Effect3D.cpp

# include <Siv3D.hpp>

struct Particle3D : IEffect
{
	Vec3 m_pos;

	Mesh m_billboardMesh;

	Texture m_texture;

	std::shared_ptr<BasicCamera3D> m_pCamera;

	explicit Particle3D(const Vec3& pos, const Mesh& billboardMesh, const Texture& texture, const std::shared_ptr<BasicCamera3D>& pCamera)
		: m_pos{ pos }
		, m_billboardMesh{ billboardMesh }
		, m_texture{ texture }
		, m_pCamera{ pCamera } {}

	bool update(double t) override
	{
		const Vec3 pos = (m_pos + Vec3{ 0, 2, 0 } * t);
		const double scale = (1.0 + t * 2.0);
		const double alpha = (1.0 - t);

		m_billboardMesh.draw(m_pCamera->billboard(pos, scale), m_texture, ColorF{ 0.97, alpha }.removeSRGBCurve());

		// 1 秒未満なら継続する
		return (t < 1.0);
	}
};

void Main()
{
	Window::Resize(1280, 720);
	const ColorF backgroundColor = ColorF{ 0.4, 0.6, 0.8 }.removeSRGBCurve();
	const Texture uvChecker{ U"example/texture/uv.png", TextureDesc::MippedSRGB };
	const Texture particleTexture{ U"example/particle.png", TextureDesc::MippedSRGB };
	const MSRenderTexture renderTexture{ Scene::Size(), TextureFormat::R8G8B8A8_Unorm_SRGB, HasDepth::Yes };

	// エフェクトに渡せるよう、カメラを shared_ptr で管理する
	std::shared_ptr<DebugCamera3D> pCamera = std::make_shared<DebugCamera3D>(renderTexture.size(), 30_deg, Vec3{ 10, 16, -32 } );
	const Mesh billboardMesh{ MeshData::Billboard() };
	Effect effect3D;

	while (System::Update())
	{
		pCamera->update(2.0);
		Graphics3D::SetCameraTransform(*pCamera);

		// 3D 描画
		{
			const ScopedRenderTarget3D target{ renderTexture.clear(backgroundColor) };
			Plane{ 64 }.draw(uvChecker);
			Sphere{ 0, 2, 0, 2 }.draw(ColorF{ 0.4, 0.8, 0.6 }.removeSRGBCurve());

			// 3D のエフェクトを描画する
			{
				// ブレンドモード有効、深度書き込み無効
				const ScopedRenderStates3D states{ BlendState::Default2D, DepthStencilState::DepthTest };
				effect3D.update();
			}
		}

		// 3D シーンを 2D シーンに描画
		{
			Graphics3D::Flush();
			renderTexture.resolve();
			Shader::LinearToScreen(renderTexture);
		}

		if (SimpleGUI::Button(U"Smoke", Vec2{ 40, 40 }))
		{
			const Vec3 pos = (Vec3{ 0, 4, 0 } + RandomVec3insideUnitSphere() * 1);
			effect3D.add<Particle3D>(pos, billboardMesh, particleTexture, pCamera);
		}
	}
}