int
detect_collision (struct pt *oldpos, struct pt *newpos,
struct groundtri *gt)
{
double dist, t;
struct vect v;
struct pt p;
dist = dist_pt_to_plane (newpos, >->pl);
//THINK THROUGH IF NORMAL WILL ALWAYS BE POINTING IN CORRECT DIRECTION
//AND IF A WALL MATTERS IF YOU GO THROUGH IT IN THE WRONG DIRECTION
//DO OTHER GAMES CARE IF YOU GO THROUGH A WALL THE WRONG WAY? I DON'T
//REMEMBER, HAVE TO CHECK
if (dist >= 0) {
return (0);
} else {
psub (&v, newpos, oldpos);
t = -(gt->pl.a * oldpos->x + gt->pl.b * oldpos->y + gt->pl.c * oldpos->z + gt->pl.d) / (gt->pl.a * v.x + gt->pl.b * v.y + gt->pl.c * v.z);
p.x = oldpos->x + v.x * t;
p.y = oldpos->x + v.y * t;
p.z = oldpos->x + v.z * t;
return (pt_in_gt (&p, gt));
}
return (0);
}
int
pt_in_gt (struct pt *p, struct groundtri *gt)
{
double theta;
struct vect v1, v2;
theta = 0;
psub (&v1, >->p1, p);
vnorm (&v1, &v1);
psub (&v2, >->p2, p);
vnorm (&v2, &v2);
theta += acos (vdot (&v1, &v2));
psub (&v1, >->p2, p);
vnorm (&v1, &v1);
psub (&v2, >->p3, p);
vnorm (&v2, &v2);
theta += acos (vdot (&v1, &v2));
psub (&v1, >->p3, p);
vnorm (&v1, &v1);
psub (&v2, >->p1, p);
vnorm (&v2, &v2);
theta += acos (vdot (&v1, &v2));
if (theta >= DTOR ((360 - 1e-7))) {
return (1);
}
return (0);
}
int main(){
int gd = DETECT,gm;
initgraph(&gd,&gm,NULL);
point p1,p2;
point l1,l2;
p1.x=100;
p1.y=100;
p2.x=300;
p2.y=300;
l1.x=80;
l1.y=130;
l2.x=330;
l2.y=150;
rectangle(p1.x, p1.y,p2.x,p2.y);
//line(l1.x,l1.y, l2.x,l2.y);
point n[4];
point p[4];
point w[4];
point d[4];
n[0].x=-1;n[0].y=0;
n[1].x=-1;n[1].y=0;
n[2].x=0;n[2].y=1;
n[3].x=0;n[3].y=-1;
p[0].x=p1.x;p[0].y=p1.y;
p[1].x=p2.x;p[1].y=p2.y;
p[2].x=p1.x;p[2].y=p1.y;
p[3].x=p2.x;p[3].y=p2.y;
psub(l1,p[0],w[0]);
psub(l1,p[1],w[1]);
psub(l1,p[2],w[2]);
psub(l1,p[3],w[3]);
for(int i=0;i<4;i++)
{
d[i].x=l2.x-l1.x;
d[i].y=l2.y-l1.y;
}
int nw[4];
int nd[4];
for(int i=0;i<4;i++){
nw[i]=mul(n[i],w[i]);
nd[i]=mul(n[i],d[i]);
}
float tl=-10000;
float tu=10000;
for(int i=0;i<4;i++)
{
if(nd[i]>0)
{
float tm=nw[i]/nd[i];
if(tm>tl) tl=tm;
}
else
{
float tm=nw[i]/nd[i];
if(tm<tu) tu=tm;
}
}
point rp1;
point rp2;
rp1.x=l1.x+d[0].x*tl;
rp1.y=l1.y+d[0].y*tl;
rp2.x=l1.x+d[0].x*tu;
rp2.y=l1.y+d[0].y*tu;
line(rp1.x,rp1.y, rp2.x,rp2.y);
delay(10000);
closegraph();
return 0;
}
void
old_grounded_moving (void)
{
double now, dt;
struct pt newpos;
struct groundtri *gt;
struct vect v1, v2, ctrl_vel;
now = get_secs ();
dt = now - player.lasttime;
ctrl_vel.x = 0;
ctrl_vel.y = 0;
ctrl_vel.z = 0;
if (player.p.z <= ground_height (&player.p)) {
switch (player.moving) {
case BACK:
ctrl_vel.x = -.3 * player.speed * cos (player.theta);
ctrl_vel.y = -.3 * player.speed * sin (player.theta);
break;
case FORW:
ctrl_vel.x = player.speed * cos (player.theta);
ctrl_vel.y = player.speed * sin (player.theta);
break;
case SIDE_Q:
ctrl_vel.x = player.speed
* cos (player.theta + DTOR (90));
ctrl_vel.y = player.speed
* sin (player.theta + DTOR (90));
break;
case SIDE_E:
ctrl_vel.x = player.speed
* cos (player.theta - DTOR (90));
ctrl_vel.y = player.speed
* sin (player.theta - DTOR (90));
break;
case FORW_Q:
ctrl_vel.x = player.speed
* cos (player.theta + DTOR (45));
ctrl_vel.y = player.speed
* sin (player.theta + DTOR (45));
break;
case FORW_E:
ctrl_vel.x = player.speed
* cos (player.theta - DTOR (45));
ctrl_vel.y = player.speed
* sin (player.theta - DTOR (45));
break;
case BACK_Q:
ctrl_vel.x = -.3 * player.speed
