ref: a08bf6831f5122fc9bfc6dccf77096f6ac2e4d03
dir: /sys/src/games/packet.c/
#include <u.h>
#include <libc.h>
#include <thread.h>
#include <draw.h>
#include <mouse.h>
#define minx -1.0
#define maxx 1.0
#define miny -1.0
#define maxy 1.0
double speedOff = 0.001;
double decay = 0.99;
double speedBonus = 0.001;
int regenRate = 5;
double thickFactor = 0.01;
double dispThresh = 0.001;
#define ncolours 200
int nnode = 40;
typedef struct Pos Pos;
typedef struct List List;
typedef struct Node Node;
typedef struct Pack Pack;
struct Pos
{
double x, y;
};
struct List
{
void *next, *prev;
};
struct Node
{
Pos;
int die, ref, targref;
};
struct Pack
{
List;
Pos;
int targ, p, q;
double λ, v;
Image *c;
};
Node *nodes;
Pack plist;
Mousectl *mctl;
double *dist, *path, *speed, *speedn;
int *nextn;
Image *col[ncolours];
Image *grey;
void *
emallocz(int size)
{
void *v;
v = mallocz(size, 1);
if(v == nil)
sysfatal("malloc: %r");
setmalloctag(v, getcallerpc(&size));
return v;
}
Point
convert(Pos* p)
{
return (Point){
screen->r.min.x + (screen->r.max.x - screen->r.min.x) *
((p->x - minx) / (maxx - minx)),
screen->r.min.y + (screen->r.max.y - screen->r.min.y) *
((p->y - minx) / (maxx - minx))};
}
Pos
deconvert(Point p)
{
return (Pos){
minx + (maxx - minx) *
((double)(p.x - screen->r.min.x) / (screen->r.max.x - screen->r.min.x)),
miny + (maxy - miny) *
((double)(p.y - screen->r.min.y) / (screen->r.max.y - screen->r.min.y))};
}
void
rect(Pos *p, int size, Image *col)
{
Point poi;
Rectangle r;
poi = convert(p);
r = insetrect(Rpt(poi, poi), -size);
draw(screen, r, col, nil, ZP);
}
List *
add(List *head, List *obj)
{
obj->prev = head->prev;
obj->next = head;
((List*)head->prev)->next = obj;
head->prev = obj;
return obj;
}
List *
unlink(List *obj)
{
((List*)obj->prev)->next = obj->next;
((List*)obj->next)->prev = obj->prev;
return obj;
}
void
calcdist(void)
{
int i, j;
double dx, dy;
dist = realloc(dist, sizeof(*dist) * nnode * nnode);
path = realloc(path, sizeof(*path) * nnode * nnode);
nextn = realloc(nextn, sizeof(*nextn) * nnode * nnode);
for(i = 0; i < nnode; i++)
for(j = 0; j < nnode; j++){
if(nodes[j].die == 2){
dist[i * nnode + j] = Inf(1);
continue;
}
dx = nodes[i].x - nodes[j].x;
dy = nodes[i].y - nodes[j].y;
dist[i * nnode + j] = sqrt(dx * dx + dy * dy);
}
}
u32int
randomcol(void)
{
int c[3] = {0, 255, 0};
int *j, t;
c[2] = rand() % 256;
j = c + rand() % 3;
t = c[2];
c[2] = *j;
*j = t;
if(rand()%2){
t = c[1];
c[1] = c[0];
c[0] = t;
}
return (c[0] << 24) | (c[1] << 16) | (c[2] << 8) | 0xFF;
}
void
createstuff(void)
{
int i;
plist.next = &plist;
plist.prev = &plist;
for(i = 0; i < ncolours; i++)
col[i] = allocimage(display, Rect(0, 0, 1, 1), screen->chan, 1, randomcol());
grey = allocimage(display, Rect(0, 0, 1, 1), screen->chan, 1, 0x888888FF);
nodes = emallocz(sizeof(*nodes) * nnode);
for(i = 0; i < nnode; i++){
nodes[i].x = frand() * (maxx - minx) + minx;
nodes[i].y = frand() * (maxy - miny) + miny;
}
calcdist();
speed = emallocz(sizeof(*speed) * nnode * nnode);
speedn = emallocz(sizeof(*speedn) * nnode * nnode);
}
void
resizespeed(int diff)
{
int nnode1, i, j;
nnode1 = nnode - diff;
speedn = realloc(speedn, sizeof(*speedn) * nnode * nnode);
for(i = 0; i < nnode; i++)
for(j = 0; j < nnode; j++)
if(i < nnode1 && j < nnode1)
speedn[i * nnode + j] = speed[i * nnode1 + j];
else
speedn[i * nnode + j] = 0;
speed = realloc(speed, sizeof(*speedn) * nnode * nnode);
memcpy(speed, speedn, sizeof(*speedn) * nnode * nnode);
}
void
createpacket(void)
{
Pack *p;
p = emallocz(sizeof(*p));
do{
p->q = rand() % nnode;
p->targ = rand() % nnode;
}while(p->q == p->targ || nodes[p->q].die || nodes[p->targ].die);
nodes[p->q].ref++;
nodes[p->targ].targref++;
p->p = -1;
p->Pos = nodes[p->q].Pos;
p->c = col[rand() % ncolours];
add(&plist, p);
}
int
getpath(int i, int j)
{
int k;
i *= nnode;
while((k = nextn[i + j]) != j)
j = k;
return j;
}
void
floyd(void)
{
int i, j, k;
double a, *b;
for(i = 0; i < nnode; i++)
