Week7 [09/11] - [11/11]

Added Backface Culling Methods to the Model Class
Added Depth, Normal and Culled Flag Variables to the Polygon3D Class
Added Vector3D Class
Added - operator to the Vertex Class
Cleaned up Code, Adding Void to Params etc

BaseFramework.vcxproj

@@ -154,6 +154,7 @@
     <ClCompile Include="Polygon3D.cpp" />
     <ClCompile Include="Rasteriser.cpp" />
     <ClCompile Include="TransformTools.cpp" />
+    <ClCompile Include="Vector3D.cpp" />
     <ClCompile Include="Vertex.cpp" />
   </ItemGroup>
   <ItemGroup>
@@ -168,6 +169,7 @@
     <ClInclude Include="Resource.h" />
     <ClInclude Include="targetver.h" />
     <ClInclude Include="TransformTools.h" />
+    <ClInclude Include="Vector3D.h" />
     <ClInclude Include="Vertex.h" />
   </ItemGroup>
   <ItemGroup>

BaseFramework.vcxproj.filters

@@ -45,6 +45,9 @@
     <ClCompile Include="TransformTools.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="Vector3D.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="Framework.h">
@@ -83,6 +86,9 @@
     <ClInclude Include="TransformTools.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="Vector3D.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <Image Include="Rasteriser.ico">

Model.cpp

@@ -59,17 +59,17 @@ void Model::ClearPendingTransforms()
 	_pendingTransforms.clear();
 }
 
-Polygon3D Model::GetPolygon(int index)
+const Polygon3D& Model::GetPolygon(int index)
 {
 	return _polygons[index];
 }
 
-Vertex Model::GetVertex(int polygonIndex, int vertexPolygonIndex)
+const Vertex& Model::GetVertex(int polygonIndex, int vertexPolygonIndex)
 {
 	return GetVertex(GetPolygon(polygonIndex).GetIndex(vertexPolygonIndex));          
 }
 
-Vertex Model::GetVertex(int index)
+const Vertex& Model::GetVertex(int index)
 {
 	return _transformedVertices[index];
 }
@@ -96,4 +96,45 @@ void Model::DehomogenizeAllVertices()
 	{
 		currentVertex.Dehomogenize();
 	}
+}
+
+void Model::CalculateBackfaces(Camera& currentCamera)
+{
+	for (Polygon3D &currentPolygon : _polygons)
+	{
+		Vector3D vectorA = _transformedVertices[currentPolygon.GetIndex(1)] - _transformedVertices[currentPolygon.GetIndex(0)];
+		Vector3D vectorB = _transformedVertices[currentPolygon.GetIndex(2)] - _transformedVertices[currentPolygon.GetIndex(0)];
+		currentPolygon.SetNormal(Vector3D::CrossProduct(vectorA, vectorB));
+		Vector3D eyeVector = _transformedVertices[currentPolygon.GetIndex(0)] - currentCamera.GetCurrentPosition();
+
+		float dotProduct = Vector3D::DotProduct(currentPolygon.GetNormal(), eyeVector);
+		if (dotProduct < 0)
+		{
+			currentPolygon.SetCulled(true);
+		}
+		else
+		{
+			currentPolygon.SetCulled(false);
+		}
+	}
+}
+
+bool DepthCompare(Polygon3D& a, Polygon3D& b)
+{
+	return a.GetDepth() > b.GetDepth();
+}
+
+void Model::Sort()
+{
+	for (Polygon3D &currentPolygon : _polygons)
+	{
+		float zTotal = 0.0f;
+		for (int i = 0; i < currentPolygon.GetPolygonVertexCount(); i++)
+		{
+			zTotal += _transformedVertices[currentPolygon.GetIndex(i)].GetZ();
+		}
+		currentPolygon.SetDepth(zTotal / currentPolygon.GetPolygonVertexCount());
+	}
+
+	sort(_polygons.begin(), _polygons.end(), DepthCompare);
 }