* cos (player.theta - DTOR (45));
ctrl_vel.y = -.3 * player.speed
* sin (player.theta - DTOR (45));
break;
case BACK_E:
ctrl_vel.x = -.3 * player.speed
* cos (player.theta + DTOR (45));
ctrl_vel.y = -.3 * player.speed
* sin (player.theta + DTOR (45));
break;
}
}
newpos.x = player.p.x + ctrl_vel.x * dt;
newpos.y = player.p.y + ctrl_vel.y * dt;
newpos.z = player.p.z + ctrl_vel.z * dt;
psub (&player.vel, &newpos, &player.p);
vscal (&player.vel, &player.vel, 1 / dt);
if ((gt = detect_plane (&newpos)) == NULL) {
printf ("Can't find ground, moving player to start position "
"to avoid seg fault\n");
player.p.x = 0;
player.p.y = 0;
player.p.z = ground_height (&player.p);
player.movtype = GROUNDED;
player.loc = detect_plane (&player.p);
return;
}
if (gt->theta < DTOR (50)) {
newpos.z = ground_height (&newpos);
psub (&player.vel, &newpos, &player.p);
vscal (&player.vel, &player.vel, 1 / dt);
player.p = newpos;
} else if (newpos.z > gt->pl.middle.z) {
player.p = newpos;
player.movtype = FALLING;
printf ("switching to falling\n");
} else if (newpos.z <= gt->pl.middle.z) {
if (gt == player.loc) {
printf ("line %d: some sort of bug caused"
" player to be in grounded mode while"
" on steep plane\n", __LINE__);
pt_on_z_plane (&newpos, &newpos, &player.loc->pl);
player.p = newpos;
printf ("shifting player to nearest point on"
" plane with same z\n");
vset (&player.vel, 0, 0, 0);
printf ("killing player velocity\n");
player.movtype = FALLING;
printf ("switching to falling\n");
paused = YES;
printf ("paused game\n");
return;
}
vnorm (&v2, &ctrl_vel);
vcross (&v1, &player.loc->normv, >->normv);
vnorm (&v1, &v1);
if (vdot (&v1, &v2) < 0)
vscal (&v1, &v1, -1);
vscal (&ctrl_vel, &v1, vdot (&ctrl_vel, &v1));
newpos.x = player.p.x + ctrl_vel.x * dt;
newpos.y = player.p.y + ctrl_vel.y * dt;
newpos.z = player.p.z + ctrl_vel.z * dt;
if ((gt = detect_plane (&newpos)) == NULL) {
printf ("can't detect plane, exiting\n");
exit (1);
}
if (gt->theta < DTOR (50)) {
newpos.z = ground_height (&newpos);
psub (&player.vel, &newpos, &player.p);
vscal (&player.vel, &player.vel, 1 / dt);
printf ("bar\n");
player.p = newpos;
} else {
// struct groundtri *first_col, *last_col, *gt2;
// int i;
//PLAYER STARTS MOVING INTO GROUND BEFORE THIS EVER
//HAPPENS
printf ("pausing\n");
paused = YES;
/* i = 0; */
/* first_col = NULL; */
/* last_col = NULL; */
/* for (gt2 = first_groundtri; gt2; gt2 = gt2->next) { */
/* if (detect_collision (&player.p, */
/* &newpos, gt2)) { */
/* if (first_col == NULL) { */
/* first_col = gt2; */
/* } else { */
/* last_col->next = gt2; */
/* } */
/* last_col = gt2; */
/* i++; */
/* } */
/* } */
/* if (first_col == NULL) { */
/* printf ("%s: %s: %d: something weird\n", */
/* __FILE__, __FUNCTION__, __LINE__); */
/* } */
/* printf ("number of collisions: %d\n", i); */
//TRY PROJECTING PLAYER TO LINE OF INTERSECTION
//BETWEEN OLD & NEW PLANES. IF PLAYER IS STILL
//INSIDE ANY PLANES, GRAB THREE PLANES AND GO
//TO INTERSECTION POINT OF THOSE. MIGHT WANT
//TO CHECK FOR OVER THREE PLANES JUST IN CASE
/* printf ("player.z: %g\n", player.p.z); */
/* newpos = player.p; */
/* rnd_escape (&newpos, gt); */
/* printf ("ran rnd_escape\n"); */
/* gt = detect_plane (&newpos); */
/* double b2; */
/* b2 = newpos.y - (gt->pl.b / gt->pl.a) * newpos.x; */
/* newpos.x = -(b2 * gt->pl.a * gt->pl.b */
/* + gt->pl.c * newpos.z * gt->pl.a */
/* + gt->pl.d * gt->pl.a) */
/* / (square (gt->pl.a) + square (gt->pl.b)); */
