/**
* @name pick_close_point
*
* Choose the edge point that is closest to the critical point. This
* point may not be exactly vertical from the critical point.
*/
EDGEPT *Wordrec::pick_close_point(EDGEPT *critical_point,
EDGEPT *vertical_point,
int *best_dist) {
EDGEPT *best_point = nullptr;
int this_distance;
int found_better;
do {
found_better = false;
this_distance = edgept_dist (critical_point, vertical_point);
if (this_distance <= *best_dist) {
if (!(same_point (critical_point->pos, vertical_point->pos) ||
same_point (critical_point->pos, vertical_point->next->pos) ||
(best_point && same_point (best_point->pos, vertical_point->pos)) ||
is_exterior_point (critical_point, vertical_point))) {
*best_dist = this_distance;
best_point = vertical_point;
if (chop_vertical_creep)
found_better = true;
}
}
vertical_point = vertical_point->next;
}
while (found_better == true);
return (best_point);
}
/**
* @name vertical_projection_point
*
* For one point on the outline, find the corresponding point on the
* other side of the outline that is a likely projection for a split
* point. This is done by iterating through the edge points until the
* X value of the point being looked at is greater than the X value of
* the split point. Ensure that the point being returned is not right
* next to the split point. Return the edge point in *best_point as
* a result, and any points that were newly created are also saved on
* the new_points list.
*/
void Wordrec::vertical_projection_point(EDGEPT *split_point, EDGEPT *target_point,
EDGEPT** best_point,
EDGEPT_CLIST *new_points) {
EDGEPT *p; /* Iterator */
EDGEPT *this_edgept; /* Iterator */
EDGEPT_C_IT new_point_it(new_points);
int x = split_point->pos.x; /* X value of vertical */
int best_dist = LARGE_DISTANCE;/* Best point found */
if (*best_point != nullptr)
best_dist = edgept_dist(split_point, *best_point);
p = target_point;
/* Look at each edge point */
do {
if (((p->pos.x <= x && x <= p->next->pos.x) ||
(p->next->pos.x <= x && x <= p->pos.x)) &&
!same_point(split_point->pos, p->pos) &&
!same_point(split_point->pos, p->next->pos) &&
!p->IsChopPt() &&
(*best_point == nullptr || !same_point((*best_point)->pos, p->pos))) {
if (near_point(split_point, p, p->next, &this_edgept)) {
new_point_it.add_before_then_move(this_edgept);
}
if (*best_point == nullptr)
best_dist = edgept_dist (split_point, this_edgept);
this_edgept =
pick_close_point(split_point, this_edgept, &best_dist);
if (this_edgept)
*best_point = this_edgept;
}
p = p->next;
}
while (p != target_point);
}
/**********************************************************************
* near_point
*
* Find the point on a line segment that is closest to a point not on
* the line segment. Return that point in near_pt. Returns whether
* near_pt was newly created.
**********************************************************************/
bool Wordrec::near_point(EDGEPT *point,
EDGEPT *line_pt_0, EDGEPT *line_pt_1,
EDGEPT **near_pt) {
TPOINT p;
float slope;
float intercept;
float x0 = line_pt_0->pos.x;
float x1 = line_pt_1->pos.x;
float y0 = line_pt_0->pos.y;
float y1 = line_pt_1->pos.y;
if (x0 == x1) {
/* Handle vertical line */
p.x = (inT16) x0;
p.y = point->pos.y;
}
else {
/* Slope and intercept */
slope = (y0 - y1) / (x0 - x1);
intercept = y1 - x1 * slope;
/* Find perpendicular */
p.x = (inT16) ((point->pos.x + (point->pos.y - intercept) * slope) /
(slope * slope + 1));
p.y = (inT16) (slope * p.x + intercept);
}
if (is_on_line (p, line_pt_0->pos, line_pt_1->pos) &&
(!same_point (p, line_pt_0->pos)) && (!same_point (p, line_pt_1->pos))) {
/* Intersection on line */
*near_pt = make_edgept(p.x, p.y, line_pt_1, line_pt_0);
return true;
} else { /* Intersection not on line */
*near_pt = closest(point, line_pt_0, line_pt_1);
return false;
}
}
bool is_valid_rect() {
int i, k;
bool marked[4];
for(i=0;i<4;i++) {
if(lines[i].length_square == 0) {
printf("length_square == 0\n");
return false;
}
marked[i] = false;
}
rect.p[0].x = lines->p[0].x;
rect.p[0].y = lines->p[0].y;
rect.p[1].x = lines->p[1].x;
rect.p[1].y = lines->p[1].y;
marked[0] = true;
bool found;
for(i=2;i<4;i++) {
found = false;
for(k=0;k<4;k++) {
if(!marked[k]) {
if(same_point(lines[k].p, rect.p+i-1)) {
found = true;
rect.p[i].x = lines[k].p[1].x;
rect.p[i].y = lines[k].p[1].y;
marked[k] = true;
break;
}
else if(same_point(lines[k].p+1, rect.p+i-1)) {
found = true;
rect.p[i].x = lines[k].p[0].x;
rect.p[i].y = lines[k].p[0].y;
marked[k] = true;
break;
}
}
}
if(!found) {
return false;
}
}
for(i=0;i<4;i++)
if(!marked[i]) {
if(same_point(lines[i].p, rect.p)) {
if(!(same_point(lines[i].p+1, rect.p+3)))
return false;
}
else if(same_point(lines[i].p+1, rect.p)) {
if(!(same_point(lines[i].p, rect.p+3)))
return false;
}
else
return false;
break;
}
for(i=0;i<4;i++) {
Point *a = i == 0 ? rect.p+3 : rect.p+i-1;
Point *o = rect.p+i;
Point *b = i == 4 ? rect.p : rect.p+i+1;
if(!perpendicular(a, o, b))
return false;
}
return true;
}
/*
* We simplify the pattern recursively, using node "start" as a
* "zipper" to zip the pattern up ("start" moves from left to
* right as the recursion proceeds, and the recusion ends when
* "start" reaches the end of the pattern).
