ref: 84351ae4cb50857fe62e0938198db0c7ea33d05c
dir: /sys/src/cmd/fplot.c/
#include <u.h> #include <libc.h> #include <ctype.h> #include <draw.h> #include <event.h> typedef struct Op Op; typedef struct Operator Operator; typedef struct Token Token; typedef struct Constant Constant; typedef struct Code Code; enum { ONONE, ONUMBER, OVAR, OUNARY, OBINARY, }; struct Op { int type; union { void (*f)(void); double val; }; }; enum { TNONE, TNUMBER, TVAR, TOP, TPARENL, TPARENR, }; struct Token { int type; union { Operator *op; double val; }; Token *next; }; double *stack, *sp; void add(void) { sp--; *sp += *(sp+1); } void sub(void) { sp--; *sp -= *(sp+1); } void mul(void) { sp--; *sp *= *(sp+1); } void div(void) { sp--; *sp /= *(sp+1); } void mod(void) { sp--; *sp = fmod(*sp, *(sp+1)); } void pot(void) { sp--; *sp = pow(*sp, *(sp+1)); } void osin(void) { *sp = sin(*sp); } void ocos(void) { *sp = cos(*sp); } void otan(void) { *sp = tan(*sp); } void oasin(void) { *sp = asin(*sp); } void oacos(void) { *sp = acos(*sp); } void oatan(void) { *sp = atan(*sp); } void osqrt(void) { *sp = sqrt(*sp); } void oexp(void) { *sp = exp(*sp); } void olog(void) { *sp = log10(*sp); } void oln(void) { *sp = log(*sp); } struct Operator { char *s; char type; char rassoc; short prec; void (*f)(void); } ops[] = { "+", OBINARY, 0, 0, add, "-", OBINARY, 0, 0, sub, "*", OBINARY, 0, 100, mul, "/", OBINARY, 0, 100, div, "%", OBINARY, 0, 100, mod, "^", OBINARY, 1, 200, pot, "sin", OUNARY, 0, 50, osin, "cos", OUNARY, 0, 50, ocos, "tan", OUNARY, 0, 50, otan, "asin", OUNARY, 0, 50, oasin, "acos", OUNARY, 0, 50, oacos, "atan", OUNARY, 0, 50, oatan, "sqrt", OUNARY, 0, 50, osqrt, "exp", OUNARY, 0, 50, oexp, "log", OUNARY, 0, 50, olog, "ln", OUNARY, 0, 50, oln, }; struct Constant { char *s; double val; } consts[] = { "pi", 3.14159265359, "π", 3.14159265359, "e", 2.71828182846, }; struct Code { Op* p; int len, cap; } *fns; int nfns; Token *opstackbot; double xmin = -10, xmax = 10; double ymin = -10, ymax = 10; Image *color; int cflag; char *imagedata; int picx = 640, picy = 480; void * emalloc(int size) { void *v; v = mallocz(size, 1); if(v == nil) sysfatal("emalloc: %r"); setmalloctag(v, getcallerpc(&size)); return v; } void addop(Code *c, Op o) { if(c->len >= c->cap) { c->cap += 32; c->p = realloc(c->p, sizeof(Op) * c->cap); if(c->p == nil) sysfatal("realloc: %r"); } c->p[c->len++] = o; } void push(Token *t) { t->next = opstackbot; opstackbot = t; } void pop(Code *c) { Token *t; Op o; t = opstackbot; if(t == nil) sysfatal("stack underflow"); opstackbot = t->next; if(t->type != TOP) sysfatal("non-operator pop"); o.type = t->op->type; o.f = t->op->f; addop(c, o); free(t); } void popdel(void) { Token *t; t = opstackbot; opstackbot = t->next; free(t); } Token * lex(char **s) { Token *t; Operator *o; Constant *c; while(isspace(**s)) (*s)++; if(**s == 0) return nil; t = emalloc(sizeof(*t)); if(isdigit(**s)) { t->type = TNUMBER; t->val = strtod(*s, s); return t; } if(**s == '(') { t->type = TPARENL; (*s)++; return t; } if(**s == ')') { t->type = TPARENR; (*s)++; return t; } if(**s == 'x') { t->type = TVAR; (*s)++; return t; } for(o = ops; o < ops + nelem(ops); o++) if(strncmp(*s, o->s, strlen(o->s)) == 0) { t->type = TOP; t->op = o; *s += strlen(o->s); return t; } for(c = consts; c < consts + nelem(consts); c++) if(strncmp(*s, c->s, strlen(c->s)) == 0) { t->type = TNUMBER; t->val = c->val; *s += strlen(c->s); return t; } sysfatal("syntax error at %s", *s); return nil; } void parse(Code *c, char *s) { Token *t; Op o; while(t = lex(&s)) { switch(t->type) { case TNUMBER: o.type = ONUMBER; o.val = t->val; addop(c, o); free(t); break; case TVAR: o.type = OVAR; addop(c, o); free(t); break; case TOP: if(t->op->type == OBINARY) while(opstackbot != nil && opstackbot->type == TOP && (opstackbot->op->prec > t->op->prec || t->op->rassoc && opstackbot->op->prec == t->op->prec)) pop(c); push(t); break; case TPARENL: push(t); break; case TPARENR: while(opstackbot != nil && opstackbot->type == TOP) pop(c); if(opstackbot == nil) sysfatal("mismatched parentheses"); popdel(); free(t); break; default: sysfatal("unknown token type %d", t->type); } } while(opstackbot != nil) switch(opstackbot->type) { case TOP: pop(c); break; case TPARENL: sysfatal("mismatched parentheses"); default: sysfatal("syntax error"); } } int calcstack(Code *c) { int cur, max; Op *o; cur = 0; max = 0; for(o = c->p; o < c->p + c->len; o++) switch(o->type) { case ONUMBER: case OVAR: if(++cur > max) max = cur; break; case OUNARY: if(cur == 0) sysfatal("syntax error"); break; case OBINARY: if(cur <= 1) sysfatal("syntax error"); cur--; break; } if(cur != 1) sysfatal("syntax error"); return max; } double calc(Code *c, double x) { Op *o; sp = stack - 1; for(o = c->p; o < c->p + c->len; o++) switch(o->type) { case ONUMBER: *++sp = o->val; break; case OVAR: *++sp = x; break; case OUNARY: case OBINARY: o->f(); } return *sp; } double convx(Rectangle *r, int x) { return (xmax - xmin) * (x - r->min.x) / (r->max.x - r->min.x) + xmin; } int deconvx(Rectangle *r, double dx) { return (dx - xmin) * (r->max.x - r->min.x) / (xmax - xmin) + r->min.x + 0.5; } double convy(Rectangle *r, int y) { return (ymax - ymin) * (r->max.y - y) / (r->max.y - r->min.y) + ymin; } int deconvy(Rectangle *r, double dy) { return (ymax - dy) * (r->max.y - r->min.y) / (ymax - ymin) + r->min.y + 0.5; } void pixel(int x, int y) { char *p; if(cflag) { if(x >= picx || y >= picy || x < 0 || y < 0) return; p = imagedata + (picx * y + x) * 3; p[0] = p[1] = p[2] = 0; } else draw(screen, Rect(x, y, x + 1, y + 1), color, nil, ZP); } void drawinter(Code *co, Rectangle *r, double x1, double x2, int n) { double y1, y2; int iy1, iy2; int ix1, ix2; ix1 = deconvx(r, x1); ix2 = deconvx(r, x2); iy1 = iy2 = 0; y1 = calc(co, x1); if(!isNaN(y1)) { iy1 = deconvy(r, y1); pixel(ix1, iy1); } y2 = calc(co, x2); if(!isNaN(y2)) { iy2 = deconvy(r, y2); pixel(ix2, iy2); } if(isNaN(y1) || isNaN(y2)) return; if(n >= 10) return; if(iy2 >= iy1 - 1 && iy2 <= iy1 + 1) return; if(iy1 > r->max.y && iy2 > r->max.y) return; if(iy1 < r->min.y && iy2 < r->min.y) return; drawinter(co, r, x1, (x1 + x2) / 2, n + 1); drawinter(co, r, (x1 + x2) / 2, x2, n + 1); } void drawgraph(Code *co, Rectangle *r) { int x; for(x = r->min.x; x < r->max.x; x++) drawinter(co, r, convx(r, x), convx(r, x + 1), 0); } void drawgraphs(void) { int i; color = display->black; for(i = 0; i < nfns; i++) drawgraph(&fns[i], &screen->r); flushimage(display, 1); } void usage(void) { fprint(2, "usage: fplot [-c [-s size]] [-r range] functions ...\n"); exits("usage"); } void zoom(void) { Mouse m; Rectangle r; double xmin_, xmax_, ymin_, ymax_; m.buttons = 7; r = egetrect(1, &m); if(Dx(r) < 1 || Dy(r) < 1) return; xmin_ = convx(&screen->r, r.min.x); xmax_ = convx(&screen->r, r.max.x); ymin_ = convy(&screen->r, r.max.y); ymax_ = convy(&screen->r, r.min.y); xmin = xmin_; xmax = xmax_; ymin = ymin_; ymax = ymax_; draw(screen, screen->r, display->white, nil, ZP); drawgraphs(); } void parsefns(int n, char **s) { int i, max, cur; max = 0; nfns = n; fns = emalloc(sizeof(*fns) * n); for(i = 0; i < nfns; i++) { parse(&fns[i], s[i]); cur = calcstack(&fns[i]); if(cur > max) max = cur; } stack = emalloc(sizeof(*stack) * max); } void parserange(char *s) { while(*s && !isdigit(*s) && *s != '-') s++; if(*s == 0) return; xmin = strtod(s, &s); while(*s && !isdigit(*s) && *s != '-') s++; if(*s == 0) return; xmax = strtod(s, &s); while(*s && !isdigit(*s) && *s != '-') s++; if(*s == 0) return; ymin = strtod(s, &s); while(*s && !isdigit(*s) && *s != '-') s++; if(*s == 0) return; ymax = strtod(s, &s); } void parsesize(char *s) { while(*s && !isdigit(*s)) s++; if(*s == 0) return; picx = strtol(s, &s, 0); while(*s && !isdigit(*s)) s++; if(*s == 0) return; picy = strtol(s, &s, 0); } void main(int argc, char **argv) { Event e; Rectangle r; int i; ARGBEGIN { case 'r': parserange(EARGF(usage())); break; case 's': parsesize(EARGF(usage())); break; case 'c': cflag++; break; default: usage(); } ARGEND; if(argc < 1) usage(); setfcr(getfcr() & ~(FPZDIV | FPINVAL)); parsefns(argc, argv); if(cflag) { imagedata = emalloc(picx * picy * 3); memset(imagedata, 0xFF, picx * picy * 3); print("%11s %11d %11d %11d %11d ", "r8g8b8", 0, 0, picx, picy); r.min.x = r.min.y = 0; r.max.x = picx; r.max.y = picy; for(i = 0; i < nfns; i++) drawgraph(&fns[i], &r); if(write(1, imagedata, picx * picy * 3) < picx * picy * 3) sysfatal("write: %r"); } else { if(initdraw(nil, nil, "fplot") < 0) sysfatal("initdraw: %r"); einit(Emouse | Ekeyboard); drawgraphs(); for(;;) { switch(event(&e)) { case Ekeyboard: switch(e.kbdc) { case 'q': exits(nil); case 'z': zoom(); } } } } } void eresized(int new) { if(new) { if(getwindow(display, Refnone) < 0) sysfatal("getwindow: %r"); drawgraphs(); } }