmsg(ParserState *ps, const char *fmt, ...);
62 static void expected(ParserState *ps, const char *str);
64 static void set_var(ParserState *ps, const char *name, const Value &value);
65 static bool have_var(ParserState *ps, const char *name);
66 static const Value &get_var(ParserState *ps, const char *name);
68 static void set_func(ParserState *ps, const char *name, Func func, int nargs = 0);
69 static bool have_func(ParserState *ps, const char *name);
70 static Func get_func(ParserState *ps, const char *name);
71 static int get_func_arity(ParserState *ps, const char *name);
73 static Gear *begin_gear(ParserState *ps);
74 static bool end_gear(ParserState *ps);
75 static Gear *this_gear(ParserState *ps);
76 static void update_gear_vars(ParserState *ps, Gear *gear);
77 static bool set_gear_var(Gear *gear, const char *name, const Value &val);
79 static void update_motor_vars(ParserState *ps, Motor *motor);
80 static bool set_motor_var(ParserState *ps, Motor *motor, const char *name, const Value &val);
83 static bool func_adjacent(ParserState *ps);
84 static bool func_coaxial(ParserState *ps);
87 bool parse_machine(Machine *mcn, const char *fname)
89 FILE *fp = fopen(fname, "rb");
100 pstate.cur_motor = 0;
102 // init built-in function table
103 set_func(&pstate, "adjacent", func_adjacent, 2);
104 set_func(&pstate, "coaxial", func_coaxial, 2);
107 bool res = machine(&pstate);
112 static bool machine(ParserState *ps)
114 char tok[MAX_ID_LEN + 1];
115 if(strcmp(get_ident(ps, tok, sizeof tok), "machine") != 0) {
116 expected(ps, "machine");
121 while(ps->nextc != '}') {
130 static bool expect(ParserState *ps, char c)
133 char buf[2] = {0, 0};
142 static bool statement(ParserState *ps)
144 char id[MAX_ID_LEN + 1];
145 if(!get_ident(ps, id, sizeof id)) {
149 if(strcmp(id, "gear") == 0) {
150 if(!expect(ps, '{')) {
154 Gear *gear = begin_gear(ps);
155 if(!gear) return false;
157 update_gear_vars(ps, gear);
159 while(ps->nextc != '}') {
172 if(strcmp(id, "motor") == 0) {
173 if(!expect(ps, '{')) {
177 errmsg(ps, "nested motors not allowed");
181 ps->cur_motor = new Motor;
182 update_motor_vars(ps, ps->cur_motor);
184 while(ps->nextc != '}') {
191 ps->mcn->add_motor(ps->cur_motor->drive, ps->cur_motor->speed);
192 delete ps->cur_motor;
197 if(ps->nextc == '=') {
199 if(!expression(ps)) {
204 set_var(ps, id, ps->val.top());
209 expected(ps, "expression");
213 static bool expression(ParserState *ps)
218 static bool term(ParserState *ps)
220 if(ps->nextc == '+') {
222 return expression(ps);
224 if(ps->nextc == '-') {
226 if(!expression(ps)) {
230 Value &v = ps->val.top();
241 expected(ps, "number or vector after an unary -");
246 if(isalpha(ps->nextc)) {
247 char buf[MAX_ID_LEN];
248 if(!get_ident(ps, buf, sizeof buf)) {
252 if(ps->nextc == '(') {
253 if(!function(ps, buf)) {
256 } else if(have_var(ps, buf)) {
257 ps->val.push(get_var(ps, buf));
259 errmsg(ps, "unknown identifier: %s", buf);
264 if(isdigit(ps->nextc)) {
266 if(!get_number(ps, &num)) {
276 if(ps->nextc == '[') {
279 if(ps->nextc == '"') {
280 char buf[MAX_ID_LEN];
281 if(!get_string(ps, buf, sizeof buf)) {
292 expected(ps, "term");
296 static bool vector(ParserState *ps)
299 if(!expect(ps, '[') ||
308 if(ps->nextc == ']') {
312 if(!expect(ps, ',') || !expression(ps) || !expect(ps, ']')) {
322 for(int i=0; i<nelem; i++) {
323 const Value &tmp = ps->val.top();
324 if(tmp.type != VAL_NUM) {
325 expected(ps, "numbers as vector elements");
336 static bool function(ParserState *ps, const char *name)
338 if(!expect(ps, '(')) {
342 if(!have_func(ps, name)) {
343 errmsg(ps, "unknown function: %s", name);
348 while(ps->nextc != ')') {
349 if(nargs && !expect(ps, ',')) {
352 if(!expression(ps)) {
359 int arity = get_func_arity(ps, name);
