Chunk-bound tree decoration

4 files changed, 134 insertions, 28 deletions

diff --git a/src/Math/Matrix.hpp b/src/Math/Matrix.hpp
index 69241d3..d467f72 100644
--- a/src/Math/Matrix.hpp
+++ b/src/Math/Matrix.hpp
@@ -9,14 +9,14 @@ template <size_t R, size_t C, typename T = float>
 struct Matrix {
     Matrix() : elements{} {};
 
-    explicit Matrix(T scalar) {
+    explicit Matrix(const T scalar) {
         std::fill(elements, elements + R * C, scalar);
     };
 
     template<typename ...Args, typename std::enable_if_t<sizeof...(Args) == R * C, int> = 0>
     Matrix(Args... args): elements{ args... } {};
 
-    explicit Matrix(T values[R * C]) {
+    explicit Matrix(const T values[R * C]) {
         std::copy(values, values + R * C, elements);
     };
 
@@ -67,11 +67,11 @@ struct Matrix {
         return rotation_x * rotation_y * rotation_z;
     }
 
-    Vector<C, T> row(size_t index) {
+    Vector<C, T> row(size_t index) const {
         return { &elements[index * C] };
     }
 
-    Vector<R, T> col(size_t index) {
+    Vector<R, T> col(size_t index) const {
         Vector<R, T> result{};
         for (int i = 0; i < R; i++) {
             result[i] = this->operator()(index, i);
@@ -79,7 +79,7 @@ struct Matrix {
         return result;
     }
 
-    Matrix transpose() {
+    Matrix transpose() const {
         Matrix result{};
         for (int y = 0; y < R; y++) {
             for (int x = 0; x < C; x++) {
@@ -89,7 +89,7 @@ struct Matrix {
         return result;
     }
 
-    Matrix operator+(Matrix other) {
+    Matrix operator+(const Matrix other) const {
         Matrix result{};
         for (int i = 0; i < R * C; i++) {
             result.elements[i] = elements[i] + other.elements[i];
@@ -106,7 +106,7 @@ struct Matrix {
     }
 
     template<size_t N>
-    Matrix<R, N, T> operator*(Matrix<C, N, T> other) {
+    Matrix<R, N, T> operator*(const Matrix<C, N, T> other) const {
         Matrix<R, N, T> result{};
         for (int y = 0; y < R; y++) {
             for (int x = 0; x < N; x++) {
@@ -121,13 +121,16 @@ struct Matrix {
         return result;
     }
 
-    Vector<R, T> operator*(Vector<R, T> vector) {
+    Vector<R, T> operator*(const Vector<R, T> vector) const {
         Matrix<R, 1, T> matrix(vector.elements);
         matrix = this->operator*(matrix);
         return { matrix.elements };
     }
 
-    auto& operator()(size_t x, size_t y) {
+    const T& operator()(const size_t x, const size_t y) const {
+        return elements[y * C + x];
+    }
+    T& operator()(const size_t x, const size_t y) {
         return elements[y * C + x];
     }
 
diff --git a/src/Math/Random.cpp b/src/Math/Random.cpp
new file mode 100644
index 0000000..e35cda7
--- /dev/null
+++ b/src/Math/Random.cpp
@@ -0,0 +1,31 @@
+#include "Random.hpp"
+
+namespace Math::Random {
+
+std::array<uint8_t, 4> break_float(const float f) {
+    static_assert(sizeof(float) == 4);
+
+    union { float f; uint8_t u[4]; } t{};
+    t.f = f;
+
+    return {
+        t.u[0], t.u[1], t.u[2], t.u[3]
+    };
+}
+
+float to_float(uint8_t u) {
+    return (float)u / (float)255;
+}
+
+uint8_t hash(uint8_t x) {
+    auto o = ((x ^ 0xAA) * 5);
+    auto rot = o % 8;
+    return o << rot | o >> (8 - rot);
+}
+
+float random() {
+    uint8_t r = std::rand() % 255;
+    return to_float(hash(r));
+}
+
+}
\ No newline at end of file
diff --git a/src/Math/Random.hpp b/src/Math/Random.hpp
new file mode 100644
index 0000000..ab94871
--- /dev/null
+++ b/src/Math/Random.hpp
@@ -0,0 +1,31 @@
+#pragma once
+
+#include "array"
+#include "Common.hpp"
+
+namespace Math::Random {
+
+std::array<uint8_t, 4> break_float(float f);
+float to_float(uint8_t u);
+
+uint8_t hash(uint8_t x);
+
+float random();
+
+template <size_t D>
+struct Noise {
+    float at(Vector<D> pos) const {
+        uint8_t to_hash[D * 4];
+        for (int i = 0; i < D; i++) {
+            auto b = break_float(pos[i]);
+            to_hash[i*4] = b[0]; to_hash[i*4+1] = b[1]; to_hash[i*4+2] = b[2]; to_hash[i*4+3] = b[3];
+        }
+        uint8_t h = 0;
+        for (int i = 0; i < D * 4; i++) {
+            h = hash(h) + to_hash[i];
+        }
+        return to_float(h);
+    }
+};
+
+}
\ No newline at end of file
diff --git a/src/Math/Vector.hpp b/src/Math/Vector.hpp
index 260891d..54207f0 100644
--- a/src/Math/Vector.hpp
+++ b/src/Math/Vector.hpp
@@ -10,31 +10,36 @@ struct Vector {
     Vector(): elements{} {};
 
     template<typename ...Args, std::enable_if_t<sizeof...(Args) == S, int> = 0>
-    Vector<S, T>(Args... args) : elements{ args... } {};
+    Vector(Args... args) : elements{ args... } {};
 
