plan9fox/sys/src/cmd/fplot.c
2020-11-27 10:51:16 +01:00

829 lines
16 KiB
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 omax(void) { sp--; if(sp[1]>*sp) *sp = sp[1]; }
void omin(void) { sp--; if(sp[1]<*sp) *sp = sp[1]; }
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 oabs(void) { *sp = fabs(*sp); }
void osin(void) { *sp = sin(*sp); }
void ocos(void) { *sp = cos(*sp); }
void otan(void) { *sp = tan(*sp); }
void osinh(void) { *sp = sinh(*sp); }
void ocosh(void) { *sp = cosh(*sp); }
void otanh(void) { *sp = tanh(*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[] = {
"max", OBINARY, 0, 0, omax,
"min", OBINARY, 0, 0, omax,
"+", OBINARY, 0, 100, add,
"-", OBINARY, 0, 100, sub,
"*", OBINARY, 0, 200, mul,
"/", OBINARY, 0, 200, div,
"%", OBINARY, 0, 200, mod,
"^", OBINARY, 1, 300, pot,
"sinh", OUNARY, 0, 400, osinh,
"cosh", OUNARY, 0, 400, ocosh,
"tanh", OUNARY, 0, 400, otanh,
"abs", OUNARY, 0, 400, oabs,
"sin", OUNARY, 0, 400, osin,
"cos", OUNARY, 0, 400, ocos,
"tan", OUNARY, 0, 400, otan,
"asin", OUNARY, 0, 400, oasin,
"acos", OUNARY, 0, 400, oacos,
"atan", OUNARY, 0, 400, oatan,
"sqrt", OUNARY, 0, 400, osqrt,
"exp", OUNARY, 0, 400, oexp,
"log", OUNARY, 0, 400, olog,
"ln", OUNARY, 0, 400, 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;
double gymin, gymax;
int icolors[] = {
DBlack,
0xCC0000FF,
0x00CC00FF,
0x0000CCFF,
0xFF00CCFF,
0xFFAA00FF,
0xCCCC00FF,
};
Image *colors[nelem(icolors)];
int cflag, aflag;
char *imagedata;
char *pixels;
int picx = 640, picy = 480;
typedef struct FRectangle FRectangle;
struct FRectangle {
double xmin, xmax, ymin, ymax;
} *zoomst;
int nzoomst;
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();
}
if(*sp < gymin) gymin = *sp;
if(*sp > gymax) gymax = *sp;
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, int c)
{
char *p;
if(cflag) {
if(x >= picx || y >= picy || x < 0 || y < 0)
return;
p = imagedata + (picx * y + x) * 3;
p[0] = icolors[c] >> 24;
p[1] = icolors[c] >> 16;
p[2] = icolors[c] >> 8;
}else{
draw(screen, Rect(x, y, x + 1, y + 1), colors[c], nil, ZP);
if(ptinrect(Pt(x, y), screen->r))
pixels[picx * (y - screen->r.min.y) + (x - screen->r.min.x)] = 1;
}
}
void
drawinter(Code *co, Rectangle *r, double x1, double x2, int n, int c)
{
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, c);
}
y2 = calc(co, x2);
if(!isNaN(y2)) {
iy2 = deconvy(r, y2);
pixel(ix2, iy2, c);
}
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, c);
drawinter(co, r, (x1 + x2) / 2, x2, n + 1, c);
}
void
drawgraph(Code *co, Rectangle *r, int c)
{
int x;
for(x = r->min.x; x < r->max.x; x++)
drawinter(co, r, convx(r, x), convx(r, x + 1), 0, c);
}
void
tickfmt(double d, double m, int n, char *fmt)
{
double e1, e2;
int x;
e1 = log10(fabs(m));
e2 = log10(fabs(m + n * d));
if(e2 > e1) e1 = e2;
if(e2 >= 4 || e2 < -3){
x = ceil(e1-log10(d)-1);
snprint(fmt, 32, "%%.%de", x);
}else{
x = ceil(-log10(d));
snprint(fmt, 32, "%%.%df", x);
}
}
int
xticklabel(char *fmt, double g, int p, int x, int y)
{
