From: John Tsiombikas <nuclear@mutantstargoat.com>
Date: Tue, 11 Oct 2016 11:35:11 +0000 (+0300)
Subject: parser sortof-works
X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?p=antikythera;a=commitdiff_plain;h=6879b81017c2662b0c5a0b9027df8cf13b10545a

parser sortof-works
---

diff --git a/src/machine.cc b/src/machine.cc
index 3d4dd73..441826e 100644
--- a/src/machine.cc
+++ b/src/machine.cc
@@ -47,6 +47,15 @@ void Machine::add_motor(int gearidx, float speed_hz)
 	motors.push_back(m);
 }
 
+int Machine::get_gear_index(Gear *g) const
+{
+	std::map<Gear*, int>::const_iterator it = gearidx.find(g);
+	if(it == gearidx.end()) {
+		return -1;
+	}
+	return it->second;
+}
+
 void Machine::invalidate_meshing()
 {
 	meshing_valid = false;
diff --git a/src/machine.h b/src/machine.h
index e0f2155..097157d 100644
--- a/src/machine.h
+++ b/src/machine.h
@@ -29,6 +29,8 @@ public:
 	void add_gear(Gear *g);	/* takes ownership */
 	void add_motor(int gearidx, float speed_hz);
 
+	int get_gear_index(Gear *g) const;
+
 	void invalidate_meshing();
 	void calc_meshing();
 
diff --git a/src/main.cc b/src/main.cc
index 772b63c..2aec0a0 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -13,6 +13,7 @@
 #include "texture.h"
 #include "machine.h"
 #include "meshgen.h"
+#include "mparser.h"
 
 static bool init();
 static void cleanup();
@@ -88,7 +89,12 @@ static bool init()
 	Mesh::use_custom_sdr_attr = false;
 
 	machine = new Machine;
+	if(!parse_machine(machine, "data/test.machine")) {
+		fprintf(stderr, "failed to parse machine\n");
+		return false;
+	}
 
+	/*
 	const float pitch = 10.0f;
 
 	Gear *gear1 = new Gear;
@@ -119,6 +125,7 @@ static bool init()
 	gear2->attach(subgear);
 	machine->add_gear(subgear);
 	subgear->color = Vec3(0.8, 0.7, 0.5);
+	*/
 
 	machine->add_motor(0, 1.0);
 
diff --git a/src/mparser.cc b/src/mparser.cc
index 90c1b6d..10ea6ba 100644
--- a/src/mparser.cc
+++ b/src/mparser.cc
@@ -1,3 +1,6 @@
+#include <stdio.h>
+#include <stdarg.h>
+#include <assert.h>
 #include <string>
 #include <map>
 #include <stack>
@@ -7,10 +10,19 @@
 enum ValueType { VAL_NUM, VAL_VEC, VAL_STR };
 struct Value {
 	ValueType type;
-	char *str;
+	std::string s;
 	float v[4];
 };
 
+struct ParserState;
+
+typedef bool (*Func)(ParserState*);
+
+struct FuncDesc {
+	Func func;
+	int arity;
+};
+
 struct ParserState {
 	FILE *fp;
 	const char *fname;
@@ -22,9 +34,11 @@ struct ParserState {
 
 	std::stack<Value> val;
 	std::map<std::string, Value> var;
-	std::string last_mod_var;
+	std::map<std::string, FuncDesc> func;
 
 	std::map<std::string, Gear*> gears;
+	std::stack<Gear*> cur_gear;
+	Motor *cur_motor;
 };
 