361 errmsg(ps, "function %s expects %d arguments", name, arity);
364 Func func = get_func(ps, name);
368 errmsg(ps, "function %s failed", name);
374 static char *get_ident(ParserState *ps, char *buf, int bsz)
377 if(!isalpha(ps->nextc)) {
378 expected(ps, "identifier");
381 while(isalnum(ps->nextc) || ps->nextc == '_') {
389 printf("get_ident -> \"%s\"\n", buf);
393 static bool get_number(ParserState *ps, float *num)
395 char buf[256], *ptr = buf, *end = buf + sizeof buf;
396 bool found_point = false;
398 if(!isdigit(ps->nextc)) {
399 expected(ps, "number");
403 while(isdigit(ps->nextc) || (ps->nextc == '.' && !found_point)) {
407 if(ps->nextc == '.') {
415 printf("get_number -> %f\n", *num);
419 static char *get_string(ParserState *ps, char *buf, int bsz)
422 if(!expect(ps, '"')) {
426 while(ps->nextc != -1 && ps->nextc != '"') {
431 if((ps->nextc = fgetc(ps->fp)) == '\n') {
437 if(ps->nextc == -1) {
442 printf("get_string -> \"%s\"\n", buf);
446 static bool skip_line(ParserState *ps)
449 while((c = fgetc(ps->fp)) != -1 && c != '\n');
451 ps->nextc = fgetc(ps->fp);
457 static bool nextchar(ParserState *ps)
459 if(ps->savedc != -1) {
460 ps->nextc = ps->savedc;
465 while((ps->nextc = fgetc(ps->fp)) != -1) {
466 if(ps->nextc == '#') {
472 if(!isspace(ps->nextc)) {
475 if(ps->nextc == '\n') {
480 /*if(ps->nextc != -1) {
481 printf("DBG: nextchar -> %c\n", ps->nextc);
483 printf("DBG: nextchar -> EOF\n");
485 return ps->nextc != -1;
488 static void putback(ParserState *ps, char c)
490 ps->savedc = ps->nextc;
494 static void errmsg(ParserState *ps, const char *fmt, ...)
496 fprintf(stderr, "%s line %d error: ", ps->fname, ps->nline);
500 vfprintf(stderr, fmt, ap);
506 static void expected(ParserState *ps, const char *str)
508 errmsg(ps, "expected: %s", str);
512 static void set_var(ParserState *ps, const char *name, const Value &value)
514 ps->var[name] = value;
516 Gear *gear = this_gear(ps);
518 set_gear_var(gear, name, value);
522 set_motor_var(ps, ps->cur_motor, name, value);
526 static bool have_var(ParserState *ps, const char *name)
528 return ps->var.find(name) != ps->var.end();
531 static const Value &get_var(ParserState *ps, const char *name)
533 return ps->var[name];
536 static void set_func(ParserState *ps, const char *name, Func func, int nargs)
541 ps->func[name] = fdesc;
544 static bool have_func(ParserState *ps, const char *name)
546 return ps->func.find(name) != ps->func.end();
549 static Func get_func(ParserState *ps, const char *name)
551 return ps->func[name].func;
554 static int get_func_arity(ParserState *ps, const char *name)
556 return ps->func[name].arity;
559 static void print_value(const Value &val, FILE *fp)
563 fprintf(fp, "%f", val.v[0]);
567 fprintf(fp, "[%f %f %f %f]", val.v[0], val.v[1], val.v[2], val.v[3]);
571 fprintf(fp, "\"%s\"", val.s.c_str());
575 fprintf(fp, "<invalid>");
579 // Gear-specific stuff
581 static Gear *begin_gear(ParserState *ps)
583 Gear *res = new Gear;
584 ps->cur_gear.push(res);
588 static bool end_gear(ParserState *ps)
590 if(ps->cur_gear.empty()) {
591 errmsg(ps, "parser error: unbalanced end_gear");
594 Gear *gear = ps->cur_gear.top();
597 printf("DBG: end_gear: %s\n", gear->name.c_str());
599 if(gear->name.empty() || ps->gears[gear->name]) {
601 sprintf(buf, "gear%04d", (int)ps->gears.size());
604 printf("DBG: adding gear: %s\n", gear->name.c_str());
605 ps->gears[gear->name] = gear;
606 ps->mcn->add_gear(gear);
608 if(!ps->cur_gear.empty()) {
609 ps->cur_gear.top()->attach(gear);
614 static Gear *this_gear(ParserState *ps)
616 return ps->cur_gear.empty() ? 0 : ps->cur_gear.top();
619 static void update_gear_vars(ParserState *ps, Gear *gear)
621 std::map<std::string, Value>::const_iterator it = ps->var.begin();
