Isle-Slingers/js/physics/camera/index.js

/* ISLE SLINGERS -- physics/camera/index.js (submodule: camera)
 * RC-375D84 S-2 modularization (behavior-neutral split of the original
 * js/core.js monolith). Installs its units into ONE shared physics scope `P`
 * that every physics submodule sees -- the same single-scope semantics the
 * monolith had. Must load before js/physics/index.js (the aggregator that
 * attaches the public ISLE_CORE API). Surface installed: updatePopups, updateCameraTarget, decayCamera.
 */
(function (root, factory) {
  var part = factory();
  if (typeof module !== 'undefined' && module.exports) module.exports = part;
  else (root.ISLE_PHYSICS_PARTS = root.ISLE_PHYSICS_PARTS || []).push(part);
})(typeof globalThis !== 'undefined' ? globalThis : this, function () {
  'use strict';
  return function (P) {
  P.updatePopups = function(g, dt) {
    for (var i = g.scorePopups.length - 1; i >= 0; i--) {
      g.scorePopups[i].age += dt;
      g.scorePopups[i].y -= 40 * dt;
      if (g.scorePopups[i].age > 1.4) g.scorePopups.splice(i, 1);
    }
  }

  P.updateCameraTarget = function(g) {
    var b = P.activeBird(g);
    var cam = g.camera;
    var tx, ty, tz;
    if (b && b.state === 'flying') {
      // in flight: follow the slinger 1:1 (the bird IS the point of interest)
      tx = Math.max(420, Math.min(P.WORLD.w - 420, b.x + 220));
      ty = Math.max(380, Math.min(P.WORLD.ground - 160, b.y + 60));
      tz = 1;
    } else {
      // aiming / waiting: frame the slingshot AND the whole action zone
      // (live blocks + enemies) so P.launch point and target are always
      // visible at once — zooming out when the level needs it. Without
      // this the sling was visible but the fort was off-screen (or
      // vice-versa mid-flight), making aiming pure guesswork.
      var left = g.level.sling.x - 190;
      var right = left + 300;
      for (var i = 0; i < g.blocks.length; i++) {
        var bl = g.blocks[i];
        if (bl.hp > 0) right = Math.max(right, bl.x + bl.w / 2 + 90);
      }
      for (var k = 0; k < g.enemies.length; k++) {
        var en = g.enemies[k];
        if (!en.dead) right = Math.max(right, en.x + en.r + 90);
      }
      var span = right - left;
      tz = Math.min(1, P.VIEW.w / span);
      tx = left + span / 2;
      // ground at ~78% down the view, whatever the zoom
      ty = Math.max(300, Math.min(P.WORLD.ground, P.WORLD.ground - (0.28 * P.VIEW.h) / tz));
    }
    if (cam.snap) { // first frame of a level: land on target, no pan
      cam.x = tx; cam.y = ty; cam.zoom = tz; cam.snap = false;
      return;
    }
    cam.x += (tx - cam.x) * 0.06;
    cam.y += (ty - cam.y) * 0.06;
    cam.zoom = (cam.zoom || 1) + (tz - (cam.zoom || 1)) * 0.08;
  }

  P.decayCamera = function(g, dt) {
    if (g.camera.shake > 0) {
      g.camera.shake *= Math.pow(0.03, dt); // fast decay
      if (g.camera.shake < 0.3) g.camera.shake = 0;
    }
  }
  };
});