BRETT/app/components/effects/EffectAurora.vue

<script setup lang="ts">
import { Color, Mesh, Program, Renderer, Triangle } from 'ogl'
import { shadeHex } from '@/lib/color'

// Portiert aus Vue Bits (DavidHDev/vue-bits), vereinfacht auf color-Prop
const props = withDefaults(defineProps<{ color?: string }>(), {
  color: '#6366f1',
})

const VERT = `#version 300 es
in vec2 position;
void main() {
  gl_Position = vec4(position, 0.0, 1.0);
}
`

const FRAG = `#version 300 es
precision highp float;

uniform float uTime;
uniform float uAmplitude;
uniform vec3 uColorStops[3];
uniform vec2 uResolution;
uniform float uBlend;
uniform float uRadius;

out vec4 fragColor;

vec3 permute(vec3 x) {
  return mod(((x * 34.0) + 1.0) * x, 289.0);
}

float snoise(vec2 v){
  const vec4 C = vec4(
      0.211324865405187, 0.366025403784439,
      -0.577350269189626, 0.024390243902439
  );
  vec2 i  = floor(v + dot(v, C.yy));
  vec2 x0 = v - i + dot(i, C.xx);
  vec2 i1 = (x0.x > x0.y) ? vec2(1.0, 0.0) : vec2(0.0, 1.0);
  vec4 x12 = x0.xyxy + C.xxzz;
  x12.xy -= i1;
  i = mod(i, 289.0);

  vec3 p = permute(
      permute(i.y + vec3(0.0, i1.y, 1.0))
    + i.x + vec3(0.0, i1.x, 1.0)
  );

  vec3 m = max(
      0.5 - vec3(
          dot(x0, x0),
          dot(x12.xy, x12.xy),
          dot(x12.zw, x12.zw)
      ),
      0.0
  );
  m = m * m;
  m = m * m;

  vec3 x = 2.0 * fract(p * C.www) - 1.0;
  vec3 h = abs(x) - 0.5;
  vec3 ox = floor(x + 0.5);
  vec3 a0 = x - ox;
  m *= 1.79284291400159 - 0.85373472095314 * (a0*a0 + h*h);

  vec3 g;
  g.x  = a0.x  * x0.x  + h.x  * x0.y;
  g.yz = a0.yz * x12.xz + h.yz * x12.yw;
  return 130.0 * dot(m, g);
}

struct ColorStop {
  vec3 color;
  float position;
};

#define COLOR_RAMP(colors, factor, finalColor) {              \\
  int index = 0;                                            \\
  for (int i = 0; i < 2; i++) {                               \\
     ColorStop currentColor = colors[i];                    \\
     bool isInBetween = currentColor.position <= factor;    \\
     index = int(mix(float(index), float(i), float(isInBetween))); \\
  }                                                         \\
  ColorStop currentColor = colors[index];                   \\
  ColorStop nextColor = colors[index + 1];                  \\
  float range = nextColor.position - currentColor.position; \\
  float lerpFactor = (factor - currentColor.position) / range; \\
  finalColor = mix(currentColor.color, nextColor.color, lerpFactor); \\
}

void main() {
  vec2 uv = gl_FragCoord.xy / uResolution;

  ColorStop colors[3];
  colors[0] = ColorStop(uColorStops[0], 0.0);
  colors[1] = ColorStop(uColorStops[1], 0.5);
  colors[2] = ColorStop(uColorStops[2], 1.0);

  vec3 rampColor;
  COLOR_RAMP(colors, uv.x, rampColor);

  // Noise x-Koordinate pixelkonsistent (~2 Einheiten pro 320px), damit
  // die Wellen in schmalen/breiten Karten nicht gestaucht/gestreckt wirken
  float height = snoise(vec2(gl_FragCoord.x / 160.0 + uTime * 0.1, uTime * 0.25)) * 0.5 * uAmplitude;
  height = exp(height);
  height = (uv.y * 2.0 - height + 0.2);
  float intensity = 0.6 * height;

  float midPoint = 0.20;
  float auroraAlpha = smoothstep(midPoint - uBlend * 0.5, midPoint + uBlend * 0.5, intensity);

  vec3 auroraColor = intensity * rampColor;

