Not clear what polygon shapes are allowed

[whitespacecode]

Okay maybe i'm doing something wrong but i'm building 2 polygon's and i want to detect wether the second shape is not colliding anymore with the first shape.

I found the collision would treat the first polygon using it bounds shape instead of the real shape. So it still treats the first polygon as a box shape instead of the L shape i'm building.

Setup for the first polygon is a shape

new Polygon(new Vector(), [
        new Vector(185,0),
        new Vector(185,160),
        new Vector(0,160),
        new Vector(0,270),
        new Vector(500,270),
        new Vector(500,0),
        new Vector(185,0),
]);

Setup for the second polygon, that can move around

new Polygon(new Vector(mouseposition.x, mouseposition.y), [
    new Vector(-object.width, -object.height),
    new Vector( object.width, -object.height),
    new Vector( object.width,  object.height),
    new Vector(-object.width,  object.height)
]);

Testing the collision

function isWithinBounds(objectPolygon, roomPolygon) {
    return testPolygonPolygon(objectPolygon, roomPolygon)
}

Visual representation what is happening. The object is clearly 'outside' the other polygon but it's still detecting collision. I'm using Pixijs to draw the polygon's i get using 'drawPolygon' and passing the polygon.points.

[whitespacecode]

Found my mistake.

Collisions uses the Separating Axis Theorem (SAT) for its narrow-phase collision tests. One caveat to SAT is that it only works properly on convex bodies.

So knowing what the limitations where i used a different library to decompose my Polygon into different convex bodies. Then looping the polygons and test for collision

const decomposedPolygons = decomposePolygon(roomPolygon.points);

for (let i = 0; i < decomposedPolygons.length; i++) {
      if (testPolygonPolygon(objectPolygon, decomposedPolygons[i])) {
          return false; // Collision detected, object is in bounds
      }
}

I used https://github.com/schteppe/poly-decomp.js to convert my polygon