From 0f1e2a3632b7b1a04c962cfcef1558febc054331 Mon Sep 17 00:00:00 2001
From: wwjjbb <dxt.wjb@gmail.com>
Date: Fri, 14 Jul 2017 16:28:01 +0100
Subject: [PATCH] Interpolate shadow position based on time of quarters
Previously assumed each quarter was 1/4 of the cycle. Which its not.
THis is not ideal either.
---
package/contents/code/lunacalc.js | 47 ++++++++++++++++---------------
package/contents/ui/main.qml | 2 +-
2 files changed, 25 insertions(+), 24 deletions(-)
diff --git a/package/contents/code/lunacalc.js b/package/contents/code/lunacalc.js
index 1c2d40c..1c6f41d 100644
--- a/package/contents/code/lunacalc.js
+++ b/package/contents/code/lunacalc.js
@@ -78,36 +78,37 @@ function reloadPhases()
return getPhasesByLunation(lunation);
}
-function getCurrentPhase() // this function assumes that today is between phases[0] (last new moon) and phases[4] (next new moon)
+function getCurrentPhase(interpolate) // this function assumes that today is between phases[0] (last new moon) and phases[4] (next new moon)
{
var oneDay = 1000 * 60 * 60 * 24;
var today = new Date().getTime();
var phases = getTodayPhases();
- /* -------------------------------------------------------------------------
- // Estimate where the terminator is - base this on knowing where it
- // is at each quarter, and interpolating. Cowboy maths.
- // Determines how far into the current quarter we are, and uses
- // the result to work out where the terminator is. This allows for
- // the quarters being different sizes, rather than assuming they are
- // each one quarter of the cycle time.
-
- var qnum = 0;
- while (today > phases[qnum+1] && qnum < 3) {
- qnum++;
+ var terminator;
+ if (interpolate) {
+ // Estimate where the terminator is - base this on knowing where it
+ // is at each quarter, and interpolating. Cowboy maths.
+ // Determines how far into the current quarter we are, and uses
+ // the result to work out where the terminator is. This allows for
+ // the quarters being different sizes, rather than assuming they are
+ // each one quarter of the cycle time.
+
+ var qnum = 0;
+ while (today > phases[qnum+1] && qnum < 3) {
+ qnum++;
+ }
+ var quarterTime = phases[qnum+1].getTime() - phases[qnum].getTime();
+ var sinceQuarter = today - phases[qnum].getTime();
+ terminator = Math.floor(((sinceQuarter / quarterTime) + qnum) * 90);
+ }
+ else {
+ // Work out where the terminator is, 0..359 degrees.
+ // This assumes a constant rate for the month, which is unlikely
+ var cycleTime = phases[4].getTime() - phases[0].getTime();
+ var sinceNew = today - phases[0].getTime();
+ terminator = Math.floor((sinceNew / cycleTime) * 360);
}
- var quarterTime = phases[qnum+1].getTime() - phases[qnum].getTime();
- var sinceQuarter = today - phases[qnum].getTime();
- var terminator = Math.floor(((sinceQuarter / quarterTime) + qnum) * 90);
- --------------------------------------------------------------------- */
-
- // /*
- // Work out where the terminator is, 0..359 degrees
- var cycleTime = phases[4].getTime() - phases[0].getTime();
- var sinceNew = today - phases[0].getTime();
- var terminator = Math.floor((sinceNew / cycleTime) * 360);
- // */
// Keep this in the range [0,360):
if (terminator >= 360) {
diff --git a/package/contents/ui/main.qml b/package/contents/ui/main.qml
index 6fab7c5..ff0e18f 100644
--- a/package/contents/ui/main.qml
+++ b/package/contents/ui/main.qml
@@ -70,7 +70,7 @@ Item {
function updateDetails() {
// set the correct image for the moon
- currentPhase = LunaCalc.getCurrentPhase();
+ currentPhase = LunaCalc.getCurrentPhase(true);
lunaIcon.phaseNumber = 13; //currentPhase.number;
lunaIcon.theta = currentPhase.terminator;
lunaIcon.hemisphere = hemisphere;
--
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