https://github.com/rozek/banglejs-2-drawmoonphase
draws the interior of two half ovals to symbolize a moon phase
https://github.com/rozek/banglejs-2-drawmoonphase
banglejs
Last synced: 12 months ago
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draws the interior of two half ovals to symbolize a moon phase
- Host: GitHub
- URL: https://github.com/rozek/banglejs-2-drawmoonphase
- Owner: rozek
- License: mit
- Created: 2022-01-11T06:34:37.000Z (over 4 years ago)
- Default Branch: main
- Last Pushed: 2022-03-01T05:59:39.000Z (over 4 years ago)
- Last Synced: 2025-06-30T00:03:14.875Z (12 months ago)
- Topics: banglejs
- Language: JavaScript
- Homepage:
- Size: 11.7 KB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE.md
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README
# banglejs-2-drawmoonphase #
draws the interior of two half ovals to symbolize a moon phase
This module adds a method `drawMoonPhase` for drawing an image symbolizing a moon phase to the global graphics context `g`. It is based on an idea of forum user [HilmarSt](http://forum.espruino.com/profiles/182487/) (see this [discussion](http://forum.espruino.com/conversations/371330/)).
The new method has the signature
```javascript
g.drawMoonPhase(cx,cy, r, left, right);
```
with the following parameters:
* `cx` - x coordinate of the moon's center
* `cy` - y coordinate of the moon's center
* `r` - moon radius
* `left` - left factor (see below)
* `right` - right factor (see below)
The moon phase is drawn and filled with current foreground color.
### Semantics of "left" and "right" ###
`left` and `right` specify the actual phase that is to be shown:
* both values range from -1...+1
* set both to `1` for a full moon
* set `right = 1` and start with `left = -1` for a waxing moon. Increase `left` until `1` for a full moon
* set `left = 1` and start with `right = 1` for a waning moon. Decrease `right` until `-1`
## Example ##
The following example illustrates how to use `drawMoonPhase` and produces the graphics shown above:
```javascript
g.setBgColor('#000000');
g.clear(false);
require('https://raw.githubusercontent.com/rozek/banglejs-2-drawmoonphase/main/drawMoonPhase.js');
let ScreenWidth = g.getWidth(), CenterX = ScreenWidth/2;
let ScreenHeight = g.getHeight(), CenterY = ScreenHeight/2;
let Diameter = Math.floor(ScreenWidth / 7);
let Radius = Diameter/2;
g.clear();
g.setColor('#FFFFFF');
g.drawMoonPhase(CenterX-3*Diameter,CenterY, Radius, 1,-1);
g.drawMoonPhase(CenterX-2*Diameter,CenterY, Radius, 1,-0.6);
g.drawMoonPhase(CenterX-1*Diameter,CenterY, Radius, 1,0.6);
g.drawMoonPhase(CenterX-0*Diameter,CenterY, Radius, 1,1);
g.drawMoonPhase(CenterX+1*Diameter,CenterY, Radius, 0.6,1);
g.drawMoonPhase(CenterX+2*Diameter,CenterY, Radius, -0.6,1);
g.drawMoonPhase(CenterX+3*Diameter,CenterY, Radius, -1,1);
```
## License ##
[MIT License](LICENSE.md)