fix(radar): fix issue with points being outside circular grid (#1189)

I reverted animating between grid shapes since it wasn't present in the previous version but caused issues above. This will still animate when changing the number of levels shown as it did previously.

Close #1178

packages/radar/src/RadarGridLevels.js

@@ -8,27 +8,67 @@
  */
 import React, { memo, useMemo } from 'react'
 import PropTypes from 'prop-types'
-import { lineRadial, curveBasisClosed, curveLinearClosed } from 'd3-shape'
-import { animated } from 'react-spring'
-import { useTheme, useAnimatedPath } from '@nivo/core'
+import { lineRadial, curveLinearClosed } from 'd3-shape'
+import { animated, useSpring } from 'react-spring'
+import { useTheme, useAnimatedPath, useMotionConfig } from '@nivo/core'
 
-const RadarGridLevels = memo(({ shape, radius, angleStep, dataLength }) => {
+const RadarGridLevelCircular = memo(({ radius }) => {
+    const theme = useTheme()
+    const { animate, config: springConfig } = useMotionConfig()
+
+    const animatedProps = useSpring({
+        radius,
+        config: springConfig,
+        immediate: !animate,
+    })
+
+    return (
+        <animated.circle
+            fill="none"
+            r={animatedProps.radius.interpolate(value => Math.max(value, 0))}
+            {...theme.grid.line}
+        />
+    )
+})
+
+RadarGridLevelCircular.displayName = 'RadarGridLevelCircular'
+RadarGridLevelCircular.propTypes = {
+    radius: PropTypes.number.isRequired,
+}
+
+const RadarGridLevelLinear = memo(({ radius, angleStep, dataLength }) => {
     const theme = useTheme()
 
     const radarLineGenerator = useMemo(
         () =>
             lineRadial()
                 .angle(i => i * angleStep)
-                .curve(shape === 'linear' ? curveLinearClosed : curveBasisClosed),
-        [angleStep, shape]
+                .radius(radius)
+                .curve(curveLinearClosed),
+        [angleStep, radius]
     )
 
     const points = Array.from({ length: dataLength }, (_, i) => i)
-    const animatedPath = useAnimatedPath(radarLineGenerator.radius(radius)(points))
+    const animatedPath = useAnimatedPath(radarLineGenerator(points))
 
     return <animated.path fill="none" d={animatedPath} {...theme.grid.line} />
 })
 
+RadarGridLevelLinear.displayName = 'RadarGridLevelLinear'
+RadarGridLevelLinear.propTypes = {
+    radius: PropTypes.number.isRequired,
+    angleStep: PropTypes.number.isRequired,
+    dataLength: PropTypes.number.isRequired,
+}
+
+const RadarGridLevels = memo(({ shape, ...props }) => {
+    return shape === 'circular' ? (
+        <RadarGridLevelCircular radius={props.radius} />
+    ) : (
+        <RadarGridLevelLinear {...props} />
+    )
+})
+
 RadarGridLevels.displayName = 'RadarGridLevels'
 RadarGridLevels.propTypes = {
     shape: PropTypes.oneOf(['circular', 'linear']).isRequired,