100 lines
3.1 KiB
HTML
100 lines
3.1 KiB
HTML
<!DOCTYPE html>
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<html>
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<!-- ahhh -->
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<body style="margin:0;">
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<canvas id="myCanvas" width="10" height="10"
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style="display: block;box-sizing: border-box;">
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Your browser does not support the HTML5 canvas tag.</canvas>
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<script>
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let c = document.getElementById("myCanvas");
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let ctx = c.getContext("2d");
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ctx.canvas.width = window.innerWidth;
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ctx.canvas.height = window.innerHeight;
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let deg_per_sec = 30;
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let time = 120;
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let fps = 60;
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centerX = ctx.canvas.width / 2;
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centerY = ctx.canvas.height / 2;
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rotation = 0; //was = j = angle
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currentFrame = 0; //was = i
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function render() {
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if (currentFrame < time / (1 / fps)) {
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setTimeout(() => {
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render();
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render_clear();
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// DrawTriangleTwist_angle(400,0,rotation,"red")
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DrawTriangleTwist_width(400,0,rotation,"red")
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}, 1000 / fps);
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rotation += deg_per_sec / fps; // was = j = innerRotation, now = rotation
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currentFrame += 1; // was = i
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}
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}
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render();
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function DrawTriangleTwist_angle(width, rotation,innerRotation, colour){
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let out_angle = innerRotation;
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// let widthMultiplier = 1 / (2 * Math.sin(Math.PI / 180 * (150 - innerRotation + 120 * Math.floor(innerRotation / 120))))
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let widthMultiplier = 1 / (2 * Math.sin(Math.PI / 180 * (150 - out_angle + 120 * Math.floor(out_angle / 120))))
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for (let i = 0; i < 25; i++) {
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draw_triangle(180+innerRotation*i,width*widthMultiplier**i, colour)
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}
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}
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function DrawTriangleTwist_width(width, rotation,innerRotation, colour){
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let out_angle = 0
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let innerAngle = innerRotation - (120*Math.floor(innerRotation/120));
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if (innerAngle < 60) {
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out_angle = 120 / (2 * Math.cos(rad(innerAngle))) - 60
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}
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else {
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out_angle = -120 / (2 * Math.cos(2 * Math.PI / 3 - (innerAngle * Math.PI / 180))) + 180
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}
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let widthMultiplier = 1 / (2 * Math.sin(Math.PI / 180 * (150 - out_angle + 120 * Math.floor(out_angle / 120)))) //150 = 90+innerangle/2
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for (let i = 0; i < 25; i++) {
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draw_triangle(180+out_angle*i,width*widthMultiplier**i, colour)
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}
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}
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function draw_triangle(ang, radius, colour) {
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ctx.beginPath();
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ctx.moveTo(centerX + Math.cos(rad(90 + 120 * 1 + ang)) * radius, centerY + Math.sin(rad(90 + 120 * 1 + ang)) * radius);
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ctx.lineTo(centerX + Math.cos(rad(90 + 120 * 2 + ang)) * radius, centerY + Math.sin(rad(90 + 120 * 2 + ang)) * radius);
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ctx.lineTo(centerX + Math.cos(rad(90 + 120 * 3 + ang)) * radius, centerY + Math.sin(rad(90 + 120 * 3 + ang)) * radius);
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ctx.lineTo(centerX + Math.cos(rad(90 + 120 * 1 + ang)) * radius, centerY + Math.sin(rad(90 + 120 * 1 + ang)) * radius);
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ctx.strokeStyle = colour;
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ctx.stroke();
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}
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function rad(degrees) {
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var pi = Math.PI;
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return degrees * (pi / 180);
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}
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function render_clear() {
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ctx.clearRect(0, 0, ctx.canvas.width, ctx.canvas.height);
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ctx.fillStyle = "black";
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ctx.fillRect(0, 0, ctx.canvas.width, ctx.canvas.height);
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}
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</script>
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</body>
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</html> |