Merge pull request #2575 from mononaut/tx-flow-diagram-algo

Improve transaction flow diagram drawing algorithm

frontend/src/app/components/transaction/transaction.component.html

@@ -191,12 +191,20 @@
     <br>
 
     <div class="title">
-      <h2 i18n="transaction.diagram|Transaction diagram">Diagram</h2>
+      <h2 i18n="transaction.flow|Transaction flow">Flow</h2>
     </div>
 
     <div class="box">
       <div class="graph-container" #graphContainer>
-        <tx-bowtie-graph [tx]="tx" [width]="graphWidth" [height]="graphExpanded ? (maxInOut * 15) : graphHeight" [maxStrands]="graphExpanded ? maxInOut : 24" [network]="network" [tooltip]="true"></tx-bowtie-graph>
+        <tx-bowtie-graph
+          [tx]="tx"
+          [width]="graphWidth"
+          [height]="graphExpanded ? (maxInOut * 15) : graphHeight"
+          [lineLimit]="inOutLimit"
+          [maxStrands]="graphExpanded ? maxInOut : 24"
+          [network]="network"
+          [tooltip]="true">
+        </tx-bowtie-graph>
       </div>
       <div class="toggle-wrapper" *ngIf="maxInOut > 24">
         <button class="btn btn-sm btn-primary graph-toggle" (click)="expandGraph();" *ngIf="!graphExpanded; else collapseBtn"><span i18n="show-more">Show more</span></button>

frontend/src/app/components/transaction/transaction.component.ts

@@ -50,7 +50,9 @@ export class TransactionComponent implements OnInit, AfterViewInit, OnDestroy {
   graphExpanded: boolean = false;
   graphWidth: number = 1000;
   graphHeight: number = 360;
+  inOutLimit: number = 150;
   maxInOut: number = 0;
+
   tooltipPosition: { x: number, y: number };
 
   @ViewChild('graphContainer')
@@ -298,7 +300,7 @@ export class TransactionComponent implements OnInit, AfterViewInit, OnDestroy {
   }
 
   setupGraph() {
-    this.maxInOut = Math.min(250, Math.max(this.tx?.vin?.length || 1, this.tx?.vout?.length + 1 || 1));
+    this.maxInOut = Math.min(this.inOutLimit, Math.max(this.tx?.vin?.length || 1, this.tx?.vout?.length + 1 || 1));
     this.graphHeight = Math.min(360, this.maxInOut * 80);
   }
 

frontend/src/app/components/tx-bowtie-graph/tx-bowtie-graph.component.ts

@@ -19,8 +19,6 @@ interface Xput {
   confidential?: boolean;
 }
 
-const lineLimit = 250;
-
 @Component({
   selector: 'tx-bowtie-graph',
   templateUrl: './tx-bowtie-graph.component.html',
@@ -31,7 +29,8 @@ export class TxBowtieGraphComponent implements OnInit, OnChanges {
   @Input() network: string;
   @Input() width = 1200;
   @Input() height = 600;
-  @Input() combinedWeight = 100;
+  @Input() lineLimit = 250;
+  @Input() maxCombinedWeight = 100;
   @Input() minWeight = 2; //
   @Input() maxStrands = 24; // number of inputs/outputs to keep fully on-screen.
   @Input() tooltip = false;
@@ -42,6 +41,7 @@ export class TxBowtieGraphComponent implements OnInit, OnChanges {
   outputs: SvgLine[];
   middle: SvgLine;
   midWidth: number;
+  combinedWeight: number;
   isLiquid: boolean = false;
   hoverLine: Xput | void = null;
   tooltipPosition = { x: 0, y: 0 };
@@ -62,20 +62,19 @@ export class TxBowtieGraphComponent implements OnInit, OnChanges {
   gradient: string[] = ['#105fb0', '#105fb0'];
 
   ngOnInit(): void {
-    this.isLiquid = (this.network === 'liquid' || this.network === 'liquidtestnet');
-    this.gradient = this.gradientColors[this.network];
-    this.midWidth = Math.min(50, Math.ceil(this.width / 20));
     this.initGraph();
   }
 
   ngOnChanges(): void {
-    this.isLiquid = (this.network === 'liquid' || this.network === 'liquidtestnet');
-    this.gradient = this.gradientColors[this.network];
-    this.midWidth = Math.min(50, Math.ceil(this.width / 20));
     this.initGraph();
   }
 
   initGraph(): void {
+    this.isLiquid = (this.network === 'liquid' || this.network === 'liquidtestnet');
+    this.gradient = this.gradientColors[this.network];
+    this.midWidth = Math.min(10, Math.ceil(this.width / 100));
+    this.combinedWeight = Math.min(this.maxCombinedWeight, Math.floor((this.width - (2 * this.midWidth)) / 6));
+
     const totalValue = this.calcTotalValue(this.tx);
     let voutWithFee = this.tx.vout.map(v => {
       return {
@@ -103,19 +102,19 @@ export class TxBowtieGraphComponent implements OnInit, OnChanges {
       } as Xput;
     });
 
