Any idea what i am doing wrong?
https://www.youtube.com/watch?v=j_VCa-5VeP8

On Sunday, 27 December 2015 at 15:53:55 UTC, TheDGuy wrote:
> Any idea what i am doing wrong?
> https://www.youtube.com/watch?v=j_VCa-5VeP8

You could post the code also, personnaly I'm always almost at 2 meters from my screen, with zoom, so I can't read the code...

On Sunday, 27 December 2015 at 16:00:34 UTC, jkpl wrote:
> On Sunday, 27 December 2015 at 15:53:55 UTC, TheDGuy wrote:
>> Any idea what i am doing wrong?
>> https://www.youtube.com/watch?v=j_VCa-5VeP8
>
> You could post the code also, personnaly I'm always almost at 2 meters from my screen, with zoom, so I can't read the code...

Sry:

		Vector3D v = ray.origin.sub(this.center).normalize();
		double a = ray.direction.dot(ray.direction);
		double b = 2.0 * ray.direction.dot(v);
		double c = v.dot(v) - (this.radius * this.radius);
		double discriminant = (b*b) - (4.0*a*c);
		if(discriminant > 0){
			double x1 = (-b - sqrt(discriminant)) / (2.0*a);
			double x2 = (-b + sqrt(discriminant)) / (2.0*a);
			if((x1 >= 0) && (x2 >= 0)){
				return x1;
			}
			if((x1 < 0) & (x2 >= 0)){
				return x2;
			}
			return -1.0;
		}else{
			return -1.0;
		}

On Sunday, 27 December 2015 at 16:01:37 UTC, TheDGuy wrote:
> Sry:
> 			if((x1 < 0) & (x2 >= 0)){

This looks like a bug, with & instead of &&.

-- Simon

On Sunday, 27 December 2015 at 16:39:18 UTC, SimonN wrote:
> On Sunday, 27 December 2015 at 16:01:37 UTC, TheDGuy wrote:
>> Sry:
>> 			if((x1 < 0) & (x2 >= 0)){
>
> This looks like a bug, with & instead of &&.
>
> -- Simon

It looks like the debugger is not working correctly because i changed the code to this:

		if(discriminant > 0){
			double x1 = (-b - sqrt(discriminant)) / (2.0*a);
			double x2 = (-b + sqrt(discriminant)) / (2.0*a);
			if((x1 >= 0) && (x2 >= 0)){
				return x1;
			}
			if((x1 < 0) && (x2 >= 0)){
				return x2;
			}
			return -1.0;
		} else{
			return -1.0;
		}

and the same problem appears.

On Sunday, 27 December 2015 at 16:41:10 UTC, TheDGuy wrote:
> It looks like the debugger is not working correctly because i changed the code to this:
> [...]
> and the same problem appears.

I can't watch youtube here. What numbers does your input generate? Which 'if' doesn't fire? What results would you like instead?

-- Simon

On Sunday, 27 December 2015 at 16:48:44 UTC, SimonN wrote:
> On Sunday, 27 December 2015 at 16:41:10 UTC, TheDGuy wrote:
>> It looks like the debugger is not working correctly because i changed the code to this:
>> [...]
>> and the same problem appears.
>
> I can't watch youtube here. What numbers does your input generate? Which 'if' doesn't fire? What results would you like instead?
>
> -- Simon

I don't understand why my program goes into the if statement if the debugger shows, that the variable "discriminant" is below zero even though:

"if(discriminant > 0)"?

On Sunday, 27 December 2015 at 16:52:39 UTC, TheDGuy wrote:
> I don't understand why my program goes into the if statement if the debugger shows, that the variable "discriminant" is below zero even though:
>
> "if(discriminant > 0)"?

I have a hard time believing this. Does the problem persist if you swap out the entire control flow, beginning with that line, with the following?

        if (discriminant > 0)
                writeln("bigger than zero");
        else
                writeln("not entering the 'if'");

On Sunday, 27 December 2015 at 15:53:55 UTC, TheDGuy wrote:
> Any idea what i am doing wrong?
> https://www.youtube.com/watch?v=j_VCa-5VeP8

Tell me one thing, what is the value returned?


Well It's working here: http://dpaste.dzfl.pl/18b27ea26b08

Maybe you would like to change the code above to look like yours and see what happens?

Bubba.

On Sunday, 27 December 2015 at 18:03:16 UTC, Bubbasaur wrote:
> On Sunday, 27 December 2015 at 15:53:55 UTC, TheDGuy wrote:
>> Any idea what i am doing wrong?
>> https://www.youtube.com/watch?v=j_VCa-5VeP8
>
> Tell me one thing, what is the value returned?
>
>
> Well It's working here: http://dpaste.dzfl.pl/18b27ea26b08
>
> Maybe you would like to change the code above to look like yours and see what happens?
>
> Bubba.

Okay, thanks. It actually returned the right value but it looked like as if it would jump into the 2nd if-statement (as you can see on the video). Strange...