From 0ba69a34726f341eb8de44dec51e882cc1afad8d Mon Sep 17 00:00:00 2001
From: Regalis <regalis@undertowgames.com>
Date: Thu, 22 Sep 2016 18:14:16 +0300
Subject: [PATCH] Using nonpremultiplied alpha when drawing damaged wall
 sections (-> no artifacts around windows anymore), particle collision
 optimization

---
 Subsurface/Source/Map/Structure.cs      |  6 +++--
 Subsurface/Source/Particles/Particle.cs | 31 ++++++-------------------
 Subsurface/Source/Screens/GameScreen.cs |  2 +-
 3 files changed, 12 insertions(+), 27 deletions(-)

diff --git a/Subsurface/Source/Map/Structure.cs b/Subsurface/Source/Map/Structure.cs
index 5eddba372..8ea943bbe 100644
--- a/Subsurface/Source/Map/Structure.cs
+++ b/Subsurface/Source/Map/Structure.cs
@@ -437,7 +437,7 @@ namespace Barotrauma
                 {
                     if (damageEffect != null)
                     {
-                        float newCutoff =  Math.Min((s.damage / prefab.MaxHealth), 0.65f);
+                        float newCutoff = Math.Min((s.damage / prefab.MaxHealth), 0.65f);
 
                         if (Math.Abs(newCutoff - prevCutoff) > 0.01f)
                         {
@@ -539,7 +539,9 @@ namespace Barotrauma
 
             var section = sections[sectionIndex];
 
-            int particleAmount = (int)(Math.Min(Health - section.damage, damage) * Rand.Range(0.1f, 1.0f));
+            int particleAmount = (int)(Math.Min(Health - section.damage, damage) * Rand.Range(0.01f, 1.0f));
+
+            particleAmount = Math.Min(particleAmount, 200);
             for (int i = 0; i < particleAmount; i++)
             {
                 Vector2 particlePos = new Vector2(
diff --git a/Subsurface/Source/Particles/Particle.cs b/Subsurface/Source/Particles/Particle.cs
index 4d9f87429..de75cadb6 100644
--- a/Subsurface/Source/Particles/Particle.cs
+++ b/Subsurface/Source/Particles/Particle.cs
@@ -38,9 +38,7 @@ namespace Barotrauma.Particles
 
         private Vector2 drawPosition;
         private float drawRotation;
-
-        //private float checkCollisionTimer;
-
+        
         private Hull currentHull;
 
         private List<Gap> hullGaps;
@@ -75,7 +73,6 @@ namespace Barotrauma.Particles
         
         public void Init(ParticlePrefab prefab, Vector2 position, Vector2 speed, float rotation, Hull hullGuess = null)
         {
-
             this.prefab = prefab;
 
             spriteIndex = Rand.Int(prefab.Sprites.Count);
@@ -116,8 +113,6 @@ namespace Barotrauma.Particles
             if (prefab.DeleteOnCollision || prefab.CollidesWithWalls)
             {
                 hullGaps = currentHull == null ? new List<Gap>() : currentHull.ConnectedGaps;
-                //hullLimits = new List<Hull>();
-                //hullLimits = FindLimits(position);
             }
 
             if (prefab.RotateToDirection)
@@ -128,18 +123,6 @@ namespace Barotrauma.Particles
             }
         }
 
-        //private List<Hull> FindLimits(Vector2 position)
-        //{
-        //    List<Hull> hullList = new List<Hull>();
-
-        //    currentHull = Hull.FindHull(position);
-        //    if (currentHull == null) return hullList;
-
-        //    hullList.Add(currentHull);
-
-        //    return FindAdjacentHulls(hullList, currentHull, Math.Abs(velocity.X) > Math.Abs(velocity.Y));
-        //}
-
         public bool Update(float deltaTime)
         {
             prevPosition = position;
@@ -190,12 +173,13 @@ namespace Barotrauma.Particles
 
                 if (currentHull == null)
                 {
-                    var collidedHull = Hull.FindHullOld(edgePos);
+                    Hull collidedHull = Hull.FindHull(position);
                     if (collidedHull != null)
                     {
                         if (prefab.DeleteOnCollision) return false;
                         OnWallCollisionOutside(collidedHull);
-                    }
+                    }                   
+
                 }
                 else if (!Submarine.RectContains(currentHull.WorldRect, edgePos))
                 {
@@ -216,11 +200,11 @@ namespace Barotrauma.Particles
                         }
 
                         gapFound = true;
+                        break;
                     }
 
                     if (!gapFound)
                     {
-
                         OnWallCollisionInside(currentHull, edgePos);
                     }
                     else
@@ -229,9 +213,8 @@ namespace Barotrauma.Particles
                         hullGaps = currentHull == null ? new List<Gap>() : currentHull.ConnectedGaps;
 
                         if (OnChangeHull != null) OnChangeHull(edgePos, currentHull);
-                    }                    
-                }
-              
+                    }
+                }              
             }
 
             lifeTime -= deltaTime;
diff --git a/Subsurface/Source/Screens/GameScreen.cs b/Subsurface/Source/Screens/GameScreen.cs
index 6fae5ad43..0b040b855 100644
--- a/Subsurface/Source/Screens/GameScreen.cs
+++ b/Subsurface/Source/Screens/GameScreen.cs
@@ -340,7 +340,7 @@ namespace Barotrauma
             spriteBatch.End();
             
             spriteBatch.Begin(SpriteSortMode.Immediate,
-                BlendState.AlphaBlend, SamplerState.LinearWrap,
+                BlendState.NonPremultiplied, SamplerState.LinearWrap,
                 null, null, 
                 damageEffect,
                 cam.Transform);