Mirror/intercept
1
0
Fork 0
mirror of https://github.com/smittix/intercept.git synced 2026-04-24 06:40:00 -07:00
Code Issues Packages Projects Releases Wiki Activity

fix: Correct globe projection orientation

Browse Source 
- Fix x-axis mirroring for proper globe viewing orientation
- Adjust rotation formula to use lon - rotation instead of lon + rotation
- Globe now correctly shows landmasses relative to ISS position

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
This commit is contained in:
Smittix
2026-01-29 16:53:31 +00:00
parent 52997b3c78
commit 21dec0d53a
1 changed files with 9 additions and 7 deletions
Download Patch File Download Diff File Expand all files Collapse all files

16
static/js/modes/sstv.js
View File

@@ -387,16 +387,18 @@ const SSTV = (function() {
* Project lat/lon to x/y on globe with rotation
*/
function projectPoint(lat, lon, cx, cy, radius, rotation) {
const lonRad = (lon + rotation) * Math.PI / 180;
// Apply rotation to longitude (negative to rotate globe eastward)
const adjustedLon = lon - rotation;
const lonRad = adjustedLon * Math.PI / 180;
const latRad = lat * Math.PI / 180;
// Check if point is on visible hemisphere
const x3d = Math.cos(latRad) * Math.sin(lonRad);
// Check if point is on visible hemisphere (front of globe)
const z3d = Math.cos(latRad) * Math.cos(lonRad);
if (z3d < 0) return null; // Behind globe
const x = cx + x3d * radius;
// Project to 2D - negate x for correct left/right orientation when viewing globe
const x3d = Math.cos(latRad) * Math.sin(lonRad);
const x = cx - x3d * radius; // Negated for correct globe orientation
const y = cy - Math.sin(latRad) * radius;
return { x, y, z: z3d };
@@ -414,8 +416,8 @@ const SSTV = (function() {
const cy = canvas.height / 2;
const radius = Math.min(cx, cy) - 10;
// Globe rotation - center on ISS longitude if available
const globeRotation = issPosition ? -issPosition.lon : 0;
// Globe rotation - center on ISS longitude
const globeRotation = issPosition ? issPosition.lon : 0;
// Clear canvas
ctx.clearRect(0, 0, canvas.width, canvas.height);