Hit-testing
In computer graphics programming, hit-testing is the process of determining whether a user-controlled cursor intersects a given graphical object drawn on the screen. Hit-testing may be performed on the movement or activation of a mouse or other pointing device.
Hit-testing is used by GUI environments to respond to user actions, such as selecting a menu item or a target in a game based on its visual location. In web programming languages such as HTML, SVG, and CSS, this is associated with the concept of pointer-events.
Collision detection is a related concept for detecting intersections of two or more different graphical objects, rather than intersection of a cursor with one or more graphical objects.
Algorithm
There are many different algorithms that may be used to perform hit-testing, with different performance or accuracy outcomes. One common hit-test algorithm for axis aligned bounding boxes. A key idea is that the box being tested must be either entirely above, entirely below, entirely to the right or left of the current box. If this is not possible, they are colliding. Example logic is presented in the pseudo-code below:function HitTest returns boolean
In Python:
def hit_test -> bool:
"""Return true if it hits else return false."""
return not or
or
or
)