refactoring
[laserbrain_demo] / src / machine / mparser.cc
diff --git a/src/machine/mparser.cc b/src/machine/mparser.cc
new file mode 100644 (file)
index 0000000..260b303
--- /dev/null
@@ -0,0 +1,819 @@
+#include <stdio.h>
+#include <stdarg.h>
+#include <assert.h>
+#include <string>
+#include <map>
+#include <stack>
+#include "mparser.h"
+#include "machine.h"
+
+enum ValueType { VAL_NUM, VAL_VEC, VAL_STR };
+struct Value {
+       ValueType type;
+       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;
+       int nline, nerrors;
+       Machine *mcn;
+
+       int nextc;
+       int savedc;
+
+       std::stack<Value> val;
+       std::map<std::string, Value> var;
+       std::map<std::string, FuncDesc> func;
+
+       std::map<std::string, Gear*> gears;
+       std::vector<Gear*> cur_gear;
+       Motor *cur_motor;
+};
+
+#define MAX_ID_LEN     31
+
+static bool machine(ParserState *ps);
+static bool expect(ParserState *ps, char c);
+static bool statement(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 Gear *find_gear(ParserState *ps, const char *name);
+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);
+static bool func_coaxial(ParserState *ps);
+
+
+bool parse_machine(Machine *mcn, const char *fname)
+{
+       FILE *fp = fopen(fname, "rb");
+       if(!fp) return false;
+
+       ParserState pstate;
+       pstate.fname = fname;
+       pstate.nline = 1;
+       pstate.nerrors = 0;
+       pstate.fp = fp;
+       pstate.mcn = mcn;
+       pstate.nextc = 0;
+       pstate.savedc = -1;
+       pstate.cur_motor = 0;
+
+       // init built-in function table
+       set_func(&pstate, "adjacent", func_adjacent, 2);
+       set_func(&pstate, "coaxial", func_coaxial, 2);
+
+       nextchar(&pstate);
+       bool res = machine(&pstate);
+       fclose(fp);
+       return res;
+}
+
+static bool machine(ParserState *ps)
+{
+       char tok[MAX_ID_LEN + 1];
+       if(strcmp(get_ident(ps, tok, sizeof tok), "machine") != 0) {
+               expected(ps, "machine");
+               return false;
+       }
+       expect(ps, '{');
+
+       while(ps->nextc != '}') {
+               if(!statement(ps)) {
+                       return false;
+               }
+       }
+       expect(ps, '}');
+       return true;
+}
+
+static bool expect(ParserState *ps, char c)
+{
+       if(c != ps->nextc) {
+               char buf[2] = {0, 0};
+               buf[0] = c;
+               expected(ps, buf);
+               return false;
+       }
+       nextchar(ps);
+       return true;
+}
+
+static bool statement(ParserState *ps)
+{
+       char id[MAX_ID_LEN + 1];
+       if(!get_ident(ps, id, sizeof id)) {
+               return false;
+       }
+
+       if(strcmp(id, "gear") == 0) {
+               if(!expect(ps, '{')) {
+                       return false;
+               }
+
+               Gear *gear = begin_gear(ps);
+               if(!gear) return false;
+
+               update_gear_vars(ps, gear);
+
+               while(ps->nextc != '}') {
+                       if(!statement(ps)) {
+                               return false;
+                       }
+               }
+               expect(ps, '}');
+
+               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 == '=') {
+               expect(ps, '=');
+               if(!expression(ps)) {
+                       return false;
+               }
+               expect(ps, ';');
+
+               set_var(ps, id, ps->val.top());
+               ps->val.pop();
+               return true;
+       }
+
+       expected(ps, "expression");
+       return false;
+}
+
+static bool expression(ParserState *ps)
+{
+       return term(ps);        // TODO expand
+}
+
+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[nelem - i - 1] = 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)
+{
+       char *ptr = buf;
+       if(!isalpha(ps->nextc)) {
+               expected(ps, "identifier");
+               return 0;
+       }
+       while(isalnum(ps->nextc) || ps->nextc == '_') {
+               if(bsz > 1) {
+                       *ptr++ = ps->nextc;
+                       --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(ParserState *ps)
+{
+       int c;
+       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)
+{
+       if(ps->savedc != -1) {
+               ps->nextc = ps->savedc;
+               ps->savedc = -1;
+               return true;
+       }
+
+       while((ps->nextc = fgetc(ps->fp)) != -1) {
+               if(ps->nextc == '#') {
+                       if(!skip_line(ps)) {
+                               return false;
+                       }
+                       ++ps->nline;
+               }
+               if(!isspace(ps->nextc)) {
+                       break;
+               }
+               if(ps->nextc == '\n') {
+                       ++ps->nline;
+               }
+       }
+
+       /*if(ps->nextc != -1) {
+               printf("DBG: nextchar -> %c\n", ps->nextc);
+       } else {
+               printf("DBG: nextchar -> EOF\n");
+       }*/
+       return ps->nextc != -1;
+}
+
+/*static void putback(ParserState *ps, char c)
+{
+       ps->savedc = ps->nextc;
+       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)
+{
