From b35f160475c967aad7c37a12230c3d2f6d4c8e1a Mon Sep 17 00:00:00 2001
From: unknown <mlokogegelmlok@gmail.com>
Date: Tue, 28 Jul 2020 14:40:20 +0200
Subject: [PATCH] switching to simpler and more perforamnt aproach of removing
 shapes from quadtree

---
 quadtree/quadtree.go      | 38 +++++++-------------------------------
 quadtree/quadtree_test.go |  4 ++++
 2 files changed, 11 insertions(+), 31 deletions(-)

diff --git a/quadtree/quadtree.go b/quadtree/quadtree.go
index 0ef9512..62bed41 100644
--- a/quadtree/quadtree.go
+++ b/quadtree/quadtree.go
@@ -1,14 +1,13 @@
 package quadtree
 
 import (
-	"errors"
-
 	"github.com/faiface/pixel"
 )
 
 // Collidable is interface that stores inserted objects
 type Collidable interface {
 	GetRect() pixel.Rect
+	IsDead() bool
 }
 
 // Common part of quadtree. Commot is always coppied to children
@@ -164,6 +163,9 @@ func (q *Quadtree) Update() {
 		q.bl.Update()
 		q.br.Update()
 		for _, c := range q.Shapes {
+			if c.IsDead() {
+				continue
+			}
 			rect := c.GetRect()
 			sub := q.getSub(rect)
 			if sub != nil {
@@ -176,6 +178,9 @@ func (q *Quadtree) Update() {
 		}
 	} else {
 		for _, c := range q.Shapes {
+			if c.IsDead() {
+				continue
+			}
 			if q.fits(c.GetRect()) || q.pr == nil {
 				new = append(new, c)
 			} else {
@@ -211,35 +216,6 @@ func (q *Quadtree) GetColliding(rect pixel.Rect, con *[]Collidable) {
 	}
 }
 
-// gets a smallest possible quadrant rect fits into.
-func (q *Quadtree) getSmallestQuad(rect pixel.Rect) *Quadtree {
-	current := q
-	for {
-		sub := current.getSub(rect)
-		if sub == nil {
-			break
-		}
-		current = sub
-	}
-	return current
-}
-
-// Remove removes shape from quadtree the fast wey. Always update before removing objects
-// unless you are not ,moving with it.
-func (q *Quadtree) Remove(c Collidable) error {
-	sq := q.getSmallestQuad(c.GetRect())
-	for i, o := range sq.Shapes {
-		if o == c {
-			last := len(sq.Shapes) - 1
-			sq.Shapes[i] = nil
-			sq.Shapes[i] = sq.Shapes[last]
-			sq.Shapes = sq.Shapes[:last]
-			return nil
-		}
-	}
-	return errors.New("shape not found, update before removing")
-}
-
 // Clear clears the tree, use this every frame before inserting all shapes
 // other wise you will run out of memory eventually and tree will not even work properly.
 // You should not use this if you are using Upsate() nethod
diff --git a/quadtree/quadtree_test.go b/quadtree/quadtree_test.go
index 13a4346..3a859c0 100644
--- a/quadtree/quadtree_test.go
+++ b/quadtree/quadtree_test.go
@@ -31,6 +31,10 @@ func (c *collider) GetRect() pixel.Rect {
 	return pixel.R(c.X-c.size, c.Y-c.size, c.X+c.size, c.Y+c.size)
 }
 
+func (c *collider) IsDead() bool {
+	return false
+}
+
 type collizionTest struct {
 	description string
 	target      collider