/* newpos.y = (gt->pl.b / gt->pl.a) * newpos.x + b2; */
/* player.p = newpos; */
/* printf ("shifting player to nearest point on" */
/* " plane with same z\n"); */
/* gt = detect_plane (&player.p); */
/* printf ("re detected plane\n"); */
/* if (gt->theta >= DTOR (50)) { */
/* printf ("rnd_escape put player on slope," */
/* " changing player to falling\n"); */
/* player.movtype = FALLING; */
/* printf ("killing velocity\n"); */
/* vset (&player.vel, 0, 0, 0); */
/* } */
/* printf ("player.z: %g\n", player.p.z); */
}
} else {
printf ("this should never be printed\n");
}
}
void
grounded_moving (void)
{
double now, dt;
struct pt newpos;
struct groundtri *gt;
struct vect ctrl_vel;
now = get_secs ();
dt = now - player.lasttime;
ctrl_vel.x = 0;
ctrl_vel.y = 0;
ctrl_vel.z = 0;
if (fabs (player.p.z - ground_height (&player.p)) <= 1e6) {
switch (player.moving) {
case BACK:
ctrl_vel.x = -.3 * player.speed * cos (player.theta);
ctrl_vel.y = -.3 * player.speed * sin (player.theta);
break;
case FORW:
ctrl_vel.x = player.speed * cos (player.theta);
ctrl_vel.y = player.speed * sin (player.theta);
break;
case SIDE_Q:
ctrl_vel.x = player.speed
* cos (player.theta + DTOR (90));
ctrl_vel.y = player.speed
* sin (player.theta + DTOR (90));
break;
case SIDE_E:
ctrl_vel.x = player.speed
* cos (player.theta - DTOR (90));
ctrl_vel.y = player.speed
* sin (player.theta - DTOR (90));
break;
case FORW_Q:
ctrl_vel.x = player.speed
* cos (player.theta + DTOR (45));
ctrl_vel.y = player.speed
* sin (player.theta + DTOR (45));
break;
case FORW_E:
ctrl_vel.x = player.speed
* cos (player.theta - DTOR (45));
ctrl_vel.y = player.speed
* sin (player.theta - DTOR (45));
break;
case BACK_Q:
ctrl_vel.x = -.3 * player.speed
* cos (player.theta - DTOR (45));
ctrl_vel.y = -.3 * player.speed
* sin (player.theta - DTOR (45));
break;
case BACK_E:
ctrl_vel.x = -.3 * player.speed
* cos (player.theta + DTOR (45));
ctrl_vel.y = -.3 * player.speed
* sin (player.theta + DTOR (45));
break;
}
}
newpos.x = player.p.x + ctrl_vel.x * dt;
newpos.y = player.p.y + ctrl_vel.y * dt;
newpos.z = player.p.z + ctrl_vel.z * dt;
psub (&player.vel, &newpos, &player.p);
vscal (&player.vel, &player.vel, 1 / dt);
if ((gt = detect_plane (&newpos)) == NULL) {
printf ("Can't find ground, moving player to start position "
"to avoid seg fault\n");
player.p.x = 0;
player.p.y = 0;
player.p.z = ground_height (&player.p);
player.movtype = GROUNDED;
player.loc = detect_plane (&player.p);
return;
}
if (gt->theta < DTOR (50)) {
newpos.z = ground_height (&newpos);
psub (&player.vel, &newpos, &player.p);
vscal (&player.vel, &player.vel, 1 / dt);
player.p = newpos;
} else if (newpos.z > gt->pl.middle.z) {
//imperfect detection of cliffs but tolerable for now
player.p = newpos;
player.movtype = FALLING;
printf ("switching to falling\n");
} else {
if (gt == player.loc) {
printf ("line %d: HORRIBLE MESSINESS\n", __LINE__);
paused = YES;
printf ("paused game\n");
return;
}
struct vect v1, v2;
vnorm (&v2, &ctrl_vel);
vcross (&v1, &player.loc->normv, >->normv);
vnorm (&v1, &v1);
if (vdot (&v1, &v2) < 0)
vscal (&v1, &v1, -1);
vscal (&ctrl_vel, &v1, vdot (&ctrl_vel, &v1));
newpos.x = player.p.x + ctrl_vel.x * dt;
newpos.y = player.p.y + ctrl_vel.y * dt;
newpos.z = player.p.z + ctrl_vel.z * dt;
newpos.z = ground_height (&newpos);
psub (&player.vel, &newpos, &player.p);
vscal (&player.vel, &player.vel, 1 / dt);
player.p = newpos;
}
}
