Make camera motion smoother

lucyydotp · Jun 6, 2024 · 10c3580 · 10c3580
1 parent 4b0cda7
commit 10c3580
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Showing 5 changed files with 77 additions and 11 deletions.
diff --git a/build.gradle.kts b/build.gradle.kts
@@ -4,7 +4,7 @@ plugins {
 }
 
 group = "me.lucyydotp"
-version = "0.1.0"
+version = "0.1.1-SNAPSHOT"
 
 java.toolchain.languageVersion = JavaLanguageVersion.of(17)
 

diff --git a/src/main/java/me/lucyydotp/papers/ArmorStandExt.java b/src/main/java/me/lucyydotp/papers/ArmorStandExt.java
@@ -0,0 +1,7 @@
+package me.lucyydotp.papers;
+
+import net.minecraft.core.Rotations;
+
+public interface ArmorStandExt {
+    Rotations paper$lastHeadRot();
+}
diff --git a/src/main/java/me/lucyydotp/papers/CameraPerspectiveMode.java b/src/main/java/me/lucyydotp/papers/CameraPerspectiveMode.java
@@ -2,6 +2,7 @@
 
 import com.mojang.blaze3d.vertex.PoseStack;
 import net.minecraft.client.Minecraft;
+import net.minecraft.util.Mth;
 import net.minecraft.world.entity.decoration.ArmorStand;
 import org.jetbrains.annotations.NotNull;
 import org.joml.Quaternionf;
@@ -21,7 +22,7 @@ public sealed interface CameraPerspectiveMode {
      *
      * @param cameraPoseStack a pose stack to mutate
      */
-    void transform(PoseStack cameraPoseStack);
+    void transform(PoseStack cameraPoseStack, float tickProgress, long time);
 
     /**
      * A perspective mode that derives rotation from an armour stand's body rotation and head pose.
@@ -51,12 +52,10 @@ public boolean canContinueToUse() {
         }
 
         @Override
-        public void transform(PoseStack cameraPoseStack) {
+        public void transform(PoseStack cameraPoseStack, float tickProgress, long time) {
             final var player = Minecraft.getInstance().player;
             if (!player.isPassenger()) return;
 
-            final var pose = armorStand.getHeadPose();
-
             // fixme: is doing this on the render thread bad?
             player.turn(
                     (armorStand.getYRot() - lastYRot) / 0.15,
@@ -65,11 +64,14 @@ public void transform(PoseStack cameraPoseStack) {
 
             lastYRot = armorStand.getYRot();
 
+            final var pose = armorStand.getHeadPose();
+            final var lastPose = ((ArmorStandExt) armorStand).paper$lastHeadRot();
+
             cameraPoseStack.rotateAround(
                     new Quaternionf()
-                            .rotateAxis((float) Math.toRadians(pose.getZ()), player.getForward().toVector3f())
-                            .rotateAxis((float) Math.toRadians(pose.getY()), player.getUpVector(1).toVector3f())
-                            .rotateAxis((float) Math.toRadians(-pose.getX()), player.getForward().toVector3f().rotateY((float) (Math.PI / 2f))),
+                            .rotateAxis((float) Math.toRadians(Mth.lerp(tickProgress, lastPose.getZ(), pose.getZ())), player.getForward().toVector3f())
+                            .rotateAxis((float) Math.toRadians(Mth.lerp(tickProgress, lastPose.getY(), pose.getY())), player.getUpVector(1).toVector3f())
+                            .rotateAxis((float) Math.toRadians(Mth.lerp(tickProgress, -lastPose.getX(), -pose.getX())), player.getForward().toVector3f().rotateY((float) (Math.PI / 2f))),
                     0,
                     // fixme: this might be a little low?
                     (float) (-player.getBbHeight() - player.getMyRidingOffset()),

diff --git a/src/main/java/me/lucyydotp/papers/mixin/ArmorStandMixin.java b/src/main/java/me/lucyydotp/papers/mixin/ArmorStandMixin.java
@@ -1,21 +1,55 @@
 package me.lucyydotp.papers.mixin;
 
+import com.llamalad7.mixinextras.sugar.Local;
+import me.lucyydotp.papers.ArmorStandExt;
 import me.lucyydotp.papers.CameraPerspectiveMode;
 import me.lucyydotp.papers.PassengerPerspectiveMod;
+import net.minecraft.core.Rotations;
 import net.minecraft.world.entity.Entity;
 import net.minecraft.world.entity.EntityType;
 import net.minecraft.world.entity.decoration.ArmorStand;
 import net.minecraft.world.level.Level;
-import org.spongepowered.asm.mixin.Mixin;
+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;
 
 @Mixin(ArmorStand.class)
-public abstract class ArmorStandMixin extends Entity {
+public abstract class ArmorStandMixin extends Entity implements ArmorStandExt {
+
+    @Shadow
+    @Final
+    private static Rotations DEFAULT_HEAD_POSE;
+
+    @Shadow
+    private Rotations headPose;
+
+    @Unique
+    private Rotations papers$lastHeadRot = DEFAULT_HEAD_POSE;
 
     public ArmorStandMixin(EntityType<?> entityType, Level level) {
         super(entityType, level);
         throw new AbstractMethodError("Mixin abstract class constructor");
     }
 
+    @Inject(
+            method = "setHeadPose",
+            at = @At("HEAD")
+    )
+    public void setLastHeadPose(Rotations rotations, CallbackInfo ci) {
+        papers$lastHeadRot = headPose;
+    }
+
+    @Inject(
+            method = "tick",
+            at = @At("HEAD")
+    )
+    public void clearLastHeadPose(CallbackInfo ci, @Local(name = "rotations") Rotations rotations) {
+        if (this.headPose.equals(rotations)) {
+            papers$lastHeadRot = headPose;
+        }
+    }
+
     /**
      * Makes the current target armour stand glow.
      */
@@ -29,4 +63,9 @@ public boolean isCurrentlyGlowing() {
                         ash.shouldGlow((ArmorStand) (Object) this)
         );
     }
+
+    @Override
+    public Rotations paper$lastHeadRot() {
+        return papers$lastHeadRot;
+    }
 }
diff --git a/src/main/java/me/lucyydotp/papers/mixin/GameRendererMixin.java b/src/main/java/me/lucyydotp/papers/mixin/GameRendererMixin.java
@@ -4,12 +4,30 @@
 import me.lucyydotp.papers.PassengerPerspectiveMod;
 import net.minecraft.client.renderer.GameRenderer;
 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.ModifyArg;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
 
 @Mixin(GameRenderer.class)
 public class GameRendererMixin {
 
+    @Unique
+    private float papers$f;
+
+    @Unique
+    private long papers$l;
+
+    @Inject(
+            method = "renderLevel",
+            at = @At("HEAD")
+    )
+    public void setF(float f, long l, PoseStack poseStack, CallbackInfo ci) {
+        papers$f = f;
+        papers$l = l;
+    }
+
     /**
      * Applies the active perspective mode's camera transformation.
      */
@@ -24,7 +42,7 @@ public class GameRendererMixin {
     public PoseStack addRidePerspectiveRotation(PoseStack poseStack) {
         final var perspectiveMode = PassengerPerspectiveMod.getPerspectiveMode();
         if (perspectiveMode != null) {
-            perspectiveMode.transform(poseStack);
+            perspectiveMode.transform(poseStack, papers$f, papers$l);
         }
         return poseStack;
     }