first implementation to fix bug #160

Signed-off-by: nicolaskolbenschlag <[email protected]>

Apps/frontend/src/components/Waves.svelte

@@ -11,15 +11,17 @@
     CANVAS_WIDTH,
     NUM_CHANNELS,
     NUM_INTERVALS_HORIZONTAL,
+    NUM_INTERVALS_VERTICAL,
     MIN_SWEEP,
     MAX_SWEEP,
     DEFAULT_STEP_SIZE,
     LINE_COLORS,
     WAVE_CURSOR_SIZE,
     LINE_THICKNESS_SMALL,
     LINE_THICKNESS_BIG,
+    UPDATE_DISPLAY_SPEED_AFTER_UPDATES,
   } from "../const";
-  import { timeSweep } from "../stores";
+  import { timeSweep, displaySpeed } from "../stores";
 
   export let scalesY;
 
@@ -47,6 +49,10 @@
   };
   resetLogVars();
 
+  let displaySpeedUpdateCounter = 0;
+  const pixelsPerDiv = CANVAS_WIDTH / NUM_INTERVALS_VERTICAL;
+  let updateTimeStorage = new Array(NUM_CHANNELS).fill(null);
+
   // ----- Svelte lifecycle hooks -----
   onMount(() => {
     resizeCanvas();
@@ -74,12 +80,21 @@
   };
 
   export const updateBuffer = (samples, startIndex, endIndex) => {
+    let updateDisplaySpeedBuffer =
+      displaySpeedUpdateCounter++ % UPDATE_DISPLAY_SPEED_AFTER_UPDATES == 0;
+    let now;
+    if (updateDisplaySpeedBuffer) {
+      now = Date.now();
+    }
+    displaySpeedUpdateCounter %= UPDATE_DISPLAY_SPEED_AFTER_UPDATES;
+
     for (
       let channelIndex = startIndex;
       channelIndex < endIndex;
       channelIndex++
     ) {
       if (!startStopLine[channelIndex]) {
+        $displaySpeed[channelIndex] = null;
         continue;
       }
       let xCurr = xArr[channelIndex];
@@ -102,6 +117,17 @@
       while (xArr[channelIndex] >= CANVAS_WIDTH) {
         xArr[channelIndex] -= CANVAS_WIDTH;
       }
+
+      // update display speed
+      if (updateDisplaySpeedBuffer) {
+        let last = updateTimeStorage[channelIndex];
+        updateTimeStorage[channelIndex] = now;
+        if (last != null) {
+          let timePerPixel = (now - last) / 1000.0 / delta;
+          let timePerDiv = timePerPixel * pixelsPerDiv;
+          $displaySpeed[channelIndex] = timePerDiv;
+        }
+      }
     }
 
     bufferCounter++;

Apps/frontend/src/const.js

@@ -36,6 +36,7 @@ export const MIN_SWEEP = 0.1; // <= 1
 export const MAX_SWEEP = 2.0; // >= 1
 export const MIN_SWEEP_SLIDER_VALUE = 0;
 export const MAX_SWEEP_SLIDER_VALUE = 10;
+export const UPDATE_DISPLAY_SPEED_AFTER_UPDATES = 10000;
 export const DEFAULT_STEP_SIZE = 1.0;
 export const MIN_AMPLITUDE = 0.0;
 export const MAX_AMPLITUDE = NUM_INTERVALS_HORIZONTAL / 2;

Apps/frontend/src/stores.js

@@ -17,3 +17,4 @@ export const thicknessAdjustment = writable(
 
 export const expandedPanelOpen = writable(false);
 export const isGND = writable(false);
+export const displaySpeed = writable(new Array(NUM_CHANNELS).fill(null));

Apps/frontend/src/views/ControlPanelBottom.svelte

@@ -11,7 +11,7 @@
     MIN_SWEEP_SLIDER_VALUE,
     NUM_CHANNELS,
   } from "../const";
-  import { expandedPanelOpen, timeSweep } from "../stores";
+  import { expandedPanelOpen, timeSweep, displaySpeed } from "../stores";
 
   export let waveElement;
   export let indicatorElement;
@@ -85,6 +85,10 @@
           min={MIN_SWEEP_SLIDER_VALUE}
           max={MAX_SWEEP_SLIDER_VALUE}
           bind:value={$timeSweep[index]}
+          calculateDisplayedValue={(_) => {
+            let speed = $displaySpeed[index];
+            return (speed != null ? speed.toFixed(2) : "-") + " sec/div";
+          }}
           dataCy={`timesweepSlider-${index}`}
         />
       </td>