File size: 7,447 Bytes
377fc96 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 | <script lang="ts">
// The world behind every screen: the flux HomeBackdrop (animated: glow, three god
// rays, three faceted ridges with scroll parallax, drifting motes, grain) and the
// PageBackdrop (still: glow, two ridges, grain), ported from SkSL to GLSL ES. One
// fixed canvas; the still variant paints once and on resize.
import { onMount } from 'svelte';
export let animated = false;
export let light = false;
// HOME_BIOME from flux theme/biome.ts, as 0-1 triples.
const rgb = (hex: string) => [0, 1, 2].map((i) => parseInt(hex.slice(1 + i * 2, 3 + i * 2), 16) / 255);
const DARK = {
top: rgb('#17252f'),
bottom: rgb('#0c1319'),
glow: rgb('#8FC6BF'),
terrain: rgb('#0f1a20'),
mote: rgb('#B5E3DC'),
};
// Light mode: the paper field, the signature as a quarter-strength glow, no motes.
const LIGHT = {
top: rgb('#F2F4F5'),
bottom: rgb('#E6EBEE'),
glow: rgb('#35576B'),
terrain: rgb('#D5DEE3'),
mote: rgb('#35576B'),
};
$: PALETTE = light ? LIGHT : DARK;
const VERT = 'attribute vec2 a; void main() { gl_Position = vec4(a, 0.0, 1.0); }';
const HEAD = `precision highp float;
uniform vec2 res; uniform float time; uniform float scroll;
uniform vec3 top; uniform vec3 bottom; uniform vec3 glow; uniform vec3 terrain; uniform vec3 mote;
uniform float strength; uniform float motes;
float hash(float n) { return fract(sin(n * 127.1) * 43758.5453); }
`;
// HomeBackdrop.tsx SRC, line for line.
const HOME = HEAD + `
float ridge(float x, float seed, float base, float amp) {
float seg = floor(x * 7.0);
float f = fract(x * 7.0);
float a = hash(seg + seed * 91.7);
float b = hash(seg + 1.0 + seed * 91.7);
return base + amp * mix(a, b, f);
}
float ray(vec2 uv, float offset, float slope, float width) {
float x = uv.x - 0.5 - offset - uv.y * slope;
float fall = 1.0 - smoothstep(0.0, 0.85, uv.y);
return (1.0 - smoothstep(0.0, width, abs(x))) * fall;
}
void main() {
vec2 xy = vec2(gl_FragCoord.x, res.y - gl_FragCoord.y);
vec2 uv = xy / res;
vec3 col = mix(top, bottom, smoothstep(0.05, 1.0, uv.y));
float d = distance(uv * vec2(1.0, 1.6), vec2(0.5, 0.16));
col += glow * exp(-d * d * 9.0) * 0.16 * strength;
float rays = ray(uv, -0.12, -0.30, 0.040) + ray(uv, 0.02, 0.04, 0.060) + ray(uv, 0.15, 0.34, 0.040);
col += glow * rays * 0.10 * strength;
float farY = ridge(uv.x + scroll * 0.00002, 3.0, 0.62, 0.12);
col = mix(col, mix(terrain, top, 0.55), smoothstep(farY, farY + 0.004, uv.y));
float midY = ridge(uv.x + scroll * 0.00004 + 0.53, 5.0, 0.72, 0.11);
col = mix(col, terrain, smoothstep(midY, midY + 0.004, uv.y));
float nearY = ridge(uv.x + scroll * 0.00008 + 0.37, 7.0, 0.82, 0.10);
col = mix(col, mix(terrain, bottom, 0.6), smoothstep(nearY, nearY + 0.003, uv.y));
for (float i = 0.0; i < 9.0; i += 1.0) {
vec2 p = vec2(hash(i + 1.0), hash(i + 40.0));
p.y = fract(p.y * 0.8 + 0.1 - time * (0.008 + 0.012 * hash(i + 80.0)));
p.x += sin(time * 0.3 + i) * 0.015;
float flicker = 0.35 + 0.65 * abs(sin(time * (0.6 + hash(i)) + i * 2.0));
float md = distance(uv * vec2(res.x / res.y, 1.0), p * vec2(res.x / res.y, 1.0));
col += mote * exp(-md * md * 90000.0) * flicker * 0.35 * motes;
col += mote * exp(-md * md * 9000.0) * flicker * 0.045 * motes;
}
float grain = hash(xy.x + xy.y * 311.7 + fract(time) * 17.0) - 0.5;
col += grain * 0.025;
gl_FragColor = vec4(col, 1.0);
}`;
// PageBackdrop.tsx SRC, line for line.
