From fec09c03ba84a22e0896e596e772c24f51be3a25 Mon Sep 17 00:00:00 2001
From: "Eevee (Evelyn Woods)" <eevee.git@veekun.com>
Date: Fri, 11 Dec 2020 21:31:07 -0700
Subject: [PATCH] Support running the game at ludicrous speed

---
 index.html | 18 ++++++++++--------
 js/main.js | 21 ++++++++++++++++-----
 2 files changed, 26 insertions(+), 13 deletions(-)

diff --git a/index.html b/index.html
index bd87c89..d094616 100644
--- a/index.html
+++ b/index.html
@@ -205,14 +205,16 @@
             </div>
             <p>Game speed:
                 <select name="speed">
-                    <option value="6">6× — 120 tics per second</option>
-                    <option value="3">3× — 60 tics per second</option>
-                    <option value="2">2× — 40 tics per second</option>
-                    <option value="3/2">1½× — 30 tics per second</option>
-                    <option value="1" selected>1× — 20 tics per second</option>
-                    <option value="1/2">½× — 10 tics per second</option>
-                    <option value="1/3">⅓× — 6⅔ tics per second</option>
-                    <option value="1/4">¼× — 5 tics per second</option>
+                    <option value="20">20× faster</option>
+                    <option value="10">10× faster</option>
+                    <option value="5">5× faster</option>
+                    <option value="3">3× faster</option>
+                    <option value="2">2× faster</option>
+                    <option value="3/2">1½× faster</option>
+                    <option value="1" selected>Normal speed</option>
+                    <option value="1/2">2× slower</option>
+                    <option value="1/3">3× slower</option>
+                    <option value="1/4">4× slower</option>
                 </select>
             </p>
 
diff --git a/js/main.js b/js/main.js
index 3064a14..27fd94e 100644
--- a/js/main.js
+++ b/js/main.js
@@ -1049,13 +1049,27 @@ class Player extends PrimaryView {
 
         this.last_advance = performance.now();
 
+        // If the game is running faster than normal, we cap the timeout between game loops at 10ms
+        // and do multiple loops at a time
+        // (Note that this is a debug feature so precision is not a huge deal and I don't bother
+        // tracking fractional updates, but asking to run at 10× and only getting 2× would suck)
+        let num_advances = 1;
+        let dt = 1000 / (TICS_PER_SECOND * this.play_speed);
+        if (dt < 10) {
+            num_advances = Math.ceil(10 / dt);
+            dt = 10;
+            console.log(this.play_speed, dt, num_advances);
+        }
+
         if (this.state === 'playing') {
-            this.advance_by(1);
+            this.advance_by(num_advances);
         }
         else if (this.state === 'rewinding') {
             if (this.level.has_undo()) {
                 // Rewind by undoing one tic every tic
-                this.undo();
+                for (let i = 0; i < num_advances; i++) {
+                    this.undo();
+                }
                 this.update_ui();
             }
             // If there are no undo entries left, freeze in place until the player stops rewinding,
@@ -1064,9 +1078,6 @@ class Player extends PrimaryView {
             // buffer dry) and change to 'waiting' instead?
         }
 
-        // FIXME if play speed is sufficiently high, we need to advance multiple frames at once or
-        // the timeout will get capped
-        let dt = 1000 / (TICS_PER_SECOND * this.play_speed);
         if (this.state === 'rewinding') {
             // Rewind faster than normal time
             dt *= 0.5;