char buf[32];
Rectangle lr;
int ny;
snprint(buf, sizeof(buf), fmt, g);
lr.min = Pt(p, y+2);
lr.max = addpt(lr.min, stringsize(display->defaultfont, buf));
lr = rectsubpt(lr, Pt(Dx(lr) / 2-1, 0));
if(lr.max.y >= screen->r.max.y){
ny = y - 7 - Dy(lr);
lr = rectsubpt(lr, Pt(0, lr.min.y - ny));
}
if(rectinrect(lr, screen->r) && (lr.min.x > x || lr.max.x <= x)){
string(screen, lr.min, display->black, ZP, display->defaultfont, buf);
return 1;
}
return 0;
}
int
yticklabel(char *fmt, double g, int p, int x, int y)
{
char buf[32];
Rectangle lr;
int nx;
snprint(buf, sizeof(buf), fmt, g);
lr.min = Pt(0, 0);
lr.max = stringsize(display->defaultfont, buf);
lr = rectaddpt(lr, Pt(x-Dx(lr)-2, p - Dy(lr) / 2));
if(lr.min.x < screen->r.min.x){
nx = x + 7;
lr = rectsubpt(lr, Pt(lr.min.x - nx, 0));
}
if(rectinrect(lr, screen->r) && (lr.min.y > y || lr.max.y <= y)){
string(screen, lr.min, display->black, ZP, display->defaultfont, buf);
return 1;
}
return 0;
}
int
calcm(double min, double max, int e, double *dp, double *mp)
{
double d, m, r;
d = pow(10, e>>1);
if((e & 1) != 0) d *= 5;
m = min;
if(min < 0 && max > 0)
m += fmod(-m, d);
else{
r = fmod(m, d);
if(r < 0)
m -= r;
else
m += d - r;
}
if(dp != nil) *dp = d;
if(mp != nil) *mp = m;
return (max-m)*0.999/d;
}
int
ticks(double min, double max, double *dp, double *mp)
{
int e, n;
double m;
int beste;
double bestm;
e = 2 * ceil(log10(max - min));
beste = 0;
bestm = Inf(1);
for(;e>-100;e--){
n = calcm(min, max, e, nil, nil);
if(n <= 0) continue;
if(n < 10) m = 10.0 / n;
else m = n / 10.0;
if(m < bestm){
beste = e;
bestm = m;
}
if(n > 10) break;
}
calcm(min, max, beste, dp, mp);
return (max - *mp) / *dp;
}
void
drawaxes(void)
{
int x, y, p;
double dx, dy, mx, my;
int nx, ny;
int i;
char fmt[32];
if(xmin < 0 && xmax > 0)
x = deconvx(&screen->r, 0);
else
x = screen->r.min.x+5;
line(screen, Pt(x, screen->r.min.y), Pt(x, screen->r.max.y), Endarrow, 0, 0, display->black, ZP);
if(ymin < 0 && ymax > 0)
y = deconvy(&screen->r, 0);
else
y = screen->r.max.y-5;
line(screen, Pt(screen->r.min.x, y), Pt(screen->r.max.x, y), 0, Endarrow, 0, display->black, ZP);
nx = ticks(xmin, xmax, &dx, &mx);
tickfmt(dx, mx, nx, fmt);
for(i = 0; i <= nx; i++){
p = deconvx(&screen->r, dx*i+mx);
if(xticklabel(fmt, dx*i+mx, p, x, y))
line(screen, Pt(p, y), Pt(p, y-5), 0, 0, 0, display->black, ZP);
}
ny = ticks(ymin, ymax, &dy, &my);
tickfmt(dy, my, ny, fmt);
for(i = 0; i <= ny; i++){
p = deconvy(&screen->r, dy*i+my);
if(yticklabel(fmt, dy*i+my, p, x, y))
line(screen, Pt(x, p), Pt(x+5, p), 0, 0, 0, display->black, ZP);
}
}
void
drawgraphs(void)
{
int i;
gymin = Inf(1);
gymax = Inf(-1);
memset(pixels, 0, picx * picy);
for(i = 0; i < nfns; i++)
drawgraph(&fns[i], &screen->r, i % nelem(icolors));
if(!aflag)
drawaxes();
flushimage(display, 1);
}
void
usage(void)
{
fprint(2, "usage: fplot [-a] [-c [-s size]] [-r range] functions ...\n");
exits("usage");
}
void
zoom(void)
{
Mouse m;
Rectangle r;
double xmin_, xmax_, ymin_, ymax_;
m.buttons = 0;
