Move labelY utility function to utils

Author: mateuuszzzzz

src/components/Charts/LineChart/LineChartContent.tsx

@@ -13,7 +13,7 @@ import fontSource from '@components/Charts/font';
 import type {HitTestArgs} from '@components/Charts/hooks';
 import {useChartInteractions, useChartLabelFormats, useChartLabelLayout, useDynamicYDomain, useTooltipData} from '@components/Charts/hooks';
 import type {CartesianChartProps, ChartDataPoint} from '@components/Charts/types';
-import {calculateMinDomainPadding, DEFAULT_CHART_COLOR, measureTextWidth, rotatedLabelCenterCorrection} from '@components/Charts/utils';
+import {calculateMinDomainPadding, DEFAULT_CHART_COLOR, measureTextWidth, rotatedLabelCenterCorrection, rotatedLabelYOffset} from '@components/Charts/utils';
 import useResponsiveLayout from '@hooks/useResponsiveLayout';
 import useTheme from '@hooks/useTheme';
 import useThemeStyles from '@hooks/useThemeStyles';
@@ -163,19 +163,7 @@ function LineChartContent({data, title, titleIcon, isLoading, yAxisUnit, yAxisUn
             const fontMetrics = font.getMetrics();
             const ascent = Math.abs(fontMetrics.ascent);
             const descent = Math.abs(fontMetrics.descent);
-
-            // Calculate labelY to maintain consistent LABEL_GAP from axis to closest point of text
-            // At 0°: closest point is top of text (baseline - ascent)
-            // At 45°: closest point is top-right corner, ascent projects as ascent * cos(45°)
-            // At 90°: text is vertical, closest point is at descent from baseline
-            let labelY: number;
-            if (angleRad === 0) {
-                labelY = args.chartBounds.bottom + LABEL_GAP + ascent;
-            } else if (angleRad >= Math.PI / 2) {
-                labelY = args.chartBounds.bottom + LABEL_GAP + descent;
-            } else {
-                labelY = args.chartBounds.bottom + LABEL_GAP + ascent * Math.cos(angleRad);
-            }
+            const labelY = args.chartBounds.bottom + LABEL_GAP + rotatedLabelYOffset(ascent, descent, angleRad);
 
             return truncatedLabels.map((label, i) => {
                 if (i % labelSkipInterval !== 0) {

src/components/Charts/utils.ts

@@ -62,6 +62,24 @@ function rotatedLabelCenterCorrection(ascent: number, descent: number, angleRad:
     return ((ascent - descent) * Math.sin(angleRad)) / 2;
 }
 
+/**
+ * Calculate the vertical offset from axis to text baseline that maintains
+ * a consistent visual gap regardless of label rotation.
+ *
+ * At 0°: gap to top of text (ascent above baseline)
+ * At 45°: gap to top-right corner after rotation (ascent projects as ascent * cos(45°))
+ * At 90°: gap to closest point of vertical text (descent from baseline)
+ */
+function rotatedLabelYOffset(ascent: number, descent: number, angleRad: number): number {
+    if (angleRad === 0) {
+        return ascent;
+    }
+    if (angleRad >= Math.PI / 2) {
+        return descent;
+    }
+    return ascent * Math.cos(angleRad);
+}
+
 /**
  * Calculate minimum horizontal domainPadding so that edge data points
  * (and their centered labels) aren't clipped by the chart boundary.
@@ -78,4 +96,4 @@ function calculateMinDomainPadding(chartWidth: number, pointCount: number, inner
     return Math.ceil(chartWidth * minPaddingRatio);
 }
 
-export {getChartColor, DEFAULT_CHART_COLOR, measureTextWidth, rotatedLabelCenterCorrection, calculateMinDomainPadding};
+export {getChartColor, DEFAULT_CHART_COLOR, measureTextWidth, rotatedLabelCenterCorrection, rotatedLabelYOffset, calculateMinDomainPadding};