From c3bd622841c58b774fb08181c487b195d3de722b Mon Sep 17 00:00:00 2001
From: Catalin Constantin Mititiuc <webdevcat@proton.me>
Date: Thu, 18 Dec 2025 14:45:45 -0800
Subject: [PATCH] Find determinant

---
 html/images/space.svg | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/html/images/space.svg b/html/images/space.svg
index 8bfe212..8777ad1 100644
--- a/html/images/space.svg
+++ b/html/images/space.svg
@@ -149,9 +149,14 @@
 
       triangles.forEach(triangle => {
         const attr = triangle.getAttribute('points').split(delim)
+        const [[xa, ya], [xb, yb], [xc, yc]] = attr.map(t => t.split(',').map(n => +n));
+        const det = (xb - xa) * (yc - ya) - (xc - xa) * (yb - ya);
         attr.pop();
         attr.push(`${positionX},${positionY}`);
         triangle.setAttribute('points', attr.join(delim));
+        triangle.style.fill = det < 0 ? "white" : "none";
+        triangle.style.stroke = det < 0 ? "red" : "none";
+        // i think i can also discard obtuse triangles?
       });
     }