Fix and improve wall handling

Use three neighbor cells for bounceback instead of three directions of a single cell.

Generalize neighbor cell determination using normal vector of wall.

1 files changed, 12 insertions, 10 deletions

diff --git a/src/vector.h b/src/vector.h
index 55c7663..e0dc239 100644
--- a/src/vector.h
+++ b/src/vector.h
@@ -4,41 +4,43 @@ inline double sq(double x) noexcept {
 	return x * x;
 }
 
+template <typename T>
 struct Vector {
-	double data[2];
+	T data[2];
 
-	double comp(int x, int y) const {
+	T comp(int x, int y) const {
 		return x*data[0] + y*data[1];
 	}
 
-	double norm() const {
+	T norm() const {
 		return std::sqrt(sq(data[0]) + sq(data[1]));
 	}
 
-	double& operator[](std::size_t i) {
+	T& operator[](std::size_t i) {
 		return data[i];
 	}
 
-	double operator[](std::size_t i) const {
+	T operator[](std::size_t i) const {
 		return data[i];
 	}
 
-	Vector operator*(double scalar) const {
-		return Vector{
+	Vector<T> operator*(T scalar) const {
+		return Vector<T>{
 			data[0] * scalar,
 			data[1] * scalar
 		};
 	}
 
-	Vector& operator+=(const Vector& rhs) {
+	Vector<T>& operator+=(const Vector<T>& rhs) {
 		data[0] += rhs[0];
 		data[1] += rhs[1];
 		return *this;
 	}
 };
 
-Vector operator*(double scalar, const Vector& vec) {
-	return Vector{
+template <typename T>
+Vector<T> operator*(T scalar, const Vector<T>& vec) {
+	return Vector<T>{
 		vec[0] * scalar,
 		vec[1] * scalar
 	};