Replace frame limiter

src/main/java/net/caffeinemc/mods/sodium/client/data/config/MixinConfig.java

@@ -69,6 +69,8 @@ private MixinConfig() {
 
         this.addMixinRule("features.render.particle", true);
 
+        this.addMixinRule("features.render.sync", true);
+
         this.addMixinRule("features.render.world", true);
         this.addMixinRule("features.render.world.clouds", true);
         this.addMixinRule("features.render.world.sky", true);

src/main/java/net/caffeinemc/mods/sodium/mixin/features/render/sync/RenderSystemMixin.java

@@ -0,0 +1,35 @@
+package net.caffeinemc.mods.sodium.mixin.features.render.sync;
+
+import com.mojang.blaze3d.systems.RenderSystem;
+import org.lwjgl.glfw.GLFW;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Overwrite;
+import org.spongepowered.asm.mixin.Shadow;
+
+@Mixin(value = RenderSystem.class, remap = false)
+public class RenderSystemMixin {
+
+    @Shadow
+    private static double lastDrawTime = Double.MIN_VALUE;
+
+    /**
+     * @author theyareonit
+     * @reason Improve frame synchronization
+     */
+    @Overwrite
+    public static void limitDisplayFPS(int fps) {
+        double frametime = 1.0 / fps;
+        double target =  lastDrawTime + frametime;
+        double now = GLFW.glfwGetTime();
+
+        for (; now < target; now = GLFW.glfwGetTime()) {
+            double waitTime = (target - now) - 0.002; // -2ms to account for inaccuracy of timeouts on some operating systems
+            if (waitTime >= 0.001) { // pretty sure you can't sleep for less than 1ms on Windows or Linux
+                GLFW.glfwWaitEventsTimeout(waitTime); // could be replaced with Thread.sleep(), but i'm not sure if it'd be as precise
+            }
+        }
+
+        lastDrawTime = now - (now % frametime); // subtracting (now % frametime) keeps frames in sync
+        GLFW.glfwPollEvents(); // glfwWaitEventsTimeout won't catch every input if subtracting 2ms from the timeout
+    }
+}

src/main/resources/sodium.mixins.json

@@ -60,6 +60,7 @@
     "features.render.model.block.ModelBlockRendererMixin",
     "features.render.model.item.ItemRendererMixin",
     "features.render.particle.SingleQuadParticleMixin",
+    "features.render.sync.RenderSystemMixin",
     "features.render.world.clouds.LevelRendererMixin",
     "features.render.world.sky.FogRendererMixin",
     "features.render.world.sky.ClientLevelMixin",