animate/Catalogue/npoly twist - accident.html

141 lines
5.1 KiB
HTML

<!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_width(7,400,0,rotation,"red")
// DrawSquareTwist_angle(3,400,0,rotation,"red")
}, 1000 / fps);
rotation += deg_per_sec / fps; // was = j = innerRotation, now = rotation
currentFrame += 1; // was = i
}
}
render();
function DrawSquareTwist_angle(sides,width, rotation,innerRotation, colour){
let out_angle = innerRotation;
// let widthMultiplier = 169 / (239 * Math.sin(Math.PI / 180 * (135 - out_angle + 90 * Math.floor(out_angle / 90))))
// let widthMultiplier = Math.sqrt(0.5) * 1/ (Math.sin(Math.PI / 180 * (135 - out_angle + 90 * Math.floor(out_angle / 90))))
let widthMultiplier = Math.sqrt(0.5) * 1/ (Math.sin(Math.PI / 180 * (135 - out_angle + 90 * Math.floor(out_angle / 90))))
for (let i = 0; i < 25; i++) {
DrawPolygon(sides,width*widthMultiplier**i,innerRotation*i, colour)
}
}
function DrawSquareTwist_width(sides,width, rotation,innerRotation, colour){
// if(innerRotation >59){
// innerRotation=59
// }
let out_angle = 0
let innerAngle = 180 - ((sides-2) *180/sides);
// console.log(innerAngle);
let scopeAngle = innerRotation - (innerAngle*Math.floor(innerRotation/innerAngle));
if (scopeAngle < innerAngle/2) {
out_angle = innerAngle / (2 * Math.cos((2*Math.PI*scopeAngle)/(3*innerAngle))) - innerAngle/2
}
else {
out_angle = -innerAngle / (2 * Math.cos( ((2*Math.PI)/3) - ((2*Math.PI*scopeAngle)/(3*innerAngle))) ) + (innerAngle*3)/2
}
let minWidth = Math.sin(rad(innerAngle/2))*(0.5/Math.tan(rad(innerAngle/2)))*2;
console.log(minWidth);
// let widthMultiplier = 169 / (239 * Math.sin(Math.PI / 180 * (135 - out_angle + 90 * Math.floor(out_angle / 90))))
// let widthMultiplier = Math.sqrt(0.5) * 1/ (Math.sin(Math.PI / 180 * (((innerAngle/2)*3) - out_angle + innerAngle * Math.floor(out_angle / innerAngle))))
// let widthMultiplier = 1 / (2 * Math.sin(Math.PI / 180 * (150 - out_angle + 120 * Math.floor(out_angle / 120)))) //triangle
let widthMultiplier = minWidth / Math.sin(Math.PI / 180 * (90+innerAngle/2 - out_angle + innerAngle * Math.floor(out_angle / innerAngle))) //triangle
console.log(innerRotation + ": " + out_angle);
for (let i = 0; i < 25; i++) {
DrawPolygon(sides,width*widthMultiplier**i,out_angle*i, colour)
// draw_triangle(180+out_angle*i,width*widthMultiplier**i, colour)
}
}
function DrawPolygon(sides, width, rotation, colour) {
ctx.beginPath();
ctx.moveTo(centerX + width * Math.cos(((rotation*4)*Math.PI/180) / sides), centerY + width * Math.sin(((rotation*4)*Math.PI/180) / sides));
for (var i = 1; i <= sides; i += 1) {
ctx.lineTo(
centerX + width * Math.cos((i * 2 * Math.PI +((rotation*4)*Math.PI/180)) / sides),
centerY + width * Math.sin((i * 2 * Math.PI +((rotation*4)*Math.PI/180)) / sides)
);
}
ctx.strokeStyle = colour;
ctx.lineWidth = 1;
ctx.stroke();
}
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 draw_triangle(ang, radius, colour) {
ctx.beginPath();
ctx.moveTo(centerX + Math.cos(rad(90 + 120 * 1 + ang)) * radius, centerY + Math.sin(rad(90 + 120 * 1 + ang)) * radius);
ctx.lineTo(centerX + Math.cos(rad(90 + 120 * 2 + ang)) * radius, centerY + Math.sin(rad(90 + 120 * 2 + ang)) * radius);
ctx.lineTo(centerX + Math.cos(rad(90 + 120 * 3 + ang)) * radius, centerY + Math.sin(rad(90 + 120 * 3 + ang)) * radius);
ctx.lineTo(centerX + Math.cos(rad(90 + 120 * 1 + ang)) * radius, centerY + Math.sin(rad(90 + 120 * 1 + ang)) * radius);
ctx.strokeStyle = colour;
ctx.stroke();
}
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>