TTMusic/entry/src/main/ets/view/spectrum/DotMatrixSpectrumRenderer.ets

import { SpectrumRenderer, SpectrumRenderOptions, buildSpectrumPalette, hslToHex, rgbaFromHex } from './SpectrumRenderer'

/**
 * 点阵频谱渲染器
 * 使用点阵网格表达频谱能量层级
 */
export class DotMatrixSpectrumRenderer implements SpectrumRenderer {
  render(ctx: CanvasRenderingContext2D, bands: number[], energy: number,
    width: number, height: number, brandColor: string, options?: SpectrumRenderOptions): void {
    if (bands.length === 0) return

    ctx.clearRect(0, 0, width, height)

    const palette = buildSpectrumPalette(brandColor)
    const complexityScale: number = Math.max(0.45, Math.min(1, options?.complexityScale ?? 1))
    const columns: number = Math.max(12, Math.floor(20 * complexityScale))
    const rows: number = Math.max(8, Math.floor(14 * complexityScale))
    const cellW: number = width / columns
    const cellH: number = height / rows
    const radius: number = Math.max(1.6, Math.min(cellW, cellH) * 0.28)

    for (let c = 0; c < columns; c++) {
      const bandIndex: number = Math.floor((c / columns) * bands.length)
      const value: number = Math.max(0, Math.min(1, bands[bandIndex]))
      const activeRows: number = Math.floor(value * rows)
      const hue: number = (palette.primaryHue + (c / columns) * 135) % 360

      for (let r = 0; r < rows; r++) {
        const lit: boolean = r >= rows - activeRows
        const x: number = c * cellW + cellW * 0.5
        const y: number = r * cellH + cellH * 0.5
        const alpha: number = lit ? (0.30 + value * 0.65) : 0.08
        const lightness: number = lit ? (0.45 + 0.28 * (r / rows)) : 0.22
        ctx.fillStyle = rgbaFromHex(hslToHex(hue, 0.82, lightness), alpha)
        ctx.beginPath()
        ctx.arc(x, y, radius, 0, Math.PI * 2)
        ctx.fill()
      }
    }

    ctx.fillStyle = rgbaFromHex(hslToHex(palette.accentHue, 0.88, 0.60), 0.10 + energy * 0.18)
    ctx.fillRect(0, height * 0.48, width, 2)
  }

  reset(): void {
    // 无状态
  }
}