548 lines
9.1 KiB
C
548 lines
9.1 KiB
C
#include <u.h>
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#include <libc.h>
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#include <ctype.h>
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#include <draw.h>
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#include <event.h>
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typedef struct Op Op;
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typedef struct Operator Operator;
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typedef struct Token Token;
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typedef struct Constant Constant;
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typedef struct Code Code;
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enum {
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ONONE,
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ONUMBER,
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OVAR,
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OUNARY,
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OBINARY,
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};
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struct Op {
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int type;
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union {
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void (*f)(void);
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double val;
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};
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};
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enum {
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TNONE,
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TNUMBER,
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TVAR,
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TOP,
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TPARENL,
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TPARENR,
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};
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struct Token {
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int type;
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union {
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Operator *op;
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double val;
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};
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Token *next;
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};
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double *stack, *sp;
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void add(void) { sp--; *sp += *(sp+1); }
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void sub(void) { sp--; *sp -= *(sp+1); }
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void mul(void) { sp--; *sp *= *(sp+1); }
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void div(void) { sp--; *sp /= *(sp+1); }
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void mod(void) { sp--; *sp = fmod(*sp, *(sp+1)); }
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void pot(void) { sp--; *sp = pow(*sp, *(sp+1)); }
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void osin(void) { *sp = sin(*sp); }
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void ocos(void) { *sp = cos(*sp); }
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void otan(void) { *sp = tan(*sp); }
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void oasin(void) { *sp = asin(*sp); }
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void oacos(void) { *sp = acos(*sp); }
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void oatan(void) { *sp = atan(*sp); }
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void osqrt(void) { *sp = sqrt(*sp); }
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void oexp(void) { *sp = exp(*sp); }
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void olog(void) { *sp = log10(*sp); }
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void oln(void) { *sp = log(*sp); }
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struct Operator {
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char *s;
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char type;
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char rassoc;
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short prec;
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void (*f)(void);
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} ops[] = {
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"+", OBINARY, 0, 0, add,
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"-", OBINARY, 0, 0, sub,
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"*", OBINARY, 0, 100, mul,
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"/", OBINARY, 0, 100, div,
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"%", OBINARY, 0, 100, mod,
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"^", OBINARY, 1, 200, pot,
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"sin", OUNARY, 0, 50, osin,
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"cos", OUNARY, 0, 50, ocos,
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"tan", OUNARY, 0, 50, otan,
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"asin", OUNARY, 0, 50, oasin,
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"acos", OUNARY, 0, 50, oacos,
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"atan", OUNARY, 0, 50, oatan,
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"sqrt", OUNARY, 0, 50, osqrt,
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"exp", OUNARY, 0, 50, oexp,
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"log", OUNARY, 0, 50, olog,
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"ln", OUNARY, 0, 50, oln,
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};
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struct Constant {
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char *s;
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double val;
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} consts[] = {
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"pi", 3.14159265359,
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"π", 3.14159265359,
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"e", 2.71828182846,
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};
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struct Code {
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Op* p;
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int len, cap;
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} *fns;
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int nfns;
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Token *opstackbot;
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double xmin = -10, xmax = 10;
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double ymin = -10, ymax = 10;
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Image *color;
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int cflag;
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char *imagedata;
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int picx = 640, picy = 480;
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void *
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emalloc(int size)
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{
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void *v;
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v = mallocz(size, 1);
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if(v == nil)
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sysfatal("emalloc: %r");
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setmalloctag(v, getcallerpc(&size));
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return v;
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}
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void
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addop(Code *c, Op o)
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{
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if(c->len >= c->cap) {
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c->cap += 32;
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c->p = realloc(c->p, sizeof(Op) * c->cap);
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if(c->p == nil)
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sysfatal("realloc: %r");
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}
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c->p[c->len++] = o;
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}
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void
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push(Token *t)
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{
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t->next = opstackbot;
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opstackbot = t;
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}
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void
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pop(Code *c)
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{
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Token *t;
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Op o;
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t = opstackbot;
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if(t == nil)
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sysfatal("stack underflow");
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opstackbot = t->next;
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if(t->type != TOP)
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sysfatal("non-operator pop");
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o.type = t->op->type;
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o.f = t->op->f;
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addop(c, o);
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free(t);
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}
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void
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popdel(void)
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{
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Token *t;
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t = opstackbot;
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opstackbot = t->next;
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free(t);
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}
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Token *
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lex(char **s)
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{
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Token *t;
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Operator *o;
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Constant *c;
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while(isspace(**s))
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(*s)++;
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if(**s == 0)
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return nil;
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t = emalloc(sizeof(*t));
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if(isdigit(**s)) {
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t->type = TNUMBER;
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t->val = strtod(*s, s);
