From f43baa8b220f9600752173c8e4ba746d3aa5490c Mon Sep 17 00:00:00 2001
From: Lightling <contactlightling@gmail.com>
Date: Sat, 15 Jan 2022 15:12:30 -0500
Subject: [PATCH] add more Mesh code

---
 Mesh.cpp | 55 ++++++++++++++++++++++++++++++++++++++++++++++++++++---
 Mesh.h   | 22 ++++++++++++----------
 2 files changed, 64 insertions(+), 13 deletions(-)

diff --git a/Mesh.cpp b/Mesh.cpp
index e2b0818..0c80d8b 100644
--- a/Mesh.cpp
+++ b/Mesh.cpp
@@ -1,28 +1,77 @@
 #include "Mesh.h"
 
+using namespace DirectX;
+
 Mesh::Mesh(Vertex* _vertices, int _vertexCount, unsigned int* _indices, int _indexCount, Microsoft::WRL::ComPtr<ID3D11Device> _device, Microsoft::WRL::ComPtr<ID3D11DeviceContext> _context)
 {
+	// Create the VERTEX BUFFER description
+	D3D11_BUFFER_DESC vbd = {};
+	vbd.Usage = D3D11_USAGE_IMMUTABLE;
+	vbd.ByteWidth = sizeof(Vertex) * _vertexCount;
+	vbd.BindFlags = D3D11_BIND_VERTEX_BUFFER;
+	vbd.CPUAccessFlags = 0;
+	vbd.MiscFlags = 0;
+	vbd.StructureByteStride = 0;
+
+	// Create the proper struct to hold the initial vertex data
+	// - This is how we put the initial data into the buffer
+	D3D11_SUBRESOURCE_DATA initialVertexData = {};
+	initialVertexData.pSysMem = _vertices;
+
+	// Actually create the buffer with the initial data
+	_device->CreateBuffer(&vbd, &initialVertexData, bufferVertex.GetAddressOf());
+
+	// Create the INDEX BUFFER description
+	D3D11_BUFFER_DESC ibd = {};
+	ibd.Usage = D3D11_USAGE_IMMUTABLE;
+	ibd.ByteWidth = sizeof(unsigned int) * _indexCount;
+	ibd.BindFlags = D3D11_BIND_INDEX_BUFFER;
+	ibd.CPUAccessFlags = 0;
+	ibd.MiscFlags = 0;
+	ibd.StructureByteStride = 0;
+
+	// Create the proper struct to hold the initial index data
+	D3D11_SUBRESOURCE_DATA initialIndexData = {};
+	initialIndexData.pSysMem = _indices;
+	countIndex = _indexCount;
+
+	// Create the buffer with the initial data
+	_device->CreateBuffer(&ibd, &initialIndexData, bufferIndex.GetAddressOf());
+
+	deviceContext = _context;
 }
 
 Mesh::~Mesh()
 {
+	// Because this is using ComPtr, destructor for now is unnecessary
 }
 
 void Mesh::Draw()
 {
+	// Set buffers in the input assembler
+	UINT stride = sizeof(Vertex);
+	UINT offset = 0;
+	deviceContext->IASetVertexBuffers(0, 1, bufferVertex.GetAddressOf(), &stride, &offset);
+	deviceContext->IASetIndexBuffer(bufferIndex.Get(), DXGI_FORMAT_R32_UINT, 0);
+
+	// Do the actual drawing
+	deviceContext->DrawIndexed(
+		countIndex, // The number of indices to use (we could draw a subset if we wanted)
+		0,          // Offset to the first index we want to use
+		0);         // Offset to add to each index when looking up vertices
 }
 
 Microsoft::WRL::ComPtr<ID3D11Buffer>* Mesh::GetVertexBuffer()
 {
-	return nullptr;
+	return &bufferVertex;
 }
 
 Microsoft::WRL::ComPtr<ID3D11Buffer>* Mesh::GetIndexBuffer()
 {
-	return nullptr;
+	return &bufferIndex;
 }
 
 int Mesh::GetIndexCount()
 {
-	return 0;
+	return countIndex;
 }
diff --git a/Mesh.h b/Mesh.h
index c07fb31..8d118cd 100644
--- a/Mesh.h
+++ b/Mesh.h
@@ -7,20 +7,22 @@
 class Mesh
 {
 private:
-	Microsoft::WRL::ComPtr<ID3D11Buffer>  bufferVertex;
-	Microsoft::WRL::ComPtr<ID3D11Buffer>  bufferIndex;
+	Microsoft::WRL::ComPtr<ID3D11Buffer>            bufferVertex;
+	Microsoft::WRL::ComPtr<ID3D11Buffer>            bufferIndex;
+	Microsoft::WRL::ComPtr<ID3D11DeviceContext>     deviceContext;
+	int                                             countIndex;
 public:
 	Mesh(
-		Vertex*       _vertices,
-		int           _vertexCount,
-		unsigned int* _indices,
-		int           _indexCount,
+		Vertex*                                     _vertices,
+		int                                         _vertexCount,
+		unsigned int*                               _indices,
+		int                                         _indexCount,
 		Microsoft::WRL::ComPtr<ID3D11Device>        _device,
 		Microsoft::WRL::ComPtr<ID3D11DeviceContext> _context);
 	~Mesh();
 
-	void                                  Draw();
-	Microsoft::WRL::ComPtr<ID3D11Buffer>* GetVertexBuffer();
-	Microsoft::WRL::ComPtr<ID3D11Buffer>* GetIndexBuffer();
-	int                                   GetIndexCount();
+	void                                            Draw();
+	Microsoft::WRL::ComPtr<ID3D11Buffer>*           GetVertexBuffer();
+	Microsoft::WRL::ComPtr<ID3D11Buffer>*           GetIndexBuffer();
+	int                                             GetIndexCount();
 };