DirectX11 3D - 기초 2D 도형 뿌리기 (버텍스버퍼,인덱스 버퍼,셰이더 ,버텍스 레이아웃, DrawIndexed)

bool DrawTestTriangle()
	{
		namespace wrl = Microsoft::WRL;
		HRESULT hr = S_OK;
		struct Vertex
		{
			struct {
				float x;
				float y;
			}pos;

			struct {
				unsigned char r;
				unsigned char g;
				unsigned char b;
				unsigned char a;
			}color;
		};
		const Vertex vertices[] =
		{
			{ 0.0f,0.5f,255.0,0,0 },
			{ 0.5f,-0.5f,0,255.0,0 },
			{ -0.5f,-0.5f,0,0,255,0 },
			{ -0.3f,0.3f, 0,255,0,0 },
			{ 0.3f,0.3f,0,0,255,0 },
			{ 0.0f,-0.8f,255,0,0,0 },
		};
		wrl::ComPtr<ID3D11Buffer> pVertexBuffer;
		D3D11_BUFFER_DESC bd;
		bd.BindFlags = D3D11_BIND_VERTEX_BUFFER;
		bd.Usage = D3D11_USAGE_DEFAULT;
		bd.CPUAccessFlags = 0u;
		bd.MiscFlags = 0u;
		bd.ByteWidth = sizeof(vertices);
		bd.StructureByteStride = sizeof(Vertex);

		D3D11_SUBRESOURCE_DATA sd;
		ZeroMemory(&sd,sizeof(D3D11_SUBRESOURCE_DATA));
		sd.pSysMem = vertices;
		hr=g_pd3dDevice->CreateBuffer(&bd, &sd, pVertexBuffer.GetAddressOf());
		if (FAILED(hr)) return false;
		const UINT stride = sizeof(Vertex);
		const UINT offset = 0u;
		//배열이 들어갈수있다.
		m_pImmediateContext->IASetVertexBuffers(0u, 1u, pVertexBuffer.GetAddressOf(), &stride, &offset);

		const unsigned short indices[] =
		{
			0,1,2,
			0,2,3,
			0,4,1,
			2,1,5,
		};
		wrl::ComPtr<ID3D11Buffer>pIndexBuffer;
		D3D11_BUFFER_DESC ibd = {};
		ibd.BindFlags = D3D11_BIND_INDEX_BUFFER;
		ibd.Usage = D3D11_USAGE_DEFAULT;
		ibd.CPUAccessFlags = 0u;
		ibd.MiscFlags = 0u;
		ibd.ByteWidth = sizeof(indices);
		ibd.StructureByteStride = sizeof(unsigned short);
		D3D11_SUBRESOURCE_DATA isd;
		isd.pSysMem = indices;
		hr = g_pd3dDevice->CreateBuffer(&ibd, &isd, pIndexBuffer.GetAddressOf());
		if (FAILED(hr)) return false;

		m_pImmediateContext->IASetIndexBuffer(pIndexBuffer.Get(),DXGI_FORMAT_R16_UINT,0);  

		wrl::ComPtr<ID3DBlob> pBlob;

		//1. 픽셀 셰이더 생성
		wrl::ComPtr<ID3D11PixelShader> pPixelShader;
		hr=D3DReadFileToBlob(L"PixelShader.cso", pBlob.GetAddressOf());
		if (FAILED(hr)) return false;
		hr = g_pd3dDevice->CreatePixelShader(pBlob->GetBufferPointer(),
			pBlob->GetBufferSize(), nullptr, pPixelShader.GetAddressOf());
		if (FAILED(hr)) return false;

		//2. 바인드 픽셀 셰이더
		m_pImmediateContext->PSSetShader(pPixelShader.Get(), nullptr, 0u);

		//3. 버텍스 셰이더 생성
		wrl::ComPtr<ID3D11VertexShader> pVertexShader;
		hr=D3DReadFileToBlob(L"VertexShader.cso", pBlob.GetAddressOf());
		if (FAILED(hr)) return false;
		hr = g_pd3dDevice->CreateVertexShader(pBlob->GetBufferPointer(),
			pBlob->GetBufferSize(), nullptr, pVertexShader.GetAddressOf());
		if (FAILED(hr)) return false;

		//4. 바인드 버텍스 셰이더
		m_pImmediateContext->VSSetShader(pVertexShader.Get(), nullptr, 0u);

		//5. Input 버텍스 레이아웃 (2D 위치만)
		wrl::ComPtr<ID3D11InputLayout> pInputLayout;

		const D3D11_INPUT_ELEMENT_DESC layout[] =
		{
			{"POSITION",0,DXGI_FORMAT_R32G32_FLOAT,0,0,D3D11_INPUT_PER_VERTEX_DATA, 0},
			{"COLOR",0,DXGI_FORMAT_R8G8B8A8_UNORM,0,8,D3D11_INPUT_PER_VERTEX_DATA, 0}
		};
		hr = g_pd3dDevice->CreateInputLayout(layout, _countof(layout),
			pBlob->GetBufferPointer(),
			pBlob->GetBufferSize(),
			pInputLayout.GetAddressOf()
		);
		if (FAILED(hr)) return false;

		//6. 바인드 버텍스 레이아웃
		m_pImmediateContext->IASetInputLayout(pInputLayout.Get());

		m_pImmediateContext->IASetPrimitiveTopology(D3D11_PRIMITIVE_TOPOLOGY_TRIANGLELIST);

		m_pImmediateContext->DrawIndexed((UINT)(std::size(indices)),0u,0u);
		
		return true;
	};
//vs
struct VS_OUTPUT
{
	float3 color : Color;
	float4 pos : SV_Position; //no user set name
};

VS_OUTPUT main(float2 pos : POSITION, float3 color : Color)
{
	VS_OUTPUT Output;
	Output.pos = float4(pos.x, pos.y, 0.0f, 1.0f);;
	Output.color = color;
	return Output;
}

//ps
struct PS_INPUT
{
};

float4 main(float3 color : Color) : SV_Target
{
	return float4(color,1.0f);
}

 

 

버텍스버퍼,인덱스 버퍼을 생성, 바인드->

PS, VS 셰이더 생성, 바인드-> 버텍스 레이아웃 생성 바인드

인덱스로 Draw 하기까지의 과정이다.

 

다렉을 사용해 한 함수로만 삼각형을 뿌리는 걸 만들어봤다.

전체적인 흐름을 읽기에 편하기 때문이다.

 

덕분에 애매하게 넘어갔던 것들을 이해할수 있었다.

 

특히, ID3D11InputLayout, 시멘틱스와 버텍스 셰이더의 입력셰이더

 

시멘틱스를 비교함으로 데이터를 타당한지 검증하는 작업이나

 

셰이더에서 전역변수로 사용하기 위해 상수버퍼가 필요하는것 등 이해하게 되었다.