-    if (truncatedInputs.length > lineLimit) {
+    if (truncatedInputs.length > this.lineLimit) {
-      const valueOfRest = truncatedInputs.slice(lineLimit).reduce((r, v) => {
+      const valueOfRest = truncatedInputs.slice(this.lineLimit).reduce((r, v) => {
         return r + (v.value || 0);
       }, 0);
-      truncatedInputs = truncatedInputs.slice(0, lineLimit);
+      truncatedInputs = truncatedInputs.slice(0, this.lineLimit);
-      truncatedInputs.push({ type: 'input', value: valueOfRest, rest: this.tx.vin.length - lineLimit });
+      truncatedInputs.push({ type: 'input', value: valueOfRest, rest: this.tx.vin.length - this.lineLimit });
     }
-    if (voutWithFee.length > lineLimit) {
+    if (voutWithFee.length > this.lineLimit) {
-      const valueOfRest = voutWithFee.slice(lineLimit).reduce((r, v) => {
+      const valueOfRest = voutWithFee.slice(this.lineLimit).reduce((r, v) => {
         return r + (v.value || 0);
       }, 0);
-      voutWithFee = voutWithFee.slice(0, lineLimit);
+      voutWithFee = voutWithFee.slice(0, this.lineLimit);
-      voutWithFee.push({ type: 'output', value: valueOfRest, rest: outputCount - lineLimit });
+      voutWithFee.push({ type: 'output', value: valueOfRest, rest: outputCount - this.lineLimit });
     }
 
     this.inputData = truncatedInputs;
@@ -126,7 +125,7 @@ export class TxBowtieGraphComponent implements OnInit, OnChanges {
 
     this.middle = {
       path: `M ${(this.width / 2) - this.midWidth} ${(this.height / 2) + 0.5} L ${(this.width / 2) + this.midWidth} ${(this.height / 2) + 0.5}`,
-      style: `stroke-width: ${this.combinedWeight + 0.5}; stroke: ${this.gradient[1]}`
+      style: `stroke-width: ${this.combinedWeight + 1}; stroke: ${this.gradient[1]}`
     };
   }
 
@@ -157,7 +156,7 @@ export class TxBowtieGraphComponent implements OnInit, OnChanges {
 
   initLines(side: 'in' | 'out', xputs: Xput[], total: number, maxVisibleStrands: number): SvgLine[] {
     if (!total) {
-      const weights = xputs.map((put): number => this.combinedWeight / xputs.length);
+      const weights = xputs.map((put) => this.combinedWeight / xputs.length);
       return this.linesFromWeights(side, xputs, weights, maxVisibleStrands);
     } else {
       let unknownCount = 0;
@@ -171,19 +170,26 @@ export class TxBowtieGraphComponent implements OnInit, OnChanges {
       });
       const unknownShare = unknownTotal / unknownCount;
       // conceptual weights
-      const weights = xputs.map((put): number => this.combinedWeight * (put.value == null ? unknownShare : put.value as number) / total);
+      const weights = xputs.map((put) => this.combinedWeight * (put.value == null ? unknownShare : put.value as number) / total);
       return this.linesFromWeights(side, xputs, weights, maxVisibleStrands);
     }
   }
 
-  linesFromWeights(side: 'in' | 'out', xputs: Xput[], weights: number[], maxVisibleStrands: number) {
+  linesFromWeights(side: 'in' | 'out', xputs: Xput[], weights: number[], maxVisibleStrands: number): SvgLine[] {
-    const lines = [];
+    const lineParams = weights.map((w) => {
-    // actual displayed line thicknesses
+      return {
-    const minWeights = weights.map((w) => Math.max(this.minWeight - 1, w) + 1);
+        weight: w,
+        thickness: Math.max(this.minWeight - 1, w) + 1,
+        offset: 0,
+        innerY: 0,
+        outerY: 0,
+      };
+    });
     const visibleStrands = Math.min(maxVisibleStrands, xputs.length);
-    const visibleWeight = minWeights.slice(0, visibleStrands).reduce((acc, v) => v + acc, 0);
+    const visibleWeight = lineParams.slice(0, visibleStrands).reduce((acc, v) => v.thickness + acc, 0);
     const gaps = visibleStrands - 1;
 
+    // bounds of the middle segment
     const innerTop = (this.height / 2) - (this.combinedWeight / 2);
     const innerBottom = innerTop + this.combinedWeight;
     // tracks the visual bottom of the endpoints of the previous line
@@ -192,39 +198,91 @@ export class TxBowtieGraphComponent implements OnInit, OnChanges {
     // gap between strands
     const spacing = (this.height - visibleWeight) / gaps;
 
