Efficient way to detect mouseover in SFML - c++

Question

I recently started to work on a 2D Tower Defense game in SFML, and I intend to put in several visual gimmicks and other functionalities that occur when the mouse hovers over certain objects (menu items, enemies, etc.). To that end, I have to constantly check whether the mouse is hovering over such an object, many of which may be moving around and have varying sizes and shapes. Does anyone know of a fast and efficient way to accomplish this?
A brute force method to solve this would be to simply check for every single object in the game world whether the mouse position intersects their bounding rectangle. My game is rather simple, so normally it would be overkill to optimize it here, but I also intend to implement more complex components elsewhere, and I wish to make sure the program wastes as little resources on the graphics as possible.
Beyond that, I've read a number of various solutions that might work, such as keeping track of objects in a grid/quadtree and only checking the area where the mouse is. There was also a solution through raycasting, but as far as I know, SFML itself doesn't have it built in. Since I assume I'm not the only one who had to work this out, I'm hoping there is some kind of solution for this that I missed. Any ideas?
Thanks in advance for helping out!

Answer 1

I'm also writing TD game right now, i started it this month using SFML too. that was also my problem last last day, and came up with this idea. i dont know if this is the standard way to do this but this is better than my first attempt of testing the entire game objects. and hoping to came up with better solution lol
i have 3 areas of my game window, which is:
MAP - the place where map,enemy is and where you build tower
SHOP - where you buy towers
INFORMATION - if you click enemy or tower or something, the information will appear in this area
then i wrote a Boundary class which defines the boundary of an area.
Example:
Boundary shopBoundary;
Boundary mapBoundary;
Boundary infoBoundary;
i can also add another Boundary if i want to add another area ( maybe area where i can click special buffs for tower? ) then i will just do this
Boundary buffsBoundary;
so this is how i do the trick
i created an enum which defines mouse location
enum AREAS { NONE, SHOP, MAP, INFO }
Areas mLoc = NONE;
i created a struct that stores an AREAS which will be use to name that area and a boundary object for the boundary of that area.
struct _Boundary
{
Areas area;
Boundary boundary;
bool isMouseInside(const sf::Vector2i v) const
{
return boundary.isMouseInside(v);
}
}
std::vector<_Boundary> boundaries; // now put all your boundary to a container
now everytime mouse move, i will only have to check where the mouse is using only 3 iteration ( for map, shop and information )
if ( mouse moved )
{
for ( int a = 0; a < boundaries.size(); a++ )
{
if ( boundaries[a].isMouseInside(mousePos) )
{
mLoc = boundaries[a].area;
break;
}
}
}
with that loop, i will be able to track where ever the mouse go by checking mLoc, by having to know the location while the clicked is occured it will narrow the game objects you need to check, (if mouse location is in shop area and then when clicked occured,check only the game objects on that area)
if ( mouse button pressed )
{
if ( click mouse left )
{
if ( mLoc == SHOP )
{
// the click has been occured in shop
// check the game objects relative to shop
}
else if ( mLoc == MAP )
{
// the click has been occured in map
// check the game objects relative to map
}
else if ( mLoc == INFO )
{
// the click has been occured in information
// check game objects relative to that area
}
}
}