Solved the npoly twist equation. works for n sides greater than 3

2025-09-28 06:55:25 +00:00 · 2022-03-21 11:41:46 +13:00
parent ec6314dae2
commit 6233468037
11 changed files with 412 additions and 12 deletions
--- a/Catalogue/square
+++ b/Catalogue/square
@@ -0,0 +1,81 @@
+<!DOCTYPE html>
+<html>
+<!-- ahhh -->
+
+<body style="margin:0;">
+  <canvas id="myCanvas" width="10" height="10"
+    style="display: block;box-sizing: border-box;">
+    Your browser does not support the HTML5 canvas tag.</canvas>
+  <script>
+    let c = document.getElementById("myCanvas");
+    let ctx = c.getContext("2d");
+    ctx.canvas.width = window.innerWidth;
+    ctx.canvas.height = window.innerHeight;
+
+    let deg_per_sec = 30;
+    let time = 120;
+    let fps = 60;
+
+    centerX = ctx.canvas.width / 2;
+    centerY = ctx.canvas.height / 2;
+
+    rotation = 0; //was = j = angle
+    currentFrame = 0; //was = i
+
+    
+    function render() {
+      if (currentFrame < time / (1 / fps)) {
+        setTimeout(() => {
+          render();
+          render_clear();
+
+          DrawSquareTwist_angle(400,0,rotation,"red")
+         
+        }, 1000 / fps);
+        rotation += deg_per_sec / fps; // was = j = innerRotation, now = rotation
+        currentFrame += 1; // was = i
+      }
+    }
+
+    render();
+
+
+
+function DrawSquareTwist_angle(width, rotation,innerRotation, colour){
+    let out_angle = innerRotation;
+    let widthMultiplier = 1 / (2 * Math.sin(Math.PI / 180 * (130 - out_angle + 90 * Math.floor(out_angle / 90))))+0.5
+
+    for (let i = 0; i < 25; i++) {
+      drawSquare(innerRotation*i,width*widthMultiplier**i, colour)
+    } 
+
+  }
+
+  function drawSquare(angle,size, colour) {
+    ctx.save();
+    ctx.translate(centerX, centerY)//-(Math.sin(rad(angle)) *centerX));
+    ctx.rotate(rad(angle + 180));
+    ctx.beginPath();
+    ctx.strokeStyle = colour;
+    ctx.rect(-size/2, -size/2, size, size);
+    ctx.stroke();
+    ctx.restore();
+    }
+
+    function rad(degrees) {
+      var pi = Math.PI;
+      return degrees * (pi / 180);
+    }
+
+
+
+    function render_clear() {
+      ctx.clearRect(0, 0, ctx.canvas.width, ctx.canvas.height);
+      ctx.fillStyle = "black";
+      ctx.fillRect(0, 0, ctx.canvas.width, ctx.canvas.height);
+    }
+    
+  </script>
+</body>
+
+</html>