init

.gitattributes

@@ -0,0 +1,9 @@
+#
+# https://help.github.com/articles/dealing-with-line-endings/
+#
+# Linux start script should use lf
+/gradlew        text eol=lf
+
+# These are Windows script files and should use crlf
+*.bat           text eol=crlf
+

.gitignore

@@ -0,0 +1,44 @@
+# gradle
+
+.gradle/
+build/
+out/
+classes/
+
+# eclipse
+
+*.launch
+
+# idea
+
+.idea/
+*.iml
+*.ipr
+*.iws
+
+# vscode
+
+.settings/
+.vscode/
+bin/
+.classpath
+.project
+
+# macos
+
+*.DS_Store
+
+# fabric
+
+run/
+
+# java
+
+hs_err_*.log
+replay_*.log
+*.hprof
+*.jfr
+
+# project 
+
+ignore/

LICENCE

@@ -0,0 +1,19 @@
+Copyright (c) 2025 LavaDesu
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

build.gradle

@@ -0,0 +1,94 @@
+plugins {
+	id 'fabric-loom' version '1.10-SNAPSHOT'
+	id 'maven-publish'
+}
+
+version = project.mod_version
+group = project.maven_group
+
+base {
+	archivesName = project.archives_base_name
+}
+
+repositories {
+	// Add repositories to retrieve artifacts from in here.
+	// You should only use this when depending on other mods because
+	// Loom adds the essential maven repositories to download Minecraft and libraries from automatically.
+	// See https://docs.gradle.org/current/userguide/declaring_repositories.html
+	// for more information about repositories.
+	exclusiveContent {
+		forRepository {
+			maven {
+				name = "Modrinth"
+				url = "https://api.modrinth.com/maven"
+			}
+		}
+		filter {
+			includeGroup "maven.modrinth"
+		}
+	}
+}
+
+loom {
+	accessWidenerPath = file("src/main/resources/cartloader.accesswidener")
+}
+
+dependencies {
+	// To change the versions see the gradle.properties file
+	minecraft "com.mojang:minecraft:${project.minecraft_version}"
+	mappings "net.fabricmc:yarn:${project.yarn_mappings}:v2"
+	modImplementation "net.fabricmc:fabric-loader:${project.loader_version}"
+
+	//modImplementation "maven.modrinth:linkart:5.4.5-1.20.6-build.29"
+
+	// Fabric API. This is technically optional, but you probably want it anyway.
+	//modImplementation "net.fabricmc.fabric-api:fabric-api:${project.fabric_version}"
+}
+
+processResources {
+	inputs.property "version", project.version
+
+	filesMatching("fabric.mod.json") {
+		expand "version": inputs.properties.version
+	}
+}
+
+tasks.withType(JavaCompile).configureEach {
+	it.options.release = 21
+}
+
+java {
+	// Loom will automatically attach sourcesJar to a RemapSourcesJar task and to the "build" task
+	// if it is present.
+	// If you remove this line, sources will not be generated.
+	withSourcesJar()
+
+	sourceCompatibility = JavaVersion.VERSION_21
+	targetCompatibility = JavaVersion.VERSION_21
+}
+
+jar {
+	inputs.property "archivesName", project.base.archivesName
+
+	from("LICENSE") {
+		rename { "${it}_${inputs.properties.archivesName}"}
+	}
+}
+
+// configure the maven publication
+publishing {
+	publications {
+		create("mavenJava", MavenPublication) {
+			artifactId = project.archives_base_name
+			from components.java
+		}
+	}
+
+	// See https://docs.gradle.org/current/userguide/publishing_maven.html for information on how to set up publishing.
+	repositories {
+		// Add repositories to publish to here.
+		// Notice: This block does NOT have the same function as the block in the top level.
+		// The repositories here will be used for publishing your artifact, not for
+		// retrieving dependencies.
+	}
+}

gradle.properties

@@ -0,0 +1,17 @@
+# Done to increase the memory available to gradle.
+org.gradle.jvmargs=-Xmx1G
+org.gradle.parallel=true
+
+# Fabric Properties
+# check these on https://fabricmc.net/develop
+minecraft_version=1.21.4
+yarn_mappings=1.21.4+build.8
+loader_version=0.16.10
+
+# Mod Properties
+mod_version=1.0.0
+maven_group=moe.lava.cartloader
+archives_base_name=cartloader
+
+# Dependencies
+fabric_version=0.118.0+1.21.4

gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,7 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.12.1-bin.zip
+networkTimeout=10000
+validateDistributionUrl=true
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists

gradlew

@@ -0,0 +1,251 @@
+#!/bin/sh
+
+#
+# Copyright © 2015-2021 the original authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+##############################################################################
+#
+#   Gradle start up script for POSIX generated by Gradle.
+#
+#   Important for running:
+#
+#   (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is
+#       noncompliant, but you have some other compliant shell such as ksh or
+#       bash, then to run this script, type that shell name before the whole
+#       command line, like:
+#
+#           ksh Gradle
+#
+#       Busybox and similar reduced shells will NOT work, because this script
+#       requires all of these POSIX shell features:
+#         * functions;
+#         * expansions «$var», «${var}», «${var:-default}», «${var+SET}»,
+#           «${var#prefix}», «${var%suffix}», and «$( cmd )»;
+#         * compound commands having a testable exit status, especially «case»;
+#         * various built-in commands including «command», «set», and «ulimit».
+#
+#   Important for patching:
+#
+#   (2) This script targets any POSIX shell, so it avoids extensions provided
+#       by Bash, Ksh, etc; in particular arrays are avoided.
+#
+#       The "traditional" practice of packing multiple parameters into a
+#       space-separated string is a well documented source of bugs and security
+#       problems, so this is (mostly) avoided, by progressively accumulating
+#       options in "$@", and eventually passing that to Java.
+#
+#       Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS,
+#       and GRADLE_OPTS) rely on word-splitting, this is performed explicitly;
+#       see the in-line comments for details.
+#
+#       There are tweaks for specific operating systems such as AIX, CygWin,
+#       Darwin, MinGW, and NonStop.
+#
+#   (3) This script is generated from the Groovy template
+#       https://github.com/gradle/gradle/blob/HEAD/platforms/jvm/plugins-application/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       within the Gradle project.
+#
+#       You can find Gradle at https://github.com/gradle/gradle/.
+#
+##############################################################################
+
+# Attempt to set APP_HOME
+
+# Resolve links: $0 may be a link
+app_path=$0
+
+# Need this for daisy-chained symlinks.
+while
+    APP_HOME=${app_path%"${app_path##*/}"}  # leaves a trailing /; empty if no leading path
+    [ -h "$app_path" ]
+do
+    ls=$( ls -ld "$app_path" )
+    link=${ls#*' -> '}
+    case $link in             #(
+      /*)   app_path=$link ;; #(
+      *)    app_path=$APP_HOME$link ;;
+    esac
+done
+
+# This is normally unused
+# shellcheck disable=SC2034
+APP_BASE_NAME=${0##*/}
+# Discard cd standard output in case $CDPATH is set (https://github.com/gradle/gradle/issues/25036)
+APP_HOME=$( cd -P "${APP_HOME:-./}" > /dev/null && printf '%s\n' "$PWD" ) || exit
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD=maximum
+
+warn () {
+    echo "$*"
+} >&2
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+} >&2
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "$( uname )" in                #(
+  CYGWIN* )         cygwin=true  ;; #(
+  Darwin* )         darwin=true  ;; #(
+  MSYS* | MINGW* )  msys=true    ;; #(
+  NONSTOP* )        nonstop=true ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD=$JAVA_HOME/jre/sh/java
+    else
+        JAVACMD=$JAVA_HOME/bin/java
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD=java
+    if ! command -v java >/dev/null 2>&1
+    then
+        die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+fi
