// Point inside polygon
// Returns true iff p is inside poly.
// PRE: The vertices of poly are ordered (either clockwise or counter-clockwise)
// POST: Modify code inside to handle the special case of "on an edge".
// REQUIRES: polarAngle(), #include <math.h>, #include <vector>, #define EPS 0.000000001
bool pointInPoly(P p, vector<P> &poly) {
int n = poly.size();
double ang = 0.0;
for (int i = n - 1, j = 0; j < n; i = j++) {
P v(poly[i].x - p.x, poly[i].y - p.y);
P w(poly[j].x - p.x, poly[j].y - p.y);
double va = polarAngle(v);
double wa = polarAngle(w);
double xx = wa - va;
if (va < -0.5 || wa < -0.5 || fabs(fabs(xx) - 2 * acos(0)) < EPS){
// POINT IS ON THE EDGE
assert(false);
ang += 2 * acos(0);
continue;
}
if (xx < -2 * acos(0)) ang += xx + 4 * acos(0);
else if (xx > 2 * acos(0)) ang += xx - 4 * acos(0);
else ang += xx;
}
return (ang * ang > 1.0);
}
int main()
{
float xcoord, ycoord;
float pRadius;
float pAngle;
printf("Enter your x and y coordinates: ");
scanf("%f %f", &xcoord, &ycoord);
pAngle = polarAngle(xcoord, ycoord);
pRadius = polarRadius(xcoord, ycoord);
printf("The polar coordinates are (%.2f, %.2f deg)\n", pRadius, pAngle);
}
void Arrow::adaptTriangle() const
{
// Don't draw triangle when arrow is too short or when arrow is actually a line
if (mLength <= zeroVectorTolerance || mStyle == Line)
{
mTriangle = sf::ConvexShape();
}
// Draw normal triangle
else
{
const float end = std::max(mLength, getTriangleHeight());
const float begin = end - getTriangleHeight();
mTriangle.setFillColor(mColor);
mTriangle.setRotation(polarAngle(mDirection));
mTriangle.setPointCount(3);
mTriangle.setPoint(0, sf::Vector2f(end, 0.f));
mTriangle.setPoint(1, sf::Vector2f(begin, 1.5f * mThickness));
mTriangle.setPoint(2, sf::Vector2f(begin, -1.5f * mThickness));
}
}
