void add_segments(DCEL_segment *n,DCEL_segment *act,DCEL_segment *first,
int direction) {
DCEL_segment *k; /* the new segment */
point p;
/* p will contain the point of the segment act that doesn't touch n */
if (point_equal(act->v1,n->v1))
p = act->v2;
else
p = act->v1;
if (visible(direction,n->v1,n->v2,p)) {
/* p is visible from n.v2 */
k = (DCEL_segment *) malloc (sizeof(DCEL_segment));
/* set the coordinats of the new segment */
k->v1 = p; /* The "smallest" point */
k->v2 = n->v2;
if (direction == l) {
/* Add segments left of the new line */
k->p1 = act->p1; /* no 5. */
k->p2 = n; /* no 2. */
k->q1 = act; /* no 4. */
k->q2 = first; /* no 8. */
n->q2 = k; /* no 1. */
/* set_previous_segment_pointer no 7. */
if (point_equal(act->p1->v1,p))
act->p1->q1 = k;
else
act->p1->q2 = k;
act->p1 = k; /* no 6. */
first->p2 = k; /* no 3. */
add_segments(k,k->p1,first,direction); }
else {
/* Add segments right of the new line */
k->q1 = act->q1; /* no 5. */
k->q2 = n; /* no 8. */
k->p1 = act; /* no 4. */
k->p2 = first; /* no 2. */
n->p2 = k; /* no 1. */
/* set_previous_segment_pointer no 7. */
if (point_equal(act->q1->v1,p))
act->q1->p1 = k;
else
act->q1->p2 = k;
act->q1 = k; /* no 6. */
first->q2 = k; /* no 3. */
add_segments(k,k->q1,first,direction); }
}
}
static int cluster_update(array_t *clusters)
{
int k = array_length(clusters);
/* update clusters */
for (int j=0; j<k; j++) {
point_t sum={0,0};
cluster_t *cl = array_at(clusters, j);
point_t old_c = cl->centroid;
int cl_size = array_length(cl->points);
/* sum all points in this cluster */
for (int i=0; i<cl_size; i++) {
point_t *p = array_at(cl->points, i);
sum.x += p->x;
sum.y += p->y;
}
cl->centroid.x = sum.x/cl_size;
cl->centroid.y = sum.y/cl_size;
if (point_equal(&cl->centroid, &old_c)) {
/* cluster centroid didn't move */
return 0;
}
}
return 1;
}
/** Deletes redundant nodes.
* @param pl Polyline
* @param eps A small number used in tests on two points being the same or
* three points belonging to one line.
*/
void poly_compact(poly* pl, double eps)
{
int n = pl->n;
double* x = pl->x;
double* y = pl->y;
int* ids = NULL;
int nnew;
int ileft, imiddle, iright;
int i;
if (n <= 4)
return; /* do not bother */
ids = malloc(pl->n * sizeof(int));
nnew = 0;
for (i = 0, imiddle = 0, ileft = n - 1; i < n - 1; ++i)
if (!point_equal(x[ileft], y[ileft], x[imiddle], y[imiddle], eps))
break;
else
ileft--;
for (i = 0, iright = 1; i < n; ++i) {
if (!point_equal(x[iright], y[iright], x[imiddle], y[imiddle], eps)) {
if (!ononeline(x, y, ileft, imiddle, iright, eps)) {
ids[nnew++] = imiddle;
ileft = imiddle;
}
imiddle = iright;
}
iright = (iright + 1) % n;
}
if (nnew != n) {
for (i = 0; i < nnew; ++i) {
x[i] = x[ids[i]];
y[i] = y[ids[i]];
}
pl->n = nnew;
}
free(ids);
pl->x = realloc(pl->x, sizeof(double) * pl->n);
pl->y = realloc(pl->y, sizeof(double) * pl->n);
pl->nallocated = pl->n;
}
int eat_self(struct snake * s) {
struct point head_pos = s->head->pos;
for (struct bone * b = s->tail;
b != s->head;
b = b->next) {
if (point_equal(b->pos, head_pos)) {
return TRUE;
}
}
return FALSE;
}
void gameloop(int nrow, int ncol) {
timeout(1000 / SAMPLING_RATE);
const clock_t checkpoint = (clock_t) (CLOCKS_PER_SEC/GAME_SPEED);
clock_t last_update = clock();
struct snake * snake = new_snake(ncol/2, nrow/2);
struct point food_pos = generate_food(nrow, ncol, snake);
redraw(snake, food_pos);
