DirectXLearningProject/Cone.h at main · Esauidk/DirectXLearningProject · GitHub

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#pragma once
#include "IndexedTriangleList.h"
#include <DirectXMath.h>
#include "ChiliMath.h"

class Cone
{
public:
	template<class V>
	static IndexTriangleList<V> MakeTesselated(int longDiv)
	{
		namespace dx = DirectX;
		assert(longDiv >= 3);

		const auto base = dx::XMVectorSet(1.0f, 0.0f, -1.0f, 0.0f);
		const float longitudeAngle = 2.0f * PI / longDiv;

		// base vertices
		std::vector<V> vertices;
		for (int iLong = 0; iLong < longDiv; iLong++)
		{
			vertices.emplace_back();
			auto v = dx::XMVector3Transform(
				base,
				dx::XMMatrixRotationZ(longitudeAngle * iLong)
			);
			dx::XMStoreFloat3(&vertices.back().pos, v);
		}
		// the center
		vertices.emplace_back();
		vertices.back().pos = { 0.0f,0.0f,-1.0f };
		const auto iCenter = (unsigned short)(vertices.size() - 1);
		// the tip :darkness:
		vertices.emplace_back();
		vertices.back().pos = { 0.0f,0.0f,1.0f };
		const auto iTip = (unsigned short)(vertices.size() - 1);


		// base indices
		std::vector<unsigned short> indices;
		for (unsigned short iLong = 0; iLong < longDiv; iLong++)
		{
			indices.push_back(iCenter);
			indices.push_back((iLong + 1) % longDiv);
			indices.push_back(iLong);
		}

		// cone indices
		for (unsigned short iLong = 0; iLong < longDiv; iLong++)
		{
			indices.push_back(iLong);
			indices.push_back((iLong + 1) % longDiv);
			indices.push_back(iTip);
		}

		return { std::move(vertices),std::move(indices) };
	}
	template<class V>
	static IndexTriangleList<V> MakeTesselatedIndependentFaces(int longDiv) {
		namespace dx = DirectX;
		assert(longDiv >= 3);

		const auto base = dx::XMVectorSet(1.0f, 0.0f, -1.0f, 0.0f);
		const float longitudeAngle = 2.0f * PI / longDiv;

		std::vector<V> vertices;

		// cone vertices
		const auto iCone = (unsigned short)vertices.size();
		for (int iLong = 0; iLong < longDiv; iLong++)
		{
			const float thetas[] = {
				longitudeAngle * iLong,
				longitudeAngle * (((iLong + 1) == longDiv) ? 0 : (iLong + 1))
			};
			vertices.emplace_back();
			vertices.back().pos = { 0.0f,0.0f,1.0f };
			for (auto theta : thetas)
			{
				vertices.emplace_back();
				const auto v = dx::XMVector3Transform(
					base,
					dx::XMMatrixRotationZ(theta)
				);
				dx::XMStoreFloat3(&vertices.back().pos, v);
			}
		}
		// base vertices
		const auto iBaseCenter = (unsigned short)vertices.size();
		vertices.emplace_back();
		vertices.back().pos = { 0.0f,0.0f,-1.0f };
		const auto iBaseEdge = (unsigned short)vertices.size();
		for (int iLong = 0; iLong < longDiv; iLong++)
		{
			vertices.emplace_back();
			auto v = dx::XMVector3Transform(
				base,
				dx::XMMatrixRotationZ(longitudeAngle * iLong)
			);
			dx::XMStoreFloat3(&vertices.back().pos, v);
		}

		std::vector<unsigned short> indices;

		// cone indices
		for (unsigned short i = 0; i < longDiv * 3; i++)
		{
			indices.push_back(i + iCone);
		}
		// base indices
		for (unsigned short iLong = 0; iLong < longDiv; iLong++)
		{
			indices.push_back(iBaseCenter);
			indices.push_back((iLong + 1) % longDiv + iBaseEdge);
			indices.push_back(iLong + iBaseEdge);
		}

		return { std::move(vertices),std::move(indices) };
	}

	template<class V>
	static IndexTriangleList<V> Make()
	{
		return MakeTesselated<V>(24);
	}
};