Planet Chili

Code: Select all

void triangle(Mesh mesh, int a, int b, int c, Graphics& gfx, std::function<void (Vec3i, EdgeWalker)> locationGiver) {
		Package vs [] = { mesh.getPackage(a),mesh.getPackage(b),mesh.getPackage(c) };
		std::sort(vs, vs + 3, [](Package a, Package b) -> bool {return a.vertex.y < b.vertex.y; });
		Package top = vs[0];
		Package middle = vs[1];
		Package bot = vs[2];

		float ratio = (middle.vertex.y - top.vertex.y) / (float)(bot.vertex.y - top.vertex.y);
		Package middleRight = top.lerp(bot, ratio);
		if (middle.vertex.x > middleRight.vertex.x)std::swap(middle, middleRight);

		auto fromTo = [&](Package topLeft, Package topRight, Package bottomLeft, Package bottomRight) {
			std::vector<FromTo> fromtosLeft;
			EdgeWalker leftWalker = EdgeWalker::copyOver(topLeft, bottomLeft, EdgeWalkerCode::y, std::vector<EdgeWalkerCode>{EdgeWalkerCode::x, EdgeWalkerCode::z, EdgeWalkerCode::uvx, EdgeWalkerCode::uvy});
			EdgeWalker rightWalker = EdgeWalker::copyOver(topRight, bottomRight, EdgeWalkerCode::y, std::vector<EdgeWalkerCode>{EdgeWalkerCode::x, EdgeWalkerCode::z, EdgeWalkerCode::uvx, EdgeWalkerCode::uvy});

			while (leftWalker.counter < (int)ceil(bottomLeft.vertex.y - 0.5f)) {
				EdgeWalker horizontalWalker = EdgeWalker::copyOver(leftWalker, rightWalker, EdgeWalkerCode::x, std::vector<EdgeWalkerCode>{EdgeWalkerCode::z, EdgeWalkerCode::uvx, EdgeWalkerCode::uvy});

				while (horizontalWalker.counter < (int)ceil(rightWalker.get(EdgeWalkerCode::x) - 0.5f)) {
					locationGiver(Vec3i(horizontalWalker.counter,leftWalker.counter,0), horizontalWalker);
					horizontalWalker.step();
				}

				leftWalker.step();
				rightWalker.step();
			}

			
		};

		fromTo(top,top,middle,middleRight);//upper triangle/flatbot
		fromTo(middle, middleRight,bot,bot);//lower triangle/flattop

	}

Code: Select all

enum EdgeWalkerCode {
	x, y, z, uvx, uvy
};

struct IEdgeCodeGetter {
	virtual float get(EdgeWalkerCode) = 0;
};

struct Package : public IEdgeCodeGetter{
	Vec3f vertex;
	Vec2f uv;

	Package() = default;

	Package(Vec3f vertex, Vec2f uv) :vertex(vertex), uv(uv) {

	}

	Package lerp(Package& v, float weight) {
		Package package;
		package.vertex = vertex.lerp(v.vertex, weight);
		package.uv = uv.lerp(v.uv, weight);
		return package;
	}

	float get(EdgeWalkerCode code) {
		switch (code) {
		case x:
			return vertex.x;
		case y:
			return vertex.y;
		case z:
			return vertex.z;
		case uvx:
			return uv.x;
		case uvy:
			return uv.y;
		default:
			return 0;
		}
	}


};

struct FromTo {
	EdgeWalkerCode edgeWalkerCode;
	float from, to;

	FromTo(EdgeWalkerCode edgeWalkerCode, float from, float to):edgeWalkerCode(edgeWalkerCode), from(from), to(to) {
		
	}
};

struct EdgeWalker : public IEdgeCodeGetter {
	int counter;
	std::map<EdgeWalkerCode, float> posMap;
	std::map<EdgeWalkerCode, float> incsMap;

	EdgeWalker(float from, float to, std::vector<FromTo> fromtos) {
		
		counter = (int)ceil(from - 0.5f);
		float diff = to - from;

		for each (FromTo package in fromtos){
			posMap[package.edgeWalkerCode] = package.from;
			incsMap[package.edgeWalkerCode] = (package.to - package.from) / diff;
		}

	}

	

	static EdgeWalker copyOver(IEdgeCodeGetter& a, IEdgeCodeGetter& b, EdgeWalkerCode walker, std::vector<EdgeWalkerCode> codes) {
		std::vector<FromTo> fromtos;
		for each (EdgeWalkerCode code in codes){
			fromtos.push_back(FromTo(code, a.get(code), b.get(code)));
		}

		return EdgeWalker(a.get(walker), b.get(walker), fromtos);
	}

	void step() {
		counter++;
		std::map<EdgeWalkerCode, float>::iterator it = posMap.begin();

		while (it != posMap.end()) {
			posMap[it->first] += incsMap[it->first];
			it++;
		}
	}


	float get(EdgeWalkerCode code) {
		return posMap[code];
	}
};

Code: Select all

	void triangle(Mesh mesh, int a, int b, int c, Graphics& gfx, std::function<void (Vec3i, EdgeWalker)> locationGiver) {
		//sort and name vertices
		Package vs [] = { mesh.getPackage(a),mesh.getPackage(b),mesh.getPackage(c) };
		std::sort(vs, vs + 3, [](Package a, Package b) -> bool {return a.vertex.y < b.vertex.y; });
		Package top = vs[0];
		Package middle = vs[1];
		Package bot = vs[2];

		//get splitting vertex
		float ratio = (middle.vertex.y - top.vertex.y) / (float)(bot.vertex.y - top.vertex.y);
		Package middleRight = top.lerp(bot, ratio);
		if (middle.vertex.x > middleRight.vertex.x)std::swap(middle, middleRight);

		//use edgewalkers to track and interpolate the edges of the triangle
		auto fromTo = [&](Package topLeft, Package topRight, Package bottomLeft, Package bottomRight) {
			std::vector<FromTo> fromtosLeft;
			EdgeWalker leftWalker = EdgeWalker::copyOver(topLeft, bottomLeft, EdgeWalkerCode::y, std::vector<EdgeWalkerCode>{EdgeWalkerCode::x, EdgeWalkerCode::z, EdgeWalkerCode::uvx, EdgeWalkerCode::uvy});
			EdgeWalker rightWalker = EdgeWalker::copyOver(topRight, bottomRight, EdgeWalkerCode::y, std::vector<EdgeWalkerCode>{EdgeWalkerCode::x, EdgeWalkerCode::z, EdgeWalkerCode::uvx, EdgeWalkerCode::uvy});

			while (leftWalker.counter < (int)ceil(bottomLeft.vertex.y - 0.5f)) {
				EdgeWalker horizontalWalker = EdgeWalker::copyOver(leftWalker, rightWalker, EdgeWalkerCode::x, std::vector<EdgeWalkerCode>{EdgeWalkerCode::z, EdgeWalkerCode::uvx, EdgeWalkerCode::uvy});

				while (horizontalWalker.counter < (int)ceil(rightWalker.get(EdgeWalkerCode::x) - 0.5f)) {
					locationGiver(Vec3i(horizontalWalker.counter,leftWalker.counter,0), horizontalWalker);
					horizontalWalker.step();
				}

				leftWalker.step();
				rightWalker.step();
			}

			
		};

		//draw top and bottom triangle
		fromTo(top,top,middle,middleRight);//upper triangle/flatbot
		fromTo(middle, middleRight,bot,bot);//lower triangle/flattop

	}