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return t;
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}
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if(**s == '(') {
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t->type = TPARENL;
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(*s)++;
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return t;
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}
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if(**s == ')') {
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t->type = TPARENR;
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(*s)++;
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return t;
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}
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if(**s == 'x') {
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t->type = TVAR;
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(*s)++;
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return t;
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}
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for(o = ops; o < ops + nelem(ops); o++)
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if(strncmp(*s, o->s, strlen(o->s)) == 0) {
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t->type = TOP;
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t->op = o;
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*s += strlen(o->s);
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return t;
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}
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for(c = consts; c < consts + nelem(consts); c++)
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if(strncmp(*s, c->s, strlen(c->s)) == 0) {
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t->type = TNUMBER;
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t->val = c->val;
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*s += strlen(c->s);
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return t;
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}
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sysfatal("syntax error at %s", *s);
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return nil;
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}
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void
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parse(Code *c, char *s)
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{
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Token *t;
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Op o;
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while(t = lex(&s)) {
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switch(t->type) {
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case TNUMBER:
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o.type = ONUMBER;
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o.val = t->val;
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addop(c, o);
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free(t);
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break;
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case TVAR:
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o.type = OVAR;
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addop(c, o);
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free(t);
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break;
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case TOP:
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if(t->op->type == OBINARY)
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while(opstackbot != nil && opstackbot->type == TOP &&
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(opstackbot->op->prec > t->op->prec ||
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t->op->rassoc && opstackbot->op->prec == t->op->prec))
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pop(c);
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push(t);
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break;
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case TPARENL:
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push(t);
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break;
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case TPARENR:
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while(opstackbot != nil && opstackbot->type == TOP)
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pop(c);
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if(opstackbot == nil)
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sysfatal("mismatched parentheses");
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popdel();
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free(t);
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break;
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default:
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sysfatal("unknown token type %d", t->type);
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}
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}
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while(opstackbot != nil)
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switch(opstackbot->type) {
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case TOP:
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pop(c);
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break;
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case TPARENL:
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sysfatal("mismatched parentheses");
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default:
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sysfatal("syntax error");
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}
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}
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int
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calcstack(Code *c)
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{
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int cur, max;
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Op *o;
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cur = 0;
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max = 0;
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for(o = c->p; o < c->p + c->len; o++)
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switch(o->type) {
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case ONUMBER: case OVAR:
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if(++cur > max)
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max = cur;
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break;
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case OUNARY:
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if(cur == 0)
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sysfatal("syntax error");
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break;
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case OBINARY:
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if(cur <= 1)
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sysfatal("syntax error");
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cur--;
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break;
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}
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if(cur != 1)
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sysfatal("syntax error");
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return max;
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}
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double
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calc(Code *c, double x)
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{
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Op *o;
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sp = stack - 1;
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for(o = c->p; o < c->p + c->len; o++)
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switch(o->type) {
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case ONUMBER:
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*++sp = o->val;
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break;
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case OVAR:
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*++sp = x;
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break;
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case OUNARY: case OBINARY:
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o->f();
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}
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return *sp;
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}
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double
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convx(Rectangle *r, int x)
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{
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return (xmax - xmin) * (x - r->min.x) / (r->max.x - r->min.x) + xmin;
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}
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int
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deconvx(Rectangle *r, double dx)
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{
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return (dx - xmin) * (r->max.x - r->min.x) / (xmax - xmin) + r->min.x + 0.5;
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}
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double
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convy(Rectangle *r, int y)
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{
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return (ymax - ymin) * (r->max.y - y) / (r->max.y - r->min.y) + ymin;
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}
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int
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deconvy(Rectangle *r, double dy)
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{
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return (ymax - dy) * (r->max.y - r->min.y) / (ymax - ymin) + r->min.y + 0.5;
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}
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void
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pixel(int x, int y)
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{
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char *p;
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if(cflag) {
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if(x >= picx || y >= picy || x < 0 || y < 0)
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return;
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p = imagedata + (picx * y + x) * 3;
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p[0] = p[1] = p[2] = 0;
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} else
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draw(screen, Rect(x, y, x + 1, y + 1), color, nil, ZP);
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}
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void
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drawinter(Code *co, Rectangle *r, double x1, double x2, int n)
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{
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double y1, y2;
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int iy1, iy2;
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int ix1, ix2;
