[Bug] v2热图的单元格未完全填充

Version

2.0.0

Link to Minimal Reproduction

https://www.visactor.io/vchart/demo/heatmap-chart/basic-heatmap?version=2.0.0

Steps to Reproduce

1. 访问 https://www.visactor.io/vchart/demo/heatmap-chart/basic-heatmap?version=2.0.0

2. 填入配置

const items = [
  'Asset Liability Ratio',
  'Asset Liability Ratio (Deducting Advance Payments)',
  'Debt-to-long Capital Ratio',
  'Long Term Asset Suitability Ratio',
  'Equity Multiplier',
  'Equity Ratio of Current Liability',
  'Interest Bearing Debt / Fully Invested Capital',
  'Current Liability / Total Liabilities',
  'Capital Fixation Ratio',
  'Expected Default Frequency'
];
const rawData = [
  1.0, 0.594527, 0.492963, -0.160995, 0.723664, 0.658646, -0.857474, 0.320706, -0.284634, -0.091423, 0.594527, 1.0,
  0.724546, -0.099318, 0.540639, 0.49214, -0.554039, 0.17127, -0.265259, 0.068577, 0.492963, 0.724546, 1.0, -0.091338,
  0.450542, 0.375839, -0.524955, 0.300627, -0.198362, 0.033209, -0.160995, -0.099318, -0.091338, 1.0, -0.049872,
  -0.028452, 0.157157, 0.009742, -0.162374, 0.155095, 0.723664, 0.540639, 0.450542, -0.049872, 1.0, 0.951933, -0.651767,
  0.079052, -0.535984, 0.00798, 0.658646, 0.49214, 0.375839, -0.028452, 0.951933, 1.0, -0.543147, -0.106139, -0.52232,
  0.011466, -0.857474, -0.554039, -0.524955, 0.157157, -0.651767, -0.543147, 1.0, -0.595016, 0.310521, 0.066397,
  0.320706, 0.17127, 0.300627, 0.009742, 0.079052, -0.106139, -0.595016, 1.0, -0.105199, -0.064886, -0.284634,
  -0.265259, -0.198362, -0.162374, -0.535984, -0.52232, 0.310521, -0.105199, 1.0, -0.080153, -0.091423, 0.068577,
  0.033209, 0.155095, 0.00798, 0.011466, 0.066397, -0.064886, -0.080153, 1.0
];
const data = [];
for (let i = 0; i < items.length; i++) {
  for (let j = 0; j < items.length; j++) {
    data.push({
      var1: items[i],
      var2: 1,
      value: rawData[i * items.length + j]
    });
  }
}

const spec = {
  type: 'common',
  padding: 12,
  data: [
    {
      id: 'data0',
      values: data
    }
  ],
  series: [
    {
      type: 'heatmap',
      regionId: 'region0',
      xField: 'var1',
      yField: 'var2',
      valueField: 'value',
      cell: {
        style: {
          fill: {
            field: 'value',
            scale: 'color'
          }
        }
      }
    }
  ],
  region: [
    {
      id: 'region0',
      width: 200, // limit the width of the region
      height: 200, // limit the height of the region
      padding: {
        top: 40
      }
    }
  ],
  color: {
    type: 'linear',
    domain: [
      {
        dataId: 'data0',
        fields: ['value']
      }
    ],
    range: ['#feedde', '#fdbe85', '#fd8d3c', '#e6550d', '#a63603']
  },
  axes: [
    {
      orient: 'bottom',
      type: 'band',
      grid: {
        visible: false
      },
      domainLine: {
        visible: false
      },
      label: {
        space: 10,
        style: {
          textAlign: 'left',
          textBaseline: 'middle',
          angle: 90,
          fontSize: 8
        }
      },
      bandPadding: 0,
      height: layoutRect => {
        // canvas height - region height - paddingTop - paddingBottom
        return layoutRect.height - 314;
      }
    },
    {
      orient: 'left',
      type: 'band',
      grid: {
        visible: false
      },
      domainLine: {
        visible: false
      },
      label: {
        space: 10,
        style: {
          fontSize: 8
        }
      },
      bandPadding: 0
    }
  ],
  legends: {
    visible: true,
    orient: 'right',
    position: 'start',
    type: 'color',
    field: 'value'
  },
  title: {
    visible: true,
    text: `Correlation Coefficient`
  }
};

const vchart = new VChart(spec, { dom: CONTAINER_ID });
vchart.renderSync();

// Just for the convenience of console debugging, DO NOT COPY!
window['vchart'] = vchart;

Current Behavior

Expected Behavior

Environment

- OS: macOS
- Browser: Chrome
- Framework: React

Any additional comments?

期望v2效果与1.x相同，或者有简易的配置项能保持一致的效果

Start by reproducing the v2 basic heatmap demo at the linked URL with the provided VChart spec, then compare its cell layout with the expected v1 behavior. Trace the heatmap region and axis sizing involved in the fixed 200×200 region and top padding. Done means the cells fully fill the intended area, or a documented configuration provides the equivalent result.