Merge pull request #101 from gm-matthew/lod-and-blending

Add LOD switching and blending out culling nodes

Src/Graphics/New3D/Model.cpp

@@ -4,12 +4,13 @@ namespace New3D {
 
 NodeAttributes::NodeAttributes()
 {
-	currentTexOffsetX	= 0;
-	currentTexOffsetY	= 0;
-	currentPage			= 0;
-	currentClipStatus	= Clip::INTERCEPT;
-	currentModelScale	= 1.0f;
-	currentModelAlpha	= 1.0;
+	currentTexOffsetX		= 0;
+	currentTexOffsetY		= 0;
+	currentPage				= 0;
+	currentClipStatus		= Clip::INTERCEPT;
+	currentModelScale		= 1.0f;
+	currentModelAlpha		= 1.0;
+	currentDisableCulling	= false;
 }
 
 bool NodeAttributes::Push()
@@ -23,12 +24,13 @@ bool NodeAttributes::Push()
 		return false;
 	}
 
-	na.page			= currentPage;
-	na.texOffsetX	= currentTexOffsetX;
-	na.texOffsetY	= currentTexOffsetY;
-	na.clip			= currentClipStatus;
-	na.modelScale	= currentModelScale;
-	na.modelAlpha	= currentModelAlpha;
+	na.page				= currentPage;
+	na.texOffsetX		= currentTexOffsetX;
+	na.texOffsetY		= currentTexOffsetY;
+	na.clip				= currentClipStatus;
+	na.modelScale		= currentModelScale;
+	na.modelAlpha		= currentModelAlpha;
+	na.disableCulling	= currentDisableCulling;
 
 	m_vecAttribs.emplace_back(na);
 
@@ -43,12 +45,13 @@ bool NodeAttributes::Pop()
 
 	auto &last = m_vecAttribs.back();
 
-	currentPage			= last.page;
-	currentTexOffsetX	= last.texOffsetX;
-	currentTexOffsetY	= last.texOffsetY;
-	currentClipStatus	= last.clip;
-	currentModelScale	= last.modelScale;
-	currentModelAlpha	= last.modelAlpha;
+	currentPage				= last.page;
+	currentTexOffsetX		= last.texOffsetX;
+	currentTexOffsetY		= last.texOffsetY;
+	currentClipStatus		= last.clip;
+	currentModelScale		= last.modelScale;
+	currentModelAlpha		= last.modelAlpha;
+	currentDisableCulling	= last.disableCulling;
 
 	m_vecAttribs.pop_back();
 
@@ -62,12 +65,13 @@ bool NodeAttributes::StackLimit()
 
 void NodeAttributes::Reset()
 {
-	currentPage			= 0;
-	currentTexOffsetX	= 0;
-	currentTexOffsetY	= 0;
-	currentClipStatus	= Clip::INTERCEPT;
-	currentModelScale	= 1.0f;
-	currentModelAlpha	= 1.0f;
+	currentPage				= 0;
+	currentTexOffsetX		= 0;
+	currentTexOffsetY		= 0;
+	currentClipStatus		= Clip::INTERCEPT;
+	currentModelScale		= 1.0f;
+	currentModelAlpha		= 1.0f;
+	currentDisableCulling	= false;
 
 	m_vecAttribs.clear();
 }

Src/Graphics/New3D/Model.h

@@ -243,6 +243,7 @@ public:
 	Clip currentClipStatus;
 	float currentModelScale;
 	float currentModelAlpha;
+	bool currentDisableCulling;
 
 private:
 
@@ -254,6 +255,7 @@ private:
 		Clip clip;
 		float modelScale;
 		float modelAlpha;	// from culling node
+		bool disableCulling;
 	};
 	std::vector<NodeAttribs> m_vecAttribs;
 };

Src/Graphics/New3D/New3D.cpp

@@ -559,11 +559,12 @@ bool CNew3D::DrawModel(UINT32 modelAddr)
 			-------- -------- -------- -----x--	Valid color table
 			-------- -------- -------- ------xx	Node type(0 = viewport, 1 = root node, 2 = culling node)
 