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ix1 = deconvx(r, x1);
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ix2 = deconvx(r, x2);
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iy1 = iy2 = 0;
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y1 = calc(co, x1);
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if(!isNaN(y1)) {
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iy1 = deconvy(r, y1);
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pixel(ix1, iy1);
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}
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y2 = calc(co, x2);
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if(!isNaN(y2)) {
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iy2 = deconvy(r, y2);
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pixel(ix2, iy2);
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}
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if(isNaN(y1) || isNaN(y2))
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return;
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if(n >= 10)
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return;
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if(iy2 >= iy1 - 1 && iy2 <= iy1 + 1)
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return;
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if(iy1 > r->max.y && iy2 > r->max.y)
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return;
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if(iy1 < r->min.y && iy2 < r->min.y)
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return;
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drawinter(co, r, x1, (x1 + x2) / 2, n + 1);
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drawinter(co, r, (x1 + x2) / 2, x2, n + 1);
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}
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void
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drawgraph(Code *co, Rectangle *r)
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{
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int x;
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for(x = r->min.x; x < r->max.x; x++)
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drawinter(co, r, convx(r, x), convx(r, x + 1), 0);
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}
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void
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drawgraphs(void)
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{
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int i;
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color = display->black;
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for(i = 0; i < nfns; i++)
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drawgraph(&fns[i], &screen->r);
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flushimage(display, 1);
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}
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void
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usage(void)
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{
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fprint(2, "usage: fplot [-c [-s size]] [-r range] functions ...\n");
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exits("usage");
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}
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void
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zoom(void)
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{
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Mouse m;
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Rectangle r;
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double xmin_, xmax_, ymin_, ymax_;
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m.buttons = 7;
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r = egetrect(1, &m);
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if(Dx(r) < 1 || Dy(r) < 1)
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return;
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xmin_ = convx(&screen->r, r.min.x);
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xmax_ = convx(&screen->r, r.max.x);
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ymin_ = convy(&screen->r, r.max.y);
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ymax_ = convy(&screen->r, r.min.y);
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xmin = xmin_;
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xmax = xmax_;
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ymin = ymin_;
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ymax = ymax_;
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draw(screen, screen->r, display->white, nil, ZP);
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drawgraphs();
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}
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void
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parsefns(int n, char **s)
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{
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int i, max, cur;
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max = 0;
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nfns = n;
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fns = emalloc(sizeof(*fns) * n);
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for(i = 0; i < nfns; i++) {
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parse(&fns[i], s[i]);
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cur = calcstack(&fns[i]);
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if(cur > max)
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max = cur;
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}
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stack = emalloc(sizeof(*stack) * max);
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}
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void
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parserange(char *s)
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{
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while(*s && !isdigit(*s) && *s != '-') s++;
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if(*s == 0) return;
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xmin = strtod(s, &s);
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while(*s && !isdigit(*s) && *s != '-') s++;
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if(*s == 0) return;
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xmax = strtod(s, &s);
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while(*s && !isdigit(*s) && *s != '-') s++;
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if(*s == 0) return;
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ymin = strtod(s, &s);
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while(*s && !isdigit(*s) && *s != '-') s++;
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if(*s == 0) return;
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ymax = strtod(s, &s);
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}
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void
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parsesize(char *s)
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{
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while(*s && !isdigit(*s)) s++;
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if(*s == 0) return;
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picx = strtol(s, &s, 0);
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while(*s && !isdigit(*s)) s++;
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if(*s == 0) return;
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picy = strtol(s, &s, 0);
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}
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void
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main(int argc, char **argv)
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{
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Event e;
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Rectangle r;
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int i;
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ARGBEGIN {
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case 'r': parserange(EARGF(usage())); break;
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case 's': parsesize(EARGF(usage())); break;
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case 'c': cflag++; break;
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default: usage();
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} ARGEND;
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if(argc < 1)
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usage();
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setfcr(getfcr() & ~(FPZDIV | FPINVAL));
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parsefns(argc, argv);
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if(cflag) {
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imagedata = emalloc(picx * picy * 3);
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memset(imagedata, 0xFF, picx * picy * 3);
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print("%11s %11d %11d %11d %11d ", "r8g8b8", 0, 0, picx, picy);
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r.min.x = r.min.y = 0;
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r.max.x = picx;
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r.max.y = picy;
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for(i = 0; i < nfns; i++)
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drawgraph(&fns[i], &r);
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if(write(1, imagedata, picx * picy * 3) < picx * picy * 3)
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sysfatal("write: %r");
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} else {
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if(initdraw(nil, nil, "fplot") < 0)
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sysfatal("initdraw: %r");
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einit(Emouse | Ekeyboard);
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drawgraphs();
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for(;;) {
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switch(event(&e)) {
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case Ekeyboard:
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switch(e.kbdc) {
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case 'q': exits(nil);
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case 'z': zoom();
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}
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}
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}
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}
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}
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void
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eresized(int new)
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{
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if(new) {
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if(getwindow(display, Refnone) < 0)
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sysfatal("getwindow: %r");
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drawgraphs();
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}
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}
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