 #define MAX_ID_LEN	31
@@ -32,24 +46,43 @@ struct ParserState {
 static bool machine(ParserState *ps);
 static bool expect(ParserState *ps, char c);
 static bool statement(ParserState *ps);
-static bool ident(ParserState *ps, std::string *s);
-static bool gear(ParserState *ps);
 static bool expression(ParserState *ps);
+static bool term(ParserState *ps);
+static bool vector(ParserState *ps);
+static bool function(ParserState *ps, const char *name);
 
 static char *get_ident(ParserState *ps, char *buf, int bsz);
+static bool get_number(ParserState *ps, float *num);
+static char *get_string(ParserState *ps, char *buf, int bsz);
 
 static bool nextchar(ParserState *ps);
 static void putback(ParserState *ps, char c);
 
+static void errmsg(ParserState *ps, const char *fmt, ...);
 static void expected(ParserState *ps, const char *str);
 
 static void set_var(ParserState *ps, const char *name, const Value &value);
 static bool have_var(ParserState *ps, const char *name);
 static const Value &get_var(ParserState *ps, const char *name);
 
+static void set_func(ParserState *ps, const char *name, Func func, int nargs = 0);
+static bool have_func(ParserState *ps, const char *name);
+static Func get_func(ParserState *ps, const char *name);
+static int get_func_arity(ParserState *ps, const char *name);
+
+static Gear *begin_gear(ParserState *ps);
+static bool end_gear(ParserState *ps);
+static Gear *this_gear(ParserState *ps);
 static void update_gear_vars(ParserState *ps, Gear *gear);
 static bool set_gear_var(Gear *gear, const char *name, const Value &val);
 
+static void update_motor_vars(ParserState *ps, Motor *motor);
+static bool set_motor_var(ParserState *ps, Motor *motor, const char *name, const Value &val);
+
+// built-in functions
+static bool func_adjacent(ParserState *ps);
+
+
 bool parse_machine(Machine *mcn, const char *fname)
 {
 	FILE *fp = fopen(fname, "rb");
@@ -61,9 +94,14 @@ bool parse_machine(Machine *mcn, const char *fname)
 	pstate.nerrors = 0;
 	pstate.fp = fp;
 	pstate.mcn = mcn;
-	pstate.nextc = fgetc(fp);	// prime the parser
+	pstate.nextc = 0;
 	pstate.savedc = -1;
+	pstate.cur_motor = 0;
+
+	// init built-in function table
+	set_func(&pstate, "adjacent", func_adjacent, 2);
 
+	nextchar(&pstate);
 	bool res = machine(&pstate);
 	fclose(fp);
 	return res;
@@ -87,7 +125,7 @@ static bool machine(ParserState *ps)
 	return true;
 }
 
-static bool expect(ParserState *ps, int c)
+static bool expect(ParserState *ps, char c)
 {
 	if(c != ps->nextc) {
 		char buf[2] = {0, 0};
@@ -107,26 +145,51 @@ static bool statement(ParserState *ps)
 	}
 
 	if(strcmp(id, "gear") == 0) {
-		if(!get_ident(ps, id, sizeof id)) {
-			fprintf(stderr, "gear name missing\n");
+		if(!expect(ps, '{')) {
 			return false;
 		}
-		expect(ps, '{');
 
-		Gear *gear = new Gear;
-		gear->name = id;
-		ps->gears[id] = gear;
+		Gear *gear = begin_gear(ps);
+		if(!gear) return false;
+
 		update_gear_vars(ps, gear);
 
 		while(ps->nextc != '}') {
 			if(!statement(ps)) {
 				return false;
 			}
-			update_gear_vars(ps, gear);
 		}
 		expect(ps, '}');
 