  // Rounded-Rect-Maske direkt im Shader — zuverlässig auch wenn der
  // Compositor den Canvas-Layer nicht an CSS-Clips bindet (Waterfox)
  vec2 p = gl_FragCoord.xy - uResolution * 0.5;
  vec2 hb = uResolution * 0.5 - vec2(uRadius);
  float rd = length(max(abs(p) - hb, 0.0)) - uRadius;
  float rm = 1.0 - smoothstep(-0.75, 0.75, rd);
  auroraAlpha *= rm;

  fragColor = vec4(auroraColor * auroraAlpha, auroraAlpha);
}
`

const ctnDom = ref<HTMLDivElement | null>(null)

let animateId = 0
let teardown: (() => void) | null = null

onMounted(() => {
  const ctn = ctnDom.value
  if (!ctn) return

  const renderer = new Renderer({ alpha: true, premultipliedAlpha: true, antialias: true })
  const gl = renderer.gl
  gl.clearColor(0, 0, 0, 0)
  gl.enable(gl.BLEND)
  gl.blendFunc(gl.ONE, gl.ONE_MINUS_SRC_ALPHA)
  // WebGL-Canvas bleibt detached: Waterfox/Firefox zeichnet WebGL-Layer nach
  // Scrollen teils an veralteter Position und ignoriert CSS-Clips — stattdessen
  // wird pro Frame in einen normalen 2D-Canvas geblittet
  const outCanvas = document.createElement('canvas')
  outCanvas.className = 'absolute inset-0 size-full rounded-[inherit]'
  const outCtx = outCanvas.getContext('2d')
  ctn.appendChild(outCanvas)

  const geometry = new Triangle(gl)
  if (geometry.attributes.uv) {
    delete geometry.attributes.uv
  }

  const colorStops = [shadeHex(props.color, -0.5), props.color, shadeHex(props.color, 0.4)]
    .map((hex) => {
      const c = new Color(hex)
      return [c.r, c.g, c.b]
    })

  const program = new Program(gl, {
    vertex: VERT,
    fragment: FRAG,
    uniforms: {
      uTime: { value: 0 },
      uAmplitude: { value: 1.0 },
      uColorStops: { value: colorStops },
      uResolution: { value: [ctn.offsetWidth, ctn.offsetHeight] },
      uBlend: { value: 0.5 },
      uRadius: { value: 0 },
    },
  })

  const mesh = new Mesh(gl, { geometry, program })

  // Farbwechsel live übernehmen (Settings-Vorschau)
  watch(() => props.color, (c) => {
    program.uniforms.uColorStops!.value = [shadeHex(c, -0.5), c, shadeHex(c, 0.4)]
      .map((hex) => {
        const col = new Color(hex)
        return [col.r, col.g, col.b]
      })
  })

  const resizeHandler = () => {
    renderer.setSize(ctn.offsetWidth, ctn.offsetHeight)
    program.uniforms.uResolution.value = [gl.drawingBufferWidth, gl.drawingBufferHeight]
    const cssRadius = parseFloat(getComputedStyle(ctn).borderTopLeftRadius) || 0
    program.uniforms.uRadius.value = ctn.offsetWidth > 0
      ? cssRadius * (gl.drawingBufferWidth / ctn.offsetWidth)
      : 0
    outCanvas.width = gl.drawingBufferWidth
    outCanvas.height = gl.drawingBufferHeight
  }
  const ro = new ResizeObserver(resizeHandler)
  ro.observe(ctn)
  resizeHandler()

  const update = (t: number) => {
    animateId = requestAnimationFrame(update)
    program.uniforms.uTime.value = t * 0.01 * 0.1
    renderer.render({ scene: mesh })
    outCtx?.clearRect(0, 0, outCanvas.width, outCanvas.height)
    outCtx?.drawImage(gl.canvas, 0, 0, outCanvas.width, outCanvas.height)
  }
  animateId = requestAnimationFrame(update)

  teardown = () => {
    cancelAnimationFrame(animateId)
    ro.disconnect()
    if (outCanvas.parentNode === ctn) ctn.removeChild(outCanvas)
    gl.getExtension('WEBGL_lose_context')?.loseContext()
  }
})

onUnmounted(() => {
  teardown?.()
  teardown = null
})
</script>

<template>
  <div ref="ctnDom" class="relative size-full overflow-hidden rounded-[inherit]" />
</template>