BangleApps/apps/widmp/widget.js

64 lines
2.4 KiB
JavaScript

WIDGETS["widmoon"] = { area: "tr", width: 24, draw: function() {
const CenterX = this.x + 12, CenterY = this.y + 12, Radius = 11;
var southernHemisphere = false; // when in southern hemisphere, use the "My Location" App
const simulate = false; // simulate one month in one minute
const updateR = 1000; // update every x ms in simulation
function moonPhase() {
const d = Date();
var month = d.getMonth(), year = d.getFullYear(), day = d.getDate();
if (simulate) day = d.getSeconds() / 2 +1;
if (month < 3) {year--; month += 12;}
mproz = ((365.25 * year + 30.6 * ++month + day - 694039.09) / 29.5305882);
mproz = mproz - (mproz | 0); // strip integral digits, result is between 0 and <1
if (simulate) console.log(mproz + " " + day);
return (mproz);
}
function loadLocation() {
// "mylocation.json" is created by the "My Location" app
location = require("Storage").readJSON("mylocation.json",1)||{"lat":50.1236,"lon":8.6553,"location":"Frankfurt"};
if (location.lat < 0) southernHemisphere = true;
}
// code source: github.com/rozek/banglejs-2-activities/blob/main/README.md#drawmoonphase
function drawMoonPhase (CenterX,CenterY, Radius, leftFactor,rightFactor) {
let x = Radius, y = 0, Error = Radius;
g.drawLine(CenterX-leftFactor*x,CenterY, CenterX+rightFactor*x,CenterY);
let dx,dy;
while (y <= x) {
dy = 1 + 2*y; y++; Error -= dy;
if (Error < 0) {
dx = 1 - 2*x; x--; Error -= dx;
}
g.drawLine(CenterX-leftFactor*x,CenterY-y, CenterX+rightFactor*x,CenterY-y);
g.drawLine(CenterX-leftFactor*x,CenterY+y, CenterX+rightFactor*x,CenterY+y);
g.drawLine(CenterX-leftFactor*y,CenterY-x, CenterX+rightFactor*y,CenterY-x);
g.drawLine(CenterX-leftFactor*y,CenterY+x, CenterX+rightFactor*y,CenterY+x);
}
}
function updateWidget() {
g.reset().setColor(g.theme.bg);
g.fillRect(CenterX - Radius, CenterY - Radius, CenterX + Radius, CenterY + Radius);
g.setColor(0x41f);
mproz = moonPhase(); // mproz = 0..<1
leftFactor = mproz * 4 - 1;
rightFactor = (1 - mproz) * 4 - 1;
if (mproz >= 0.5) leftFactor = 1; else rightFactor = 1;
if (true == southernHemisphere) {
var tmp=leftFactor; leftFactor=rightFactor; rightFactor=tmp;
}
drawMoonPhase(CenterX,CenterY, Radius, leftFactor,rightFactor);
if (simulate) setTimeout(updateWidget, updateR);
}
loadLocation();
updateWidget();
} };