Model.h

@@ -1,8 +1,11 @@
 #pragma once
-#include "Polygon3D.h"
+#include "Vector3D.h"
 #include "Vertex.h"
+#include "Polygon3D.h"
 #include "Matrix.h"
+#include "Camera.h"
 #include <vector>
+#include <algorithm>
 
 using namespace std;
 
@@ -10,29 +13,31 @@ class Model
 {
 public:
 	Model();
-
 	~Model();
 
-	const vector<Polygon3D>& GetPolygons();
-	const vector<Vertex>& GetVertices();
-	const vector<Matrix>& GetPendingTransforms();
+	const vector<Polygon3D>& GetPolygons(void);
+	const vector<Vertex>& GetVertices(void);
+	const vector<Matrix>& GetPendingTransforms(void);
 
-	size_t GetPolygonCount();
-	size_t GetVerticesCount();
-	size_t GetPendingTransformCount();
+	size_t GetPolygonCount(void);
+	size_t GetVerticesCount(void);
+	size_t GetPendingTransformCount(void);
 
 	void AddVertex(float x, float y, float z);
 	void AddPolygon(int index0, int index1, int index2);
 	void EnqueueTransform(Matrix transform);
 	void ClearPendingTransforms();
 
-	Polygon3D GetPolygon(int index);
-	Vertex GetVertex(int polygonIndex, int vertexPolygonIndex);
-	Vertex GetVertex(int index);	
+	const Polygon3D& GetPolygon(int index);
+	const Vertex& GetVertex(int polygonIndex, int vertexPolygonIndex);
+	const Vertex& GetVertex(int index);	
 
 	void ApplyTransformToLocalVertices(const Matrix& transform);
 	void ApplyTransformToTransformedVertices(const Matrix& transform);
-	void DehomogenizeAllVertices();
+	void DehomogenizeAllVertices(void);
+
+	void CalculateBackfaces(Camera& currentCamera);
+	void Sort(void);
 
 private:
 	vector<Polygon3D> _polygons;

Polygon3D.cpp

@@ -9,6 +9,7 @@ Polygon3D::Polygon3D(int index0, int index1, int index2)
 	_indices[0] = index0;
 	_indices[1] = index1;
 	_indices[2] = index2;
+	_depth = 0.0f;
 }
 
 Polygon3D::Polygon3D(const Polygon3D& other)
@@ -20,7 +21,7 @@ Polygon3D::~Polygon3D()
 {
 }
 
-size_t Polygon3D::GetPolygonVertexCount()
+size_t Polygon3D::GetPolygonVertexCount() const
 {
 	return sizeof(_indices) / sizeof(_indices[0]);
 }
@@ -30,6 +31,36 @@ int Polygon3D::GetIndex(const int index) const
 	return _indices[index];
 }
 
+void Polygon3D::SetNormal(const Vector3D& normal)
+{
+	_normal = normal;
+}
+
+Vector3D Polygon3D::GetNormal() const
+{
+	return _normal;
+}
+
+void Polygon3D::SetDepth(float depth)
+{
+	_depth = depth;
+}
+
+float Polygon3D::GetDepth() const
+{
+	return _depth;
+}
+
+void Polygon3D::SetCulled(bool culled)
+{
+	_culled = culled;
+}
+
+bool Polygon3D::GetCulled() const
+{
+	return _culled;
+}
+
 Polygon3D& Polygon3D::operator= (const Polygon3D& rhs)
 {
 	if (this != &rhs)
@@ -44,5 +75,8 @@ void Polygon3D::Copy(const Polygon3D& other)
 	for (int i = 0; i < sizeof(_indices)/sizeof(_indices[0]); i++)
 	{
 		_indices[i] = other.GetIndex(i);
+		_normal = other.GetNormal();
+		_culled = other.GetCulled();
+		_depth = other.GetDepth();
 	}
 }

