check if line hits start and end

[RobbeBruneel]

In my game, players have the ability to draw freely, but for the puzzle element, there is a challenge to determine whether the drawn line touches both the starting and ending marks. I need to verify if the line intersects with both the marks. Is this achievable? Your guidance would be appreciated.

I am interested in a game called ‘The Looker’ as an example of what I am seeking. This game requires the player to draw lines and succeed if they hit the start and end points. this is the kind of mechanic I am looking for?

[Kurt-Dekker]

You can use Vector2.Distance() to compute the distance between any two points.

In your case compare each end of the line to each place it’s supposed to be.

When both are “close enough” (whatever that means in your case), off you go.

Here’s why you must use “close enough” rather than “exactly”:

Floating (float) point imprecision:

Never test floating point (float) quantities for equality / inequality. Here’s why:

https://starmanta.gitbooks.io/unitytipsredux/content/floating-point.html

Debug.Log(2000.0f * 000.1f); is 200

Now that you have had your coffee, don't forget about floating point imprecision: // @kurtdekker: don't forget about floating point imprecision using UnityEngine; public class FloatingPointImprecision : MonoBehaviour { void Start () { float a = 2000.0f; float b = 0.1f; float product = (a * b); float answer = 200; Debug.Log( "a = " + a); Debug.Log( "b = " + b); Debug.Log( "product of a*b = " + product); Debug.Log( "answer …

Why Doesn't This Code Work?

This will explain it all. In an IEEE single-floating point number you can represent certain numbers perfectly and unambiguously. For instance, 0.5f is precisely represented as 0x3f000000 However, 0.1f CANNOT be precisely represented. One possible approximate representation is 0x3DCCCCCD The analogy is that you cannot show 1/3rd precisely as a decimal. 0.33 is correct to 2 decimal places 0.3333 is correct to 4 places etc. But you can never exactly represent 1/3rd as a decimal numeral. Yo…

“Think of [floating point] as JPEG of numbers.” - orionsyndrome on the Unity3D Forums

[RobbeBruneel]

Thank you this helped me a lot