Keep hats and cloaks on the posed head and body

The hat only took the head's rotation from 1.21.5, and the cloak sat at
a fixed spot with a hard-coded crouch, so crouching and emotes left them
where the head and body had been. Both now follow the whole player (the
root, which emotes like the backflip turn) and then the head or body, as
vanilla places head items, and the cloak leans with the chest when an
emote bends the torso.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/main/java/org/saturnclient/impl/cosmetics/CloakFeatureRenderer.java

@@ -4,15 +4,20 @@ import java.util.Arrays;
 
 import org.joml.Matrix3f;
 import org.joml.Matrix4f;
+import org.joml.Quaternionf;
 import org.joml.Vector3f;
 import org.joml.Vector4f;
 import org.saturnclient.client.player.SaturnPlayer;
 import org.saturnclient.common.ref.asset.IdentifierRef;
 import org.saturnclient.config.Config;
 import org.saturnclient.cosmetics.Cloaks;
+import org.saturnclient.emotes.core.bend.LimbBend;
+import org.saturnclient.emotes.core.bend.Vec3;
+import org.saturnclient.emotes.fabric.access.BendablePart;
 import org.saturnclient.impl.cosmetics.utils.ShaderUtils;
 import org.saturnclient.saturnclient.SaturnRenderState;
 
+import net.minecraft.client.model.ModelPart;
 import net.minecraft.client.render.OverlayTexture;
 import net.minecraft.client.render.VertexConsumer;
 //? if >=1.21.9 {
@@ -33,7 +38,6 @@ import net.minecraft.item.ItemStack;
 import net.minecraft.item.equipment.EquipmentAsset;
 import net.minecraft.registry.RegistryKey;
 import net.minecraft.util.math.MathHelper;
-import net.minecraft.util.math.RotationAxis;
 import net.minecraft.util.math.Vec3d;
 
 /**
@@ -383,6 +387,25 @@ public class CloakFeatureRenderer extends FeatureRenderer<PlayerEntityRenderStat
         }
     }
 
+    /**
+     * An emote that bends the torso leans the chest from the hips, so the cloak hangs from where the
+     * top of the back ends up, turned as much as the torso is there.
+     */
+    private static void followBend(MatrixStack matrices, ModelPart body) {
+        LimbBend bend = ((BendablePart) (Object) body).saturnEmotes$getBend();
+        if (bend == null || bend.isStraight()) {
+            return;
+        }
+
+        // The top of the torso, in the body's own pixels
+        float[] top = new float[3];
+        bend.bendPoint(0, 0, 0, top);
+        matrices.translate(top[0] / 16.0f, top[1] / 16.0f, top[2] / 16.0f);
+
+        Vec3 axis = bend.axis();
+        matrices.multiply(new Quaternionf().rotationAxis(bend.angleAt(0), axis.x(), axis.y(), axis.z()));
+    }
+
     // Shift array left and insert new value at the start
     private void updateSegmentValues(float value) {
         // Shift all elements one position to the right (from end to start)
@@ -436,17 +459,24 @@ public class CloakFeatureRenderer extends FeatureRenderer<PlayerEntityRenderStat
 
         matrices.push();
 
+        // On the back: the whole player (which emotes like the backflip turn), then the body's position
+        // and turn (which crouching and emotes move), then the chest's lean when an emote bends the torso
+        PlayerEntityModel model = this.getContextModel();
+        //? if >=1.21.5 {
+        model.getRootPart().applyTransform(matrices);
+        model.body.applyTransform(matrices);
+        //?} else {
+        /*model.getRootPart().rotate(matrices);
+        model.body.rotate(matrices);
+        *///?}
+        followBend(matrices, model.body);
+
         matrices.translate(0.0f, 0.0f, 0.12f);
 
         if (this.hasCustomModelForLayer(state.equippedChestStack, LayerType.HUMANOID)) {
             matrices.translate(0.0F, -0.053125F, 0.06875F);
         }
 
-        if (state.isInSneakingPose) {
-            matrices.translate(0, 0.16f, 0.0f);
-            matrices.multiply(RotationAxis.POSITIVE_X.rotationDegrees(29.0f));
-        }
-
         long now = System.currentTimeMillis();
         if (now - lastUpdate >= 20) {
             float velX = Math.min(0.8f, state.field_53537 / 108.0f);

src/main/java/org/saturnclient/impl/cosmetics/HatFeatureRenderer.java

@@ -1,6 +1,5 @@
 package org.saturnclient.impl.cosmetics;
 
-import org.joml.Quaternionf;
 import org.saturnclient.client.player.SaturnPlayer;
 import org.saturnclient.impl.cosmetics.obj.MtlLoader;
 import org.saturnclient.impl.cosmetics.obj.ObjModel;
@@ -16,7 +15,6 @@ import net.minecraft.client.render.entity.feature.FeatureRendererContext;
 import net.minecraft.client.render.entity.model.PlayerEntityModel;
 import net.minecraft.client.render.entity.state.PlayerEntityRenderState;
 import net.minecraft.client.util.math.MatrixStack;
-import net.minecraft.client.model.ModelPart;
 
 public class HatFeatureRenderer extends FeatureRenderer<PlayerEntityRenderState, PlayerEntityModel> {
     public HatFeatureRenderer(FeatureRendererContext<PlayerEntityRenderState, PlayerEntityModel> context) {
@@ -41,11 +39,16 @@ public class HatFeatureRenderer extends FeatureRenderer<PlayerEntityRenderState,
 
         matrices.push();
 
+        // On the head, as vanilla places head items: the whole player (which emotes like the backflip
+        // turn), then the head's position, turn and scale (which crouching and emotes move)
+        PlayerEntityModel model = this.getContextModel();
         //? if >=1.21.5 {
-        ModelPart head = this.getContextModel().head;
-        matrices.multiply(new Quaternionf().rotationZYX(head.roll, head.yaw, head.pitch));
-        //?} else
-        //this.getContextModel().head.rotate(matrices);
+        model.getRootPart().applyTransform(matrices);
+        model.head.applyTransform(matrices);
+        //?} else {
+        /*model.getRootPart().rotate(matrices);
+        model.head.rotate(matrices);
+        *///?}
 
         ObjModel.cosmetic("hat", player.hat).render(MtlLoader.cosmetic(player.hat),
                 matrices, output, light,