Circle vs pie segment collision detection

[paul_nicholls]

You can just cut that out, you mostly just want the TG2Vec2 record and the methods that go with it, Gen2.inc controls some of the compiler directives which you don't need.

Ah ok, no worries

cheers,
Paul

[paul_nicholls]

hmm...the code seems to be returning true for me most of the time, so I get flickering energy discharges at the target as it thinks the circle and pie are intersecting lots...

I am setting up the circle and pie like this:

    BeamHasHitPlayer := False;

    if Assigned(FPlayer) then
    begin
      Circle.c := G2Vec2(FPlayer.x,FPlayer.y);
      Circle.r := FPlayer.Width * 0.4;

      Pie.c := G2Vec2(aSentry.x,aSentry.y);
      Pie.r := aSentry.BeamRange;
      Pie.AngStart := aSentry.Angle - aSentry.BeamWidth/2;
      Pie.AngEnd   := aSentry.Angle + aSentry.BeamWidth/2;

      BeamHasHitPlayer := CircleVsPieIntersect(Circle,Pie);
    end;

Any ideas?

If it helps, the beam width is 50 degrees wide, and the screen coordinate system being used is this (if it makes a difference?):

0,0
+----------------------  +X
|
|
|
|
|
|
|

+Y

cheers,
Paul

[Dan]

The function assumes that the angles are in radians so you might need to multiply your degree angles by (Pi / 180).
EDIT: Here's my test app.

[paul_nicholls]

The function assumes that the angles are in radians so you might need to multiply your degree angles by (Pi / 180)

<Drumroll...> that was it...it is now working, sweet!! thanks mate

<gives a beer>

Now that it is working, I might convert the function to use my plain, vanilla records so lesser versions of Delphi can compile the code too

cheers,
Paul

[Dan]

it was an interesting problem to solve.

[paul_nicholls]

Here is a picture of the Sentry zapping the user character



Thanks again

cheers,
Paul