Mouse click in circle

[led]

Hey,
I'm trying to click inside a image that has a circle in it (its centered) with the mouse so i tried doing a circle using the sf::Shape and checking if the X,Y of the mouse is inside the X,Y of the circle but ofcourse it doesnt work (silly idea). How can I know if the Mouse is been clicked inside the circle?

[K-Bal]

Create a vector that contains the difference of your mouse click and the object location and check if the length of this vector is lower than your radius.

[led]

How am I able to do that? X1-X2 and Y1-Y2 <=24?

EDIT: Got it working following this example http://www.bigresource.com/Tracker/Track-vb-AjRXbampf6/

Code: [Select]


int dx= Window.GetInput().GetMouseX() - sprite1.GetPosition().x;
int dy= Window.GetInput().GetMouseY() - sprite1.GetPosition().y;
if (dx < 0) { dx = dx - (dx * 2); }
if (dy < 0) { dy = dy - (dy * 2); }
float d1= dx * dx;
float d2= dy * dy;
float d3= d1+d2;
float d = sqrt(d3);

if (d <= 24)
sprite1.SetColor(Color(0,0,0,0));
Thanks anyway :wink:

[Dravere]

What the? The following lines are just nonsense:

Code: [Select]


if (dx < 0) { dx = dx - (dx * 2); }
if (dy < 0) { dy = dy - (dy * 2); }

1. You don't need them. If a value is negative, then the value multiplied with itself will be positive anyway.
2. It would have been easier to write: dx = -dx;

Also as an recommendation:
Don't take the square root. Instead compare against the squared radius.

And perhaps you should read this:
http://en.wikipedia.org/wiki/Euclidean_vector

Dravere