void ofxGrahamsScan::scan(LinkedPoint *linkedPoint)
{
LinkedPoint *tempPrev, *tempNext;
if (linkedPoint==firstPoint) //IF RETURNED TO FIRST POINT, DONE
return;
if (!isConvexPoint(linkedPoint)) //IF POINT IS CONCAVE, ELIMINATE FROM PERIMETER
{
tempPrev=linkedPoint->prev;
tempNext=linkedPoint->next;
tempPrev->next=tempNext;
tempNext->prev=tempPrev;
// drawLine(tempPrev, tempNext,3); //DRAW LINE SHOWING NEW EDGE
delete linkedPoint; //FREE MEMORY
scan(tempPrev); //RUN GRAHAM'S SCAN ON PREVIOUS POINT TO CHECK IF CONVEXITY HAS CHANGED IT
}
else //POINT IS CONVEX
{
scan(linkedPoint->next); //PROCEED TO NEXT POINT
}
}
/**
*remove the no convex points when the new point is comming
*/
void unionConvex(convexhull *convex, tuple *newpoint, int eps) {
if (convex == NULL ) {
return;
}
if (convex->numofconvex == 0) {
convex->convexheader = newpoint;
convex->convexheader->next = NULL;
convex->numofconvex++;
return;
} else if (convex->numofconvex == 1) {
convex->convexheader->next = newpoint;
newpoint->next = convex->convexheader;
convex->numofconvex++;
return;
} else if (convex->numofconvex == 2) {
tuple *tmp = convex->convexheader->next;
tmp->next = newpoint;
newpoint->next = convex->convexheader;
convex->numofconvex++;
return;
} else {
int i = 0;
tuple *header = convex->convexheader;
tuple *current = header->next;
tuple *previous = header;
tuple *beginpoint = current;
tuple *tangleOne = NULL;
tuple *tangleTwo = NULL;
bool firstone = false;
bool secondone = false;
bool shouldchangeTangle = false;
while (i <= convex->numofconvex) {
tuple *nextone = current->next;
//print_onetuple(current);
if (nextone == NULL || previous == NULL )
break;
if (isTangentPoint(newpoint, previous, current, nextone)) {
if (firstone == false ) {
tangleOne = current;
firstone = true;
} else {
if (current != tangleOne) {
tangleTwo = current;
secondone = true;
}
}
} else if (firstone == true && secondone == false ) {
if (isConvexPoint(newpoint, previous, current, nextone)) {
shouldchangeTangle = true;
}
}
previous = current;
current = current->next;
/*if(current==beginpoint)
break;*/
i++;
}
int lostnumber = 0;
if (tangleTwo != NULL && tangleOne != NULL ) {
//int value=crossproduct(newpoint, tangleOne, tangleTwo);
//printf("inner product value %d \n", value);
//printf("tangle point one: ");
//print_onetuple(tangleOne);
//printf("tangle point two: ");
//print_onetuple(tangleTwo);
//printf("should change %d \n", shouldchangeTangle);
if (shouldchangeTangle) {
tuple *tmp = tangleTwo;
tangleTwo = tangleOne;
tangleOne = tmp;
}
lostnumber = delete_from_to_connect(convex, tangleOne, tangleTwo,newpoint);
convex->numofconvex = convex->numofconvex - lostnumber + 1;
} else {
//printf("problem \n");
}
}
}