refactor movement

1 files changed, 62 insertions, 0 deletions

diff --git a/test-client/movement.ts b/test-client/movement.ts
new file mode 100644
index 00000000..883a64ec
--- /dev/null
+++ b/test-client/movement.ts
@@ -0,0 +1,62 @@
+import { data } from "./main.ts";
+import { tiles, players, PlayerData } from "./main.ts";
+import { V2, normalize, length, sub_v2, lerp_exp_v2_mut } from "./util.ts";
+
+export const PLAYER_SIZE = 0.4;
+
+export function player_movement_update(p: PlayerData, dt: number, input: V2) {
+    if (length(input) > 0.1) lerp_exp_v2_mut(p.facing, input, dt * 10.)
+    p.rot = Math.atan2(p.facing.x, p.facing.y)
+    p.vel.x += input.x * dt * 25
+    p.vel.y += input.y * dt * 25
+    p.x += p.vel.x * dt
+    p.y += p.vel.y * dt
+    collide_player(p, dt)
+    lerp_exp_v2_mut(p.vel, { x: 0, y: 0 }, dt * 5.)
+}
+
+function collide_player(p: PlayerData, dt: number) {
+    for (const [_, tile] of tiles) {
+        if (!data.tile_collide[tile.kind]) continue
+
+        const d = aabb_point_distance(tile.x, tile.y, tile.x + 1, tile.y + 1, p.x, p.y)
+        if (d > PLAYER_SIZE) continue
+
+        const h = 0.01
+        const d_sample_x = aabb_point_distance(tile.x, tile.y, tile.x + 1, tile.y + 1, p.x + h, p.y)
+        const d_sample_y = aabb_point_distance(tile.x, tile.y, tile.x + 1, tile.y + 1, p.x, p.y + h)
+        const grad_x = (d_sample_x - d) / h
+        const grad_y = (d_sample_y - d) / h
+
+        p.x += (PLAYER_SIZE - d) * grad_x
+        p.y += (PLAYER_SIZE - d) * grad_y
+
+        const vdotn = (grad_x * p.vel.x) + (grad_y * p.vel.y)
+        p.vel.x -= grad_x * vdotn
+        p.vel.y -= grad_y * vdotn
+    }
+
+    for (const [_, player] of players) {
+        const diff = sub_v2(p, player)
+        const d = length(diff)
+        if (d < 0.01) continue
+        if (d >= PLAYER_SIZE * 2) continue
+        const norm = normalize(diff);
+        const f = 1 / (1 + d)
+        p.vel.x += norm.x * f * dt
+        p.vel.y += norm.y * f * dt
+    }
+}
+
+export function aabb_point_distance(
+    min_x: number,
+    min_y: number,
+    max_x: number,
+    max_y: number,
+    px: number,
+    py: number
+): number {
+    const dx = px - Math.max(min_x, Math.min(max_x, px))
+    const dy = py - Math.max(min_y, Math.min(max_y, py))
+    return Math.sqrt(dx * dx + dy * dy)
+}