dial: (WIP) new module to dial settings/levels etc

Author: thyttan

modules/dial.js

@@ -0,0 +1,71 @@
+// upload to ram via espruino web ide while in development.
+
+{
+  /*
+Bangle.on('drag', function(event) { ... });
+Parameters
+
+event - Object of form {x,y,dx,dy,b} containing touch coordinates, difference in touch coordinates, and an integer b containing number of touch points (currently 1 or 0)
+
+
+   */
+
+let cumulativeDxPlusDy = 0;
+let level = 0;
+let dragHandler = function(e) { "ram"
+    // Use cross product to decide if dialing down/left/screwing out or up/right/screwing in?
+/*
+    // Quadrants: (1 || 2 || 3 || 4)
+    if ((e.dx>0&&e.dy>0) || (e.dx>0&&e.dy>0) || (e.dx>0&&e.dy>0) || (e.dx>0&&e.dy>0)) { //screwing into the screen - increase
+
+    }
+
+    if ((e.dx>0&&e.dy>0) || (e.dx>0&&e.dy>0) || (e.dx>0&&e.dy>0) || (e.dx>0&&e.dy>0)) { //screwing out of the screen - decrease
+
+    }
+
+*/
+
+    const PREV_DX_PLUS_DY = cumulativeDxPlusDy;
+    if (e.y<g.getHeight()/2 ) {
+      cumulativeDxPlusDy += e.dx;
+    } else {
+      cumulativeDxPlusDy -= e.dx;
+    }
+    if (e.x<g.getWidth()/2 ) {
+      cumulativeDxPlusDy -= e.dy;
+    } else {
+      cumulativeDxPlusDy += e.dy;
+    }
+
+    if (Math.abs(cumulativeDxPlusDy)<Math.abs(PREV_DX_PLUS_DY)) {
+      cumulativeDxPlusDy = 0;
+    }
+
+    let onStep = (step)=>{
+      if (step>0) {
+      level ++;
+      }
+      if (step<0) {
+      level --;
+      }
+      print(step, level);
+      g.clear().setFont("Vector:40").setFontAlign(0,0).drawString(level, 85, 85);
+      Bangle.buzz(20, 0.2)
+      cumulativeDxPlusDy = 0;
+    }
+
+    if (cumulativeDxPlusDy > 50) {
+      onStep(1);
+    }
+    if (cumulativeDxPlusDy < -50) {
+      onStep(-1);
+    }
+ 
+
+  }
+
+Bangle.on("drag", dragHandler);
+}
+
+