*
* Overall strategy: We "check" whether we can remove "start" without
* changing what ordinal the pointed pattern notates. But if we remove
* "start", we have to remove anything connected to it (via less1,
* or via decompositions), so we have to ask the same question about
* all those nodes as well, which in turn requires asking the same
* question about any node THEY'RE connected to, and so on.
*/
static pattern *simplify_recurse( pattern *p, node *start )
{
node *n;
pattern *q;
/*
* Mark all nodes in the pattern as being unchecked during this iteration
*/
for ( n = p->first_node; n; n = n->next )
n->simplify_data = SIMPL_UNCHECKED;
/*
* Under no circumstances would we remove the pattern's designated point
*/
if ( start == p->point )
{
start = start->next;
if ( !start )
return p;
}
/*
* Attempt to mark "start" for removal.
* If the attempt fails (because it would
* require removing p->point) then move on
* to the next start.
*/
if ( ! mark_for_removal(p,start,start) )
{
if ( !start->next )
return p;
return simplify_recurse( p, start->next );
}
/*
* If "start" was successfully marked for
* removal, then remove it, along with anything
* else that was marked as collateral damage.
* Actually, do all this in a copy q of p.
*/
q = execute_removal(p);
/*
* Check whether the copy q, with "start" removed,
* still notates the same ordinal that p does.
* If so, continue trying to further simplify q.
* If not, revert back to p and increment "start".
*/
if ( same_point(q,p) )
{
start = isom(start,q);
if ( start )
return simplify_recurse( q, start );
else
return q;
}
else
{
if ( start->next )
return simplify_recurse( p, start->next );
else
return p;
}
}
/* Move pt to a random, valid position within the
* but it won't be on the map borders. */
inline Point
random_point_within_rect(Rect r)
{
return (Point) { .x = r.x + (rand() % (r.w - 1)) + 1,
.y = r.y + (rand() % (r.h - 1)) + 1 };
}
/* Move given point one unit in the given direction. */
inline void
move_point(Point p[static 1], int direction)
{
switch (direction) {
case KEY_UP: p->y -= 1; break;
case KEY_LEFT: p->x -= 1; break;
case KEY_DOWN: p->y += 1; break;
case KEY_RIGHT: p->x += 1; break;
}
}
/*** Snake utilities ***/
/* Is this point the snake? */
inline bool
point_is_snake(Point p, Snake s[static 1])
{
for (size_t i = 0; i < s->length; ++i)
if (same_point(p, s->history[i]))
return true;
return false;
}
/* Identical to above, but does not include the head. */
inline bool
point_is_tail(Point p, Snake s[static 1])
{
for (size_t i = 1; i < s->length; ++i)
if (same_point(p, s->history[i]))
return true;
return false;
}
/* Move all the snake's tail pieces up one place, then move its head one unit in
* the given direction. */
void
move_snake(Snake s[static 1], int direction)
{
for (size_t i = s->length; i > 0; --i)
s->history[i] = s->history[i-1];
move_point(&s->history[0], direction);
}
/* Will pathing to this point lose the game? */
inline bool
point_is_unpathable(Point p, Rect r, Snake s[static 1])
{
return (!point_is_within_rect(p, r) || point_is_tail(p, s));
}
/*** Directions ***/
/* Is this integer a valid direction? */
inline bool
input_is_direction(int input)
{
switch (input) {
case KEY_LEFT:
case KEY_UP:
case KEY_RIGHT:
case KEY_DOWN:
return true;
default:
return false;
}
}
/* Return the opposite direction of input */
inline int
opposite_direction(int direction)
{
int opp = ERR;
switch (direction) {
case KEY_LEFT: opp = KEY_RIGHT; break;
case KEY_UP: opp = KEY_DOWN; break;
case KEY_RIGHT: opp = KEY_LEFT; break;
case KEY_DOWN: opp = KEY_UP; break;
}
return opp;
}