diff --git a/html/images/space.svg b/html/images/space.svg
index 70d6791..ff193e8 100644
--- a/html/images/space.svg
+++ b/html/images/space.svg
@@ -217,41 +217,20 @@
triangles.forEach(t => {
const attr = t.getAttribute('points').split(delim);
- const [[xa, ya], [xb, yb], [xc, yc]] = attr.map(t => t.split(','));
-
- // https://en.wikipedia.org/wiki/Curve_orientation#Practical_considerations
- // Determinant for a convex polygon
- const det = (+xb - +xa) * (+yc - +ya) - (+xc - +xa) * (+yb - +ya);
+ const [a, b,] = attr.map(t => t.split(','));
+ const cw = isClockwise(a, b, [positionX, positionY]);
+ const acute = isAcute(a, b, [positionX, positionY]);
const pos = `${positionX},${positionY}`;
- const isClockwise = det < 0;
- let isAcute = false;
-
- if (isClockwise) {
- const [[ax, ay], [bx, by], [shipx, shipy]] =
- t.getAttribute('points').split(' ').map(n => n.split(',').map(n => +n));
-
- const da = distance(ax, ay, shipx, shipy);
- const db = distance(bx, by, shipx, shipy);
- const dc = distance(ax, ay, bx, by);
-
- // https://en.wikipedia.org/wiki/Law_of_cosines
- // Solve for angles alpha and beta with inverse cosine (arccosine)
- const alpha = Math.acos((db ** 2 + dc ** 2 - da ** 2) / (2 * db * dc));
- const beta = Math.acos((da ** 2 + dc ** 2 - db ** 2) / (2 * da * dc));
- isAcute = alpha < halfPi && beta < halfPi;
- }
if (pos !== attr.pop()) {
attr.push(pos);
t.setAttribute('points', attr.join(delim));
}
- if (drawCollisionLines) {
- t.classList[isClockwise && isAcute ? "add" : "remove"](className);
- t.classList[isClockwise && !isAcute ? "add" : "remove"]("obtuse");
- t.classList[!isClockwise ? "add" : "remove"]("anti-clockwise");
- }
+ t.classList[cw && acute ? "add" : "remove"](className);
+ t.classList[cw && !acute ? "add" : "remove"]("obtuse");
+ t.classList[!cw ? "add" : "remove"]("anti-clockwise");
});
}