WIP: bounce off corners

README.md

@@ -122,5 +122,4 @@ Delete your `.sitegen_cache` file.
 
 --
 
-- Bounce off corners algo
 - Bounce off multiple simultaneous contacts

html/images/space.svg

@@ -127,11 +127,12 @@
   <!-- <polygon class="wall" points="20,-50 10,-50 10,-60 20,-60" /> -->
   <!-- <polygon class="wall" points="-10,10 10,10 10,40 -10,40" /> -->
   <!-- <polygon class="wall" points="-10,-40 10,-40 10,-20 -10,-20" /> -->
+
   <polygon class="wall" points="-10,-40 10,-40 10,-15 -10,-15" />
+  <polygon class="wall" points="-20,-10 20,10 -20,20 -30,0" />
 
   <!-- <polygon class="wall" points="-10,10 10,30 -10,40 -20,20" /> -->
   <!-- <polygon class="wall" points="-20,-10 0,10 -20,20 -30,0" /> -->
-  <polygon class="wall" points="-20,-10 20,10 -20,20 -30,0" />
 
   <!-- <polygon class="wall" points="-20,-50 -10,-50 -10,-60 -20,-60" /> -->
   <!-- <polygon class="wall" points="20,50 10,50 10,60 20,60" /> -->
@@ -476,6 +477,59 @@ const Move = (() => {
     return [...edgeColl, ...cornerColl];
   }
 
+  function vector(x, y) {
+    const vector = { x: x, y: y };
+    vector.magnitude = Math.sqrt(x**2+y**2);
+    vector.dx = vector.x / vector.magnitude;
+    vector.dy = vector.y / vector.magnitude;
+    vector.rightNormal = { x: vector.y, y: -vector.x };
+    vector.rightNormal.dx = vector.rightNormal.x / vector.magnitude;
+    vector.rightNormal.dy = vector.rightNormal.y / vector.magnitude;
+
+    return vector;
+  }
+
+  function bounceVector(v, run, rise) {
+    const vec1 = vector(v.x, v.y);
+    const vec2 = vector(run, rise);
+
+    // From https://stackoverflow.com/a/14886099
+
+    // 1. Find the dot product of vec1 and vec2
+    // Note: dx and dy are vx and vy divided over the length of the vector (magnitude)
+    // var dpA:Number = vec1.vx * vec2.dx + vec1.vy * vec2.dy;
+    const dpA = vec1.x * vec2.dx + vec1.y * vec2.dy;
+
+    // 2. Project vec1 over vec2
+    // var prA_vx:Number = dpA * vec2.dx;
+    const prAvx = dpA * vec2.dx;
+    // var prA_vy:Number = dpA * vec2.dy;
+    const prAvy = dpA * vec2.dy;
+
+    // 3. Find the dot product of vec1 and vec2's normal
+    // (left or right normal depending on line's direction, let's say left)
+    // vec.leftNormal --> vx = vec.vy; vy = -vec.vx;
+    // vec.rightNormal --> vx = -vec.vy; vy = vec.vx;
+    // var dpB:Number = vec1.vx * vec2.leftNormal.dx + vec1.vy * vec2.leftNormal.dy;
+    const dpB = vec1.x * vec2.rightNormal.dx + vec1.y * vec2.rightNormal.dy;
+
+    // 4. Project vec1 over vec2's left normal
+    // var prB_vx:Number = dpB * vec2.leftNormal.dx;
+    const prBvx = dpB * vec2.rightNormal.dx;
+    // var prB_vy:Number = dpB * vec2.leftNormal.dy;
+    const prBvy = dpB * vec2.rightNormal.dy;
+
+    // 5. Add the first projection prA to the reverse of the second -prB
+    // var new_vx:Number = prA_vx - prB_vx;
+    // var new_vy:Number = prA_vy - prB_vy;
+    return {
+      x: prAvx - prBvx,
+      y: prAvy - prBvy,
+      vec1,
+      vec2
+    };
+  }
+
   return {
     update: ({ entity_id }, elapsed) => {
       const { x: px, y: py } = Position[entity_id];
@@ -496,88 +550,46 @@ const Move = (() => {
 
       if (contacts.length !== 0) {
         console.log("!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!");
+        console.log("CONTACTS", contacts);
         let posP;
         const contact = contacts[0];
 
