From c499e6640cdf2d618e8e236fb8b0579a088eef4a Mon Sep 17 00:00:00 2001
From: Ian Curtis <i.curtis@gmail.com>
Date: Fri, 29 Apr 2016 23:03:46 +0000
Subject: [PATCH] fixed shading code

---
 Src/Graphics/New3D/New3D.cpp      | 14 ++++++++------
 Src/Graphics/New3D/PolyHeader.cpp | 10 +++++-----
 Src/Graphics/New3D/PolyHeader.h   |  7 ++++---
 3 files changed, 17 insertions(+), 14 deletions(-)

diff --git a/Src/Graphics/New3D/New3D.cpp b/Src/Graphics/New3D/New3D.cpp
index 1e1fadb..3b0a2b4 100644
--- a/Src/Graphics/New3D/New3D.cpp
+++ b/Src/Graphics/New3D/New3D.cpp
@@ -906,12 +906,6 @@ void CNew3D::CacheModel(Model *m, const UINT32 *data)
 				p.v[j].color[1] = (m_polyRAM[0x400 + colorIdx] >> 8) & 0xFF;
 				p.v[j].color[0] = (m_polyRAM[0x400 + colorIdx] >> 16) & 0xFF;
 			}
-			else if (0 /* fixed shading bit as of yet unknown */) {
-				UINT8 shade = (UINT8)((ix & 0xFF) + 128);
-				p.v[j].color[0] = shade;
-				p.v[j].color[1] = shade;
-				p.v[j].color[2] = shade;
-			}
 			else {
 				if (ph.ColorDisabled()) {		// no colours were set
 					p.v[j].color[0] = 255;
@@ -925,6 +919,14 @@ void CNew3D::CacheModel(Model *m, const UINT32 *data)
 				}
 			}
 
+			if (ph.FixedShading() && ph.LightEnabled()) {
+				float shade = ((ix & 0xFF) + 128) / 255.f;
+				UINT8 colour = (UINT8)(p.v[j].color[0] * shade);	// green & blue values seem not to be valid
+				p.v[j].color[0] = colour;
+				p.v[j].color[1] = colour;
+				p.v[j].color[2] = colour;
+			}
+
 			if ((ph.header[6] & 0x00800000)) {	// if set, polygon is opaque
 				p.v[j].color[3] = 255;
 			}
diff --git a/Src/Graphics/New3D/PolyHeader.cpp b/Src/Graphics/New3D/PolyHeader.cpp
index daceca1..9a9f6e7 100644
--- a/Src/Graphics/New3D/PolyHeader.cpp
+++ b/Src/Graphics/New3D/PolyHeader.cpp
@@ -144,6 +144,11 @@ bool PolyHeader::PolyColor()
 	return (header[1] & 2) > 0;
 }
 
+bool PolyHeader::FixedShading()
+{
+	return (header[1] & 0x20) > 0;
+}
+
 //
 // header 2
 //
@@ -255,11 +260,6 @@ UINT8 PolyHeader::Transparency()
 	return (UINT8)(((header[6] >> 18) & 0x1F)  * 255.f / 0x1F);	
 }
 
-bool PolyHeader::FixedShading()
-{
-	return (header[6] & 0x2000000) > 0;
-}
-
 bool PolyHeader::PolyAlpha()
 {
 	return (header[6] & 0x00800000) == 0;
diff --git a/Src/Graphics/New3D/PolyHeader.h b/Src/Graphics/New3D/PolyHeader.h
index 129e713..c684f81 100644
--- a/Src/Graphics/New3D/PolyHeader.h
+++ b/Src/Graphics/New3D/PolyHeader.h
@@ -21,10 +21,11 @@ x------- -------- -------- --------		Specular enable
 0x01: 
 xxxxxxxx xxxxxxxx xxxxxxxx--------		Polygon normal X coordinate(2.22 fixed point)
 -------- -------- -------- -x------		UV scale (0 = 13.3, 1 = 16.0)
+-------- -------- -------- --x-----		Fixed shading (seems to only be enabled if lighting is enabled)
 -------- -------- -------- ---x----		1 = Double-sided polygon
 -------- -------- -------- -----x--		If set, this is the last polygon
 -------- -------- -------- ------x-		Poly color, 1 = RGB, 0 = color table
--------- -------- -------- x-x-x--x		?
+-------- -------- -------- x---x--x		?
 
 0x02: 
 xxxxxxxx xxxxxxxx xxxxxxxx --------		Polygon normal Y coordinate(2.22 fixed point)
@@ -41,8 +42,8 @@ xxxxxxxx xxxxxxxx xxxxxxxx --------		Polygon normal Z coordinate(2.22 fixed poin
 xxxxxxxx xxxxxxxx xxxxxxxx --------		Color(RGB888)
 -------- -------- -------- x-------		Color disabled
 -------- -------- -------- -x------		Texture page
--------- -------- -------- --x-----		?
 -------- -------- -------- ---xxxxx		Upper 5 bits of texture U coordinate
+-------- -------- -------- --x-----		?
 
 0x05 : 
 xxxxxxxx xxxxxxxx xxxxxxxx --------		Specular color ?
@@ -94,6 +95,7 @@ public:
 	bool	DoubleSided();
 	bool	LastPoly();
 	bool	PolyColor();	// if false uses LUT from ram
+	bool	FixedShading();
 
 	//header 2
 	bool	TexUMirror();
@@ -118,7 +120,6 @@ public:
 	bool	LightEnabled();
 	bool	AlphaTest();
 	UINT8	Transparency();			// 0-255
-	bool	FixedShading();
 	bool	PolyAlpha();
 	bool	TextureAlpha();
 	bool	StencilPoly();