From 1116c22a66c8341065a1745a47bcfec3889f7cba Mon Sep 17 00:00:00 2001
From: UnknownShadow200 <unknownshadow200@gmail.com>
Date: Fri, 25 Dec 2015 11:11:57 +1100
Subject: [PATCH] Fix held block bobbing being jerky when leaving the ground.
 (Thanks WolfgangNS)

---
 ClassicalSharp/Entities/AnimatedEntity.cs     |  2 +-
 ClassicalSharp/Game/Game.cs                   |  3 +-
 ClassicalSharp/Network/NetworkProcessor.cs    |  1 +
 ClassicalSharp/Rendering/BlockHandRenderer.cs | 42 ++++++++++++++-----
 4 files changed, 36 insertions(+), 12 deletions(-)

diff --git a/ClassicalSharp/Entities/AnimatedEntity.cs b/ClassicalSharp/Entities/AnimatedEntity.cs
index 2ea2f5c94..9e1a09720 100644
--- a/ClassicalSharp/Entities/AnimatedEntity.cs
+++ b/ClassicalSharp/Entities/AnimatedEntity.cs
@@ -11,7 +11,7 @@ namespace ClassicalSharp {
 		}
 		public float legXRot, armXRot, armZRot;
 		public float bobYOffset, tilt, walkTime, swing;
-		protected float walkTimeO, walkTimeN, swingO, swingN;
+		protected internal float walkTimeO, walkTimeN, swingO, swingN;
 		
 		/// <summary> Calculates the next animation state based on old and new position. </summary>
 		protected void UpdateAnimState( Vector3 oldPos, Vector3 newPos, double delta ) {
diff --git a/ClassicalSharp/Game/Game.cs b/ClassicalSharp/Game/Game.cs
index f5b160bc1..7a2c29601 100644
--- a/ClassicalSharp/Game/Game.cs
+++ b/ClassicalSharp/Game/Game.cs
@@ -199,7 +199,7 @@ namespace ClassicalSharp {
 				bool right = IsMousePressed( MouseButton.Right );
 				InputHandler.PickBlocks( true, left, middle, right );
 				if( !HideGui )
-					BlockHandRenderer.Render( e.Time );
+					BlockHandRenderer.Render( e.Time, t );
 			} else {
 				SelectedPos.SetAsInvalid();
 			}
@@ -242,6 +242,7 @@ namespace ClassicalSharp {
 				ParticleManager.Tick( ticksPeriod );
 				Animations.Tick( ticksPeriod );
 				AudioPlayer.Tick( ticksPeriod );
+				BlockHandRenderer.Tick( ticksPeriod );
 				ticksThisFrame++;
 				ticksAccumulator -= ticksPeriod;
 			}
diff --git a/ClassicalSharp/Network/NetworkProcessor.cs b/ClassicalSharp/Network/NetworkProcessor.cs
index 08d4f19d8..86068ab05 100644
--- a/ClassicalSharp/Network/NetworkProcessor.cs
+++ b/ClassicalSharp/Network/NetworkProcessor.cs
@@ -175,6 +175,7 @@ namespace ClassicalSharp {
 			reader.Remove( 1 ); // remove opcode
 			lastOpcode = (PacketId)opcode;
 			Action handler = handlers[opcode];
+			Console.WriteLine( lastOpcode );
 			
 			if( handler == null )
 				throw new NotImplementedException( "Unsupported packet:" + (PacketId)opcode );
diff --git a/ClassicalSharp/Rendering/BlockHandRenderer.cs b/ClassicalSharp/Rendering/BlockHandRenderer.cs
index 660b481f7..3ddec1b4f 100644
--- a/ClassicalSharp/Rendering/BlockHandRenderer.cs
+++ b/ClassicalSharp/Rendering/BlockHandRenderer.cs
@@ -31,7 +31,7 @@ namespace ClassicalSharp.Renderers {
 			game.Events.HeldBlockChanged += HeldBlockChanged;
 		}
 		
-		public void Render( double delta ) {
+		public void Render( double delta, float t ) {
 			if( game.Camera.IsThirdPerson || !game.ShowBlockInHand )
 				return;
 			game.Graphics.Texturing = true;
@@ -42,7 +42,7 @@ namespace ClassicalSharp.Renderers {
 			type = (byte)game.Inventory.HeldBlock;
 			if( playAnimation )
 				DoAnimation( delta );
-			PerformViewBobbing();
+			PerformViewBobbing( t );
 			SetupMatrices();
 			
 			if( game.BlockInfo.IsSprite[type] )
@@ -113,7 +113,7 @@ namespace ClassicalSharp.Renderers {
 			angleX = 0;
 			animPeriod = period;
 			animSpeed = Math.PI / period;
-			 
+			
 			if( updateLastType )
 				lastType = (byte)game.Inventory.HeldBlock;
 			fakeP.Position = Vector3.Zero;
@@ -134,19 +134,21 @@ namespace ClassicalSharp.Renderers {
 			playAnimation = true;
 		}
 		
-		void PerformViewBobbing() {
-			if( !game.ViewBobbing || !game.LocalPlayer.onGround ) return;
+		float bobTimeO, bobTimeN;
+		void PerformViewBobbing( float t ) {
+			if( !game.ViewBobbing ) return;
 			LocalPlayer p = game.LocalPlayer;
+			float bobTime = Utils.Lerp( bobTimeO, bobTimeN, t );
 			
-			double horTime = Math.Sin( p.curWalkTime ) * p.curSwing;
+			double horTime = Math.Sin( bobTime ) * p.curSwing;
 			// (0.5 + 0.5cos(2x)) is smoother than abs(cos(x)) at endpoints
-			double verTime = Math.Cos( p.curWalkTime * 2f );
-			float horAngle = 0.2f * (float)horTime;			
+			double verTime = Math.Cos( bobTime * 2 );
+			float horAngle = 0.2f * (float)horTime;
 			float verAngle = 0.2f * (float)(0.5 + 0.5 * verTime) * p.curSwing;
 			
-			if( horAngle > 0 ) 
+			if( horAngle > 0 )
 				fakeP.Position.X += horAngle;
-			else 
+			else
 				fakeP.Position.Z += horAngle;
 			fakeP.Position.Y -= verAngle;
 		}
@@ -155,6 +157,26 @@ namespace ClassicalSharp.Renderers {
 			SetAnimationSwitchBlock();
 		}
 		
+		bool stop = false;
+		public void Tick( double delta ) {
+			Player p = game.LocalPlayer;
+			float bobTimeDelta = p.walkTimeN - p.walkTimeO;
+			bobTimeO = bobTimeN;
+
+			if( game.LocalPlayer.onGround ) stop = false;
+			if( stop ) return;
+			bobTimeN += bobTimeDelta;
+			if( game.LocalPlayer.onGround ) return;
+
+			// Keep returning the held block back to centre position.
+			if( Math.Sign( Math.Sin( bobTimeO ) ) == Math.Sign( Math.Sin( bobTimeN ) ) )
+				return;
+			// Stop bob time at next periodic '0' angle.
+			double left = Math.PI - (bobTimeO % Math.PI);
+			bobTimeN = (float)(bobTimeO + left);
+			stop = true;
+		}
+		
 		public void Dispose() {
 			game.Events.HeldBlockChanged -= HeldBlockChanged;
 		}