Polygon3D.h

@@ -1,4 +1,6 @@
 #pragma once
+#include "Vector3D.h"
+
 class Polygon3D
 {
 public:
@@ -8,14 +10,25 @@ public:
 
 	~Polygon3D();
 
-	size_t GetPolygonVertexCount();
+	size_t GetPolygonVertexCount() const;
 
 	int GetIndex(int index) const;
+
+	void SetNormal(const Vector3D& normal);
+	Vector3D GetNormal() const;
+
+	void SetDepth(float depth);
+	float GetDepth() const;
+	void SetCulled(bool culled);
+	bool GetCulled() const;		
 	                                                          
 	Polygon3D& operator= (const Polygon3D& rhs);
 		
 private:
 	int _indices[3];
+	Vector3D _normal;
+	float _depth = 0.0f;
+	bool _culled = false;	
 
 	void Copy(const Polygon3D& other);
 };

Rasteriser.cpp

@@ -90,7 +90,9 @@ void Rasteriser::Render(const Bitmap& bitmap)
 			workingMatrix *= currentTransform;
 		}
 		currentModel.ApplyTransformToLocalVertices(workingMatrix);
+		currentModel.CalculateBackfaces(mainCamera);
 		currentModel.ApplyTransformToTransformedVertices(mainCamera.GetCurrentCameraTransformMatrix());
+		currentModel.Sort();
 		currentModel.ApplyTransformToTransformedVertices(_currentPerspectiveMatrix);
 		currentModel.DehomogenizeAllVertices();
 		currentModel.ApplyTransformToTransformedVertices(_currentViewMatrix);
@@ -139,19 +141,25 @@ void Rasteriser::DrawWireFrame(HDC hDc, Model& model)
 	vector<POINT> pointArray;
 	vector<int> sizeArray;	
 
+	int unculledPolyCount = 0;
 	int modelPolygonCount = (int) model.GetPolygonCount();
 	for (int i = 0; i < modelPolygonCount; i++)
-	{
-		int currentPolygonVertexCount = (int) model.GetPolygon(i).GetPolygonVertexCount();
-		for (int j = 0; j < currentPolygonVertexCount; j++)
+	{	
+		
+		if (!model.GetPolygon(i).GetCulled())
 		{
-			POINT newPoint;
-			newPoint.x = (long) model.GetVertex(i, j).GetX();
-			newPoint.y = (long) model.GetVertex(i, j).GetY();
-			pointArray.push_back(newPoint);
+			int currentPolygonVertexCount = (int)model.GetPolygon(i).GetPolygonVertexCount();
+			for (int j = 0; j < currentPolygonVertexCount; j++)
+			{
+				POINT newPoint;
+				newPoint.x = (long)model.GetVertex(i, j).GetX();
+				newPoint.y = (long)model.GetVertex(i, j).GetY();
+				pointArray.push_back(newPoint);
+			}
+			sizeArray.push_back(currentPolygonVertexCount);
+			unculledPolyCount++;
 		}
-		sizeArray.push_back(currentPolygonVertexCount);
 	}
 
-	PolyPolygon(hDc, pointArray.data(), sizeArray.data(), modelPolygonCount);
+	PolyPolygon(hDc, pointArray.data(), sizeArray.data(), unculledPolyCount);
 }

Rasteriser.h

@@ -29,9 +29,7 @@ private:
 
 	Matrix _currentPerspectiveMatrix;
 	Matrix _currentViewMatrix;
-	float  _currentAspectRatio;
-
-	int _rotation;
-
+	float  _currentAspectRatio = 0.0f;
+	int _rotation = 0;
 };
 

