BangleApps/apps/magnav/magnav.min.js

var Yoff=80,pal2color=new Uint16Array([0,65535,2047,50712],0,2),buf=Graphics.createArrayBuffer(240,60,2,{msb:!0});Bangle.setLCDTimeout(30);function flip(b,c){g.drawImage({width:240,height:60,bpp:2,buffer:b.buffer,palette:pal2color},0,c);b.clear()}var labels="N NE E SE S SW W NW".split(" "),brg=null;
function drawCompass(b){buf.setColor(1);buf.setFont("Vector",24);var c=b-90;0>c&&(c+=360);buf.fillRect(28,45,212,49);var a=30,d=15-c%15;15>d?a+=d:d=0;for(var e=d;e<=180-d;e+=15){var f=c+e;0==f%90?(buf.drawString(labels[Math.floor(f/45)%8],a-8,0),buf.fillRect(a-2,25,a+2,45)):0==f%45?(buf.drawString(labels[Math.floor(f/45)%8],a-12,0),buf.fillRect(a-2,30,a+2,45)):0==f%15&&buf.fillRect(a,35,a+1,45);a+=15}brg&&(b=brg-b,180<b&&(b-=360),-180>b&&(b+=360),b+=120,30>b&&(b=14),210<b&&(b=226),buf.setColor(2),
buf.fillCircle(b,40,8));flip(buf,Yoff)}var heading=0;function newHeading(b,c){var a=Math.abs(b-c),d=b>c?1:-1;180<=a&&(a=360-a,d=-d);if(2>a)return c;a=c+d*(1+Math.round(a/5));0>a&&(a+=360);360<a&&(a-=360);return a}var candraw=!1,CALIBDATA=require("Storage").readJSON("magnav.json",1)||null;
function tiltfixread(b,c){Date.now();var a=Bangle.getCompass(),d=Bangle.getAccel();a.dx=(a.x-b.x)*c.x;a.dy=(a.y-b.y)*c.y;a.dz=(a.z-b.z)*c.z;var e=Math.atan(-d.x/-d.z),f=Math.cos(e);e=Math.sin(e);d=Math.atan(-d.y/(-d.x*e-d.z*f));var k=Math.sin(d);a=180*Math.atan2(a.dz*e-a.dx*f,a.dy*Math.cos(d)+a.dx*e*k+a.dz*f*k)/Math.PI;0>a&&(a+=360);return a}
function reading(){var b=tiltfixread(CALIBDATA.offset,CALIBDATA.scale);heading=newHeading(b,heading);drawCompass(heading);buf.setColor(1);buf.setFont("6x8",2);buf.setFontAlign(-1,-1);buf.drawString("o",170,0);buf.setFont("Vector",54);b=Math.round(heading);var c=b.toString();buf.drawString(10>b?"00"+c:100>b?"0"+c:c,70,10);flip(buf,Yoff+80)}
function calibrate(){var b=-32E3,c=-32E3,a=-32E3,d=32E3,e=32E3,f=32E3,k=setInterval(function(){var h=Bangle.getCompass();b=h.x>b?h.x:b;c=h.y>c?h.y:c;a=h.z>a?h.z:a;d=h.x<d?h.x:d;e=h.y<e?h.y:e;f=h.z<f?h.z:f},100);return new Promise(function(h){setTimeout(function(){k&&clearInterval(k);var m=(b-d)/2,n=(c-e)/2,p=(a-f)/2,l=(m+n+p)/3;h({offset:{x:(b+d)/2,y:(c+e)/2,z:(a+f)/2},scale:{x:l/m,y:l/n,z:l/p}})},1E4)})}
function docalibrate(b,c){function a(d){d?(buf.setColor(1),buf.setFont("Vector",24),buf.setFontAlign(0,-1),buf.drawString("Fig 8s to",120,0),buf.drawString("Calibrate",120,26),flip(buf,Yoff),calibrate().then(function(e){require("Storage").write("magnav.json",e);CALIBDATA=e;startdraw();setButtons()})):(startdraw(),setTimeout(setButtons,1E3))}void 0===c&&(c=!1);stopdraw();clearWatch();c?E.showAlert("takes 10 seconds","Calibrate").then(a.bind(null,!0)):E.showPrompt("takes 10 seconds",{title:"Calibrate",
buttons:{Start:!0,Cancel:!1}}).then(a)}Bangle.on("touch",function(b){candraw&&(1==b&&(brg=heading),2==b&&(brg=null))});var intervalRef;function startdraw(){g.clear();g.setColor(1,.5,.5);g.fillPoly([120,Yoff+60,110,Yoff+80,130,Yoff+80]);g.setColor(1,1,1);Bangle.drawWidgets();candraw=!0;intervalRef=setInterval(reading,200)}function stopdraw(){candraw=!1;intervalRef&&clearInterval(intervalRef)}
function setButtons(){setWatch(function(){load()},BTN1,{repeat:!1,edge:"falling"});setWatch(Bangle.showLauncher,BTN2,{repeat:!1,edge:"falling"});setWatch(docalibrate,BTN3,{repeat:!1,edge:"falling"})}var SCREENACCESS={withApp:!0,request:function(){this.withApp=!1;stopdraw();clearWatch()},release:function(){this.withApp=!0;startdraw();setButtons()}};Bangle.on("lcdPower",function(b){SCREENACCESS.withApp&&(b?startdraw():stopdraw())});Bangle.on("kill",function(){Bangle.setCompassPower(0)});Bangle.loadWidgets();
Bangle.setCompassPower(1);CALIBDATA?(startdraw(),setButtons()):docalibrate({},!0);