i’ve made a physics simulator for the mars lander problem, but seems like it’s having an error in position calculations, and it’s growing fast with turns
dir = vector(-sin(newRotationInRadians), cos(newRotationInRadians))*newPower;
newPos = pos+(dir+(GravityVec+velocity)/2).rounded();
newVelocity = GravityVec+velocity;
newVelocity is the same as in Game Info for all the time, but newPos’s getting a huge error in 30 turns
what’s the right formula?
// game loop
long double x,y,vx,vy;
for(int k=0;;++k) {
int X, Y;
int hSpeed, vSpeed; // the horizontal & vertical speed (in m/s), can be negative.
int fuel; // the quantity of remaining fuel in liters.
int rotate; // the rotation angle in degrees (-90 to 90).
int power; // the thrust power (0 to 4).
scanf("%d%d%d%d%d%d%d", &X, &Y, &hSpeed, &vSpeed, &fuel, &rotate, &power);
if(k==0) {
x = X; y = Y;
vx = hSpeed; vy = vSpeed;
}
int angle = 18, thrust = 3;
if(angle>rotate+15) angle = rotate+15;
if(angle<rotate-15) angle = rotate-15;
if(thrust>power+1) thrust = power+1;
if(thrust<power-1) thrust = power-1;
x = x+vx-0.5*sin(angle*PI/180.)*thrust;
y = y+vy+0.5*(cos(angle*PI/180.)*thrust-G);
vx = vx-1.*sin(angle*PI/180.)*thrust;
vy = vy+1.*(cos(angle*PI/180.)*thrust-G);
fprintf(stderr,"x -> %.0Lf ; y = %.0Lf\n",x,y);
fprintf(stderr,"vx -> %.0Lf ; vy = %.0Lf\n",vx,vy);
printf("%d %d\n",angle,thrust);
}
while (1) {
cout << “-90 4” << endl;
if(rotate>-90)rotate-=15;
if(power!=4)power++;
vec2d dir=vec2d(-sin(rotatePI/180.),cos(rotatePI/180.))*power;
pos+=velocity+(G+dir)*0.5;
velocity+=G+dir;
cerr<< pos<<" "<< velocity<< endl;
}
yea, looks like now it works
thk