-		ps->mcn->add_gear(gear);
+		if(!end_gear(ps)) {
+			return false;
+		}
+		return true;
+	}
+
+	if(strcmp(id, "motor") == 0) {
+		if(!expect(ps, '{')) {
+			return false;
+		}
+		if(ps->cur_motor) {
+			errmsg(ps, "nested motors not allowed");
+			return false;
+		}
+
+		ps->cur_motor = new Motor;
+		update_motor_vars(ps, ps->cur_motor);
+
+		while(ps->nextc != '}') {
+			if(!statement(ps)) {
+				return false;
+			}
+		}
+		expect(ps, '}');
+
+		ps->mcn->add_motor(ps->cur_motor->drive, ps->cur_motor->speed);
+		delete ps->cur_motor;
+		ps->cur_motor = 0;
+		return true;
 	}
 
 	if(ps->nextc == '=') {
@@ -138,13 +201,172 @@ static bool statement(ParserState *ps)
 
 		set_var(ps, id, ps->val.top());
 		ps->val.pop();
-		ps->last_mod_var = id;
+		return true;
 	}
+
+	expected(ps, "expression");
+	return false;
 }
 
 static bool expression(ParserState *ps)
 {
-	// TODO
+	return term(ps);
+}
+
+static bool term(ParserState *ps)
+{
+	if(ps->nextc == '+') {
+		expect(ps, '+');
+		return expression(ps);
+	}
+	if(ps->nextc == '-') {
+		expect(ps, '-');
+		if(!expression(ps)) {
+			return false;
+		}
+
+		Value &v = ps->val.top();
+		switch(v.type) {
+		case VAL_VEC:
+			v.v[3] = -v.v[3];
+			v.v[2] = -v.v[2];
+			v.v[1] = -v.v[1];
+		case VAL_NUM:
+			v.v[0] = -v.v[0];
+			break;
+
+		default:
+			expected(ps, "number or vector after an unary -");
+			return false;
+		}
+		return true;
+	}
+	if(isalpha(ps->nextc)) {
+		char buf[MAX_ID_LEN];
+		if(!get_ident(ps, buf, sizeof buf)) {
+			return false;
+		}
+
+		if(ps->nextc == '(') {
+			if(!function(ps, buf)) {
+				return false;
+			}
+		} else if(have_var(ps, buf)) {
+			ps->val.push(get_var(ps, buf));
+		} else {
+			errmsg(ps, "unknown identifier: %s", buf);
+			return false;
+		}
+		return true;
+	}
+	if(isdigit(ps->nextc)) {
+		float num;
+		if(!get_number(ps, &num)) {
+			return false;
+		}
+
+		Value v;
+		v.type = VAL_NUM;
+		v.v[0] = num;
+		ps->val.push(v);
+		return true;
+	}
+	if(ps->nextc == '[') {
+		return vector(ps);
+	}
+	if(ps->nextc == '"') {
+		char buf[MAX_ID_LEN];
+		if(!get_string(ps, buf, sizeof buf)) {
+			return false;
+		}
+
+		Value v;
+		v.type = VAL_STR;
+		v.s = buf;
+		ps->val.push(v);
+		return true;
+	}
+
+	expected(ps, "term");
+	return false;
+}
+
+static bool vector(ParserState *ps)
+{
+	int nelem;
+	if(!expect(ps, '[') ||
+			!expression(ps) ||
+			!expect(ps, ',') ||
+			!expression(ps) ||
+			!expect(ps, ',') ||
+			!expression(ps)) {
+		return false;
+	}
+
+	if(ps->nextc == ']') {
+		expect(ps, ']');
+		nelem = 3;
+	} else {
+		if(!expect(ps, ',') || !expression(ps) || !expect(ps, ']')) {
+			return false;
+		}
+		nelem = 4;
+	}
+
+	Value vec;
+	vec.type = VAL_VEC;
+	vec.v[3] = 1.0f;
+
+	for(int i=0; i<nelem; i++) {
+		const Value &tmp = ps->val.top();
+		if(tmp.type != VAL_NUM) {
+			expected(ps, "numbers as vector elements");
+			return false;
+		}
+		vec.v[i] = tmp.v[0];
+		ps->val.pop();
+	}
+
+	ps->val.push(vec);
+	return true;
+}
+
+static bool function(ParserState *ps, const char *name)
+{
+	if(!expect(ps, '(')) {
+		return false;
+	}
+
+	if(!have_func(ps, name)) {
+		errmsg(ps, "unknown function: %s", name);
+		return false;
+	}
+
+	int nargs = 0;
+	while(ps->nextc != ')') {
+		if(nargs && !expect(ps, ',')) {
+			return false;
+		}
+		if(!expression(ps)) {
+			return false;
+		}
+		++nargs;
+	}
+	expect(ps, ')');
+
+	int arity = get_func_arity(ps, name);
+	if(arity != nargs) {
+		errmsg(ps, "function %s expects %d arguments", name, arity);
+		return false;
+	}
+	Func func = get_func(ps, name);
+	assert(func);
+
+	if(!func(ps)) {
+		errmsg(ps, "function %s failed", name);
+		return false;
+	}
+	return true;
 }
 
