Function prepare

src/renderers/createAreaRenderer.ts:217–261

(seriesConfig, data, xScale, yScale, baseline)

  };

  const prepare: AreaRenderer['prepare'] = (seriesConfig, data, xScale, yScale, baseline) => {
    assertNotDisposed();

    const vertices = createAreaVertices(data);
    const requiredSize = vertices.byteLength;
    const bufferSize = Math.max(4, requiredSize);

    if (!vertexBuffer || vertexBuffer.size < bufferSize) {
      if (vertexBuffer) {
        try {
          vertexBuffer.destroy();
        } catch {
          // best-effort
        }
      }
      vertexBuffer = device.createBuffer({
        label: 'areaRenderer/vertexBuffer',
        size: bufferSize,
        usage: GPUBufferUsage.VERTEX | GPUBufferUsage.COPY_DST,
      });
    }

    if (vertices.byteLength > 0) {
      device.queue.writeBuffer(vertexBuffer, 0, vertices.buffer, 0, vertices.byteLength);
    }
    vertexCount = vertices.length / 2;

    const { xMin, xMax, yMin, yMax } = computeDataBounds(data);
    const { a: ax, b: bx } = computeClipAffineFromScale(xScale, xMin, xMax);
    const { a: ay, b: by } = computeClipAffineFromScale(yScale, yMin, yMax);

    const baselineValue =
      Number.isFinite(baseline ?? Number.NaN) ? (baseline as number) : Number.isFinite(yMin) ? yMin : 0;

    writeVsUniforms(ax, bx, ay, by, baselineValue);

    // Use the resolved fill color from areaStyle.color (not seriesConfig.color).
    const [r, g, b, a] = parseSeriesColorToRgba01(seriesConfig.areaStyle.color);
    const opacity = clamp01(seriesConfig.areaStyle.opacity);
    fsUniformScratchF32[0] = r;
    fsUniformScratchF32[1] = g;
    fsUniformScratchF32[2] = b;
    fsUniformScratchF32[3] = clamp01(a * opacity);
    writeUniformBuffer(device, fsUniformBuffer, fsUniformScratchF32);
  };

  const render: AreaRenderer['render'] = (passEncoder) => {
    assertNotDisposed();