+
+# Increase the maximum file descriptors if we can.
+if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
+    case $MAX_FD in #(
+      max*)
+        # In POSIX sh, ulimit -H is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
+        MAX_FD=$( ulimit -H -n ) ||
+            warn "Could not query maximum file descriptor limit"
+    esac
+    case $MAX_FD in  #(
+      '' | soft) :;; #(
+      *)
+        # In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
+        ulimit -n "$MAX_FD" ||
+            warn "Could not set maximum file descriptor limit to $MAX_FD"
+    esac
+fi
+
+# Collect all arguments for the java command, stacking in reverse order:
+#   * args from the command line
+#   * the main class name
+#   * -classpath
+#   * -D...appname settings
+#   * --module-path (only if needed)
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables.
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if "$cygwin" || "$msys" ; then
+    APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
+    CLASSPATH=$( cygpath --path --mixed "$CLASSPATH" )
+
+    JAVACMD=$( cygpath --unix "$JAVACMD" )
+
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    for arg do
+        if
+            case $arg in                                #(
+              -*)   false ;;                            # don't mess with options #(
+              /?*)  t=${arg#/} t=/${t%%/*}              # looks like a POSIX filepath
+                    [ -e "$t" ] ;;                      #(
+              *)    false ;;
+            esac
+        then
+            arg=$( cygpath --path --ignore --mixed "$arg" )
+        fi
+        # Roll the args list around exactly as many times as the number of
+        # args, so each arg winds up back in the position where it started, but
+        # possibly modified.
+        #
+        # NB: a `for` loop captures its iteration list before it begins, so
+        # changing the positional parameters here affects neither the number of
+        # iterations, nor the values presented in `arg`.
+        shift                   # remove old arg
+        set -- "$@" "$arg"      # push replacement arg
+    done
+fi
+
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Collect all arguments for the java command:
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, JAVA_OPTS, and optsEnvironmentVar are not allowed to contain shell fragments,
+#     and any embedded shellness will be escaped.
+#   * For example: A user cannot expect ${Hostname} to be expanded, as it is an environment variable and will be
+#     treated as '${Hostname}' itself on the command line.
+
+set -- \
+        "-Dorg.gradle.appname=$APP_BASE_NAME" \
+        -classpath "$CLASSPATH" \
+        org.gradle.wrapper.GradleWrapperMain \
+        "$@"
+
+# Stop when "xargs" is not available.
+if ! command -v xargs >/dev/null 2>&1
+then
+    die "xargs is not available"
+fi
+
+# Use "xargs" to parse quoted args.
+#
+# With -n1 it outputs one arg per line, with the quotes and backslashes removed.
+#
+# In Bash we could simply go:
+#
+#   readarray ARGS < <( xargs -n1 <<<"$var" ) &&
+#   set -- "${ARGS[@]}" "$@"
+#
+# but POSIX shell has neither arrays nor command substitution, so instead we
+# post-process each arg (as a line of input to sed) to backslash-escape any
+# character that might be a shell metacharacter, then use eval to reverse
+# that process (while maintaining the separation between arguments), and wrap
+# the whole thing up as a single "set" statement.
+#
+# This will of course break if any of these variables contains a newline or
+# an unmatched quote.
+#
+
+eval "set -- $(
+        printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" |
+        xargs -n1 |
+        sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' |
+        tr '\n' ' '
+    )" '"$@"'
+
+exec "$JAVACMD" "$@"

