Fixed jumpy interpolation caused by multiple interpolations per frame.

src/SlatedGameToolkit.Framework/Graphics/Camera.cs

@@ -180,9 +180,9 @@ namespace SlatedGameToolkit.Framework.Graphics
             Logger.Log(string.Format("Camera initial dimensions: {0}x{1}, ratio of view: {2}", width, height, width / height), LogLevel.DEBUG);
         }
 
-        public void InterpolatePosition(float delta)
+        public void InterpolatePosition(double delta)
         {
-            this.Position += delta * (MoveTo - Position);
+            this.Position += (float) delta * (MoveTo - Position);
         }
     }
 }

src/SlatedGameToolkit.Framework/Graphics/Render/IPositionInterpolable.cs

@@ -5,9 +5,9 @@ namespace SlatedGameToolkit.Framework.Graphics.Render
     public interface IPositionInterpolable
     {
         /// <summary>
-        /// Is called between each update to allow rendered meshes to be interpolated between positions and time steps.
+        /// Allows this object to perform interpolation based on the position (delta) between the update frames.
         /// </summary>
         /// <param name="delta">A normalized value between [0, 1] representing the current position between the updates.</param>
-        void InterpolatePosition(float delta);
+        void InterpolatePosition(double delta);
     }
 }

src/SlatedGameToolkit.Framework/Graphics/Render/MeshBatchRenderer.cs

@@ -20,7 +20,6 @@ namespace SlatedGameToolkit.Framework.Graphics.Render
         public bool Debug { get; set; }
         private const int VERTEX_LENGTH = 9;
         private bool disposed;
-        private float batchDelta;
         public GLContext GLContext {get; private set; }
         private int projULoc, viewULoc, modelULoc, texturedULoc, singleChanneledULoc, flippedULoc;
         private Camera camera;
@@ -123,12 +122,10 @@ namespace SlatedGameToolkit.Framework.Graphics.Render
         /// </summary>
         /// <param name="modelsMatrix">The models matrix.</param>
         /// <param name="delta">The time elapsed since the last update.</param>
-        public virtual void Begin(Matrix4x4 modelsMatrix, double delta) {
+        public virtual void Begin(Matrix4x4 modelsMatrix) {
             if (Batching) throw new InvalidOperationException("This batch is already started.");
             this.Batching = true;
             this.modelsMatrix = modelsMatrix;
-
-            this.batchDelta = (float)delta;
         }
 
         /// <summary>
@@ -137,10 +134,6 @@ namespace SlatedGameToolkit.Framework.Graphics.Render
         /// <param name="mesh">Draws the given mesh.</param>
         public virtual void Draw(IMesh mesh) {
             if (!Batching) throw new InvalidOperationException("This batch has not been begun.");
-            IPositionInterpolable moveable = mesh as IPositionInterpolable;
-            if (moveable != null) {
-                moveable.InterpolatePosition(batchDelta);
-            }
             if (mesh.Texture?.Handle != this.texture?.Handle) {
                 Flush();
                 this.texture = mesh.Texture;
@@ -200,8 +193,6 @@ namespace SlatedGameToolkit.Framework.Graphics.Render
                 GLContext.BindTexture(TextureTarget.Texture2D, texture.Handle);
             }
             renderProgram.Use();
-            camera.InterpolatePosition(batchDelta);
-
             vertexBuffers.BufferVertices(data, true);
             vertexBuffers.BufferIndices(indices, true);
             GLContext.UniformMatrix4fv(modelULoc, 1, false, modelsMatrix.ToColumnMajorArray());

src/SlatedGameToolkit.Framework/Graphics/Render/RectangleMesh.cs

@@ -9,8 +9,8 @@ namespace SlatedGameToolkit.Framework.Graphics.Render
     {
         private Matrix4x4 matRot;
         private bool changed;
+        private RectangleF rectangle;
         private Vector3 rotation;
-        private Vector2 origin, dimensions;
         private RectangleF textureBounds;
         private ValueTuple<Vector3, Vector2>[] vertices;
         private uint[] indices;
@@ -26,26 +26,26 @@ namespace SlatedGameToolkit.Framework.Graphics.Render
         public float X {
             get 
             {
-                return origin.X;
+                return rectangle.X;
             }
 
             set 
             {
                 changed = true;
-                origin.X = value;
+                rectangle.X = value;
             }
         }
 
         public float Y {
             get
             {
-                return origin.Y;
+                return rectangle.Y;
             }
 
             set
             {
                 changed = true;
-                origin.Y = value;
+                rectangle.Y = value;
             }
         }
 
@@ -53,13 +53,13 @@ namespace SlatedGameToolkit.Framework.Graphics.Render
         {
             get
             {
-                return dimensions.X;
+                return rectangle.Width;
             }
 
             set
             {
                 changed = true;
-                dimensions.X = value;
+                rectangle.Width = value;
             }
         }
 
@@ -67,14 +67,14 @@ namespace SlatedGameToolkit.Framework.Graphics.Render
         {
             get
             {
-                return dimensions.Y;
+                return rectangle.Height;
             }
 
             
             set
             {
                 changed = true;
-                dimensions.Y = value;
+                rectangle.Height = value;
             }
         }
 
@@ -140,8 +140,7 @@ namespace SlatedGameToolkit.Framework.Graphics.Render
         public RectangleMesh(RectangleF meshBounds, ITexture texture, Color color) {
             this.changed = true;
             this.rotation = Vector3.Zero;
-            this.origin = Vector2.Zero;
+            this.rectangle = RectangleF.Empty;
-            this.dimensions = Vector2.Zero;
             this.Texture = texture;
             this.Color = color;
             this.indices = new uint[] {0, 1, 3, 1, 2, 3};
@@ -166,10 +165,10 @@ namespace SlatedGameToolkit.Framework.Graphics.Render
         private void CalculateVertices() {
             if (!changed) return;
             Vector3[] baseVerts = new Vector3[4];
-            baseVerts[0] = new Vector3(this.origin, 0);
+            baseVerts[0] = new Vector3(this.rectangle.X, this.rectangle.Y, 0);
-            baseVerts[1] = new Vector3(this.origin.X + this.dimensions.X, this.origin.Y, 0);
+            baseVerts[1] = new Vector3(this.rectangle.Right, this.rectangle.Y, 0);
-            baseVerts[2] = new Vector3(baseVerts[1].X, this.origin.Y + this.dimensions.Y, 0);
+            baseVerts[2] = new Vector3(baseVerts[1].X, this.rectangle.Bottom, 0);
-            baseVerts[3] = new Vector3(this.origin.X, baseVerts[2].Y, 0);
+            baseVerts[3] = new Vector3(this.rectangle.X, baseVerts[2].Y, 0);
 
             for (int i = 0; i < vertices.Length; i++)
             {