From ff8e9d6aadcbb08def41c10fe1abe99bc86b5172 Mon Sep 17 00:00:00 2001
From: Ian Curtis <i.curtis@gmail.com>
Date: Mon, 30 May 2016 23:10:56 +0000
Subject: [PATCH] Check for overflow. Fixes some fade effects

---
 Src/Graphics/New3D/PolyHeader.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Src/Graphics/New3D/PolyHeader.cpp b/Src/Graphics/New3D/PolyHeader.cpp
index 9cfa079..ab37e89 100644
--- a/Src/Graphics/New3D/PolyHeader.cpp
+++ b/Src/Graphics/New3D/PolyHeader.cpp
@@ -320,6 +320,10 @@ bool PolyHeader::AlphaTest()
 
 UINT8 PolyHeader::Transparency()
 {
+	if (header[6] & 0x800000) {		// check top bit to see if its 1. Star wars is writing 1 for opaque, but the rest of the bits are garbage and are ignored
+		return 255;					// without this check we get overflow. In the SDK, values are explicitly clamped to 0-32.
+	}
+
 	return (UINT8)((((header[6] >> 18) & 0x3F) * 255) / 32.f);	
 }