-    for (let i = 0; i < xputs.length; i++) {
+    // curve adjustments to prevent overlaps
-      const weight = weights[i];
+    let offset = 0;
-      const minWeight = minWeights[i];
+    let minOffset = 0;
+    let maxOffset = 0;
+    let lastWeight = 0;
+    let pad = 0;
+    lineParams.forEach((line, i) => {
       // set the vertical position of the (center of the) outer side of the line
-      let outer = lastOuter + (minWeight / 2);
+      line.outerY = lastOuter + (line.thickness / 2);
-      const inner = Math.min(innerBottom + (minWeight / 2), Math.max(innerTop + (minWeight / 2), lastInner + (weight / 2)));
+      line.innerY = Math.min(innerBottom + (line.thickness / 2), Math.max(innerTop + (line.thickness / 2), lastInner + (line.weight / 2)));
 
       // special case to center single input/outputs
       if (xputs.length === 1) {
-        outer = (this.height / 2);
+        line.outerY = (this.height / 2);
       }
 
-      lastOuter += minWeight + spacing;
+      lastOuter += line.thickness + spacing;
-      lastInner += weight;
+      lastInner += line.weight;
-      lines.push({
+
-        path: this.makePath(side, outer, inner, minWeight),
+      // calculate conservative lower bound of the amount of horizontal offset
-        style: this.makeStyle(minWeight, xputs[i].type),
+      // required to prevent this line overlapping its neighbor
+
+      if (this.tooltip || !xputs[i].rest) {
+        const w = (this.width - Math.max(lastWeight, line.weight)) / 2; // approximate horizontal width of the curved section of the line
+        const y1 = line.outerY;
+        const y2 = line.innerY;
+        const t = (lastWeight + line.weight) / 2; // distance between center of this line and center of previous line
+
+        // slope of the inflection point of the bezier curve
+        const dx = 0.75 * w;
+        const dy = 1.5 * (y2 - y1);
+        const a = Math.atan2(dy, dx);
+
+        // parallel curves should be separated by >=t at the inflection point to prevent overlap
+        // vertical offset is always = t, contributing tCos(a)
+        // horizontal offset h will contribute hSin(a)
+        // tCos(a) + hSin(a) >= t
+        // h >= t(1 - cos(a)) / sin(a)
+        if (Math.sin(a) !== 0) {
+          // (absolute value clamped to t for sanity)
+          offset += Math.max(Math.min(t * (1 - Math.cos(a)) / Math.sin(a), t), -t);
+        }
+
+        line.offset = offset;
+        minOffset = Math.min(minOffset, offset);
+        maxOffset = Math.max(maxOffset, offset);
+        pad = Math.max(pad, line.thickness / 2);
+        lastWeight = line.weight;
+      } else {
+        // skip the offsets for consolidated lines in unfurls, since these *should* overlap a little
+      }
+    });
+
+    // normalize offsets
+    lineParams.forEach((line) => {
+      line.offset -= minOffset;
+    });
+    maxOffset -= minOffset;
+
+    return lineParams.map((line, i) => {
+      return {
+        path: this.makePath(side, line.outerY, line.innerY, line.thickness, line.offset, pad + maxOffset),
+        style: this.makeStyle(line.thickness, xputs[i].type),
         class: xputs[i].type
+      };
     });
   }
 
-    return lines;
+  makePath(side: 'in' | 'out', outer: number, inner: number, weight: number, offset: number, pad: number): string {
-  }
+    const start = (weight * 0.5);
+    const curveStart = Math.max(start + 1, pad - offset);
+    const end =  this.width / 2 - (this.midWidth * 0.9) + 1;
+    const curveEnd = end - offset - 10;
+    const midpoint = (curveStart + curveEnd) / 2;
 
-  makePath(side: 'in' | 'out', outer: number, inner: number, weight: number): string {
-    const start = side === 'in' ? (weight * 0.5) : this.width - (weight * 0.5);
-    const center =  this.width / 2 + (side === 'in' ? -(this.midWidth * 0.9) : (this.midWidth * 0.9) );
-    const midpoint = (start + center) / 2;
     // correct for svg horizontal gradient bug
     if (Math.round(outer) === Math.round(inner)) {
       outer -= 1;
     }
-    return `M ${start} ${outer} C ${midpoint} ${outer}, ${midpoint} ${inner}, ${center} ${inner}`;
+
+    if (side === 'in') {
+      return `M ${start} ${outer} L ${curveStart} ${outer} C ${midpoint} ${outer}, ${midpoint} ${inner}, ${curveEnd} ${inner} L ${end} ${inner}`;
+    } else { // mirrored in y-axis for the right hand side
+      return `M ${this.width - start} ${outer} L ${this.width - curveStart} ${outer} C ${this.width - midpoint} ${outer}, ${this.width - midpoint} ${inner}, ${this.width - curveEnd} ${inner} L ${this.width - end} ${inner}`;
+    }
   }
 
   makeStyle(minWeight, type): string {