From 8a70d4411010c8bceff146a6811aeeab3f38fdee Mon Sep 17 00:00:00 2001
From: Sergey Lipskiy <gonetz@ngs.ru>
Date: Sat, 6 Dec 2014 00:17:03 +0600
Subject: [PATCH] Disable near plane clipping for NoN ucodes.

---
 GBI.cpp    | 11 +++++++++++
 GBI.h      |  1 +
 OpenGL.cpp |  6 ++++--
 Shaders.h  |  3 ++-
 4 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/GBI.cpp b/GBI.cpp
index 6318e7d4..866c7669 100644
--- a/GBI.cpp
+++ b/GBI.cpp
@@ -24,6 +24,7 @@
 #include "ZSort.h"
 #include "CRC.h"
 #include "Log.h"
+#include "OpenGL.h"
 #include "Debug.h"
 
 u32 last_good_ucode = (u32) -1;
@@ -170,6 +171,16 @@ void GBIInfo::_makeCurrent(MicrocodeInfo * _pCurrent)
 			case ZSortp:	ZSort_Init();	break;
 			case F3DEX2CBFD:F3DEX2CBFD_Init(); break;
 		}
+
+		if (m_pCurrent->NoN) {
+			// Disable near and far plane clipping
+			glEnable(GL_DEPTH_CLAMP);
+			// Enable Far clipping plane in vertex shader
+			glEnable(GL_CLIP_DISTANCE0);
+		} else {
+			glDisable(GL_DEPTH_CLAMP);
+			glDisable(GL_CLIP_DISTANCE0);
+		}
 	}
 }
 
diff --git a/GBI.h b/GBI.h
index 63e5ecce..2c90b1ed 100644
--- a/GBI.h
+++ b/GBI.h
@@ -691,6 +691,7 @@ struct GBIInfo
 	void loadMicrocode(u32 uc_start, u32 uc_dstart, u16 uc_dsize);
 	u32 getMicrocodeType() const {return m_pCurrent != NULL ? m_pCurrent->type : NONE;}
 	bool isHWLSupported() const;
+	bool isNoN() const { return m_pCurrent != NULL ? m_pCurrent->NoN != 0 : false; }
 
 private:
 	void _makeCurrent(MicrocodeInfo * _pCurrent);
diff --git a/OpenGL.cpp b/OpenGL.cpp
index 2656e971..761f3736 100644
--- a/OpenGL.cpp
+++ b/OpenGL.cpp
@@ -556,11 +556,13 @@ void OGLRender::_updateStates() const
 	} else {
 		if ((gSP.geometryMode & G_ZBUFFER) || gDP.otherMode.depthSource == G_ZS_PRIM) {
 			glEnable(GL_DEPTH_TEST);
-			glDisable(GL_DEPTH_CLAMP);
+			if (!GBI.isNoN())
+				glDisable(GL_DEPTH_CLAMP);
 		}
 		else {
 			glDisable(GL_DEPTH_TEST);
-			glEnable(GL_DEPTH_CLAMP);
+			if (!GBI.isNoN())
+				glEnable(GL_DEPTH_CLAMP);
 		}
 
 		if ((gDP.changed & CHANGED_RENDERMODE) > 0) {
diff --git a/Shaders.h b/Shaders.h
index ff8736bd..0213f6b9 100644
--- a/Shaders.h
+++ b/Shaders.h
@@ -120,8 +120,9 @@ static const char* vertex_shader =
 "    break;														\n"
 "  }															\n"
 "  vFogFragCoord = clamp(vFogFragCoord, 0.0, 1.0);				\n"
-"  if ((uFogUsage&255) == 1 && uFogMode == 0)							\n"
+"  if ((uFogUsage&255) == 1 && uFogMode == 0)					\n"
 "     vShadeColor.a = vFogFragCoord;							\n"
+"  gl_ClipDistance[0] = gl_Position.w - gl_Position.z;			\n"
 "}																\n"
 ;