From 13a232aa9b5c44ddd461bab60279c6b481faa45f Mon Sep 17 00:00:00 2001
From: cutealien <cutealien@dfc29bdd-3216-0410-991c-e03cc46cb475>
Date: Tue, 26 May 2020 13:01:02 +0000
Subject: [PATCH] updateTriangles in CTriangleSelector can handle some broken
 meshes without crash now. Before it crashed when index-count wasn't a
 multiple of 3, now it just doesn't create the last triangle then.

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@6110 dfc29bdd-3216-0410-991c-e03cc46cb475
---
 source/Irrlicht/CTriangleSelector.cpp | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/source/Irrlicht/CTriangleSelector.cpp b/source/Irrlicht/CTriangleSelector.cpp
index 0342b349..531c62d6 100644
--- a/source/Irrlicht/CTriangleSelector.cpp
+++ b/source/Irrlicht/CTriangleSelector.cpp
@@ -127,22 +127,22 @@ static void updateTriangles(u32& triangleCount, core::array<core::triangle3df>&
 {
 	if ( bufferTransform )
 	{
-		for (u32 index = 0; index < idxCnt; index += 3)
+		for (u32 index = 2; index < idxCnt; index += 3)
 		{
 			core::triangle3df& tri = triangles[triangleCount++];
-			bufferTransform->transformVect( tri.pointA, (*reinterpret_cast<const video::S3DVertex*>(&vertices[indices[index + 0]*vertexPitch])).Pos );
-			bufferTransform->transformVect( tri.pointB, (*reinterpret_cast<const video::S3DVertex*>(&vertices[indices[index + 1]*vertexPitch])).Pos );
-			bufferTransform->transformVect( tri.pointC, (*reinterpret_cast<const video::S3DVertex*>(&vertices[indices[index + 2]*vertexPitch])).Pos );
+			bufferTransform->transformVect( tri.pointA, (*reinterpret_cast<const video::S3DVertex*>(&vertices[indices[index - 2]*vertexPitch])).Pos );
+			bufferTransform->transformVect( tri.pointB, (*reinterpret_cast<const video::S3DVertex*>(&vertices[indices[index - 1]*vertexPitch])).Pos );
+			bufferTransform->transformVect( tri.pointC, (*reinterpret_cast<const video::S3DVertex*>(&vertices[indices[index - 0]*vertexPitch])).Pos );
 		}
 	}
 	else
 	{
-		for (u32 index = 0; index < idxCnt; index += 3)
+		for (u32 index = 2; index < idxCnt; index += 3)
 		{
 			core::triangle3df& tri = triangles[triangleCount++];
-			tri.pointA = (*reinterpret_cast<const video::S3DVertex*>(&vertices[indices[index + 0]*vertexPitch])).Pos;
-			tri.pointB = (*reinterpret_cast<const video::S3DVertex*>(&vertices[indices[index + 1]*vertexPitch])).Pos;
-			tri.pointC = (*reinterpret_cast<const video::S3DVertex*>(&vertices[indices[index + 2]*vertexPitch])).Pos;
+			tri.pointA = (*reinterpret_cast<const video::S3DVertex*>(&vertices[indices[index - 2]*vertexPitch])).Pos;
+			tri.pointB = (*reinterpret_cast<const video::S3DVertex*>(&vertices[indices[index - 1]*vertexPitch])).Pos;
+			tri.pointC = (*reinterpret_cast<const video::S3DVertex*>(&vertices[indices[index - 0]*vertexPitch])).Pos;
 		}
 	}
 }