add docs

source/funkin/graphics/framebuffer/FrameBuffer.hx

@@ -8,6 +8,9 @@ import flixel.FlxCamera;
 import openfl.Lib;
 import openfl.display3D.textures.TextureBase;
 
+/**
+ * A single frame buffer. Used by `FrameBufferManager`.
+ */
 class FrameBuffer
 {
   /**
@@ -37,8 +40,7 @@ class FrameBuffer
   public function create(width:Int, height:Int, bgColor:FlxColor):Void
   {
     dispose();
-    final c3d = Lib.current.stage.context3D;
-    texture = c3d.createTexture(width, height, BGRA, true);
+    texture = Lib.current.stage.context3D.createTexture(width, height, BGRA, true);
     bitmap = BitmapData.fromTexture(texture);
     camera.bgColor = bgColor;
   }
@@ -88,13 +90,15 @@ class FrameBuffer
   /**
    * Unlocks the frame buffer and makes the bitmap ready to use.
    */
-  @:access(flixel.FlxCamera)
   public function unlock():Void
   {
     bitmap.fillRect(new Rectangle(0, 0, bitmap.width, bitmap.height), 0);
     bitmap.draw(camera.flashSprite, new Matrix(1, 0, 0, 1, camera.flashSprite.x, camera.flashSprite.y));
   }
 
+  /**
+   * Diposes stuff. Call `create` again if you want to reuse the instance.
+   */
   public function dispose():Void
   {
     if (texture != null)
@@ -104,8 +108,13 @@ class FrameBuffer
       bitmap.dispose();
       bitmap = null;
     }
+    spriteCopies.clear();
   }
 
+  /**
+   * Adds a sprite copy to the frame buffer.
+   * @param spriteCopy the sprite copy
+   */
   public function addSpriteCopy(spriteCopy:SpriteCopy):Void
   {
     spriteCopies.push(spriteCopy);

source/funkin/graphics/framebuffer/FrameBufferManager.hx

@@ -5,6 +5,9 @@ import openfl.display.BitmapData;
 import flixel.FlxSprite;
 import flixel.FlxCamera;
 
+/**
+ * Manages frame buffers and gives access to each frame buffer.
+ */
 class FrameBufferManager
 {
   final camera:FlxCamera;

source/funkin/graphics/framebuffer/SpriteCopy.hx

@@ -1,9 +1,12 @@
 package funkin.graphics.framebuffer;
 
-import flixel.util.FlxColor;
 import flixel.FlxCamera;
 import flixel.FlxSprite;
+import flixel.util.FlxColor;
 
+/**
+ * A copy of a `FlxSprite` with a specified color. Used to render the sprite to a frame buffer.
+ */
 class SpriteCopy
 {
   final sprite:FlxSprite;