gradlew.bat

@@ -0,0 +1,94 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+@rem SPDX-License-Identifier: Apache-2.0
+@rem
+
+@if "%DEBUG%"=="" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%"=="" set DIRNAME=.
+@rem This is normally unused
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if %ERRORLEVEL% equ 0 goto execute
+
+echo. 1>&2
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto execute
+
+echo. 1>&2
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME% 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
+
+goto fail
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %*
+
+:end
+@rem End local scope for the variables with windows NT shell
+if %ERRORLEVEL% equ 0 goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+set EXIT_CODE=%ERRORLEVEL%
+if %EXIT_CODE% equ 0 set EXIT_CODE=1
+if not ""=="%GRADLE_EXIT_CONSOLE%" exit %EXIT_CODE%
+exit /b %EXIT_CODE%
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega

settings.gradle

@@ -0,0 +1,10 @@
+pluginManagement {
+	repositories {
+		maven {
+			name = 'Fabric'
+			url = 'https://maven.fabricmc.net/'
+		}
+		mavenCentral()
+		gradlePluginPortal()
+	}
+}

src/main/java/moe/lava/cartloader/accessor/ExperimentalMinecartControllerAccessor.java

@@ -0,0 +1,9 @@
+package moe.lava.cartloader.accessor;
+
+import net.minecraft.util.Pair;
+import org.spongepowered.asm.mixin.Unique;
+
+public interface ExperimentalMinecartControllerAccessor {
+    Pair<Double, Double> cartloader$getSpeedMultiplers();
+    void cartloader$finishSlowdown();
+}

src/main/java/moe/lava/cartloader/mixin/AbstractMinecartEntityMixin.java

@@ -0,0 +1,82 @@
+package moe.lava.cartloader.mixin;
+
+import moe.lava.cartloader.accessor.ExperimentalMinecartControllerAccessor;
+import net.minecraft.entity.EntityType;
+import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.entity.vehicle.AbstractMinecartEntity;
+import net.minecraft.entity.vehicle.MinecartController;
+import net.minecraft.entity.vehicle.VehicleEntity;
+import net.minecraft.server.world.ChunkTicketType;
+import net.minecraft.server.world.ServerWorld;
+import net.minecraft.util.ActionResult;
+import net.minecraft.util.Hand;
+import net.minecraft.util.Pair;
+import net.minecraft.util.math.ChunkPos;
+import net.minecraft.util.math.Vec3d;
+import net.minecraft.world.World;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.spongepowered.asm.mixin.*;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
+
+import java.util.Comparator;
+import java.util.Objects;
+
+@Mixin(AbstractMinecartEntity.class)
+public abstract class AbstractMinecartEntityMixin extends VehicleEntity {
+	@Final
+	@Shadow
+    private MinecartController controller;
+
+	public AbstractMinecartEntityMixin(EntityType<?> entityType, World world) {
+		super(entityType, world);
+    }
+
+	@Unique
+	private ChunkPos lastChunk;
+
+	@Unique
+	private static final Logger log = LoggerFactory.getLogger("cartloader@ameMixin");
+
+	@Unique
+	private static final ChunkTicketType<ChunkPos> TICKET = ChunkTicketType.create("minecart", Comparator.comparingLong(ChunkPos::toLong), 50);
+
+	@Inject(at = @At("HEAD"), method = "tick")
+	private void onTick(CallbackInfo info) {
+		if (!(getWorld() instanceof ServerWorld world))
+			return;
+		if (lastChunk == getChunkPos())
+			return;
+		lastChunk = getChunkPos();
+		world.getChunkManager().addTicket(TICKET, lastChunk, 3, lastChunk);
+	}
+
+	@Inject(method = "applySlowdown", at = @At(value = "RETURN"), cancellable = true)
+	private void cartloader$slowDown(Vec3d velocity, CallbackInfoReturnable<Vec3d> cir) {
+		if (!(this.getWorld() instanceof ServerWorld world))
+			return;
+		if (!(controller instanceof ExperimentalMinecartControllerAccessor mixedController)) {
+			return;
+		}
+
+		Pair<Double, Double> multiplers = mixedController.cartloader$getSpeedMultiplers();
+		if (Objects.equals(multiplers.getLeft(), multiplers.getRight()))
+			return;
+
+		double base = controller.getMaxSpeed(world);
+		double mult = multiplers.getRight() / multiplers.getLeft();
+		double newMax = base * mult;
+
+		Vec3d ret = cir.getReturnValue();
+		double diff = ret.horizontalLength() - newMax;
+		if (diff > 0) {
+			if (diff < 0.15)
+				mixedController.cartloader$finishSlowdown();
+			else
+				cir.setReturnValue(ret.multiply(0.95f));
+		}
+	}
+}

src/main/java/moe/lava/cartloader/mixin/DebugHudMixin.java

@@ -0,0 +1,26 @@
+package moe.lava.cartloader.mixin;
+
+import net.minecraft.client.MinecraftClient;
+import net.minecraft.client.gui.hud.DebugHud;
+import net.minecraft.entity.Entity;
+import net.minecraft.util.math.Vec3d;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Unique;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
+
+import java.util.List;
+
+@Mixin(DebugHud.class)
+public class DebugHudMixin {
+    @Inject(at = @At("RETURN"), method = "getLeftText")
+    private void cartloader$addLeftText(CallbackInfoReturnable<List<String>> cir) {
+        Entity ent = MinecraftClient.getInstance().getCameraEntity();
+        if (ent == null)
+            return;
+
+        double speed = ent.getLastRenderPos().subtract(ent.getPos()).length();
+        cir.getReturnValue().add("Speeed: " + speed * 20);
+    }
+}

