[포트폴리오 구조] AlphaBlend 적용 방법

SpriteComponent이던, StaticMeshComponent이던 Material을 갖고 있다. Material은 멤버로 아래와 같은 녀석들을 갖고 있다.

    CSharedPtr<CGraphicShader>  m_Shader;
    std::vector<MaterialTextureInfo>    m_TextureInfo;
    Vector4     m_BaseColor;
    float       m_Opacity;
    class CMaterialConstantBuffer* m_CBuffer;
    CSharedPtr<class CRenderState>  m_RenderStateArray[(int)RenderState_Type::Max];

enum class RenderState_Type
{
	Blend,
	Rasterizer,
	DepthStencil,
	Max
};

여기서 m_RenderStateArray에 RenderState_Type::Blend에 미리 생성해둔 "AlphaBlend"라는 BlendState 클래스를 할당해줘야 한다. 그러면 Material의 Render에서 m_RenderStateArray에 BlendState가 들어있으면 그 BlendState를 아래와 같이 Set해준다.

void CMaterial::Render()
{
	// 말 그대로 완성된 m_VS, m_Ps등을 SetShader해주는 함수
	if (m_Shader)
		m_Shader->SetShader();

	// 출력 직전에 m_BaseColor 갱신 후
	// 상수버퍼에 갱신한 m_BaseColor로 업데이트
	if (m_CBuffer)
	{
		m_CBuffer->SetBaseColor(m_BaseColor);
		m_CBuffer->SetOpacity(m_Opacity);

		m_CBuffer->UpdateCBuffer();
	}

	for (int i = 0; i < (int)RenderState_Type::Max; ++i)
	{
		if (m_RenderStateArray[i])
			m_RenderStateArray[i]->SetState();
	}

	size_t	Size = m_TextureInfo.size();

	for (size_t i = 0; i < Size; ++i)
	{
		// Texture에 대한 Resource view를 Set해주는 함수
		m_TextureInfo[i].Texture->SetShader(m_TextureInfo[i].Register, m_TextureInfo[i].ShaderType, 0);
	}
}

void CBlendState::SetState()
{
	CDevice::GetInst()->GetContext()->OMGetBlendState((ID3D11BlendState**)&m_PrevState, m_PrevBlendFactor, &m_PrevSampleMask);

	CDevice::GetInst()->GetContext()->OMSetBlendState((ID3D11BlendState*)m_State, m_BlendFactor, m_SampleMask);
}

SpriteComponent나 StaticMeshComponent가 SetTransParency(true)를 호출하면 Material이 미리 만들어둔 "AlphaBlend"라는 이름의 BlendState를 출력병합기에 Set해줄것이다.

void CSpriteComponent::SetTransparency(bool Enable)
{
	m_Material->SetTransparency(Enable);
}

void CMaterial::SetTransparency(bool Enable)
{
	if (Enable)
		m_RenderStateArray[(int)RenderState_Type::Blend] = CRenderManager::GetInst()->FindRenderState("AlphaBlend");
}

위에서 언급했듯이 "AlphaBlend"라는 이름의 BlendState 클래스는 RenderStateManager에서 이미 만들어서 m_mapRenderState에 넣어뒀다.

bool CRenderStateManager::Init()
{
	AddBlendInfo("AlphaBlend");
	CreateBlendState("AlphaBlend", true, false);

	return true;
}

void CRenderStateManager::AddBlendInfo(const std::string& Name, 
	bool BlendEnable, D3D11_BLEND SrcBlend,
	D3D11_BLEND DestBlend, D3D11_BLEND_OP BlendOp, D3D11_BLEND SrcBlendAlpha,
	D3D11_BLEND DestBlendAlpha, D3D11_BLEND_OP BlendOpAlpha, 
	UINT8 RenderTargetWriteMask)
{
	CBlendState* State = (CBlendState*)FindRenderState(Name);

	if (!State)
	{
		State = new CBlendState;

		State->SetName(Name);

		m_mapRenderState.insert(std::make_pair(Name, State));
	}

	State->AddBlendInfo(BlendEnable, SrcBlend, DestBlend, BlendOp,
		SrcBlendAlpha, DestBlendAlpha, BlendOpAlpha, RenderTargetWriteMask);
}

bool CRenderStateManager::CreateBlendState(const std::string& Name, bool AlphaToCoverageEnable,
	bool IndependentBlendEnable)
{
	CBlendState* State = (CBlendState*)FindRenderState(Name);

	if (!State)
		return false;

	if (!State->CreateState(AlphaToCoverageEnable, IndependentBlendEnable))
	{
		SAFE_RELEASE(State);
		return false;
	}

	return true;
}

void CBlendState::AddBlendInfo(bool BlendEnable, D3D11_BLEND SrcBlend, D3D11_BLEND DestBlend, 
	D3D11_BLEND_OP BlendOp, D3D11_BLEND SrcBlendAlpha, D3D11_BLEND DestBlendAlpha, D3D11_BLEND_OP BlendOpAlpha,
	UINT8 RenderTargetWriteMask)
{
	D3D11_RENDER_TARGET_BLEND_DESC	Desc = {};

	Desc.BlendEnable = BlendEnable;
	Desc.SrcBlend = SrcBlend;
	Desc.DestBlend = DestBlend;
	Desc.BlendOp = BlendOp;
	Desc.SrcBlendAlpha = SrcBlendAlpha;
	Desc.DestBlendAlpha = DestBlendAlpha;
	Desc.BlendOpAlpha = BlendOpAlpha;
	Desc.RenderTargetWriteMask = RenderTargetWriteMask;

	m_vecDesc.push_back(Desc);
}

bool CBlendState::CreateState(bool AlphaToCoverageEnable, bool IndependentBlendEnable)
{
	if (m_vecDesc.empty())
		return false;

	D3D11_BLEND_DESC	Desc = {};

	Desc.AlphaToCoverageEnable = AlphaToCoverageEnable;
	Desc.IndependentBlendEnable = IndependentBlendEnable;

	memcpy(Desc.RenderTarget, &m_vecDesc[0], sizeof(D3D11_RENDER_TARGET_BLEND_DESC) * m_vecDesc.size());

	if (FAILED(CDevice::GetInst()->GetDevice()->CreateBlendState(&Desc, (ID3D11BlendState**)&m_State)))
		return false;

	return true;
}