animate/Catalogue/npoly twist.html

179 lines
6.1 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
let depth = 300 //custom to npoly twist
function render() {
if (currentFrame < time / (1 / fps)) {
setTimeout(() => {
render();
render_clear();
colour1 = [255, 0, 0];
colour2 = [0, 0, 0];
DrawPolyTwistColour_angle(15,400,-90,rotation/20,colour1, colour2)
// DrawPolyTwist_angle(15,400,-90,rotation/20,"red")
// DrawPolyTwistColour_width(4,400,-45,rotation/4,colour1,colour2)
// DrawPolyTwist_width(10,400,-90,rotation/20,"red")
}, 1000 / fps);
rotation += deg_per_sec / fps; // was = j = innerRotation, now = rotation
currentFrame += 1; // was = i
}
}
render();
function DrawPolyTwist_angle(sides,width, rotation,innerRotation, colour){
let out_angle = innerRotation;
let innerAngle = 180 - ((sides-2) *180/sides);
let minWidth = Math.sin(rad(innerAngle/2))*(0.5/Math.tan(rad(innerAngle/2)))*2;
let widthMultiplier = minWidth / Math.sin(Math.PI / 180 * (90+innerAngle/2 - out_angle + innerAngle * Math.floor(out_angle / innerAngle)))
for (let i = 0; i < depth; i++) {
DrawPolygon(sides,width*widthMultiplier**i,innerRotation*i, colour)
}
}
function DrawPolyTwist_width(sides,width, rotation,innerRotation, colour){
let out_angle = 0
let innerAngle = 180 - ((sides-2) *180/sides);
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;
let widthMultiplier = minWidth / Math.sin(Math.PI / 180 * (90+innerAngle/2 - out_angle + innerAngle * Math.floor(out_angle / innerAngle)))
for (let i = 0; i < depth; i++) {
DrawPolygon(sides,width*widthMultiplier**i,out_angle*i+rotation, colour)
}
}
function DrawPolyTwistColour_angle(sides,width, rotation,innerRotation,colour1,colour2){
let out_angle = innerRotation;
let innerAngle = 180 - ((sides-2) *180/sides);
let minWidth = Math.sin(rad(innerAngle/2))*(0.5/Math.tan(rad(innerAngle/2)))*2;
let widthMultiplier = minWidth / Math.sin(Math.PI / 180 * (90+innerAngle/2 - out_angle + innerAngle * Math.floor(out_angle / innerAngle)))
for (let i = 0; i < depth; i++) {
let fraction = i/depth;
// let fraction = Math.cos(rad(i / 2));
// let fraction = (-1*(i-depth)**2)/depth**2+1
let ncolour = LerpRGB(colour1,colour2,fraction);
// let ncolour = LerpRGB(colour1,colour2,((i-depth)**2)/depth**2);
DrawPolygon(sides,width*widthMultiplier**i,out_angle*i+rotation, colourToText(ncolour))
}
}
function DrawPolyTwistColour_width(sides,width, rotation,innerRotation, colour1,colour2){
let out_angle = 0
let innerAngle = 180 - ((sides-2) *180/sides);
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;
let widthMultiplier = minWidth / Math.sin(Math.PI / 180 * (90+innerAngle/2 - out_angle + innerAngle * Math.floor(out_angle / innerAngle)))
for (let i = 0; i < depth; i++) {
// let ncolour = LerpRGB(colour1,colour2,i/depth);
let fraction = i/depth;
// let fraction = Math.cos(rad(i / 2));
// let fraction = (-1*(i-depth)**2)/depth**2+1
let ncolour = LerpRGB(colour1,colour2,fraction);
// let ncolour = LerpRGB(colour1,colour2,((i-depth)**2)/depth**2);
DrawPolygon(sides,width*widthMultiplier**i,out_angle*i+rotation, colourToText(ncolour))
}
}
function DrawPolygon(sides, width, rotation, colour) {
ctx.beginPath();
ctx.moveTo (centerX + width * Math.cos(rotation*Math.PI/180), centerY + width * Math.sin(rotation*Math.PI/180));
for (var i = 1; i <= sides; i += 1) {
ctx.lineTo(
centerX + width * Math.cos(i * 2 * Math.PI / sides + (rotation*Math.PI/180)),
centerY + width * Math.sin(i * 2 * Math.PI / sides + (rotation*Math.PI/180))
);
}
ctx.strokeStyle = colour;
ctx.lineWidth = 1;
ctx.stroke();
}
function rad(degrees) {
var pi = Math.PI;
return degrees * (pi / 180);
}
function colourToText(colour) {
return "rgb(" + colour[0] + "," + colour[1] + "," + colour[2] + ")"
}
function LerpRGB(a, b, t) {
if (t < 0) {
t *= -1;
}
var newColor = [0, 0, 0];
newColor[0] = a[0] + (b[0] - a[0]) * t;
newColor[1] = a[1] + (b[1] - a[1]) * t;
newColor[2] = a[2] + (b[2] - a[2]) * t;
return newColor;
}
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>