for (;;) {
struct point tail_pos = snake->tail->pos;
int ch;
if ((ch = getch()) != ERR) {
switch (ch) {
case KEY_UP:
case KEY_DOWN:
case KEY_LEFT:
case KEY_RIGHT:
if (to_dir(ch) == reverse_dir(snake->heading)) {
break;
}
else {
snake->heading = to_dir(ch);
step_snake(snake);
tail_pos = snake->tail->pos;
redraw(snake, food_pos);
}
break;
default:
break;
}
}
if (clock() - last_update >= checkpoint) {
step_snake(snake);
tail_pos = snake->tail->pos;
redraw(snake, food_pos);
last_update = clock();
}
if (point_equal(snake->head->pos, food_pos)) {
grow_snake(snake, tail_pos);
food_pos = generate_food(nrow, ncol, snake);
redraw(snake, food_pos);
}
if (out_of_border(snake->head->pos, nrow, ncol)
|| eat_self(snake)) {
display_lose(nrow, ncol);
return;
}
if (snake->length == (nrow-2)*(ncol-2)) {
display_win(nrow, ncol);
return;
}
}
}
struct point generate_food(int nrow, int ncol, struct snake * s) {
struct point p;
p.x = rand() % (ncol-2) + 1;
p.y = rand() % (nrow-2) + 1;
for (struct bone * b = s->tail;
b != NULL;
b = b->next) {
if (point_equal(b->pos, p)) {
return generate_food(nrow, ncol, s);
}
}
return p;
}
BOOL stack_has_point(SqStack *stack, Point *p){
Point *base = (Point *)stack->base;
Point *top = (Point *)stack->top;
while(base < top){
if (point_equal(base, p)){
return TRUE;
}
base++;
}
return FALSE;
}
CHpoints *get_points_on_hull(DCEL_segment *left,DCEL_segment *right) {
DCEL_segment *n;
DCEL_segment *end, *tmp;
CHpoints *P=NULL;
end = right;
/* line((int) right->v1.x,(int) right->v1.y,
(int) right->v2.x,(int) right->v2.y); */
point_list_insert(&P,left->v2);
if (left->q1 == right)
tmp=left->p2;
else
tmp=left->p1;
right=left;
left=tmp;
if (left != end) {
while (left != end) {
/* line((int) right->v1.x,(int) right->v1.y,
(int) right->v2.x,(int) right->v2.y); */
if (left->q1 == right) {
point_list_insert(&P,left->v1);
tmp=left->p2; }
else {
point_list_insert(&P,left->v2);
tmp=left->p1; }
right=left;
left=tmp; }
if (left->q1 == right)
point_list_insert(&P,left->v1);
else
point_list_insert(&P,left->v2);
/* line((int) right->v1.x,(int) right->v1.y,
(int) right->v2.x,(int) right->v2.y);*/ }
else {
if (!(point_equal(right->v2,right->v1)))
point_list_insert(&P,right->v1); }
return P;
}
/** Resamples a polyline including only points more than the threshold
* distance apart.
* @param pl Polyline
* @param eps Threshold distance
*/
void poly_resample(poly* pl, double eps)
{
double* xs = pl->x;
double* ys = pl->y;
int n = pl->n;
int i, nn;
if (pl->n <= 1)
return;
for (i = 1, nn = 0; i < n; ++i) {
if (!point_equal(xs[nn], ys[nn], xs[i], ys[i], eps)) {
nn++;
xs[nn] = xs[i];
ys[nn] = ys[i];
}
}
if (pl->n != nn + 1) {
pl->n = nn + 1;
poly_recalcextent(pl);
}
}
static void layer_trace_block_edge__( const layer_type * layer , int_point2d_type start_point , int i , int j , int value , edge_dir_enum dir , struct_vector_type * corner_list, int_vector_type * cell_list) {
int_point2d_type current_point;
int_point2d_type next_point;
current_point.i = i;
current_point.j = j;
next_point = current_point;
if (dir == BOTTOM_EDGE)
point_shift( &next_point , 1 , 0 );
else if (dir == RIGHT_EDGE) {
point_shift( ¤t_point , 1 , 0 );
point_shift( &next_point , 1 , 1 );
} else if (dir == TOP_EDGE) {
point_shift( ¤t_point , 1 , 1 );
point_shift( &next_point , 0 , 1 );
} else if (dir == LEFT_EDGE)
point_shift( ¤t_point , 0 , 1 );
