time scale command

docs/tutorials/timescale.md

@@ -21,5 +21,83 @@ var x = 1n * 1n; //Success
 ```
 To allow us to both speed up and slow down time, we'll need to check if the speed inputted is greater or equal to 1. If it is, we round it and then convert it to a `BigInt`, which we'll store on the `globalThis` object. If it's less we'll need to find the speed to the power of -1, or `1 / speed`. We can then round this value and convert that to a `BigInt` to store on `globalThis`. We'll also set `globalThis.timeScaleDividing` to `true`, to signal to replaced `getCurrentTimeMillis()` to divide by the `BigInt` speed factor instead of multiply.\
 \
-Finally, due to our `BigInt` rounding shenanigans on the server, we have to replicate the rounding inaccuracy on the client.
+Finally, due to our `BigInt` rounding shenanigans on the server, we have to replicate the rounding inaccuracy on the client.\
+\
+Let's implement the client side part.
+```javascript
+(function TimescaleCommand() {
+    ModAPI.meta.title("Timescale Command");
+    ModAPI.meta.description("use /timescale to control time");
+    ModAPI.meta.credits("By <author_name>");
 
+    ModAPI.addEventListener("sendchatmessage", (event) => { // before a message gets sent to the server
+        if (event.message.toLowerCase().startsWith("/timescale")) { //if it is the timescale command
+            var speed = parseFloat(event.message.split(" ")[1]); //get the part of the message after the space
+            if (!speed) { //If it doesn't exist, set it to 1.
+                speed = 1;
+            } else { //If it does exist:
+                if (speed < 1) { //When the speed is less than 1, round the denominator (1 over x)
+                    speed = 1 / Math.round(1 / speed);
+                } else {
+                    // When the speed is greater or equal to 1, round the numerator (x over 1)
+                    speed = Math.round(speed);
+                }
+                // Set the speed
+                ModAPI.mc.timer.timerSpeed = speed;
+            }
+            // Log the speed to chat
+            ModAPI.displayToChat("[Timescale] Set world timescale to " + speed.toFixed(2) + ".");
+        }
+    });
+})()
+```
+Now for the serverside part.
+```javascript
+(function TimescaleCommand() {
+    //...
+
+    ModAPI.dedicatedServer.appendCode(function () { // Run on the server
+        globalThis.timeScale = 1n; // Initialize globalThis.timeScale
+        globalThis.timeScaleDividing = false; // Initialize globalThis.timeScaleDividing
+
+        ModAPI.addEventListener("processcommand", (event) => { // when the server receives a command
+            if (event.command.toLowerCase().startsWith("/timescale")) { // if it is a timescale command
+                var speed = parseFloat(event.command.split(" ")[1]); // get the second part of the command (the speed of time)
+                if (!speed) { // If it doesn't exist, set it to 1.
+                    globalThis.timeScale = 1n;
+                    globalThis.timeScaleDividing = false;
+                } else { // If it does exist:
+                    if (speed < 1) {
+                        // When the speed is less than 1, round the denominator (1 over x)
+                        // And enable division mode
+                        globalThis.timeScaleDividing = true;
+                        globalThis.timeScale = BigInt(Math.round(1 / speed));
+                    } else {
+                        // When the speed is greater or equal to 1, round the numerator (x over 1)
+                        // And disable division mode
+                        globalThis.timeScaleDividing = false;
+                        globalThis.timeScale = BigInt(Math.round(speed));
+                    }
+                }
+                if (ModAPI.server) { //If the server is initialized
+                    //Bump the current time forward so the server doesn't try to play catch-up
+                    ModAPI.server.currentTime = ModAPI.hooks.methods[ModAPI.util.getMethodFromPackage("net.minecraft.server.MinecraftServer", "getCurrentTimeMillis")]();
+                }
+
+                //Prevent the command not found error from appearing
+                event.preventDefault = true;
+            }
+        });
+        
+        //Monkey patch the getCurrentTime function.
+        const original_getCurrentTime = ModAPI.hooks.methods[ModAPI.util.getMethodFromPackage("net.minecraft.server.MinecraftServer", "getCurrentTimeMillis")];
+        ModAPI.hooks.methods[ModAPI.util.getMethodFromPackage("net.minecraft.server.MinecraftServer", "getCurrentTimeMillis")] = function () {
+            if (globalThis.timeScaleDividing) { //If we are in divide mode
+                return original_getCurrentTime() / globalThis.timeScale; //Return the current time divided by the time scale
+            } else {
+                return original_getCurrentTime() * globalThis.timeScale; //Else, return the current time multiplied by the time scale
+            }
+        };
+    });
+})()
+```

examplemods/timescale_command.js

@@ -6,6 +6,7 @@
         if (event.message.toLowerCase().startsWith("/timescale")) {
             var speed = parseFloat(event.message.split(" ")[1]);
             if (!speed) {
+                speed = 1;
                 PluginAPI.mc.timer.timerSpeed = 1;
             } else {
                 if (speed < 1) {