src/main/java/moe/lava/cartloader/mixin/ExperimentalMinecartControllerMixin.java

@@ -0,0 +1,143 @@
+package moe.lava.cartloader.mixin;
+
+import moe.lava.cartloader.accessor.ExperimentalMinecartControllerAccessor;
+import net.minecraft.block.BlockState;
+import net.minecraft.block.Blocks;
+import net.minecraft.block.PoweredRailBlock;
+import net.minecraft.block.enums.RailShape;
+import net.minecraft.entity.vehicle.AbstractMinecartEntity;
+import net.minecraft.entity.vehicle.ExperimentalMinecartController;
+import net.minecraft.entity.vehicle.MinecartController;
+import net.minecraft.server.world.ServerWorld;
+import net.minecraft.util.Pair;
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.util.math.Vec3d;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Unique;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
+
+@Mixin(ExperimentalMinecartController.class)
+public abstract class ExperimentalMinecartControllerMixin extends MinecartController implements ExperimentalMinecartControllerAccessor {
+    @Unique
+    private static final Logger log = LoggerFactory.getLogger("cartloader@emcmixin");
+
+    @Unique
+    private double currentMultiplier = 0.5;
+
+    @Unique
+    private double targetMultiplier = 0.5;
+
+    @Unique
+    private boolean specialAcceleration = false;
+
+    protected ExperimentalMinecartControllerMixin(AbstractMinecartEntity minecart) {
+        super(minecart);
+    }
+
+    @Unique
+    public Pair<Double, Double> cartloader$getSpeedMultiplers() {
+        //return this.speedMultiplier;
+        return new Pair<>(this.currentMultiplier, this.targetMultiplier);
+    }
+
+    @Unique
+    public void cartloader$finishSlowdown() {
+        this.currentMultiplier = this.targetMultiplier;
+    }
+
+    @Inject(method = "calcNewHorizontalVelocity", at = @At("HEAD"))
+    private void cartloader$checkRail(
+            ServerWorld world,
+            Vec3d horizontalVelocity,
+            ExperimentalMinecartController.MoveIteration iteration,
+            BlockPos pos,
+            BlockState railState,
+            RailShape railShape,
+            CallbackInfoReturnable<Vec3d> cir
+    ) {
+        if (!(railState.isOf(Blocks.DETECTOR_RAIL) || (railState.isOf(Blocks.POWERED_RAIL) && !railState.get(PoweredRailBlock.POWERED)))) {
+            return;
+        }
+
+        BlockState under = this.getWorld().getBlockState(pos.down());
+        double newMultiplier = 0;
+        if (under.isOf(Blocks.IRON_BLOCK))
+            newMultiplier = 0.25;
+        else if (under.isOf(Blocks.GOLD_BLOCK))
+            newMultiplier = 0.5;
+        else if (under.isOf(Blocks.EMERALD_BLOCK))
+            newMultiplier = 0.75;
+        else if (under.isOf(Blocks.DIAMOND_BLOCK))
+            newMultiplier = 1.0;
+
+        if (newMultiplier != 0) {
+            specialAcceleration = true;
+            targetMultiplier = newMultiplier;
+        }
+
+
+        if (targetMultiplier > currentMultiplier)
+            currentMultiplier = targetMultiplier;
+    }
+
+    @Inject(method = "getMaxSpeed", at = @At(value = "RETURN"), cancellable = true)
+    private void cartloader$applyMaxSpeedMultiplier(ServerWorld world, CallbackInfoReturnable<Double> cir) {
+        double ret = cir.getReturnValue();
+        cir.setReturnValue(ret * currentMultiplier);
+        //cir.setReturnValue(ret * speedMultiplier);
+    }
+
+    @Unique
+    private static final double TOTAL_ACCELERATION = 0.075;
+    @Unique
+    private static final double ACCELERATION_DECAY = 0.5;
+    @Unique
+    private static final double MAX_ACCELERATION = TOTAL_ACCELERATION * (1 - ACCELERATION_DECAY);
+    @Unique
+    private static final double FINAL_ACCELERATION = TOTAL_ACCELERATION * Math.pow(ACCELERATION_DECAY, 5);
+
+    @Unique
+    private double currentAcceleration = 0.0;
+
+    @Inject(method = "accelerateFromPoweredRail", at = @At("HEAD"), cancellable = true)
+    private void accelerateFromPoweredRail(Vec3d velocity, BlockPos railPos, BlockState railState, CallbackInfoReturnable<Vec3d> cir) {
+        if (!specialAcceleration)
+            return;
+
+        if (railState.isOf(Blocks.POWERED_RAIL) && railState.get(PoweredRailBlock.POWERED))
+            currentAcceleration = MAX_ACCELERATION;
+
+        if (!railState.isOf(Blocks.POWERED_RAIL)) {
+            currentAcceleration = currentAcceleration * ACCELERATION_DECAY;
+            if (currentAcceleration <= FINAL_ACCELERATION)
+                currentAcceleration = 0.0;
+        }
+
+        //log.info(String.valueOf(currentAcceleration));
+
+        if (velocity.length() > 0.01)
+            cir.setReturnValue(velocity.normalize().multiply(velocity.length() * (1 + currentAcceleration)));
+        else {
+            Vec3d vec3d = this.minecart.getLaunchDirection(railPos);
+            cir.setReturnValue(vec3d.lengthSquared() <= 0.0 ? velocity : vec3d.multiply(velocity.length() + MAX_ACCELERATION));
+        }
+    }
+
+    @Inject(method = "decelerateFromPoweredRail", at = @At("HEAD"), cancellable = true)
+    private void decelerateFromPoweredRail(Vec3d velocity, BlockState railState, CallbackInfoReturnable<Vec3d> cir) {
+        if (!specialAcceleration)
+            return;
+
+        if (railState.isOf(Blocks.POWERED_RAIL) && !(Boolean)railState.get(PoweredRailBlock.POWERED)) {
+            log.info("Decel");
+            log.info(String.valueOf(velocity.length()));
+			cir.setReturnValue(velocity.length() < 0.03 ? Vec3d.ZERO : velocity.multiply(0.915));
+		} else {
+			cir.setReturnValue(velocity);
+		}
+    }
+}