Vector3D.cpp

@@ -0,0 +1,78 @@
+#include "Vector3D.h"
+
+Vector3D::Vector3D()
+{
+	SetX(1);
+	SetY(1);
+	SetZ(1);
+}
+
+Vector3D::Vector3D(float x, float y, float z)
+{
+	SetX(x);
+	SetY(y);
+	SetZ(z);
+}
+
+Vector3D::Vector3D(const Vector3D& other)
+{
+	Copy(other);
+}
+
+Vector3D::~Vector3D()
+{
+}
+
+// Accessors
+float Vector3D::GetX() const
+{
+	return _x;
+}
+
+void Vector3D::SetX(const float x)
+{
+	_x = x;
+}
+
+float Vector3D::GetY() const
+{
+	return _y;
+}
+
+void Vector3D::SetY(const float y)
+{
+	_y = y;
+}
+
+float Vector3D::GetZ() const 
+{
+	return _z;
+}
+
+void Vector3D::SetZ(const float z)
+{
+	_z = z;
+}
+
+float Vector3D::DotProduct(const Vector3D v1, const Vector3D v2)
+{
+	return ((v1.GetX() * v2.GetX()) + (v1.GetY() * v2.GetY()) + (v1.GetZ() * v2.GetZ()));
+
+}
+
+Vector3D Vector3D::CrossProduct(const Vector3D v1, const Vector3D v2)
+{
+	return Vector3D((v1.GetY() * v2.GetZ()) - (v1.GetZ() * v2.GetY()), (v1.GetZ() * v2.GetX()) - (v1.GetX() * v2.GetZ()), (v1.GetX() * v2.GetY()) - (v1.GetY() * v2.GetX()));
+}
+
+const Vector3D Vector3D::operator+ (const Vector3D& rhs) const
+{
+	return Vector3D(_x + rhs.GetX(), _y + rhs.GetY(), _z + rhs.GetZ());
+}
+
+void Vector3D::Copy(const Vector3D& other)
+{
+	_x = other.GetX();
+	_y = other.GetY();
+	_z = other.GetZ();
+}

Vector3D.h

@@ -0,0 +1,32 @@
+#pragma once
+
+class Vector3D
+{
+public:
+	Vector3D();
+	Vector3D(float x, float y, float z);
+	Vector3D(const Vector3D& other);
+
+	~Vector3D();
+
+	// Accessors
+	float GetX() const;
+	void SetX(const float x);
+	float GetY() const;
+	void SetY(const float y);
+	float GetZ() const;
+	void SetZ(const float z);
+
+	static float DotProduct(const Vector3D v1, const Vector3D v2);
+	static Vector3D CrossProduct(const Vector3D v1, const Vector3D v2);
+
+	const Vector3D operator+ (const Vector3D& rhs) const;
+
+private:
+	float _x;
+	float _y;
+	float _z;
+
+	void Copy(const Vector3D& other);
+};
+

Vertex.cpp

@@ -88,6 +88,11 @@ Vertex& Vertex::operator=(const Vertex& rhs)
 	return *this;
 }
 
+const Vector3D Vertex::operator-(const Vertex& rhs) const
+{		
+	return Vector3D(rhs.GetX() - GetX(), rhs.GetY() - GetY(), rhs.GetZ() - GetZ());
+}
+
 // The const at the end of the declaraion for '==" indicates that this operation does not change
 // any of the member variables in this class.
 

Vertex.h

@@ -1,10 +1,12 @@
 #pragma once
+#include "Vector3D.h"
+
 class Vertex
 {
 public:
 	Vertex();
-	Vertex(const float x, const float y, const float z);
-	Vertex(const float x, const float y, const float z, const float w);
+	Vertex(float x, float y, float z);
+	Vertex(float x, float y, float z, float w);
 	Vertex(const Vertex& other);
 
 	// Accessors
@@ -25,6 +27,7 @@ public:
 	bool operator== (const Vertex& rhs) const;
 
 	const Vertex operator+ (const Vertex& rhs) const;
+	const Vector3D operator- (const Vertex& rhs) const;
 
 private:
 	float _x;