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Merge the review fixes, and take Junie's on the hit radius with them

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Carries the shared reference-viewport module and the cached card lookup up from
the branch they were reviewed on, and answers the one comment left against this
one.

The orthographic branch of the star field's hit test multiplied the angular size
by the frustum's half-height and then divided the result by that same
half-height. The two cancel: `setProjection` had already sized the sprite as
`angular * halfHeight / tan(REFERENCE_FOV/2)`, so dividing back out by the
half-height leaves the reference field of view and nothing else. Both
projections are one formula over a different angle now — which is also one
fewer division by a number that is zero if the frustum ever degenerates.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016jxMkwA2rbicdGxHosecYi
This commit is contained in:
Senrokai
2026-08-21 14:55:59 +02:00
co-authored by Claude Fable 5
parent d9bd913458 50c0351870
commit b2cb307b60
4 changed files with 35 additions and 26 deletions
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src/app/features/galaxy-system/star-field-renderer.ts
+8 -21
View File
@@ -4,21 +4,12 @@ import { float, instancedBufferAttribute, mix, modelViewMatrix, smoothstep, unif
import { spectralTypeToColorIndex } from '../../shared/astro/spectral';
import { SceneCamera } from '../../core/engine/engine.service';
import { StarRecord } from '../../shared/models/star.model';
import { PIXELS_TO_ANGULAR_SIZE, REFERENCE_FOV_DEGREES, REFERENCE_VIEWPORT_HEIGHT_PX } from './angular-size';
/** Apparent star diameters, in pixels at {@link REFERENCE_VIEWPORT_HEIGHT_PX}. */
const MIN_POINT_SIZE = 1.5;
const MAX_POINT_SIZE = 6;
/**
* Star size is expressed in pixels for readability, but the material works in angular size, so
* the two are related through the scene's vertical field of view and a reference viewport.
* Because the size is angular, a star keeps the same share of the screen at any window size —
* these pixel figures are exact only at this reference height.
*/
const REFERENCE_VIEWPORT_HEIGHT_PX = 900;
const REFERENCE_FOV_DEGREES = 55;
const PIXELS_TO_ANGULAR_SIZE =
(2 * Math.tan((REFERENCE_FOV_DEGREES * Math.PI) / 180 / 2)) / REFERENCE_VIEWPORT_HEIGHT_PX;
/**
* Extra click forgiveness added to a star's drawn radius, in NDC — roughly 4 px on the
@@ -270,13 +261,13 @@ export class StarFieldRenderer {
* sub-pixel at the far end of the camera's range.
*/
pickAt(pointerNdc: THREE.Vector2, camera: SceneCamera, aspect: number): number | undefined {
// What a unit of angular size is worth on screen. Under perspective that is set by the
// field of view; under an orthographic camera the same size was already turned into a world
// size by `setProjection`, so it is the frustum that converts it back.
// What a unit of angular size is worth on screen. Under perspective the field of view sets
// it. Under an orthographic camera the frustum does — but `setProjection` sized the sprite
// as `angular * halfHeight / tan(REFERENCE_FOV/2)` in the first place, so dividing back out
// by that same half-height leaves the reference field of view and nothing else. Both cases
// are therefore one formula over a different angle.
const perspective = (camera as THREE.PerspectiveCamera).isPerspectiveCamera;
const orthographic = camera as THREE.OrthographicCamera;
const halfHeightWorld = perspective ? 0 : (orthographic.top - orthographic.bottom) / (2 * orthographic.zoom);
const tanHalfFov = perspective ? Math.tan(((camera as THREE.PerspectiveCamera).fov * Math.PI) / 360) : 0;
const tanHalfFov = Math.tan(((perspective ? (camera as THREE.PerspectiveCamera).fov : REFERENCE_FOV_DEGREES) * Math.PI) / 360);
const projected = new THREE.Vector3();
let bestIndex: number | undefined;
@@ -293,11 +284,7 @@ export class StarFieldRenderer {
// A sprite square in view space projects to an ellipse in NDC: the same half-extent in y,
// divided by the aspect ratio in x. Scaling dx by the aspect makes the comparison circular.
const ndcRadius =
(perspective
? (0.5 * this.angularSizes[index]) / tanHalfFov
: // The world size the star is drawn at, as a fraction of the frustum's half-height.
(0.5 * this.angularSizes[index] * (halfHeightWorld / Math.tan((REFERENCE_FOV_DEGREES * Math.PI) / 360))) / halfHeightWorld) + PICK_NDC_SLOP;
const ndcRadius = (0.5 * this.angularSizes[index]) / tanHalfFov + PICK_NDC_SLOP;
const dx = (projected.x - pointerNdc.x) * aspect;
const dy = projected.y - pointerNdc.y;
const score = Math.hypot(dx, dy) / ndcRadius;