From 9c2809be293166b40bef8c57d353ddd9a1b27af5 Mon Sep 17 00:00:00 2001
From: "Eevee (Evelyn Woods)" <eevee.git@veekun.com>
Date: Sat, 26 Dec 2020 03:41:35 -0700
Subject: [PATCH] Fix interpolation after the tic -> frame change

---
 js/game.js    |  2 +-
 js/tileset.js | 16 ++++++++--------
 2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/js/game.js b/js/game.js
index 2c20d13..6b1e26d 100644
--- a/js/game.js
+++ b/js/game.js
@@ -40,7 +40,7 @@ export class Tile {
         else {
             // For a movement speed of N, the cooldown is set to N during the tic an actor starts
             // moving, and we interpolate it from there to N - 1 over the course of the duration
-            let p = ((this.movement_speed - this.movement_cooldown) + tic_offset) / this.movement_speed;
+            let p = ((this.movement_speed - this.movement_cooldown) + tic_offset * 3) / this.movement_speed;
             return [
                 (1 - p) * this.previous_cell.x + p * x,
                 (1 - p) * this.previous_cell.y + p * y,
diff --git a/js/tileset.js b/js/tileset.js
index 58ae498..35c95ef 100644
--- a/js/tileset.js
+++ b/js/tileset.js
@@ -915,8 +915,8 @@ export class Tileset {
         if (coords[0] instanceof Array) {
             if (tic !== null) {
                 if (tile && tile.movement_speed) {
-                    // This tile reports its own animation timing (in tics), so trust that, and just
-                    // use the current tic's fraction.
+                    // This tile reports its own animation timing (in frames), so trust that, and
+                    // just use the current tic's fraction.
                     // That said: adjusting animation speed complicates this slightly.  Consider the
                     // player's walk animation, which takes 4 tics to complete, during which time we
                     // cycle through 8 frames.  Playing that at half speed means only half the
@@ -926,7 +926,7 @@ export class Tileset {
                     // first half; if it started on tics 5-8, play the second half.  They could get
                     // out of sync if the player hesitates, but no one will notice that, and this
                     // approach minimizes storing extra state.
-                    let i = ((tile.movement_speed - tile.movement_cooldown) + tic % 1) / tile.movement_speed;
+                    let i = ((tile.movement_speed - tile.movement_cooldown) + tic % 1 * 3) / tile.movement_speed;
                     // But do NOT do this for explosions or splashes, which have a fixed duration
                     // and only play once
                     if (this.animation_slowdown > 1 && ! tile.type.ttl) {
@@ -934,7 +934,7 @@ export class Tileset {
                         // 1/N of it before the game ends (or loops) the animation.
                         // So increase by [0..N-1] to get it in some other range, then divide by N
                         // to scale back down to [0, 1)
-                        i += Math.floor(tic / tile.movement_speed % this.animation_slowdown);
+                        i += Math.floor(tic * 3 / tile.movement_speed % this.animation_slowdown);
                         i /= this.animation_slowdown;
                     }
                     coords = coords[Math.floor(i * coords.length)];
@@ -1234,8 +1234,8 @@ export class Tileset {
         if (coords[0] instanceof Array) {
             if (tic !== null) {
                 if (tile && tile.movement_speed) {
-                    // This tile reports its own animation timing (in tics), so trust that, and just
-                    // use the current tic's fraction.
+                    // This tile reports its own animation timing (in frames), so trust that, and
+                    // just use the current tic's fraction.
                     // That said: adjusting animation speed complicates this slightly.  Consider the
                     // player's walk animation, which takes 4 tics to complete, during which time we
                     // cycle through 8 frames.  Playing that at half speed means only half the
@@ -1245,7 +1245,7 @@ export class Tileset {
                     // first half; if it started on tics 5-8, play the second half.  They could get
                     // out of sync if the player hesitates, but no one will notice that, and this
                     // approach minimizes storing extra state.
-                    let i = ((tile.movement_speed - tile.movement_cooldown) + tic % 1) / tile.movement_speed;
+                    let i = ((tile.movement_speed - tile.movement_cooldown) + tic % 1 * 3) / tile.movement_speed;
                     // But do NOT do this for explosions or splashes, which have a fixed duration
                     // and only play once
                     if (this.animation_slowdown > 1 && ! tile.type.ttl) {
@@ -1253,7 +1253,7 @@ export class Tileset {
                         // 1/N of it before the game ends (or loops) the animation.
                         // So increase by [0..N-1] to get it in some other range, then divide by N
                         // to scale back down to [0, 1)
-                        i += Math.floor(tic / tile.movement_speed % this.animation_slowdown);
+                        i += Math.floor(tic * 3 / tile.movement_speed % this.animation_slowdown);
                         i /= this.animation_slowdown;
                     }
                     coords = coords[Math.floor(i * coords.length)];