From 0319df06cc6d055cbaa2f642bfe1d265ddfb1755 Mon Sep 17 00:00:00 2001
From: Ladd <ladd@dgov.io>
Date: Sun, 28 Dec 2025 03:16:58 -0600
Subject: [PATCH] tweaks

---
 display.js |  2 +-
 pointer.js | 31 ++++++++++++++++---------------
 2 files changed, 17 insertions(+), 16 deletions(-)

diff --git a/display.js b/display.js
index e44a805..6ec320a 100644
--- a/display.js
+++ b/display.js
@@ -109,7 +109,7 @@ export class Display {
       ctx.beginPath();
       let dash = false;
       for (let i = 0; i < obj.history.length ; i++) {
-        // if (i % 2) continue;
+        // if (i % 2 > 0) continue;
         const {position: {x, y}} = obj.history[i];
         if (dashedTraces) {
           if (dash) {
diff --git a/pointer.js b/pointer.js
index 73aaf15..ebaaedb 100644
--- a/pointer.js
+++ b/pointer.js
@@ -14,7 +14,7 @@ export class Pointer {
 
   pointerHistory = [];
   draggingElement = undefined;
-  panning = undefined;
+  panning = undefined; // { velocity: {x and y in sim coordinates}, paused: boolean }
   panTouchStart = undefined; // {x: undefined, y: undefined, t: undefined};
   panTouchLatest = undefined; // {x: undefined, y: undefined, t: undefined};
   suppressClick = false;
@@ -133,15 +133,15 @@ export class Pointer {
   handlePointerDown({x: clientX, y: clientY}) {
     this.clearPointerHistory(5);
     this.updatePointer({x: clientX, y: clientY});
-    const {x, y} = this.sim.screenToSim(clientX, clientY)
 
     if (this.sim.isCurrentMode(MODE_MASS_GENERATION)) {
+      const {x, y} = this.sim.screenToSim(clientX, clientY)
       this.sim.objects.handlePointerDown({x, y});
 
     } else if (this.sim.isCurrentMode(MODE_PAN_VIEW)) {
       this.panTouchStart = {
-        x,
-        y,
+        x: clientX,
+        y: clientY,
         t: document.timeline.currentTime,
         viewOrigin: {...this.sim.display.viewOrigin},
       };
@@ -160,12 +160,15 @@ export class Pointer {
     } else if (this.sim.isCurrentMode(MODE_PAN_VIEW)) {
       // Set panning velocity
       if (this.panTouchStart && this.panTouchLatest) {
-        const dt = this.panTouchLatest.t - this.panTouchStart.t;
-        const current = this.panning?.velocity;
+        const dt = (this.panTouchLatest.t - this.panTouchStart.t) / 1000;
+        const latest = this.panTouchLatest;
+        const start = this.panTouchStart;
+        // const speed = Math.sqrt((latest.x - start.x)**2 + (latest.y - start.y)**2) / dt;
+        const { scale } = this.sim.display;
         this.panning = {
           velocity: {
-            x: (current?.x ?? 0) + (this.panTouchLatest.x - this.panTouchStart.x) / dt,
-            y: (current?.y ?? 0) + (this.panTouchLatest.y - this.panTouchStart.y) / dt,
+            x: 2 * (latest.x - start.x) / scale / dt,
+            y: 2 * (latest.y - start.y) / scale / dt,
           }
         };
         this.panTouchStart = undefined;
@@ -186,18 +189,16 @@ export class Pointer {
     // v.x = v.x + a.x * v.dt / this.sim.display.scale / 2;
     // v.y = v.y + a.y * v.dt / this.sim.display.scale / 2;
     
-    const {x, y} = this.sim.screenToSim(clientX, clientY);
-
     if (this.sim.isCurrentMode(MODE_MASS_GENERATION)) {
+      const {x, y} = this.sim.screenToSim(clientX, clientY);
       this.sim.objects.handlePointerMove({x, y, vx: v.x, vy: v.y});
 
     } else if (this.sim.isCurrentMode(MODE_PAN_VIEW)) {
       // Event loop should be able to read
       this.panTouchLatest = {
-        x,
-        y,
+        x: clientX,
+        y: clientY,
         t: document.timeline.currentTime,
-        viewOrigin: {...this.sim.display.viewOrigin},
       };
     }
   }
@@ -212,8 +213,8 @@ export class Pointer {
       // Direct translate
       const start = this.panTouchStart;
       const latest = this.panTouchLatest;
-      this.sim.display.viewOrigin.x -= latest.x - start.x;
-      this.sim.display.viewOrigin.y -= latest.y - start.y;
+      this.sim.display.viewOrigin.x = start.viewOrigin.x - (latest.x - start.x) / this.sim.display.scale;
+      this.sim.display.viewOrigin.y = start.viewOrigin.y - (latest.y - start.y) / this.sim.display.scale;
     } else if (this.panning && !this.panning.paused) {
       // Apply update to viewOrigin based on panning
       const { velocity } = this.panning;