src/main/java/moe/lava/cartloader/mixin/PlayerEntityMixin.java

@@ -0,0 +1,18 @@
+package moe.lava.cartloader.mixin;
+
+import net.minecraft.entity.Entity;
+import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.entity.vehicle.AbstractMinecartEntity;
+import net.minecraft.util.ActionResult;
+import net.minecraft.util.Hand;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Redirect;
+
+@Mixin(PlayerEntity.class)
+public class PlayerEntityMixin {
+    @Redirect(method = "interact", at = @At(value = "INVOKE", target = "Lnet/minecraft/entity/Entity;interact(Lnet/minecraft/entity/player/PlayerEntity;Lnet/minecraft/util/Hand;)Lnet/minecraft/util/ActionResult;"))
+    private ActionResult meth(Entity entity, PlayerEntity player, Hand hand) {
+            return entity.interact(player, hand);
+    }
+}

src/main/resources/cartloader.accesswidener

@@ -0,0 +1,2 @@
+accessWidener v2 named
+accessible class net/minecraft/entity/vehicle/ExperimentalMinecartController$MoveIteration

src/main/resources/cartloader.mixins.json

@@ -0,0 +1,15 @@
+{
+	"required": true,
+	"package": "moe.lava.cartloader.mixin",
+	"compatibilityLevel": "JAVA_21",
+	"mixins": [
+		"AbstractMinecartEntityMixin",
+		"ExperimentalMinecartControllerMixin"
+	],
+	"injectors": {
+		"defaultRequire": 1
+	},
+	"client": [
+		"DebugHudMixin"
+	]
+}

src/main/resources/fabric.mod.json

@@ -0,0 +1,25 @@
+{
+	"schemaVersion": 1,
+	"id": "cartloader",
+	"version": "${version}",
+	"name": "Cartloader",
+	"description": "Make moving minecarts load a small radius of chunks around it",
+	"authors": [
+		"LavaDesu"
+	],
+	"contact": {
+		"sources": "https://github.com/LavaDesu/Cartloader"
+	},
+	"license": "CC0-1.0",
+	"icon": "assets/cartloader/icon.png",
+	"environment": "*",
+	"accessWidener": "cartloader.accesswidener",
+	"mixins": [
+		"cartloader.mixins.json"
+	],
+	"depends": {
+		"fabricloader": ">=0.15",
+		"minecraft": "~1.21.4",
+		"java": ">=21"
+	}
+}