ref: afa5c513017b1d6dccd1dbee33fa79d110d4b19a
dir: /sim.move.c/
#include <u.h>
#include <libc.h>
#include <draw.h>
#include "dat.h"
#include "fns.h"
void
linktomap(Mobj *mo)
{
Map *m;
m = map + mo->y / Node2Tile * mapwidth + mo->x / Node2Tile;
mo->mapl = linkmobj(mo->o->f & Fair ? m->ml.lp : &m->ml, mo, mo->mapl);
}
static void
resetcoords(Mobj *mo)
{
markmobj(mo, 0);
mo->subpx = mo->px << Subpxshift;
mo->subpy = mo->py << Subpxshift;
markmobj(mo, 1);
}
static double
facegoal(Point p, Mobj *mo)
{
int dx, dy;
double vx, vy, d, θ, θ256, Δθ;
dx = p.x - mo->px;
dy = p.y - mo->py;
d = sqrt(dx * dx + dy * dy);
vx = dx / d;
vy = dy / d;
/* angle in radians [0;2π[ with 0 facing north */
θ = atan2(vy, vx) + PI / 2;
if(θ < 0)
θ += 2 * PI;
else if(θ >= 2 * PI)
θ -= 2 * PI;
/* movement calculations use values in [0;256[, drawing in [0;32[ */
θ256 = θ * 256.0 / (2 * PI);
mo->u = vx;
mo->v = vy;
Δθ = θ256 - mo->θ;
if(Δθ <= -256 / 2)
Δθ += 256;
else if(Δθ >= 256 / 2)
Δθ -= 256;
mo->Δθs = Δθ < 0 ? -1: 1;
mo->Δθ = fabs(Δθ);
return θ256;
}
static void
nextpathnode(Mobj *mo)
{
resetcoords(mo);
facegoal(*mo->pathp, mo);
}
static void
clearpath(Mobj *mo)
{
mo->speed = 0.0;
mo->pathp = nil;
resetcoords(mo);
}
static void
cleanup(Mobj *mo)
{
clearpath(mo);
mo->target = (Point){0,0};
mo->goalblocked = 0;
mo->pathlen = 0.0;
mo->npatherr = 0;
}
static void
movedone(Mobj *mo)
{
dprint("%M successfully reached goal\n", mo);
nextstate(mo);
}
static void
abortmove(Mobj *mo)
{
werrstr("move aborted");
abortcommands(mo);
}
static int
repath(Point p, Mobj *mo)
{
clearpath(mo);
mo->target = p;
if(findpath(p, mo) < 0){
mo->θ = facegoal(p, mo);
return -1;
}
mo->pathp = mo->paths;
nextpathnode(mo);
return 0;
}
static void
accelerate(Mobj *mo)
{
if(1 + mo->pathlen < (mo->speed / 8) * (mo->speed / 8) / 2 / (mo->o->accel / 8)){
mo->speed -= mo->o->accel;
if(mo->speed < 0.0)
mo->speed = 0.0;
}else if(mo->speed < mo->o->speed){
mo->speed += mo->o->accel;
if(mo->speed > mo->o->speed)
mo->speed = mo->o->speed;
}
}
static int
trymove(Mobj *mo)
{
int x, y, px, py, sx, sy, Δx, Δy, Δu, Δv, Δrx, Δry, Δpx, Δpy;
double dx, dy;
markmobj(mo, 0);
px = mo->px;
py = mo->py;
sx = mo->subpx;
sy = mo->subpy;
Δu = mo->u * (1 << Subpxshift);
Δv = mo->v * (1 << Subpxshift);
Δx = abs(Δu);
Δy = abs(Δv);
Δrx = fabs(mo->u * mo->speed) * (1 << Subpxshift);
Δry = fabs(mo->v * mo->speed) * (1 << Subpxshift);
Δpx = abs((mo->pathp->x << Subpxshift) - sx);
Δpy = abs((mo->pathp->y << Subpxshift) - sy);
if(Δpx < Δrx)
Δrx = Δpx;
if(Δpy < Δry)
Δry = Δpy;
while(Δrx > 0 || Δry > 0){
x = mo->x;
y = mo->y;
if(Δrx > 0){
sx += Δu;
Δrx -= Δx;
if(Δrx < 0)
sx += mo->u < 0 ? -Δrx : Δrx;
x = (sx >> Subpxshift) + ((sx & Subpxmask) != 0);
x /= Nodewidth;
}
if(Δry > 0){
sy += Δv;
Δry -= Δy;
if(Δry < 0)
sy += mo->v < 0 ? -Δry : Δry;
y = (sy >> Subpxshift) + ((sy & Subpxmask) != 0);
y /= Nodewidth;
}
if(isblocked(x, y, mo->o))
goto end;