r = egetrect(1, &m);
if(Dx(r) < 1 || Dy(r) < 1)
return;
zoomst = realloc(zoomst, sizeof(FRectangle) * (nzoomst + 1));
if(zoomst == nil) sysfatal("realloc: %r");
zoomst[nzoomst++] = (FRectangle){xmin, xmax, ymin, ymax};
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
unzoom(void)
{
if(nzoomst == 0) return;
xmin = zoomst[nzoomst - 1].xmin;
xmax = zoomst[nzoomst - 1].xmax;
ymin = zoomst[nzoomst - 1].ymin;
ymax = zoomst[nzoomst - 1].ymax;
zoomst = realloc(zoomst, sizeof(FRectangle) * --nzoomst);
if(zoomst == nil && nzoomst != 0) sysfatal("realloc: %r");
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
alloccolors(void)
{
int i;
for(i = 0; i < nelem(icolors); i++){
freeimage(colors[i]);
colors[i] = allocimage(display, Rect(0, 0, 1, 1), screen->chan, 1, icolors[i]);
}
}
void
readout(Point p)
{
int i, j;
double x, y;
vlong d, best;
Point bestp;
double ny, besty;
char buf[64];
/*TODO: do something more intelligent*/
best = (uvlong)(-1)>>1;
for(j = screen->r.min.y; j < screen->r.max.y; j++)
for(i = screen->r.min.x; i < screen->r.max.x; i++){
if(!pixels[(j - screen->r.min.y) * picx + (i - screen->r.min.x)]) continue;
d = (i - p.x) * (i - p.x) + (j - p.y) * (j - p.y);
if(d < best){
best = d;
bestp = Pt(i, j);
}
}
ellipse(screen, bestp, 3, 3, 0, display->black, ZP);
x = convx(&screen->r, bestp.x);
y = convy(&screen->r, bestp.y);
besty = calc(&fns[0], x);
for(i = 1; i < nfns; i++){
ny = calc(&fns[i], x);
if(abs(ny - y) < abs(besty - y))
besty = ny;
}
snprint(buf, sizeof(buf), "%#.4g %#.4g", x, besty);
string(screen, addpt(Pt(10, 10), screen->r.min), display->black, ZP, display->defaultfont, buf);
}
void
main(int argc, char **argv)
{
Event e;
Rectangle r;
int i;
static int lbut;
ARGBEGIN {
case 'a': aflag++; break;
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, i % nelem(icolors));
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);
picx = Dx(screen->r);
picy = Dy(screen->r);
pixels = emalloc(picx * picy);
alloccolors();
drawgraphs();
for(;;) {
switch(event(&e)) {
case Emouse:
if((e.mouse.buttons & 1) != 0)
zoom();
if(((lbut|e.mouse.buttons) & 2) != 0){
draw(screen, screen->r, display->white, nil, ZP);
drawgraphs();
}
if((e.mouse.buttons & 2) != 0)
readout(e.mouse.xy);
if((~e.mouse.buttons & lbut & 4) != 0)
unzoom();
lbut = e.mouse.buttons;
break;
case Ekeyboard:
switch(e.kbdc) {
case 'q': case 127: exits(nil); break;
case 'y':
if(!isInf(ymin, 1) && !isInf(ymax, -1)){
zoomst = realloc(zoomst, sizeof(FRectangle) * (nzoomst + 1));
if(zoomst == nil) sysfatal("realloc: %r");
zoomst[nzoomst++] = (FRectangle){xmin, xmax, ymin, ymax};
ymin = gymin-0.05*(gymax-gymin);
ymax = gymax+0.05*(gymax-gymin);
draw(screen, screen->r, display->white, nil, ZP);
drawgraphs();
}
break;
}
}
}
}
}
void
eresized(int new)
{
if(new) {
if(getwindow(display, Refnone) < 0)
sysfatal("getwindow: %r");
picx = Dx(screen->r);
picy = Dy(screen->r);
pixels = realloc(pixels, picx * picy);
if(pixels == nil) sysfatal("realloc: %r");
alloccolors();
drawgraphs();
}
}