for(j = 0; j < nnode; j++){
path[i * nnode + j] = dist[i * nnode + j] / (speedOff + speed[i * nnode + j]);
nextn[i * nnode + j] = j;
}
for(k = 0; k < nnode; k++)
for(i = 0; i < nnode; i++)
for(j = 0; j < nnode; j++){
a = path[i * nnode + k] + path[k * nnode + j];
b = path + i * nnode + j;
if(a < *b){
*b = a;
nextn[i * nnode + j] = k;
}
}
}
void
createnode(Pos p)
{
int i, j;
j = nnode;
for(i = 0; i < nnode; i++){
if(nodes[i].Pos.x == p.x && nodes[i].Pos.y == p.y)
return;
if(nodes[i].die == 3 && j == nnode)
j = i;
}
if(j == nnode){
nodes = realloc(nodes, sizeof(*nodes) * ++nnode);
resizespeed(1);
}
nodes[j].Pos = p;
nodes[j].die = 0;
nodes[j].ref = 0;
nodes[j].targref = 0;
calcdist();
floyd();
}
Pack *
advancepacket(Pack *p)
{
Pack *n;
Node *np, *nq;
if(p->p == -1){
p->p = p->q;
p->q = getpath(p->q, p->targ);
nodes[p->q].ref++;
p->λ = 0;
p->v = (speedOff + speed[p->p * nnode + p->q]) / dist[p->p * nnode + p->q];
}else{
p->λ += p->v;
if(p->λ >= 1){
speedn[p->p * nnode + p->q] += speedBonus;
speedn[p->q * nnode + p->p] += speedBonus;
nodes[p->p].ref--;
p->p = -1;
if(p->q == p->targ){
n = p->next;
nodes[p->q].ref--;
nodes[p->q].targref--;
free(unlink(p));
return n;
}
p->Pos = nodes[p->q].Pos;
return p->next;
}
}
np = nodes + p->p;
nq = nodes + p->q;
p->x = np->x * (1 - p->λ) + nq->x * p->λ;
p->y = np->y * (1 - p->λ) + nq->y * p->λ;
return p->next;
}
long sync;
void
timing()
{
for(;;){
semrelease(&sync, 1);
sleep(25);
}
}
void
simstep(void)
{
static int regen;
Pack *p;
int i, j;
for(p = plist.next; p != &plist; )
p = advancepacket(p);
for(i = 0; i < nnode; i++){
if(nodes[i].die == 1 && nodes[i].targref == 0){
nodes[i].die++;
calcdist();
}
if(nodes[i].die == 2 && nodes[i].ref == 0){
nodes[i].die++;
for(j = 0; j < nnode; j++)
speedn[i * nnode + j] = speedn[i + j * nnode] = 0;
}
}
for(i = 0; i < nnode * nnode; i++)
speed[i] = speedn[i] *= decay;
floyd();
if(regen-- == 0){
regen = rand() % regenRate;
createpacket();
createpacket();
}
}
void
domouse(void)
{
static Mouse m;
int lastbut;
double dx, dy, d;
int i;
Point poi;
if(nbrecv(mctl->resizec, &i) == 1)
if(getwindow(display, Refnone) < 0)
sysfatal("getwindow: %r");
lastbut = m.buttons;
nbrecv(mctl->c, &m);
if(lastbut & 4 && !(m.buttons & 4))
for(i = 0; i < nnode; i++){
poi = convert(&nodes[i]);
dx = poi.x - m.xy.x;
dy = poi.y - m.xy.y;
d = sqrt(dx * dx + dy * dy);
if(d < 5){
nodes[i].die = 1;
break;
}
}
if(lastbut & 1 && !(m.buttons & 1))
createnode(deconvert(m.xy));
}
void
usage(void)
{
fprint(2, "USAGE: %s options\n", argv0);
fprint(2, " -n number of nodes [40]\n");
fprint(2, " -o speed of unused connections [0.001]\n");
fprint(2, " -d decay rate [0.99]\n");
fprint(2, " -b speed bonus per packet [0.001]\n");
fprint(2, " -r packet generation period [5]\n");
fprint(2, " -t line thickness factor [0.01]\n");
fprint(2, " -T display threshold [0.001]\n");
exits("usage");
}
void
threadmain(int argc, char **argv)
{
Node *n;
Pack *p;
int i, j;
ARGBEGIN{
case 'n': nnode = atoi(EARGF(usage())); break;
case 'o': speedOff = atof(EARGF(usage())); break;
case 'd': decay = atof(EARGF(usage())); break;
case 'b': speedBonus = atof(EARGF(usage())); break;
case 'r': regenRate = atoi(EARGF(usage())); break;
case 't': thickFactor = atof(EARGF(usage())); break;
case 'T': dispThresh = atof(EARGF(usage())); break;
default: usage();
}ARGEND;
initdraw(nil, nil, nil);
mctl = initmouse(nil, screen);
srand(time(0));
createstuff();
floyd();
proccreate(timing, nil, mainstacksize);
for(;;){
domouse();
draw(screen, screen->r, display->white, nil, ZP);
for(i = 0; i < nnode; i++)
for(j = 0; j < i; j++)
if(speed[i * nnode + j] >= dispThresh)
line(screen, convert(nodes + i), convert(nodes + j), 0, 0, speed[i * nnode + j] / thickFactor, display->black, ZP);
for(n = nodes; n < nodes + nnode; n++)
if(!n->die || n->ref)
rect(n, 3, n->die ? grey : display->black);
for(p = plist.next; p != &plist; p = p->next)
rect(p, 2, p->c);
flushimage(display, 1);
simstep();
semacquire(&sync, 1);
}
}