change title scaling to use a minimum height instead of a minimum scale

packages/klighd-core/src/options/render-options-registry.ts

@@ -156,24 +156,23 @@ export class TextSimplificationThreshold implements RangeOption {
 }
 
 /**
- * The factor by which titles of collapsed regions get scaled by
- * in relation to their size at native resolution.
+ * The minimum size a title should attempt to scale up to
  */
-export class TitleScalingFactor implements RangeOption {
-    static readonly ID: string = 'title-scaling-factor'
-    static readonly NAME: string = 'Title Scaling Factor'
-    static readonly DEFAULT: number = 1
-    readonly id: string = TitleScalingFactor.ID
-    readonly name: string = TitleScalingFactor.NAME
+export class MinimumTitleHeight implements RangeOption {
+    static readonly ID: string = 'min-title-height'
+    static readonly NAME: string = 'Minimum Title Height'
+    static readonly DEFAULT: number = 10
+    readonly id: string = MinimumTitleHeight.ID
+    readonly name: string = MinimumTitleHeight.NAME
     readonly type: TransformationOptionType = TransformationOptionType.RANGE
     readonly values: any[] = []
     readonly range = {
-        first: 0.5,
-        second: 3
+        first: 0,
+        second: 80
     }
-    readonly stepSize = 0.01
-    readonly initialValue: number = TitleScalingFactor.DEFAULT
-    currentValue = 1
+    readonly stepSize = 1
+    readonly initialValue: number = MinimumTitleHeight.DEFAULT
+    currentValue = MinimumTitleHeight.DEFAULT
 }
 
 /**
@@ -270,7 +269,7 @@ export class RenderOptionsRegistry extends Registry {
         this.register(SimplifySmallText);
         this.register(TextSimplificationThreshold);
 
-        this.register(TitleScalingFactor);
+        this.register(MinimumTitleHeight);
 
         this.register(UseMinimumLineWidth);
         this.register(MinimumLineWidth);

packages/klighd-core/src/views-rendering.tsx

@@ -20,7 +20,7 @@ import { svg } from 'sprotty'; // eslint-disable-line @typescript-eslint/no-unus
 import { Bounds } from 'sprotty-protocol';
 import { KGraphData, KNode } from '@kieler/klighd-interactive/lib/constraint-classes';
 import { DetailLevel } from './depth-map';
-import { PaperShadows, SimplifySmallText, TextSimplificationThreshold, TitleScalingFactor, UseSmartZoom } from './options/render-options-registry';
+import { PaperShadows, SimplifySmallText, TextSimplificationThreshold, MinimumTitleHeight, UseSmartZoom } from './options/render-options-registry';
 import { SKGraphModelRenderer } from './skgraph-model-renderer';
 import {
     Arc, HorizontalAlignment, isRendering, KArc, KChildArea, KContainerRendering, KForeground, KHorizontalAlignment, KImage, KPolyline, KRendering, KRenderingLibrary, KRenderingRef, KRoundedBendsPolyline,
@@ -898,12 +898,11 @@ export function renderKRendering(kRendering: KRendering,
     // zoomed in far enough or remember it to be rendered later scaled up and overlayed on top of the parent rendering.
     if (applyTitleScaling && boundsAndTransformation.bounds.width && boundsAndTransformation.bounds.height && kRendering.isNodeTitle) {
 
-		// Scale to limit of bounding box or max size.
-        const titleScalingFactorOption = context.renderOptionsRegistry.getValueOrDefault(TitleScalingFactor) as number
-        const maxScale = titleScalingFactorOption / context.viewport.zoom
+        const overlayThreshold = context.renderOptionsRegistry.getValueOrDefault(MinimumTitleHeight) as number
+
 
         // is the rendering at the current zoom level smaller in height than our set threshold (apparently the threshold is minimum height?)
-        const tooSmall = kRendering.calculatedBounds && kRendering.calculatedBounds.height * context.viewport.zoom <= titleScalingFactorOption * kRendering.calculatedBounds.height
+        const tooSmall = kRendering.calculatedBounds && kRendering.calculatedBounds.height * context.viewport.zoom <= overlayThreshold
         const notFullDetail = providingRegion && providingRegion.detail !== DetailLevel.FullDetails
         const multipleChildren = parent.children.length > 1
 
@@ -927,6 +926,8 @@ export function renderKRendering(kRendering: KRendering,
             const maxScaleX = parentBounds.width / originalWidth
             const maxScaleY = parentBounds.height / originalHeight
 
+            let maxScale = overlayThreshold / (boundingBox.height * context.viewport.zoom);
+
             // limit the scaling so that it does not exceed the parents size
             let scalingFactor = Math.min(maxScaleX, maxScaleY, maxScale)
             // Make sure we never scale down.