-	0x01, 0x02 only present on Step 2 +
+	0x01, 0x02 only present on Step 1.5+
 
 	0x01:   xxxxxxxx xxxxxxxx xxxxxxxx xxxxxx--	Model scale (float32) last 2 bits are control words
 			-------- -------- -------- ------x- Disable culling
 			-------- -------- -------- -------x	Valid model scale
+
 	0x02 :	-------- -------- x------- --------	Texture replace
 			-------- -------- -x------ --------	Switch bank
 			-------- -------- --xxxxxx x-------	X offset
@@ -595,7 +596,7 @@ void CNew3D::DescendCullingNode(UINT32 addr)
 {
 	enum class NodeType { undefined = -1, viewport = 0, rootNode = 1, cullingNode = 2 };
 
-	const UINT32	*node, *lodTable;
+	const UINT32	*node, *lodPtr;
 	UINT32			matrixOffset, child1Ptr, sibling2Ptr;
 	BBox			bbox;
 	UINT16			uCullRadius;
@@ -645,10 +646,11 @@ void CNew3D::DescendCullingNode(UINT32 addr)
 
 	if (!m_offset) {		// Step 1.5+
 
-		float modelScale = Util::Uint32AsFloat(node[1]);
-		if (modelScale > std::numeric_limits<float>::min()) {
-			m_nodeAttribs.currentModelScale = modelScale;
-		}
+		if (node[0x01] & 1)
+			m_nodeAttribs.currentModelScale = Util::Uint32AsFloat(node[0x01] & ~3);	// mask out control bits
+
+		if (node[0x01] & 2)
+			m_nodeAttribs.currentDisableCulling = true;
 
 		// apply texture offsets, else retain current ones
 		if ((node[0x02] & 0x8000))	{
@@ -660,8 +662,6 @@ void CNew3D::DescendCullingNode(UINT32 addr)
 		}
 	}
 
-	m_nodeAttribs.currentModelAlpha = 1;	// TODO fade out if required
-
 	// Apply matrix and translation
 	m_modelMat.PushMatrix();
 
@@ -705,19 +705,42 @@ void CNew3D::DescendCullingNode(UINT32 addr)
 		}
 	}
 
-	if (m_nodeAttribs.currentClipStatus != Clip::OUTSIDE && fCullRadius > R3DFloat::Pro16BitFltMin) {
+	float LODscale = fBlendRadius * m_nodeAttribs.currentModelScale / std::abs(m_modelMat.currentMatrix[14]);
+
+	LODFeatureType lodTableEntry = m_LODBlendTable->table[lodTablePointer];
+
+	if (m_nodeAttribs.currentDisableCulling)
+	{
+		m_nodeAttribs.currentModelAlpha = 1.0f;
+	}
+	else
+	{
+		float nodeAlpha = lodTableEntry.lod[3].blendFactor * (LODscale - lodTableEntry.lod[3].deleteSize);
+		nodeAlpha = std::clamp(nodeAlpha, 0.0f, 1.0f);
+		m_nodeAttribs.currentModelAlpha *= nodeAlpha;	// alpha of each node multiples by the alpha of its parent
+	}
+
+	if (m_nodeAttribs.currentClipStatus != Clip::OUTSIDE && m_nodeAttribs.currentModelAlpha > 0.0f) {
 
 		// Descend down first link
 		if ((node[0x00] & 0x08))	// 4-element LOD table
 		{
-			lodTable = TranslateCullingAddress(child1Ptr);
+			lodPtr = TranslateCullingAddress(child1Ptr);
 
-			if (NULL != lodTable) {
+			// determine which LOD to use; we do not currently blend between LODs
+			int modelLOD;
+			for (modelLOD = 0; modelLOD < 3; modelLOD++)
+			{
+				if (LODscale >= lodTableEntry.lod[modelLOD].deleteSize)
+					break;
+			}
+
+			if (NULL != lodPtr) {
 				if ((node[0x03 - m_offset] & 0x20000000)) {
-					DescendCullingNode(lodTable[0] & 0xFFFFFF);
+					DescendCullingNode(lodPtr[modelLOD] & 0xFFFFFF);
 				}
 				else {
-					DrawModel(lodTable[0] & 0xFFFFFF);	//TODO
+					DrawModel(lodPtr[modelLOD] & 0xFFFFFF);
 				}
 			}
 		}

Src/Graphics/New3D/R3DData.h

@@ -3,8 +3,8 @@
 
 struct LOD
 {
-	float startRange;		// possibly specified as angles also, yeah who knows >_<
-	float deleteRange;
+	float deleteSize;
+	float blendFactor;
 };
 
 struct LODFeatureType