From 0cbdc5210b535623977d3ef534e422e5260b5d43 Mon Sep 17 00:00:00 2001
From: Hilmar Strauch <56518493+HilmarSt@users.noreply.github.com>
Date: Fri, 11 Feb 2022 19:13:33 +0100
Subject: [PATCH] Update widget.js

Replace the 8 phases by a more exact drawing, see forum.espruino.com/conversations/371985
---
 apps/widmp/widget.js | 65 ++++++++++++++++++++++++++++++--------------
 1 file changed, 45 insertions(+), 20 deletions(-)

diff --git a/apps/widmp/widget.js b/apps/widmp/widget.js
index d8abc3a9c..08cc4e6f1 100644
--- a/apps/widmp/widget.js
+++ b/apps/widmp/widget.js
@@ -1,26 +1,51 @@
 WIDGETS["widmoon"] = { area: "tr", width: 24, draw: function() {
-  const MC = 29.5305882, NM = 694039.09; 
-  var r = 11, mx = this.x + 12; my = this.y + 12;
+  const CenterX = this.x + 12, CenterY = this.y + 12, Radius = 11;
 
-  function moonPhase(d) {
-    var tmp, month = d.getMonth(), year = d.getFullYear(), day = d.getDate();
+  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;}
-    tmp = ((365.25 * year + 30.6 * ++month + day - NM) / MC);
-    return Math.round(((tmp - (tmp | 0)) * 7)+1);
+    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);
   }
 
-  const BLACK = g.theme.bg, MOON = 0x41f;
-  var moon = {
-    0: () => { g.reset().setColor(BLACK).fillRect(mx - r, my - r, mx + r, my + r);},
-    1: () => { moon[0](); g.setColor(MOON).drawCircle(mx, my, r);},
-    2: () => { moon[3](); g.setColor(BLACK).fillEllipse(mx - r / 2, my - r, mx + r / 2, my + r);},
-    3: () => { moon[0](); g.setColor(MOON).fillCircle(mx, my, r).setColor(BLACK).fillRect(mx - r, my - r, mx, my + r);},
-    4: () => { moon[3](); g.setColor(MOON).fillEllipse(mx - r / 2, my - r, mx + r / 2, my + r);},
-    5: () => { moon[0](); g.setColor(MOON).fillCircle(mx, my, r);},
-    6: () => { moon[7](); g.setColor(MOON).fillEllipse(mx - r / 2, my - r, mx + r / 2, my + r);},
-    7: () => { moon[0](); g.setColor(MOON).fillCircle(mx, my, r).setColor(BLACK).fillRect(mx, my - r, mx + r, my + r);},
-    8: () => { moon[7](); g.setColor(BLACK).fillEllipse(mx - r / 2, my - r, mx + r / 2, my + r);}
-  };
-  moon[moonPhase(Date())]();
-} };
+  // 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;
+
+    drawMoonPhase(CenterX,CenterY, Radius, leftFactor,rightFactor);
+
+    if (simulate) setTimeout(updateWidget, updateR);
+  }
+  updateWidget();
+} };