From 8dacc62bbd5a5595315b5daa443a56d29d22bf1f Mon Sep 17 00:00:00 2001
From: Jonathan <jakedude435@live.com>
Date: Tue, 8 Aug 2023 17:56:47 -0500
Subject: [PATCH] improved slope and bogie alignment logic

- bogie alignment seems to work more or less how it should now, it's a little jittery, but not enough to tell unless you're actually staring at the hitboxes.
- Fixed bogie logic for interacting with slopes, should improve performance a little and it's also dramatically more reliable.
---
 .../java/ebf/tim/entities/EntityBogie.java    | 26 ++++++++++++-------
 .../tim/entities/GenericRailTransport.java    | 14 +++++-----
 2 files changed, 22 insertions(+), 18 deletions(-)

diff --git a/src/main/java/ebf/tim/entities/EntityBogie.java b/src/main/java/ebf/tim/entities/EntityBogie.java
index fa07fce0a..eb3892688 100644
--- a/src/main/java/ebf/tim/entities/EntityBogie.java
+++ b/src/main/java/ebf/tim/entities/EntityBogie.java
@@ -247,6 +247,22 @@ public void minecartMove(GenericRailTransport host) {
             //update using spline movement
             //} else if (block instanceof BlockRailBase)
 
+            if(!(block instanceof BlockRailBase)){
+                if(CommonUtil.getBlockAt(getWorld(), xFloor, yFloor+1, zFloor) instanceof BlockRailBase) {
+                    prevPosY=posY;
+                    posY++;
+                    yFloor++;
+                    block = CommonUtil.getBlockAt(getWorld(), xFloor, yFloor, zFloor);
+                } else if(CommonUtil.getBlockAt(getWorld(), xFloor, yFloor-1, zFloor) instanceof BlockRailBase) {
+                    prevPosY=posY;
+                    posY--;
+                    yFloor--;
+                    block = CommonUtil.getBlockAt(getWorld(), xFloor, yFloor, zFloor);
+                } else if(block instanceof BlockAir) {
+                    moveOffRail();
+                }
+            }
+
             //update on normal rails
             if (block instanceof BlockRailBase) {
                 this.yOffset=(block instanceof BlockRailCore?0.425f:0.3425f);
@@ -256,16 +272,6 @@ public void minecartMove(GenericRailTransport host) {
             //} else if (block instanceof ITrackBase) {
                 //update position for ZnD rails.
                 //moveBogieZnD(motionX, motionZ, floorX, floorY, floorZ, (ITrackBase) block);
-            } else if(CommonUtil.getBlockAt(getWorld(), xFloor, yFloor+1, zFloor) instanceof BlockRailBase) {
-                prevPosY=posY;
-                posY++;
-                yFloor++;
-            } else if(CommonUtil.getBlockAt(getWorld(), xFloor, yFloor-1, zFloor) instanceof BlockRailBase) {
-                prevPosY=posY;
-                posY--;
-                yFloor--;
-            } else if(block instanceof BlockAir) {
-                moveOffRail();
             }
            velocity[2]=0;velocity[3]=0;
         }
diff --git a/src/main/java/ebf/tim/entities/GenericRailTransport.java b/src/main/java/ebf/tim/entities/GenericRailTransport.java
index 3f424b6bc..5696bc28a 100644
--- a/src/main/java/ebf/tim/entities/GenericRailTransport.java
+++ b/src/main/java/ebf/tim/entities/GenericRailTransport.java
@@ -954,12 +954,12 @@ public void addLinkingMove(double velocity){
      * if X or Z is null, the bogie's existing motion velocity will be used
      */
     public void finalMove(){
-        backBogie.minecartMove(this);
         cachedVectors[1] = new Vec3f(-rotationPoints()[0], 0, 0).rotatePoint(0, rotationYaw, 0)
                 .addVector(backBogie.posX,backBogie.posY,backBogie.posZ);
         setPosition(cachedVectors[1].xCoord, cachedVectors[1].yCoord,cachedVectors[1].zCoord);
 
         frontBogie.minecartMove(this);
+        backBogie.minecartMove(this);
         //reset the y coord so they will re-calculate the yaw
         if(hasDrag()) {
             applyDrag();
@@ -1220,13 +1220,11 @@ else if (backBogie !=null && frontBogie != null && ticksExisted>5){
             if(backLinkedID!=null && getWorld().getEntityByID(backLinkedID) instanceof GenericRailTransport){
                manageLink((GenericRailTransport) getWorld().getEntityByID(backLinkedID));
             }
-            double x2=frontBogie.posX- posX;
-            double z2=frontBogie.posZ- posZ;
-            double dist=Math.abs(Math.sqrt(x2*x2+z2*z2)+rotationPoints()[1]);
-            if(Math.sqrt(x2*x2+z2*z2)<0){
-                dist*=-1;
-            }
-            frontBogie.addLinking(this, dist*0.000625);
+            //for some off reason, this madness works pretty reliably from my tests.
+            cachedVectors[1]=new Vec3f(rotationPoints()[1],0,0).rotatePoint(0,rotationYaw,0)
+                    .addVector(posX,0,posZ).subtract((float)frontBogie.posX,0,(float)frontBogie.posZ);
+            frontBogie.velocity[2]+=cachedVectors[1].xCoord;
+            frontBogie.velocity[3]+=cachedVectors[1].zCoord;
             updatePosition();
 
             if(collisionHandler!=null){