622 while(it != ps->var.end()) {
623 set_gear_var(gear, it->first.c_str(), it->second);
628 #define ASSERT_TYPE(v, t) \
630 if((v).type != (t)) { \
631 fprintf(stderr, "type mismatch while trying to set %s to value: ", name); \
632 print_value(val, stderr); \
633 fputc('\n', stderr); \
638 #define VVEC3(val) Vec3((val).v[0], (val).v[1], (val).v[2])
639 #define VVEC4(val) Vec4((val).v[0], (val).v[1], (val).v[2], (val).v[3])
641 static bool set_gear_var(Gear *gear, const char *name, const Value &val)
643 if(strcmp(name, "name") == 0) {
644 ASSERT_TYPE(val, VAL_STR);
647 } else if(strcmp(name, "position") == 0) {
648 ASSERT_TYPE(val, VAL_VEC);
649 gear->pos = VVEC3(val);
651 } else if(strcmp(name, "plane") == 0) {
652 ASSERT_TYPE(val, VAL_VEC);
653 gear->axis = VVEC3(val);
654 gear->pdist = val.v[3];
656 } else if(strcmp(name, "thickness") == 0) {
657 ASSERT_TYPE(val, VAL_NUM);
658 gear->thickness = val.v[0];
660 } else if(strcmp(name, "teeth") == 0) {
661 ASSERT_TYPE(val, VAL_NUM);
662 gear->set_teeth(val.v[0]); // set teeth and recalc radius
664 } else if(strcmp(name, "teeth_length") == 0) {
665 ASSERT_TYPE(val, VAL_NUM);
666 gear->teeth_length = val.v[0];
668 } else if(strcmp(name, "pitch") == 0) {
669 ASSERT_TYPE(val, VAL_NUM);
670 gear->set_teeth(gear->nteeth, val.v[0]); // set pitch and recalc radius
672 } else if(strcmp(name, "color") == 0) {
673 ASSERT_TYPE(val, VAL_VEC);
674 gear->color = VVEC3(val);
676 } else if(strcmp(name, "roughness") == 0) {
677 ASSERT_TYPE(val, VAL_NUM);
678 gear->roughness = val.v[0];
690 static void update_motor_vars(ParserState *ps, Motor *motor)
692 std::map<std::string, Value>::const_iterator it = ps->var.begin();
693 while(it != ps->var.end()) {
694 set_motor_var(ps, motor, it->first.c_str(), it->second);
699 static bool set_motor_var(ParserState *ps, Motor *motor, const char *name, const Value &val)
701 if(strcmp(name, "drive") == 0) {
702 ASSERT_TYPE(val, VAL_STR);
703 Gear *gear = ps->gears[val.s];
705 errmsg(ps, "undefined gear: %s", val.s.c_str());
708 int idx = ps->mcn->get_gear_index(gear);
712 } else if(strcmp(name, "speed") == 0) {
713 ASSERT_TYPE(val, VAL_NUM);
714 motor->speed = val.v[0];
723 // built-in functions
724 static bool func_adjacent(ParserState *ps)
726 Value val_angle = ps->val.top(); ps->val.pop();
727 Value val_gear_name = ps->val.top(); ps->val.pop();
729 if(val_gear_name.type != VAL_STR) {
730 expected(ps, "gear name (string) as 1st arg to adjacent");
733 if(val_angle.type != VAL_NUM) {
734 expected(ps, "angle as 2nd arg to adjacent");
738 Gear *gthis = this_gear(ps);
740 errmsg(ps, "adjacent: called outside of a gear block");
744 Gear *gother = ps->gears[val_gear_name.s];
746 errmsg(ps, "adjacent: gear \"%s\" not found", val_gear_name.s.c_str());
751 xform.rotation(deg_to_rad(val_angle.v[0]), gother->axis);
752 Vec3 dir = xform * Vec3(0, 1, 0);
754 float sum_radii = gthis->radius + gother->radius;
755 float avg_teeth_len = (gthis->teeth_length + gother->teeth_length) * 0.5;
756 Vec3 pos = gother->pos + dir * (sum_radii - avg_teeth_len * 0.75);
767 static bool func_coaxial(ParserState *ps)
769 Value val_dist = ps->val.top(); ps->val.pop();
770 Value val_gear_name = ps->val.top(); ps->val.pop();
772 if(val_gear_name.type != VAL_STR) {
773 expected(ps, "gear name (string) as 1st arg to func_coaxial");
776 if(val_dist.type != VAL_NUM) {
777 expected(ps, "stacking distance as 2nd arg to func_coaxial");
781 Gear *gthis = this_gear(ps);
783 errmsg(ps, "coaxial: called outside of a gear block");
787 Gear *gother = ps->gears[val_gear_name.s];
789 errmsg(ps, "coaxial: gear \"%s\" not found", val_gear_name.s.c_str());
793 Vec3 pos = gother->pos + gother->axis * val_dist.v[0];