From a0f580da95631f2d2300fa76f71c1904b7c533c4 Mon Sep 17 00:00:00 2001
From: Catalin Constantin Mititiuc <webdevcat@proton.me>
Date: Sun, 4 Jan 2026 11:01:01 -0800
Subject: [PATCH] WIP: Add edge collision back

---
 html/images/space.svg | 44 ++++++++++++++++++++++++++++++++++---------
 1 file changed, 35 insertions(+), 9 deletions(-)

diff --git a/html/images/space.svg b/html/images/space.svg
index 4b6ea77..347ad83 100644
--- a/html/images/space.svg
+++ b/html/images/space.svg
@@ -118,8 +118,12 @@
   <!-- <polygon class="wall" points="20,-50 10,-50 10,-60 20,-60" /> -->
   <!-- <polygon class="wall" points="-20,50 -10,50 -10,60 -20,60" /> -->
 
-  <polygon class="wall" points="-20,-50 -10,-50 -10,-60 -20,-60" />
-  <polygon class="wall" points="20,50 10,50 10,60 20,60" />
+  <!-- <polygon class="wall" points="-20,-50 -10,-50 -10,-60 -20,-60" /> -->
+  <!-- <polygon class="wall" points="20,50 10,50 10,60 20,60" /> -->
+
+  <!-- <polygon class="wall" points="-100,-50 -10,-50 -10,-60 -100,-60" /> -->
+  <polygon class="wall" points="-100,-60 -10,-60 -10,-50 -100,-50" />
+  <polygon class="wall" points="10,50 100,50 100,60 10,60" />
 
   <!-- <polygon class="wall" points="-10,20 10,10 10,20" /> -->
   <!-- <polygon class="wall" points="20,20 40,20 40,40 20,40" /> -->
@@ -196,7 +200,7 @@
 
     const s = {
       position: { x: 0, y: 0 },
-      velocity: { x: 0, y: 0 },
+      velocity: { x: -10, y: -10 },
 
       // velocity: { x: 5, y: -10 },
       // velocity: { x: -5*mult, y: -10*mult },
@@ -390,7 +394,7 @@
       return walls.reduce((acc, wall) => {
         return [...acc, ...wall.edges.filter(({ xa, ya, xb, yb }) => {
           return [isClockwise, isAcute].every(c => c([xa, ya], [xb, yb], [xc, yc]));
-        }).map(e => { return { edge: e, node: wall }; })];
+        }).map(edge => ({ edge, wall }))];
       }, []);
     }
 
@@ -471,7 +475,7 @@
       }
 
       const { a, b } = perppts;
-      if (a && b) drawLine(a.x, a.y, b.x, b.y);
+      // if (a && b) drawLine(a.x, a.y, b.x, b.y);
 
       return walls.reduce((acc, w) => {
         const filtered = a && b ? w.corners.filter(c => {
@@ -681,7 +685,7 @@
         return c;
       });
 
-      const edge = z.find(({ edge: pts, node: ee }) => {
+      const edge = z.find(({ edge: pts, wall: ee }) => {
         const str = `${pts.xa},${pts.ya} ${pts.xb},${pts.yb}`;
         const r =  Object.is(slope(pts), 0) && s.gearDown ? shipRadius + 1 : shipRadius;
 
@@ -876,7 +880,7 @@
 
       // corners within collision distance
       cwcd = fCollC.filter(withinCollisionDistance({ x, y }, s.velocity));
-      console.log("corners on collision path", cwcd);
+      // console.log("corners on collision path", cwcd);
 
       // cwcd.forEach(c => {
         // const positionSeg = { xa: x, ya: y, xb: xc, yb: yc };
@@ -891,12 +895,32 @@
       ccps = fCollC.filter(cornerCollisionPosition({ x, y }, s.velocity));
       // console.log("corner collision position", ccps);
 
-      console.log("collision edges", collE);
+      // console.log("collision edges", collE);
 
       current = s.collision;
       // s.collision = detectCollisions(position, allWallCorners, collE);
 
-      s.collision = cwcd.find(detectCornerCollision([xc, yc], [x, y], shipRadius));
+      const cornerColl = cwcd.find(detectCornerCollision([xc, yc], [x, y], shipRadius));
+      console.log("edge we are tracking", collE);
+      const edgeColl = collE.find(({ edge, wall }) => {
+        const { xa, ya, xb, yb } = edge;
+        const da = distance(xa, ya, xc, yc);
+        const db = distance(xb, yb, xc, yc);
+        // TODO: calculate this one ahead of time
+        const dc = distance(xa, ya, xb, yb);
+
+        // https://en.wikipedia.org/wiki/Altitude_(triangle)#Altitude_in_terms_of_the_sides
+        // Find altitude of side c (the base)
+        const s = (1 / 2) * (da + db + dc);
+        const hc = (2 / dc) * Math.sqrt(s * (s - da) * (s - db) * (s - dc));
+        console.log("hc", hc);
+
+        return +hc.toFixed(2) <= shipRadius;
+      });
+
+      s.collision = cornerColl || edgeColl;
+
+      console.log("COLLISION", s.collision);
 
       legs.style.display = s.gearDown ? "initial" : "none";
 
@@ -908,6 +932,8 @@
         let posP;
         if (s.collision.corner) {
           posP = cornerContactPosition(xc, yc, x, y, s.collision.corner, shipRadius);
+        } else if (s.collision.edge) {
+          posP = collisionPosition(s.collision.edge, s.position, s.velocity, shipRadius);
         }
 
         s.velocity = { x: 0, y: 0 };