折线图和面积图的颜色渐变需要考虑坐标系 #5361

AntV Open Source Contribution Plan（可选）

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Issue 类型

中级任务

任务介绍

保证折线图和面积图颜色渐变在 transpose 的情况下正常。下图中颜色从上到下渐变，期望效果是从左到右渐变。

<img src="https://github.com/antvis/G2/assets/49330279/74e00efb-7c92-4ec8-b100-0953796ae70c" height=640 />

/**
 * A recreation of this demo: https://observablehq.com/@d3/gradient-encoding
 */
import { Chart } from '@antv/g2';

const chart = new Chart({
  container: 'container',
  theme: 'classic',
  padding: 'auto',
  height: 640,
  width: 480,
});

chart
  .line()
  .coordinate({transform:[{type:'transpose'}]})
  .data({
    type: 'fetch',
    value: 'https://assets.antv.antgroup.com/g2/temperatures2.json',
  })
  .scale('x', { utc: true })
  .scale('y', { nice: true })
  .scale('color', { palette: 'turbo' })
  .encode('x', (d) => new Date(d.date))
  .encode('y', 'value')
  .encode('shape', 'hvh')
  .encode('color', 'value')
  .encode('series', () => undefined)
  .style('gradient', 'y')
  .style('lineWidth', 2)
  .style('lineJoin', 'round')
  .axis('x', { title: 'date' });

chart.render();

参考说明

• Discussed in https://github.com/antvis/G2/discussions/5333
• 水平方向正确的例子：https://g2.antv.antgroup.com/examples/general/line/#line-gradient-encoding