v1 slob

src/client/graphics/layers/SegmentMotionSample.ts

@@ -0,0 +1,103 @@
+import { TileRef } from "../../../core/game/GameMap";
+import type { GameView } from "../../../core/game/GameView";
+
+export type GridSegmentMotionPlanView = {
+  planId: number;
+  startTick: number;
+  ticksPerStep: number;
+  points: Uint32Array;
+  segmentSteps: Uint32Array;
+  segCumSteps: Uint32Array;
+};
+
+export type SampledMotionPosition = {
+  x: number;
+  y: number;
+  isComplete: boolean;
+  tile0: TileRef;
+  tile1: TileRef;
+};
+
+function clamp01(v: number): number {
+  if (v <= 0) return 0;
+  if (v >= 1) return 1;
+  return v;
+}
+
+export function sampleGridSegmentPlan(
+  game: GameView,
+  plan: GridSegmentMotionPlanView,
+  tickFloat: number,
+): SampledMotionPosition | null {
+  const points = plan.points;
+  if (points.length === 0) {
+    return null;
+  }
+  if (points.length === 1 || plan.segmentSteps.length === 0) {
+    const t = points[0] as TileRef;
+    return { x: game.x(t), y: game.y(t), isComplete: true, tile0: t, tile1: t };
+  }
+
+  const ticksPerStep = Math.max(1, plan.ticksPerStep);
+  const stepFloat = (tickFloat - plan.startTick) / ticksPerStep;
+
+  const segCum = plan.segCumSteps;
+  const totalSteps = segCum.length === 0 ? 0 : segCum[segCum.length - 1] >>> 0;
+  if (totalSteps <= 0) {
+    const t = points[points.length - 1] as TileRef;
+    return { x: game.x(t), y: game.y(t), isComplete: true, tile0: t, tile1: t };
+  }
+
+  if (stepFloat <= 0) {
+    const t = points[0] as TileRef;
+    const t1 = points[1] as TileRef;
+    return {
+      x: game.x(t),
+      y: game.y(t),
+      isComplete: false,
+      tile0: t,
+      tile1: t1,
+    };
+  }
+  if (stepFloat >= totalSteps) {
+    const t = points[points.length - 1] as TileRef;
+    return { x: game.x(t), y: game.y(t), isComplete: true, tile0: t, tile1: t };
+  }
+
+  // Find the segment containing stepFloat.
+  let seg = 0;
+  let lo = 0;
+  let hi = plan.segmentSteps.length - 1;
+  while (lo <= hi) {
+    const mid = (lo + hi) >>> 1;
+    const start = segCum[mid] >>> 0;
+    const end = segCum[mid + 1] >>> 0;
+    if (stepFloat < start) {
+      hi = mid - 1;
+    } else if (stepFloat >= end) {
+      lo = mid + 1;
+    } else {
+      seg = mid;
+      break;
+    }
+  }
+
+  const segStart = segCum[seg] >>> 0;
+  const steps = Math.max(1, plan.segmentSteps[seg] >>> 0);
+  const u = clamp01((stepFloat - segStart) / steps);
+
+  const tile0 = points[seg] as TileRef;
+  const tile1 = points[seg + 1] as TileRef;
+  const x0 = game.x(tile0);
+  const y0 = game.y(tile0);
+  const x1 = game.x(tile1);
+  const y1 = game.y(tile1);
+
+  return {
+    x: x0 + (x1 - x0) * u,
+    y: y0 + (y1 - y0) * u,
+    isComplete: false,
+    tile0,
+    tile1,
+  };
+}