Updated RenderHandler zoom functionality.

RenderHandler.cs

@@ -11,14 +11,14 @@ namespace LunaLightXMG
         private SpriteBatch spriteBatch;
         private RenderTarget2D renderTarget;
         private Rectangle renderDestination;
-
-        private int retroWidth;
-        private int retroHeight;
+        
+        private float retroWidth;
+        private float retroHeight;
         private float zoomLevel = 1.0f;
         private float zoomTarget = 1.0f;
-        private readonly float zoomMin = 0.75f;
+        private readonly float zoomMin = 0.50f;
         private readonly float zoomNorm = 1.0f;
-        private readonly float zoomMax = 1.25f;
+        private readonly float zoomMax = 1.50f;
         private readonly float zoomSpeed = 0.1f;
         public float ZoomLevel {get => zoomLevel;}
         
@@ -49,24 +49,32 @@ namespace LunaLightXMG
         {
             zoomTarget = zoomMax;
         }
-
+        
         public void UpdateZoom()
         {
+            // interpolate to target
             zoomLevel = MathHelper.Lerp(zoomLevel, zoomTarget, zoomSpeed);
+            // snap to target when we're close enough
+            if (Math.Abs(zoomLevel - zoomTarget) < 0.001f) 
+            {
+                zoomLevel = zoomTarget;
+            }
+            // stay in bounds (just in case)
             zoomLevel = MathHelper.Clamp(zoomLevel, zoomMin, zoomMax);
+            // calc new zoomed render destination
             CalculateRenderDestination();
         }
-
+        
         public void CalculateRenderDestination()
         {
             Point screenSize = graphicsDevice.Viewport.Bounds.Size;
             // Calculate the integer scale factor
-            int scaleX = screenSize.X / (int)(retroWidth * zoomLevel);
-            int scaleY = screenSize.Y / (int)(retroHeight * zoomLevel);
+            float scaleX = screenSize.X / (retroWidth * zoomLevel);
+            float scaleY = screenSize.Y / (retroHeight * zoomLevel);
 
             // Set renderDestination 
-            renderDestination.Width = retroWidth * scaleX;
-            renderDestination.Height = retroHeight * scaleY;
+            renderDestination.Width = (int)(retroWidth * scaleX);
+            renderDestination.Height = (int)(retroHeight * scaleY);
             renderDestination.X = (screenSize.X - renderDestination.Width) / 2;
             renderDestination.Y = (screenSize.Y - renderDestination.Height) / 2;
         }

UpdateNotes/RenderHandler.md

@@ -15,6 +15,6 @@ Here's what the render handler can do.
 
 Trying out zoom using the render target. The render target is set by retroWidth and retroHeight (320x180). 
 
-- ZoomIn() should smoothly zoom to 75% retroWidth x retroHeight, 240x135
+- ZoomIn() should smoothly zoom to 50% retroWidth x retroHeight, 160x90
 
-- ZoomOut() should smoothly zoom to 125% retroWidth x retroHeight, 400x225
+- ZoomOut() should smoothly zoom to 150% retroWidth x retroHeight, 480x270