 static char *get_ident(ParserState *ps, char *buf, int bsz)
@@ -154,7 +376,7 @@ static char *get_ident(ParserState *ps, char *buf, int bsz)
 		expected(ps, "identifier");
 		return 0;
 	}
-	while((isalnum(ps->nextc) || ps->nextc == '_')) {
+	while(isalnum(ps->nextc) || ps->nextc == '_') {
 		if(bsz > 1) {
 			*ptr++ = ps->nextc;
 			--bsz;
@@ -162,14 +384,72 @@ static char *get_ident(ParserState *ps, char *buf, int bsz)
 		nextchar(ps);
 	}
 	*ptr = 0;
+	printf("get_ident -> \"%s\"\n", buf);
+	return buf;
+}
+
+static bool get_number(ParserState *ps, float *num)
+{
+	char buf[256], *ptr = buf, *end = buf + sizeof buf;
+	bool found_point = false;
+
+	if(!isdigit(ps->nextc)) {
+		expected(ps, "number");
+		return false;
+	}
+
+	while(isdigit(ps->nextc) || (ps->nextc == '.' && !found_point)) {
+		if(ptr < end) {
+			*ptr++ = ps->nextc;
+		}
+		if(ps->nextc == '.') {
+			found_point = true;
+		}
+		nextchar(ps);
+	}
+	*ptr = 0;
+
+	*num = atof(buf);
+	printf("get_number -> %f\n", *num);
+	return true;
+}
+
+static char *get_string(ParserState *ps, char *buf, int bsz)
+{
+	char *ptr = buf;
+	if(!expect(ps, '"')) {
+		return 0;
+	}
+
+	while(ps->nextc != -1 && ps->nextc != '"') {
+		if(bsz > 1) {
+			*ptr++ = ps->nextc;
+			--bsz;
+		}
+		if((ps->nextc = fgetc(ps->fp)) == '\n') {
+			++ps->nline;
+		}
+	}
+	*ptr = 0;
+
+	if(ps->nextc == -1) {
+		return 0;
+	}
+	nextchar(ps);
+
+	printf("get_string -> \"%s\"\n", buf);
 	return buf;
 }
 
-static bool skip_line(FILE *fp)
+static bool skip_line(ParserState *ps)
 {
 	int c;
-	while((c = fgetc(fp)) != -1 && c != '\n');
-	return c != -1;
+	while((c = fgetc(ps->fp)) != -1 && c != '\n');
+	if(c != -1) {
+		ps->nextc = fgetc(ps->fp);
+		return true;
+	}
+	return false;
 }
 
 static bool nextchar(ParserState *ps)
@@ -182,7 +462,7 @@ static bool nextchar(ParserState *ps)
 
 	while((ps->nextc = fgetc(ps->fp)) != -1) {
 		if(ps->nextc == '#') {
-			if(!skip_line(ps->fp)) {
+			if(!skip_line(ps)) {
 				return false;
 			}
 			++ps->nline;
@@ -195,6 +475,11 @@ static bool nextchar(ParserState *ps)
 		}
 	}
 
