From a79fd2786ad6d5df9b0a71cee38f0d4c526313c8 Mon Sep 17 00:00:00 2001
From: Ian Curtis <i.curtis@gmail.com>
Date: Thu, 19 May 2016 19:04:44 +0000
Subject: [PATCH] optimise hash table access for better performance

---
 Src/Graphics/New3D/New3D.cpp        |  6 +++---
 Src/Graphics/New3D/TextureSheet.cpp | 13 +++++++------
 2 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/Src/Graphics/New3D/New3D.cpp b/Src/Graphics/New3D/New3D.cpp
index f81a9b3..79df5d6 100644
--- a/Src/Graphics/New3D/New3D.cpp
+++ b/Src/Graphics/New3D/New3D.cpp
@@ -2,7 +2,7 @@
 #include "PolyHeader.h"
 #include "Texture.h"
 #include "Vec.h"
-#include <cmath>  // needed by gcc
+#include <cmath>
 #include <algorithm>
 #include <limits>
 
@@ -283,9 +283,9 @@ bool CNew3D::DrawModel(UINT32 modelAddr)
 
 		// try to find meshes in the rom cache
 
+		m->meshes = m_romMap[modelAddr];	// will create an entry with a null pointer if empty
 
-		if (m_romMap.count(modelAddr)) {
-			m->meshes = m_romMap[modelAddr];
+		if (m->meshes) {
 			cached = true;
 		}
 		else {
diff --git a/Src/Graphics/New3D/TextureSheet.cpp b/Src/Graphics/New3D/TextureSheet.cpp
index 9612fdd..e2dc338 100644
--- a/Src/Graphics/New3D/TextureSheet.cpp
+++ b/Src/Graphics/New3D/TextureSheet.cpp
@@ -31,9 +31,11 @@ std::shared_ptr<Texture> TextureSheet::BindTexture(const UINT16* src, int format
 
 	index = ToIndex(x, y);
 
-	if (m_texMap[format&TEXTURE_DEBUG_MASK].count(index) == 0) {
+	auto range = m_texMap[format&TEXTURE_DEBUG_MASK].equal_range(index);
 
-		//no textures at this position or format so add it to the map
+	if (range.first == range.second) {	
+
+		// nothing found so create a new texture 
 
 		std::shared_ptr<Texture> t(new Texture());
 		m_texMap[format&TEXTURE_DEBUG_MASK].insert(std::pair<int, std::shared_ptr<Texture>>(index, t));
@@ -41,10 +43,8 @@ std::shared_ptr<Texture> TextureSheet::BindTexture(const UINT16* src, int format
 		return t;
 	}
 	else {
-		//scan for duplicates
-		//only texture width/height and wrap modes can change here. Since key is based on x/y pos, and each map is a separate format
 
-		auto range = m_texMap[format&TEXTURE_DEBUG_MASK].equal_range(index);
+		// iterate to try and find a match
 
 		for (auto it = range.first; it != range.second; ++it) {
 
@@ -57,10 +57,11 @@ std::shared_ptr<Texture> TextureSheet::BindTexture(const UINT16* src, int format
 			}
 		}
 
+		// nothing found so create a new entry
+
 		std::shared_ptr<Texture> t(new Texture());
 		m_texMap[format&TEXTURE_DEBUG_MASK].insert(std::pair<int, std::shared_ptr<Texture>>(index, t));
 		t->UploadTexture(src, m_temp.data(), format, mirrorU, mirrorV, x, y, width, height);
-
 		return t;
 	}
 }