+       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)
+{
+       return ps->var.find(name) != ps->var.end();
+}
+
+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) {
+       case VAL_NUM:
+               fprintf(fp, "%f", val.v[0]);
+               break;
+
+       case VAL_VEC:
+               fprintf(fp, "[%f %f %f %f]", val.v[0], val.v[1], val.v[2], val.v[3]);
+               break;
+
+       case VAL_STR:
+               fprintf(fp, "\"%s\"", val.s.c_str());
+               break;
+
+       default:
+               fprintf(fp, "<invalid>");
+       }
+}
+
+// Gear-specific stuff
+
+static Gear *begin_gear(ParserState *ps)
+{
+       Gear *res = new Gear;
+       ps->cur_gear.push_back(res);
+       return res;
+}
+
+static bool end_gear(ParserState *ps)
+{
+       if(ps->cur_gear.empty()) {
+               errmsg(ps, "parser error: unbalanced end_gear");
+               return false;
+       }
+       Gear *gear = ps->cur_gear.back();
+       ps->cur_gear.pop_back();
+
+       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);
+
+       if(!ps->cur_gear.empty()) {
+               ps->cur_gear.back()->attach(gear);
+       }
+       return true;
+}
+
+static Gear *this_gear(ParserState *ps)
+{
+       return ps->cur_gear.empty() ? 0 : ps->cur_gear.back();
+}
+
+static Gear *find_gear(ParserState *ps, const char *name)
+{
+       // search progressively wider lexical scopes
+       std::vector<Gear*>::const_reverse_iterator it = ps->cur_gear.rbegin();
+       while(it != ps->cur_gear.rend()) {
+               Gear *g = *it++;
+               if(g->name == std::string(name)) {
+                       return g;
+               }
+       }
+
+       return ps->gears[name];
+}
+
+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);
+               ++it;
+       }
+}
+
+#define ASSERT_TYPE(v, t) \
+       do { \
+               if((v).type != (t)) { \
+                       fprintf(stderr, "type mismatch while trying to set %s to value: ", name); \
+                       print_value(val, stderr); \
+                       fputc('\n', stderr); \
+                       return false; \
+               } \
+       } while(0)
+
+#define VVEC3(val) Vec3((val).v[0], (val).v[1], (val).v[2])
+#define VVEC4(val) Vec4((val).v[0], (val).v[1], (val).v[2], (val).v[3])
+
+static bool set_gear_var(Gear *gear, const char *name, const Value &val)
+{
+       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);
+
+       } else if(strcmp(name, "plane") == 0) {
+               ASSERT_TYPE(val, VAL_VEC);
+               gear->axis = VVEC3(val);
+               gear->pdist = val.v[3];
+               printf("setting plane eqn: %f %f %f  %f\n", val.v[0], val.v[1], val.v[2], val.v[3]);
+
+       } else if(strcmp(name, "thickness") == 0) {
+               ASSERT_TYPE(val, VAL_NUM);
+               gear->thickness = val.v[0];
+
+       } else if(strcmp(name, "teeth") == 0) {
+               ASSERT_TYPE(val, VAL_NUM);
+               gear->set_teeth(val.v[0]);      // set teeth and recalc radius
+
+       } else if(strcmp(name, "teeth_length") == 0) {
+               ASSERT_TYPE(val, VAL_NUM);
+               gear->teeth_length = val.v[0];
+
+       } else if(strcmp(name, "pitch") == 0) {
+               ASSERT_TYPE(val, VAL_NUM);
+               gear->set_teeth(gear->nteeth, val.v[0]); // set pitch and recalc radius
+
+       } else if(strcmp(name, "color") == 0) {
+               ASSERT_TYPE(val, VAL_VEC);
+               gear->color = VVEC3(val);
+
+       } else if(strcmp(name, "roughness") == 0) {
+               ASSERT_TYPE(val, VAL_NUM);
+               gear->roughness = val.v[0];
+
+       } else {
+               return false;
+       }
+
+       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_angle = 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_angle.type != VAL_NUM) {
+               expected(ps, "angle 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;
+       }
+
+       Mat4 xform;
+       xform.rotation(deg_to_rad(val_angle.v[0]), gother->axis);
+       Vec3 dir = xform * Vec3(0, 1, 0);
+
+       float sum_radii = gthis->radius + gother->radius;
+       float avg_teeth_len = (gthis->teeth_length + gother->teeth_length) * 0.5;
+       Vec3 pos = gother->pos + 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;
+}
+
+static bool func_coaxial(ParserState *ps)
+{
+       Value val_dist = 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 func_coaxial");
+               return false;
+       }
+       if(val_dist.type != VAL_NUM) {
+               expected(ps, "stacking distance as 2nd arg to func_coaxial");
+               return false;
+       }
+
+       Gear *gthis = this_gear(ps);
+       if(!gthis) {
+               errmsg(ps, "coaxial: called outside of a gear block");
+               return false;
+       }
+
+       Gear *gother = find_gear(ps, val_gear_name.s.c_str());
+       if(!gother) {
+               errmsg(ps, "coaxial: gear \"%s\" not found", val_gear_name.s.c_str());
+               return false;
+       }
+
+       float avg_thickness = (gthis->thickness + gother->thickness) * 0.5;
+       Vec3 pos = gother->pos + gother->axis * val_dist.v[0] * avg_thickness;
+
+       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;
+}