/* disallow corner coasting */
if(x != mo->x && y != mo->y
&& (isblocked(x, mo->y, mo->o) || isblocked(mo->x, y, mo->o))){
dprint("%M detected corner coasting at %d,%d\n",
mo, x, y);
goto end;
}
mo->subpx = sx;
mo->subpy = sy;
mo->px = sx >> Subpxshift;
mo->py = sy >> Subpxshift;
mo->x = mo->px / Nodewidth;
mo->y = mo->py / Nodeheight;
}
markmobj(mo, 1);
dx = mo->px - px;
dx *= dx;
dy = mo->py - py;
dy *= dy;
mo->pathlen -= sqrt(dx + dy) / Nodewidth;
return 0;
end:
werrstr("trymove: can't move to %d,%d", x, y);
mo->subpx = mo->px << Subpxshift;
mo->subpy = mo->py << Subpxshift;
markmobj(mo, 1);
dx = mo->px - px;
dx *= dx;
dy = mo->py - py;
dy *= dy;
mo->pathlen -= sqrt(dx + dy) / Nodewidth;
return -1;
}
static int
continuemove(Mobj *mo)
{
int r;
accelerate(mo);
unlinkmobj(mo->mapl);
r = trymove(mo);
linktomap(mo);
return r;
}
static int
tryturn(Mobj *mo)
{
int r;
double Δθ;
r = 1;
if(mo->Δθ <= mo->o->turn){
r = 0;
Δθ = mo->Δθ;
}else
Δθ = mo->o->turn;
mo->θ += mo->Δθs * Δθ;
if(mo->θ < 0)
mo->θ += 256;
else if(mo->θ >= 256)
mo->θ -= 256;
mo->Δθ -= Δθ;
return r;
}
static int
nodereached(Mobj *mo)
{
return mo->px == mo->pathp->x && mo->py == mo->pathp->y;
}
static void
step(Mobj *mo)
{
int nerr;
nerr = 0;
restart:
if(tryturn(mo))
return;
if(continuemove(mo) < 0){
if(nerr > 1){
fprint(2, "%M stepmove: bug: infinite loop!\n", mo);
return;
}
dprint("%M stepmove: failed moving from %d,%d to %d,%d: %r\n",
mo, mo->px, mo->py, mo->pathp->x, mo->pathp->y);
if(repath(mo->target, mo) < 0){
dprint("%M stepmove: failed moving towards target: %r\n", mo);
abortcommands(mo);
return;
}
nerr++;
goto restart;
}
if(!nodereached(mo))
return;
mo->pathp++;
if(mo->pathp < mo->pathe){
nextpathnode(mo);
return;
}else if(mo->x == mo->target.x && mo->y == mo->target.y){
movedone(mo);
return;
}
/* FIXME: this is a shitty hack, see notes */
if(isnextto(mo, mo->cmds[0].target1)){
dprint("%M stepmove: next to target, stopping\n", mo);
movedone(mo);
return;
}
dprint("%M stepmove: reached final node, but not target\n", mo);
if(mo->goalblocked && isblocked(mo->target.x, mo->target.y, mo->o)){
dprint("%M stepmove: goal still blocked, stopping\n", mo);
abortmove(mo);
return;
}
dprint("%M stepmove: trying again\n", mo);
if(mo->npatherr++ > 1 || repath(mo->target, mo) < 0){
dprint("%M stepmove: still can't reach target: %r\n", mo);
abortmove(mo);
return;
}
}
int
pushmove(Mobj *mo)
{
Point goal;
Command *c;
c = mo->cmds;
c->cleanupfn = cleanup;
goal = c->goal;
setgoal(&goal, mo, c->target1); /* FIXME: target[12] might be a problem for returns */
if(repath(goal, mo) < 0)
return -1;
c->stepfn = step;
mo->state = OSmove;
return 0;
}
int
pushmovecommand(Point goal, Mobj *mo, Mobj *target)
{
Command *c;
if((c = pushcommand(mo)) == nil){
fprint(2, "pushmovecommand: %r\n");
return -1;
}
c->name = "move";
c->initfn = pushmove;
c->goal = goal;
c->target1 = target;
c->nextfn = nil;
return 0;
}