Rewrite projection maths based upon previously unknown viewport values. The previous values used roughly worked as the normals for frustum planes. Perhaps they were only used for culling and not actually rendering, as sometimes the values don't work correctly.

Src/Graphics/New3D/New3D.cpp

@@ -757,26 +757,30 @@ void CNew3D::RenderViewport(UINT32 addr)
 
 		m_LODBlendTable = (LODBlendTable*)TranslateCullingAddress(vpnode[0x17] & 0xFFFFFF);
 
-		vp->angle_left		= -atan2(*(float *)&vpnode[12],  *(float *)&vpnode[13]);
+		/*
-		vp->angle_right		=  atan2(*(float *)&vpnode[16], -*(float *)&vpnode[17]);
+		vp->angle_left		= -atan2(*(float *)&vpnode[12],  *(float *)&vpnode[13]);	// These values work out as the normals for the clipping planes.
-		vp->angle_top		=  atan2(*(float *)&vpnode[14],  *(float *)&vpnode[15]);
+		vp->angle_right		=  atan2(*(float *)&vpnode[16], -*(float *)&vpnode[17]);	// Sometimes these values (dirt devils,lost world) are totally wrong
-		vp->angle_bottom	= -atan2(*(float *)&vpnode[18], -*(float *)&vpnode[19]);
+		vp->angle_top		=  atan2(*(float *)&vpnode[14],  *(float *)&vpnode[15]);	// and don't work for the frustum values exactly.
+		vp->angle_bottom	= -atan2(*(float *)&vpnode[18], -*(float *)&vpnode[19]);	// Perhaps they are just used for culling and not rendering.
+		*/
 
-		// I don't really know what these paramaters are for. They are derived from the view angles somehow.
+		float cv = *(float *)&vpnode[0x8];	// 1/tan(left-right)
-		// In the sdk it's they are someting like (1/tan(left)-tan(right)) * tan(left)
+		float cw = *(float *)&vpnode[0x9];	// 1/tan(top-bottom)
-		// But we know when left=right the value is always 0.5. Any other value and we have off-axis projection
+		float io = *(float *)&vpnode[0xa];	// top / bottom (ratio) - ish
-		// My theory is, the h/w is using these values to actually set the frustum planes angles
+		float jo = *(float *)&vpnode[0xb];	// left / right (ratio)
-		// The above vpnode[12], vpnode[13] actually work as a normal vector for the clipping planes (used for culling)
-		// I think in lost world and dirt devils, there is a missmatch between the computed plane normals, and the view angles
-		if (*(float *)&vpnode[0xa] == 0.5f) {
-			vp->angle_bottom = -vp->angle_top;
-		}
 
-		if (*(float *)&vpnode[0xb] == 0.5f) {
+		float left		= (1.0f / cv) * (0.0f - jo);
-			vp->angle_right = -vp->angle_left;
+		float right		= (1.0f / cv) * (1.0f - jo);
-		}
+		float bottom	= (1.0f / cw) * (0.0f - io);
+		float top		= (1.0f / cw) * (1.0f - io);
+
+		vp->angle_left		= std::atan(left);		// probably could skip atan
+		vp->angle_right		= std::atan(right);
+		vp->angle_bottom	= std::atan(bottom);
+		vp->angle_top		= std::atan(top);
 
 		// calculate the frustum shape, near/far pair are dummy values
+
 		CalcViewport(vp, 1, 1000);
 
 		// calculate frustum planes

VS2008/Supermodel.vcxproj

@@ -93,7 +93,7 @@
     <ClCompile>
       <Optimization>Disabled</Optimization>
       <AdditionalIncludeDirectories>..\Src;..\Src\OSD;..\Src\OSD\SDL;..\Src\OSD\Windows;..\Libraries\zlib-1.2.4;..\Libraries\SDL-1.2.14\include;$(DXSDK_DIR)\Include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <PreprocessorDefinitions>SUPERMODEL_WIN32;INLINE=static __inline;_MBCS;_CRT_SECURE_NO_WARNINGS;GLEW_STATIC;NET_BOARD</PreprocessorDefinitions>
+      <PreprocessorDefinitions>SUPERMODEL_WIN32;INLINE=static __inline;_MBCS;_CRT_SECURE_NO_WARNINGS;GLEW_STATIC</PreprocessorDefinitions>
       <MinimalRebuild>true</MinimalRebuild>
       <BasicRuntimeChecks>EnableFastChecks</BasicRuntimeChecks>
       <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
@@ -157,7 +157,7 @@ xcopy /D /Y "$(ProjectDir)\SDL\$(Platform)\$(Configuration)\SDL.dll" "$(TargetDi
       <Optimization>Full</Optimization>
       <IntrinsicFunctions>false</IntrinsicFunctions>
       <AdditionalIncludeDirectories>..\Src;..\Src\OSD;..\Src\OSD\SDL;..\Src\OSD\Windows;..\Libraries\zlib-1.2.4;..\Libraries\SDL-1.2.14\include;$(DXSDK_DIR)\Include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <PreprocessorDefinitions>SUPERMODEL_WIN32;INLINE=static __inline;_MBCS;_CRT_SECURE_NO_WARNINGS;GLEW_STATIC;NET_BOARD</PreprocessorDefinitions>
+      <PreprocessorDefinitions>SUPERMODEL_WIN32;INLINE=static __inline;_MBCS;_CRT_SECURE_NO_WARNINGS;GLEW_STATIC</PreprocessorDefinitions>
       <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
       <FunctionLevelLinking>true</FunctionLevelLinking>
       <PrecompiledHeader />