         if (contact.corner) {
-          Velocity[entity_id] = { x: 0, y: 0 };
+          contact.position = cornerContactPosition(p.x, p.y, px, py, contact.corner, s.radius);
+          console.log("contact position", contact.position);
+          drawLine(contact.position.x, contact.position.y, contact.position.x + vx, contact.position.y + vy, "blue");
+
+          const contactV = { x: contact.position.y - contact.corner.y, y: contact.position.x - contact.corner.x };
+          console.log("contactV", contactV);
+          const normalVect = { x:  contact.position.x - contact.corner.x, y: contact.position.y - contact.corner.y };
+          console.log("normal vector", normalVect);
+          drawLine(contact.corner.x, contact.corner.y, contact.corner.x + normalVect.x, contact.corner.y + normalVect.y, "black");
+
+          const tangentVect = { x: normalVect.y, y: -normalVect.x };
+          drawLine(contact.position.x, contact.position.y, contact.position.x + tangentVect.x, contact.position.y + tangentVect.y, "green");
+          contact.velocity = bounceVector(v, tangentVect.x, tangentVect.y);
+
+          console.log("tangent vector", tangentVect);
+
+          drawLine(contact.position.x, contact.position.y, contact.position.x + contact.velocity.x, contact.position.y + contact.velocity.y, "blue");
+
+          // Velocity[entity_id] = { x: 0, y: 0 };
+          Velocity[entity_id] = contact.velocity;
           Position[entity_id] = cornerContactPosition(p.x, p.y, px, py, contact.corner, s.radius);
         } else if (contact.edge) {
           // if (isLandable(contact.edge) && s.gearDown) s.isLanded = true;
-          const isHorizontal = contact.edge.ya === contact.edge.yb;
+          // console.log("CURRENT POSITION", px, py);
-          const isVertical = contact.edge.xa === contact.edge.xb;
+          // console.log("INTENDED POSITION", p.x, p.y);
-
+          // console.log("CONTACT POSITION", contact.position);
-          console.log("CURRENT POSITION", px, py);
-          console.log("INTENDED POSITION", p.x, p.y);
-          console.log("CONTACT POSITION", contact.position);
 
           const rise = contact.edge.yb-contact.edge.ya;
           const run = contact.edge.xb-contact.edge.xa;
 
           drawLine(p.x - v.x, p.y - v.y, p.x, p.y, "blue"); // velocity vector
-          console.log("velocity vector", v.x, v.y);
           const det = v.x * rise - v.y * run;
-          console.log("DEEEEEEEETTTTTTTTTTTTTTT", det);
 
           drawLine(contact.edge.xa, contact.edge.ya, contact.edge.xb, contact.edge.yb, "green"); // edge vector
 
-          let newY;
-          let newX;
-
-          function vector(x, y) {
-            const vector = { x: x, y: y };
-            vector.magnitude = Math.sqrt(x**2+y**2);
-            vector.dx = vector.x / vector.magnitude;
-            vector.dy = vector.y / vector.magnitude;
-            vector.rightNormal = { x: vector.y, y: -vector.x };
-            vector.rightNormal.dx = vector.rightNormal.x / vector.magnitude;
-            vector.rightNormal.dy = vector.rightNormal.y / vector.magnitude;
-
-            return vector;
-          }
-
-
-          function bounceVector(v, run, rise) {
-            const vec1 = vector(v.x, v.y);
-            const vec2 = vector(run, rise);
-
-            // From https://stackoverflow.com/a/14886099
-
-            // 1. Find the dot product of vec1 and vec2
-            // Note: dx and dy are vx and vy divided over the length of the vector (magnitude)
-            // var dpA:Number = vec1.vx * vec2.dx + vec1.vy * vec2.dy;
-            const dpA = vec1.x * vec2.dx + vec1.y * vec2.dy;
-
-            // 2. Project vec1 over vec2
-            // var prA_vx:Number = dpA * vec2.dx;
-            const prAvx = dpA * vec2.dx;
-            // var prA_vy:Number = dpA * vec2.dy;
-            const prAvy = dpA * vec2.dy;
-
-            // 3. Find the dot product of vec1 and vec2's normal
-            // (left or right normal depending on line's direction, let's say left)
-            // vec.leftNormal --> vx = vec.vy; vy = -vec.vx;
-            // vec.rightNormal --> vx = -vec.vy; vy = vec.vx;
-            // var dpB:Number = vec1.vx * vec2.leftNormal.dx + vec1.vy * vec2.leftNormal.dy;
-            const dpB = vec1.x * vec2.rightNormal.dx + vec1.y * vec2.rightNormal.dy;
-
-            // 4. Project vec1 over vec2's left normal
-            // var prB_vx:Number = dpB * vec2.leftNormal.dx;
-            const prBvx = dpB * vec2.rightNormal.dx;
-            // var prB_vy:Number = dpB * vec2.leftNormal.dy;
-            const prBvy = dpB * vec2.rightNormal.dy;
-
-            // 5. Add the first projection prA to the reverse of the second -prB
-            // var new_vx:Number = prA_vx - prB_vx;
-            // var new_vy:Number = prA_vy - prB_vy;
-            return {
-              x: prAvx - prBvx,
-              y: prAvy - prBvy,
-              vec1,
-              vec2
-            };
-          }
-
           // contact.velocity = { x: prAvx - prBvx, y: prAvy - prBvy };
           contact.velocity = bounceVector(v, run, rise);
 
@@ -685,7 +697,7 @@ function init() {
   s.position = { x: 0, y: -10 };
   // s.velocity = { x: 0, y: -10 };
   // s.velocity = { x: 10, y: 20 };
-  s.velocity = { x: 0, y: 0 };
+  s.velocity = { x: 5, y: 0 };
   s.angularVelocity = 0;
 
   // s. velocity = { x: -5*mult, y: 7*mult };
@@ -986,7 +998,7 @@ function drawLine(xa, ya, xb, yb, color = "black") {
   arrow.setAttribute('cx', xb);
   arrow.setAttribute('cy', yb);
   arrow.setAttribute('r', 1);
-  arrow.setAttribute('fill', 'teal');
+  arrow.setAttribute('fill', color);
 
   svg.appendChild(arrow);
   svg.appendChild(el);