-    Vector<S, T>(T values[S]) {
+    Vector(const T values[S]) {
         std::copy(values, values + S, elements);
     };
 
-    Vector<S, T>(T scalar) {
+    explicit Vector(const T scalar) {
         std::fill(elements, elements + S, scalar);
     };
 
-    Vector<S, T>(Vector<S - 1, T> vector, T scalar) {
+    Vector(const Vector<S - 1, T> vector, const T scalar) {
         std::copy(vector.elements, vector.elements + S - 1, elements);
         elements[S - 1] = scalar;
     }
 
-    Vector<S, T> map(std::function<T(T)> f) const {
-        Vector<S, T> result{};
+    template<size_t N, std::enable_if_t<(N > S), int> = 0>
+    explicit Vector(const Vector<N, T> vector) {
+        std::copy(vector.elements, vector.elements + S, elements);
+    }
+
+    Vector map(std::function<T(T)> f) const {
+        Vector result{};
         for (int i = 0; i < S; i++) {
             result[i] = f(elements[i]);
         }
         return result;
     }
 
-    Vector<S, T> map(std::function<T(size_t, T)> f) const {
-        Vector<S, T> result{};
+    Vector map(std::function<T(size_t, T)> f) const {
+        Vector result{};
         for (int i = 0; i < S; i++) {
             result[i] = f(i, elements[i]);
         }
@@ -57,20 +62,27 @@ struct Vector {
         return sqrt(map([](auto x) { return x * x;}).sum());
     }
 
-    Vector<S, T> normalize() const {
+    Vector normalize() const {
         auto m = magnitude();
         return map([=](auto x) { return x / m; });
     }
 
-    T distance(Vector<S, T> other) const {
+    T distance(const Vector other) const {
         return (*this - other).magnitude();
     }
 
-    Vector<S, T> abs() const {
+    Vector<3, T> any_orthogonal() {
+        if (Vector a{y(), -x(), 0.0f}; a != zero()) return a;
+        if (Vector b{z(), 0.0f, -x()}; b != zero()) return b;
+        if (Vector c{0.0f, z(), -y()}; c != zero()) return c;
+        return zero();
+    }
+
+    Vector abs() const {
         return map([=](auto x) { return std::abs(x); });
     }
 
-    Vector<3, T> cross(Vector<3, T> other) const {
+    Vector<3, T> cross(const Vector<3, T> other) const {
         return {
             y() * other.z() - z() * other.y(),
             z() * other.x() - x() * other.z(),
@@ -86,34 +98,52 @@ struct Vector {
         return elements[index];
     }
 
-    Vector<S, T> operator+(Vector<S, T> other) const {
+    Vector operator+(const Vector other) const {
         return map([&](auto i, auto x) { return x + other[i]; });
     }
 
-    Vector<S, T> operator+(T scalar) const {
+    Vector operator+(T scalar) const {
         return map([=](auto x) { return x + scalar; });
     }
 
-    Vector<S, T> operator*(T scalar) const {
+    Vector operator*(T scalar) const {
         return map([=](auto x) { return x * scalar; });
     }
 
-    T operator*(Vector<S, T> other) const {
+    T operator*(const Vector other) const {
         return map([&](auto i, auto x) { return x * other[i]; }).sum();
     }
 
-    Vector<S, T> operator-(Vector<S, T> other) const {
+    Vector operator-(const Vector other) const {
         return map([&](auto i, auto x) { return x - other[i]; });
     }
 
-    Vector<S, T> operator-() const {
+    Vector operator-() const {
         return map([](T x) -> T { return -x; });
     }
 
-    Vector<S, T> operator/(T scalar) const {
+    Vector operator/(T scalar) const {
         return map([=](auto x) { return x / scalar; });
     }
 
+    bool operator==(const Vector& other) {
+        for (int i = 0; i < S; i++) {
+            if (elements[i] != other[i]) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    bool operator!=(const Vector& other) {
+        return !this->operator==(other);
+    }
+
+    Vector& operator+=(const Vector& other) {
+        *this = *this + other;
+        return *this;
+    }
+
     T& x() { static_assert(S > 0); return elements[0]; }
     const T& x() const { static_assert(S > 0); return elements[0]; }
 
@@ -138,5 +168,16 @@ struct Vector {
         return str.str();
     }
 
+    static Vector<3, T> up() { return {(T)0, (T)1, (T)0}; }
+    static Vector<3, T> down() { return {(T)0, (T)-1, (T)0}; }
+    static Vector<3, T> forward() { return {(T)0, (T)0, (T)1}; }
+    static Vector<3, T> back() { return {(T)0, (T)0, (T)-1}; }
+    static Vector<3, T> right() { return {(T)1, (T)0, (T)0}; }
+    static Vector<3, T> left() { return {(T)-1, (T)0, (T)0}; }
+
+    static Vector<3, T> one() { return Vector{(T)1}; }
+    static Vector<3, T> zero() { return Vector{(T)0}; }
+    static Vector<3, T> max() { return Vector{(T)std::numeric_limits<T>::max()}; }
+
     T elements[S];
 };