Function altToY

altToY(altitudeDeg: number, height: number, maxAltitude?: number): number
Map a sun altitude to a y coordinate in the arc's SVG box (y grows downward).
Parameters
- altitudeDeg: number
  Sun altitude in degrees; maxAltitude maps to y 0 (top), -6 maps to y height (bottom), so the horizon (0°) sits near the bottom. Values are clamped.
- height: number
  Drawing height in SVG user units (px).
- maxAltitude: number = 75
  Altitude in degrees that maps to the top of the box. Default 75.
Returns number
The y coordinate in [0, height].