Method StarField

Engine/source/EtRendering/PlanetTech/StarField.cpp:16–61

StarField::StarField(core::HashString const assetId)
{
	AssetPtr<core::StubData> jsonDbText = core::ResourceManager::Instance()->GetAssetData<core::StubData>(assetId);

	core::JSON::Parser parser = core::JSON::Parser(std::string(jsonDbText->GetText(), jsonDbText->GetLength()));
	core::JSON::Object* root = parser.GetRoot();

	uint32 starCount = 0;

	core::JSON::Array* jstarArray = (*root)["stars"]->arr();
	for (auto jStar : jstarArray->value)
	{
		vec4 star;
		if (core::JSON::ArrayVector(jStar, star) && m_MaxStars == 0 ? true : starCount < m_MaxStars)
		{
			//HYG coordinates are in a different coordinate system Z up Y forward 
			//first component is magnitude
			//output [X, Z, Y, mag]
			m_Stars.push_back(vec4(star[1], star[3], star[2], star[0]));
			starCount++;
		}
	}

	I_GraphicsApiContext* const api = Viewport::GetCurrentApiContext();

	m_pShader = core::ResourceManager::Instance()->GetAssetData<ShaderData>(core::HashString("FwdStarField.glsl"));
	m_pSprite = core::ResourceManager::Instance()->GetAssetData<TextureData>(core::HashString("starSprite.png"));

	//Generate buffers and arrays
	m_VAO = api->CreateVertexArray();
	m_VBO = api->CreateBuffer();

	//bind
	api->BindVertexArray(m_VAO);
	api->BindBuffer(E_BufferType::Vertex, m_VBO);

	//set data and attributes
	api->SetBufferData(E_BufferType::Vertex, m_Stars.size() * sizeof(vec4), m_Stars.data(), E_UsageHint::Dynamic);

	api->SetVertexAttributeArrayEnabled(0, true);
	api->DefineVertexAttributePointer(0, 4, E_DataType::Float, false, sizeof(vec4), 0);

	//unbind
	api->BindBuffer(E_BufferType::Vertex, 0);
	api->BindVertexArray(0);
}

StarField::~StarField()
{