struct_vector_append( corner_list , ¤t_point );
{
int cell_index = i + j*layer->nx;
int_vector_append( cell_list , cell_index );
}
if ( !point_equal(&start_point , &next_point) ) {
if (dir == BOTTOM_EDGE) {
if (layer_iget_edge_value( layer , i,j,RIGHT_EDGE) == value)
layer_trace_block_edge__( layer , start_point , i , j , value , RIGHT_EDGE , corner_list , cell_list);
else if (layer_iget_edge_value( layer , i + 1 , j ,BOTTOM_EDGE) == value)
layer_trace_block_edge__( layer , start_point , i + 1 , j , value , BOTTOM_EDGE , corner_list , cell_list);
else if (layer_iget_edge_value( layer , i + 1 , j - 1 , LEFT_EDGE) == -value)
layer_trace_block_edge__( layer , start_point , i + 1 , j -1 , value , LEFT_EDGE , corner_list , cell_list);
else
util_abort("%s: dir == BOTTOM_EDGE \n",__func__);
}
if (dir == RIGHT_EDGE) {
if (layer_iget_edge_value( layer , i,j,TOP_EDGE) == -value)
layer_trace_block_edge__( layer , start_point , i , j , value , TOP_EDGE , corner_list , cell_list);
else if (layer_iget_edge_value( layer , i , j + 1 ,RIGHT_EDGE) == value)
layer_trace_block_edge__( layer , start_point , i , j + 1, value , RIGHT_EDGE , corner_list , cell_list);
else if (layer_iget_edge_value( layer , i + 1 , j + 1 ,BOTTOM_EDGE) == value)
layer_trace_block_edge__( layer , start_point , i + 1 , j + 1, value , BOTTOM_EDGE , corner_list , cell_list);
else
util_abort("%s: dir == RIGHT_EDGE \n",__func__);
}
if (dir == TOP_EDGE) {
if (layer_iget_edge_value( layer , i , j , LEFT_EDGE) == -value)
layer_trace_block_edge__( layer , start_point , i , j , value , LEFT_EDGE , corner_list , cell_list);
else if (layer_iget_edge_value( layer , i - 1 , j ,TOP_EDGE) == -value)
layer_trace_block_edge__( layer , start_point , i - 1 , j , value , TOP_EDGE , corner_list , cell_list);
else if (layer_iget_edge_value( layer , i - 1 , j + 1 ,RIGHT_EDGE) == value)
layer_trace_block_edge__( layer , start_point , i - 1 , j + 1, value , RIGHT_EDGE , corner_list , cell_list);
else
util_abort("%s: dir == TOP_EDGE \n",__func__);
}
if (dir == LEFT_EDGE) {
if (layer_iget_edge_value( layer , i , j , BOTTOM_EDGE) == value)
layer_trace_block_edge__( layer , start_point , i , j , value , BOTTOM_EDGE , corner_list , cell_list);
else if (layer_iget_edge_value( layer , i , j - 1 , LEFT_EDGE) == -value)
layer_trace_block_edge__( layer , start_point , i , j - 1, value , LEFT_EDGE , corner_list , cell_list);
else if (layer_iget_edge_value( layer , i -1 , j - 1 , TOP_EDGE) == -value)
layer_trace_block_edge__( layer , start_point , i-1 , j - 1, value , TOP_EDGE , corner_list , cell_list);
else
util_abort("%s: dir == LEFT_EDGE \n",__func__);
}
}
}
/** Checks whether the polyline is closed.
* @param pl Polyline
* @param eps Distance tolerance
* @return 1 for yes, 0 for no
*/
int poly_isclosed(poly* pl, double eps)
{
return pl->n > 1 && point_equal(pl->x[0], pl->y[0], pl->x[pl->n - 1], pl->y[pl->n - 1], eps);
}
bool line_ispoint(line l)
{
return (point_equal(l->v1,l->v2));
}
/*!\fn bool line_equal(line l1, line l2)
Compara dos segmentos de linea, en este caso el orden de los extremos
importa en la operacion
\param [in] l1 Linea en 2 dimensiones
\param [in] l2 Linea en 2 dimensiones
\return Verdadero si los segmentos de recta son iguales,
falso en caso contrario
*/
bool line_equal(line l1, line l2)
{
return (point_equal(l1->v1,l2->v1) && point_equal(l1->v2, l2->v2));
}