fix(glass): preserve content clarity across transparency (#656) (#657)

Co-authored-by: InfinityPacer <160988576+InfinityPacer@users.noreply.github.com>

src/utils/__tests__/glassOptics.spec.ts

@@ -6,6 +6,7 @@ import {
   getGlassCssFrostBlur,
   getGlassCoverScale,
   getGlassMaterialResponse,
+  getGlassOverlayClarityBlur,
   getGlassOpticalCssTransmissionBrightness,
   getGlassOpticalDecay,
   getGlassOpticalBufferSize,
@@ -269,6 +270,34 @@ describe('glass optics geometry', () => {
     ).toBe(true)
   })
 
+  it('derives a continuous overlay clarity floor from transparency anchors', () => {
+    const anchors = [
+      [0, 8.9],
+      [20, 7.8],
+      [50, 6.7],
+      [70, 5.8],
+      [85, 5.4],
+      [100, 5],
+    ] as const
+
+    for (const [transparency, blur] of anchors) {
+      expect(getGlassOverlayClarityBlur(transparency)).toBe(blur)
+    }
+
+    expect(getGlassOverlayClarityBlur(-1)).toBe(8.9)
+    expect(getGlassOverlayClarityBlur(101)).toBe(5)
+    expect(getGlassOverlayClarityBlur(Number.NaN)).toBe(6.7)
+
+    const samples = Array.from({ length: 101 }, (_, value) => getGlassOverlayClarityBlur(value))
+    expect(samples.every((sample, index) => index === 0 || sample <= samples[index - 1])).toBe(true)
+
+    for (const anchor of [20, 50, 70, 85]) {
+      const blur = getGlassOverlayClarityBlur(anchor)
+      expect(Math.abs(getGlassOverlayClarityBlur(anchor - 1) - blur)).toBeLessThan(0.02)
+      expect(Math.abs(getGlassOverlayClarityBlur(anchor + 1) - blur)).toBeLessThan(0.03)
+    }
+  })
+
   it('returns preset copies so previews cannot mutate the shared matrix', () => {
     const first = getGlassOpticalPresetParameters('tinted', 'high', 'glide')
     first.translation = 0

src/utils/glassOptics.ts

@@ -250,6 +250,7 @@ const GLASS_SURFACE_DENSITY: Record<GlassAppearance, readonly number[]> = {
 const GLASS_TINT_DENSITY = [1, 0.9, 0.65, 0.48, 0.36, 0.28] as const
 const GLASS_FROST_DENSITY = [1, 0.9, 0.7, 0.34, 0.12, 0.04] as const
 const GLASS_FROSTED_DENSITY = [1, 0.82, 0.55, 0.28, 0.1, 0.025] as const
+const GLASS_OVERLAY_CLARITY_BLUR = [8.9, 7.8, 6.7, 5.8, 5.4, 5] as const
 
 /** 在相邻业务锚点之间使用零斜率边界插值，避免滑杆经过锚点时出现视觉折线。 */
 function interpolateGlassResponse(value: unknown, anchors: readonly number[]) {
@@ -292,6 +293,11 @@ export function getGlassCssFrostBlur(value: unknown) {
   }
 }
 
+/** 透明与色调浮层保留独立模糊下限，避免高通透度使临时内容直接暴露在复杂壁纸上。 */
+export function getGlassOverlayClarityBlur(value: unknown) {
+  return interpolateGlassResponse(value, GLASS_OVERLAY_CLARITY_BLUR)
+}
+
 /** 计算与 CSS `ease` 相同的交叉淡化进度，使 DOM 壁纸与 shader 双纹理保持同一时钟。 */
 export function getGlassWallpaperTransitionProgress(elapsed: number, duration: number) {
   if (duration <= 0 || elapsed >= duration) return 1