+	/*if(ps->nextc != -1) {
+		printf("DBG: nextchar -> %c\n", ps->nextc);
+	} else {
+		printf("DBG: nextchar -> EOF\n");
+	}*/
 	return ps->nextc != -1;
 }
 
@@ -204,15 +489,36 @@ static void putback(ParserState *ps, char c)
 	ps->nextc = c;
 }
 
+static void errmsg(ParserState *ps, const char *fmt, ...)
+{
+	fprintf(stderr, "%s line %d error: ", ps->fname, ps->nline);
+
+	va_list ap;
+	va_start(ap, fmt);
+	vfprintf(stderr, fmt, ap);
+	va_end(ap);
+
+	fputc('\n', stderr);
+}
+
 static void expected(ParserState *ps, const char *str)
 {
-	fprintf(stderr, "%s line %d error, expected: %s\n", ps->fname, ps->nline, str);
+	errmsg(ps, "expected: %s", str);
 	++ps->nerrors;
 }
 
 static void set_var(ParserState *ps, const char *name, const Value &value)
 {
 	ps->var[name] = value;
+
+	Gear *gear = this_gear(ps);
+	if(gear) {
+		set_gear_var(gear, name, value);
+	}
+
+	if(ps->cur_motor) {
+		set_motor_var(ps, ps->cur_motor, name, value);
+	}
 }
 
 static bool have_var(ParserState *ps, const char *name)
@@ -225,6 +531,29 @@ static const Value &get_var(ParserState *ps, const char *name)
 	return ps->var[name];
 }
 
+static void set_func(ParserState *ps, const char *name, Func func, int nargs)
+{
+	FuncDesc fdesc;
+	fdesc.func = func;
+	fdesc.arity = nargs;
+	ps->func[name] = fdesc;
+}
+
+static bool have_func(ParserState *ps, const char *name)
+{
+	return ps->func.find(name) != ps->func.end();
+}
+
+static Func get_func(ParserState *ps, const char *name)
+{
+	return ps->func[name].func;
+}
+
+static int get_func_arity(ParserState *ps, const char *name)
+{
+	return ps->func[name].arity;
+}
+
 static void print_value(const Value &val, FILE *fp)
 {
 	switch(val.type) {
@@ -237,7 +566,7 @@ static void print_value(const Value &val, FILE *fp)
 		break;
 
 	case VAL_STR:
-		fprintf(fp, "\"%s\"", val.str);
+		fprintf(fp, "\"%s\"", val.s.c_str());
 		break;
 
 	default:
@@ -247,15 +576,42 @@ static void print_value(const Value &val, FILE *fp)
 
 // Gear-specific stuff
 
-static void update_gear_vars(ParserState *ps, Gear *gear)
+static Gear *begin_gear(ParserState *ps)
+{
+	Gear *res = new Gear;
+	ps->cur_gear.push(res);
+	return res;
+}
+
+static bool end_gear(ParserState *ps)
 {
-	if(!ps->last_mod_var.empty()) {
-		const char *name = ps->last_mod_var.c_str();
-		set_gear_var(gear, name, get_var(ps, name));
-		ps->last_mod_var.clear();
-		return;
+	if(ps->cur_gear.empty()) {
+		errmsg(ps, "parser error: unbalanced end_gear");
+		return false;
+	}
+	Gear *gear = ps->cur_gear.top();
+	ps->cur_gear.pop();
+
+	printf("DBG: end_gear: %s\n", gear->name.c_str());
+
+	if(gear->name.empty() || ps->gears[gear->name]) {
+		char buf[32];
+		sprintf(buf, "gear%04d", (int)ps->gears.size());
+		gear->name = buf;
 	}
+	printf("DBG: adding gear: %s\n", gear->name.c_str());
+	ps->gears[gear->name] = gear;
+	ps->mcn->add_gear(gear);
+	return true;
+}
 