const PAGE = HEAD + `
float ridge(float x, float seed, float base, float amp) {
float seg = floor(x * 6.0);
float f = fract(x * 6.0);
float a = hash(seg + seed * 91.7);
float b = hash(seg + 1.0 + seed * 91.7);
return base + amp * mix(a, b, f);
}
void main() {
vec2 xy = vec2(gl_FragCoord.x, res.y - gl_FragCoord.y);
vec2 uv = xy / res;
vec3 col = mix(top, bottom, smoothstep(0.0, 1.0, uv.y));
float d = distance(uv * vec2(1.0, 1.7), vec2(0.5, 0.06));
col += glow * exp(-d * d * 7.0) * 0.13 * strength;
float farY = ridge(uv.x, 3.0, 0.80, 0.10);
col = mix(col, mix(terrain, top, 0.5), smoothstep(farY, farY + 0.004, uv.y));
float nearY = ridge(uv.x + 0.37, 7.0, 0.90, 0.08);
col = mix(col, mix(terrain, bottom, 0.55), smoothstep(nearY, nearY + 0.003, uv.y));
float grain = hash(xy.x + xy.y * 311.7) - 0.5;
col += grain * 0.02;
gl_FragColor = vec4(col, 1.0);
}`;
let canvas: HTMLCanvasElement;
let failed = false;
onMount(() => {
const gl = canvas.getContext('webgl', { antialias: false, alpha: false, preserveDrawingBuffer: false });
if (!gl) {
failed = true;
return;
}
const compile = (type: number, src: string) => {
const s = gl.createShader(type)!;
gl.shaderSource(s, src);
gl.compileShader(s);
if (!gl.getShaderParameter(s, gl.COMPILE_STATUS)) throw new Error(gl.getShaderInfoLog(s) ?? 'shader');
return s;
};
let program: WebGLProgram;
try {
program = gl.createProgram()!;
gl.attachShader(program, compile(gl.VERTEX_SHADER, VERT));
gl.attachShader(program, compile(gl.FRAGMENT_SHADER, animated ? HOME : PAGE));
gl.linkProgram(program);
if (!gl.getProgramParameter(program, gl.LINK_STATUS)) throw new Error('link');
} catch {
failed = true;
return;
}
gl.useProgram(program);
const buffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, buffer);
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array([-1, -1, 1, -1, -1, 1, 1, 1]), gl.STATIC_DRAW);
const a = gl.getAttribLocation(program, 'a');
gl.enableVertexAttribArray(a);
gl.vertexAttribPointer(a, 2, gl.FLOAT, false, 0, 0);
const u = (name: string) => gl.getUniformLocation(program, name);
for (const [name, value] of Object.entries(PALETTE)) gl.uniform3fv(u(name), value);
gl.uniform1f(u('strength'), light ? 0.25 : 1.0);
gl.uniform1f(u('motes'), light ? 0.0 : 1.0);
const reduce = matchMedia('(prefers-reduced-motion: reduce)');
let frame = 0;
let scrollY = 0;
const resize = () => {
const dpr = Math.min(devicePixelRatio || 1, 2);
canvas.width = Math.round(innerWidth * dpr);
canvas.height = Math.round(innerHeight * dpr);
gl.viewport(0, 0, canvas.width, canvas.height);
gl.uniform2f(u('res'), canvas.width, canvas.height);
};
let frames = 0;
const draw = (t: number) => {
gl.uniform1f(u('time'), reduce.matches ? 42 : t / 1000);
gl.uniform1f(u('scroll'), scrollY);
gl.drawArrays(gl.TRIANGLE_STRIP, 0, 4);
canvas.dataset.frames = String(++frames); // a check can tell a live scene from a frozen one
};
const tick = (t: number) => {
draw(t);
frame = requestAnimationFrame(tick);
};
const onScroll = () => {
scrollY = window.scrollY;
if (!animated || reduce.matches) draw(42000);
};
resize();
if (animated && !reduce.matches) frame = requestAnimationFrame(tick);
else draw(42000);
const onResize = () => {
resize();
if (!animated || reduce.matches) draw(42000);
};
addEventListener('resize', onResize);
if (animated) addEventListener('scroll', onScroll, { passive: true });
return () => {
cancelAnimationFrame(frame);
removeEventListener('resize', onResize);
removeEventListener('scroll', onScroll);
};
});
</script>
<canvas class="backdrop" class:failed bind:this={canvas} aria-hidden="true"></canvas>
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