refactor(Clusters, ForceLink, ForceManyBody, Lines, Points): Improve …

…vector calculations

With the assistance of CodeRabbit 🐇

src/modules/Clusters/force-cluster.frag

@@ -28,11 +28,10 @@ void main() {
     }
     vec4 clusterCustomCoeff = texture2D(clusterForceCoefficient, textureCoords);
     vec2 distVector = clusterPositions.xy - pointPosition.xy;
-    float dist = sqrt(dot(distVector, distVector));
+    float dist = length(distVector);
     if (dist > 0.0) {
-      float angle = atan(distVector.y, distVector.x);
       float addV = alpha * dist * clusterCoefficient * clusterCustomCoeff.r;
-      velocity.rg += addV * vec2(cos(angle), sin(angle));
+      velocity.rg += addV * normalize(distVector);
     }
   }
 

src/modules/Clusters/index.ts

@@ -30,7 +30,7 @@ export class Clusters extends CoreModule {
 
     // Find the highest cluster index in the array and add 1 (since cluster indices start at 0).
     const clusterNumber = (data.pointClusters ?? []).reduce<number>((max, clusterIndex) => {
-      if (clusterIndex === undefined) return max
+      if (clusterIndex === undefined || clusterIndex < 0) return max
       return Math.max(max, clusterIndex)
     }, 0) + 1
 

src/modules/ForceLink/index.ts

@@ -45,8 +45,12 @@ export class ForceLink extends CoreModule {
           this.indices[linkIndex * 4 + 1] = Math.floor(connectedPointIndex / pointsTextureSize)
           const degree = data.degree?.[connectedPointIndex] ?? 0
           const connectedDegree = data.degree?.[pointIndex] ?? 0
-          const bias = degree / (degree + connectedDegree)
-          let strength = data.linkStrength?.[initialLinkIndex] ?? (1 / Math.min(degree, connectedDegree))
+          const degreeSum = degree + connectedDegree
+          // Prevent division by zero
+          const bias = degreeSum !== 0 ? degree / degreeSum : 0.5
+          const minDegree = Math.min(degree, connectedDegree)
+          // Prevent division by zero
+          let strength = data.linkStrength?.[initialLinkIndex] ?? (1 / Math.max(minDegree, 1))
           strength = Math.sqrt(strength)
           linkBiasAndStrengthState[linkIndex * 4 + 0] = bias
           linkBiasAndStrengthState[linkIndex * 4 + 1] = strength

src/modules/ForceManyBody/force-level.frag

@@ -29,13 +29,12 @@ vec2 calculateAdditionalVelocity (vec2 ij, vec2 pp) {
     float l = dot(distVector, distVector);
     float dist = sqrt(l);
     if (l > 0.0) {
-      float angle = atan(distVector.y, distVector.x);
       float c = alpha * repulsion * centermass.b;
 
       float distanceMin2 = 1.0;
       if (l < distanceMin2) l = sqrt(distanceMin2 * l);
       float addV = c / sqrt(l);
-      add = addV * vec2(cos(angle), sin(angle));
+      add = addV * normalize(distVector);
     }
   }
   return add;

src/modules/Lines/index.ts

@@ -116,16 +116,19 @@ export class Lines extends CoreModule {
   public updatePointsBuffer (): void {
     const { reglInstance, data, store } = this
     if (data.linksNumber === undefined || data.links === undefined) return
-    const instancePoints: [number, number][] = [] // new Float32Array(data.linksNumber * 2)
+    const instancePoints = new Float32Array(data.linksNumber * 4)
     for (let i = 0; i < data.linksNumber; i++) {
       const fromIndex = data.links[i * 2] as number
       const toIndex = data.links[i * 2 + 1] as number
       const fromX = fromIndex % store.pointsTextureSize
       const fromY = Math.floor(fromIndex / store.pointsTextureSize)
       const toX = toIndex % store.pointsTextureSize
       const toY = Math.floor(toIndex / store.pointsTextureSize)
-      instancePoints[i * 2] = [fromX, fromY]
-      instancePoints[i * 2 + 1] = [toX, toY]
+      const offset = i * 4
+      instancePoints[offset] = fromX
+      instancePoints[offset + 1] = fromY
+      instancePoints[offset + 2] = toX
+      instancePoints[offset + 3] = toY
     }
 
     if (!this.pointsBuffer) this.pointsBuffer = reglInstance.buffer(0)

src/modules/Points/index.ts

@@ -2,7 +2,7 @@ import regl from 'regl'
 // import { scaleLinear } from 'd3-scale'
 // import { extent } from 'd3-array'
 import { CoreModule } from '@/graph/modules/core-module'
-// import { defaultConfigValues } from '@/graph/variables'
+import { defaultConfigValues } from '@/graph/variables'
 import drawPointsFrag from '@/graph/modules/Points/draw-points.frag'
 import drawPointsVert from '@/graph/modules/Points/draw-points.vert'
 import findPointsOnAreaSelectionFrag from '@/graph/modules/Points/find-points-on-area-selection.frag'
@@ -465,7 +465,8 @@ export class Points extends CoreModule {
 
   public updateSampledPointsGrid (): void {
     const { store: { screenSize }, config: { pointSamplingDistance }, reglInstance } = this
-    const dist = pointSamplingDistance ?? Math.min(...screenSize) / 2
+    let dist = pointSamplingDistance ?? Math.min(...screenSize) / 2
+    if (dist === 0) dist = defaultConfigValues.pointSamplingDistance
     const w = Math.ceil(screenSize[0] / dist)
     const h = Math.ceil(screenSize[1] / dist)
     destroyFramebuffer(this.sampledPointsFbo)