+static Gear *this_gear(ParserState *ps)
+{
+	return ps->cur_gear.empty() ? 0 : ps->cur_gear.top();
+}
+
+static void update_gear_vars(ParserState *ps, Gear *gear)
+{
 	std::map<std::string, Value>::const_iterator it = ps->var.begin();
 	while(it != ps->var.end()) {
 		set_gear_var(gear, it->first.c_str(), it->second);
@@ -263,7 +619,6 @@ static void update_gear_vars(ParserState *ps, Gear *gear)
 	}
 }
 
-
 #define ASSERT_TYPE(v, t) \
 	do { \
 		if((v).type != (t)) { \
@@ -279,7 +634,11 @@ static void update_gear_vars(ParserState *ps, Gear *gear)
 
 static bool set_gear_var(Gear *gear, const char *name, const Value &val)
 {
-	if(strcmp(name, "position") == 0) {
+	if(strcmp(name, "name") == 0) {
+		ASSERT_TYPE(val, VAL_STR);
+		gear->name = val.s;
+
+	} else if(strcmp(name, "position") == 0) {
 		ASSERT_TYPE(val, VAL_VEC);
 		gear->pos = VVEC3(val);
 
@@ -318,3 +677,81 @@ static bool set_gear_var(Gear *gear, const char *name, const Value &val)
 
 	return true;
 }
+
+
+// motor stuff
+
+static void update_motor_vars(ParserState *ps, Motor *motor)
+{
+	std::map<std::string, Value>::const_iterator it = ps->var.begin();
+	while(it != ps->var.end()) {
+		set_motor_var(ps, motor, it->first.c_str(), it->second);
+		++it;
+	}
+}
+
+static bool set_motor_var(ParserState *ps, Motor *motor, const char *name, const Value &val)
+{
+	if(strcmp(name, "drive") == 0) {
+		ASSERT_TYPE(val, VAL_STR);
+		Gear *gear = ps->gears[val.s];
+		if(!gear) {
+			errmsg(ps, "undefined gear: %s", val.s.c_str());
+			return false;
+		}
+		int idx = ps->mcn->get_gear_index(gear);
+		assert(idx >= 0);
+		motor->drive = idx;
+
+	} else if(strcmp(name, "speed") == 0) {
+		ASSERT_TYPE(val, VAL_NUM);
+		motor->speed = val.v[0];
+
+	} else {
+		return false;
+	}
+	return true;
+}
+
+
+// built-in functions
+static bool func_adjacent(ParserState *ps)
+{
+	Value val_dir = ps->val.top(); ps->val.pop();
+	Value val_gear_name = ps->val.top(); ps->val.pop();
+
+	if(val_gear_name.type != VAL_STR) {
+		expected(ps, "gear name (string) as 1st arg to adjacent");
+		return false;
+	}
+	if(val_dir.type != VAL_VEC) {
+		expected(ps, "direction vector as 2nd arg to adjacent");
+		return false;
+	}
+
+	Gear *gthis = this_gear(ps);
+	if(!gthis) {
+		errmsg(ps, "adjacent: called outside of a gear block");
+		return false;
+	}
+
+	Gear *gother = ps->gears[val_gear_name.s];
+	if(!gother) {
+		errmsg(ps, "adjacent: gear \"%s\" not found", val_gear_name.s.c_str());
+		return false;
+	}
+
+	Vec3 dir = Vec3(val_dir.v[0], val_dir.v[1], val_dir.v[2]);
+
+	float sum_radii = gthis->radius + gother->radius;
+	float avg_teeth_len = (gthis->teeth_length + gother->teeth_length) * 0.5;
+	Vec3 pos = gother->pos + normalize(dir) * (sum_radii - avg_teeth_len * 0.75);
+
+	Value res;
+	res.type = VAL_VEC;
+	res.v[0] = pos.x;
+	res.v[1] = pos.y;
+	res.v[2] = pos.z;
+	ps->val.push(res);
+	return true;
+}