Non-camera relative movement

5 files changed, 109 insertions, 77 deletions

diff --git a/src/Math/MVP.cpp b/src/Math/MVP.cpp
index 37675b4..146b208 100644
--- a/src/Math/MVP.cpp
+++ b/src/Math/MVP.cpp
@@ -1,62 +1,21 @@
 #include <cmath>
-#include <glm/glm.hpp>
-#include <glm/gtc/matrix_transform.hpp>
-#include <glm/gtc/type_ptr.hpp>
-#include <glm/gtx/string_cast.hpp>
 #include "MVP.hpp"
 #include "Math.hpp"
 
 namespace Math::MVP {
 
-Matrix<4, 4> transformation_matrix(Vector<3> position) {
-    return {
-            1.0f, 0.0f, 0.0f, position.x(),
-            0.0f, 1.0f, 0.0f, position.y(),
-            0.0f, 0.0f, 1.0f, position.z(),
-            0.0f, 0.0f, 0.0f, 1.0f
-    };
-}
-
-Matrix<4, 4> rotation_matrix(Rotation angles) {
-    auto c = angles.vector.apply(cos);
-    auto s = angles.vector.apply(sin);
-
-    Matrix<4, 4> rotation_x{
-            1.0f, 0.0f,  0.0f,   0.0f,
-            0.0f, c.x(), -s.x(), 0.0f,
-            0.0f, s.x(), c.x(),  0.0f,
-            0.0f, 0.0f,  0.0f,   1.0f,
-    };
-
-    Matrix<4, 4> rotation_y{
-            c.y(),  0.0f, s.y(),  0.0f,
-            0.0f,   1.0f, 0.0f,   0.0f,
-            -s.y(), 0.0f, c.y(),  0.0f,
-            0.0f,   0.0f, 0.0f,   1.0f,
-    };
-
-    Matrix<4, 4> rotation_z{
-            c.z(), -s.z(), 0.0f,  0.0f,
-            s.z(), c.z(),  0.0f,  0.0f,
-            0.0f,  0.0f,   1.0f,  0.0f,
-            0.0f,  0.0f,   0.0f,  1.0f,
-    };
-
-    return rotation_x * rotation_y * rotation_z;
-}
-
 Matrix<4, 4> model(Vector<3> position, Rotation angles) {
-    auto transformation = transformation_matrix(position);
-    auto rotation = rotation_matrix(angles);
+    auto transformation = Matrix<4, 4>::transformation(position);
+    auto rotation = Matrix<4, 4>::rotation(angles);
 
     return transformation * rotation;
 }
 
 Matrix<4, 4> view(Vector<3> position, Rotation angles) {
-    auto transformation = transformation_matrix(position);
-    auto rotation = rotation_matrix(angles);
+    auto rotation = Matrix<4, 4>::rotation(angles);
+    auto transformation = Matrix<4, 4>::transformation(-position);
 
-    return transformation * rotation;
+    return rotation * transformation;
 }
 
 Matrix<4, 4> projection(float aspect, float fov, float near, float far) {
diff --git a/src/Math/Matrix.hpp b/src/Math/Matrix.hpp
index 9a6b7e6..43f0721 100644
--- a/src/Math/Matrix.hpp
+++ b/src/Math/Matrix.hpp
@@ -3,6 +3,7 @@
 #include <sstream>
 #include <cstddef>
 #include <iostream>
+#include "Rotation.hpp"
 
 template <size_t R, size_t C, typename T = float>
 struct Matrix {
@@ -28,6 +29,43 @@ public:
         return result;
     }
 
+    static Matrix<4, 4> transformation(Vector<3> position) {
+        return {
+            1.0f, 0.0f, 0.0f, position.x(),
+            0.0f, 1.0f, 0.0f, position.y(),
+            0.0f, 0.0f, 1.0f, position.z(),
+            0.0f, 0.0f, 0.0f, 1.0f
+        };
+    }
+
+    static Matrix<4, 4> rotation(Rotation angles) {
+        auto c = angles.vector.map([](auto a) { return cos(a); });
+        auto s = angles.vector.map([](auto a) { return sin(a); });
+
+        Matrix<4, 4> rotation_x{
+            1.0f, 0.0f,  0.0f,   0.0f,
+            0.0f, c.x(), -s.x(), 0.0f,
+            0.0f, s.x(), c.x(),  0.0f,
+            0.0f, 0.0f,  0.0f,   1.0f,
+        };
+
+        Matrix<4, 4> rotation_y{
+            c.y(),  0.0f, s.y(),  0.0f,
+            0.0f,   1.0f, 0.0f,   0.0f,
+            -s.y(), 0.0f, c.y(),  0.0f,
+            0.0f,   0.0f, 0.0f,   1.0f,
+        };
+
+        Matrix<4, 4> rotation_z{
+            c.z(), -s.z(), 0.0f,  0.0f,
+            s.z(), c.z(),  0.0f,  0.0f,
+            0.0f,  0.0f,   1.0f,  0.0f,
+            0.0f,  0.0f,   0.0f,  1.0f,
+        };
+
+        return rotation_x * rotation_y * rotation_z;
+    }
+
     Vector<C, T> row(size_t index) {
         return { &elements[index * C] };
     }
diff --git a/src/Math/Rotation.hpp b/src/Math/Rotation.hpp
index 334ede2..73a8219 100644
--- a/src/Math/Rotation.hpp
+++ b/src/Math/Rotation.hpp
@@ -24,7 +24,7 @@ public:
     }
 
     static Vector<3> wrap(Vector<3> v) {
-        return v.apply([=](float a) -> float { return fmod(a, 360.0f); });
+        return v.map([](auto a) { return fmod(a, 360.0f); });
     }
 
     Vector<3> vector;
diff --git a/src/Math/Vector.hpp b/src/Math/Vector.hpp
index 2e97217..b6690ef 100644
--- a/src/Math/Vector.hpp
+++ b/src/Math/Vector.hpp
@@ -4,6 +4,7 @@
 #include <sstream>
 #include <iostream>
 #include <iterator>
+#include <cmath>
 
 template <size_t S, typename T = float>
 struct Vector {
@@ -22,62 +23,95 @@ public:
         elements[S - 1] = scalar;
     }
 
-    Vector<S, T> apply(T f(T)) {
-        return apply(static_cast<std::function<T(T)>>(f));
+    Vector<S, T> map(std::function<T(T)> f) const {
+        Vector<S, T> result{};
+        for (int i = 0; i < S; i++) {
+            result[i] = f(elements[i]);
+        }
+        return result;
     }
 
-    Vector<S, T> apply(std::function<T(T)> f) {
+    Vector<S, T> map(std::function<T(size_t, T)> f) const {
         Vector<S, T> result{};
         for (int i = 0; i < S; i++) {
-            result[i] = f(elements[i]);
+            result[i] = f(i, elements[i]);
         }
         return result;
     }
 
+    T reduce(std::function<T(T, T)> f) const {
+        T result = elements[0];
+        for (int i = 1; i < S; i++) {
+            result = f(result, elements[i]);
+        }
+        return result;
+    }
+
+    T sum() const {
+        return reduce([](auto x, auto y) { return x + y; });
+    }
+
+    T magnitude() const {
+        return sqrt(map([](auto x) { return x * x;}).sum());
+    }
+
+    Vector<S, T> normalize() const {
+        auto m = magnitude();
+        return map([=](auto x) { return x / m; });
+    }
+
+    Vector<3, T> cross(Vector<3, T> other) const {
+        return {
+            y() * other.z() - z() * other.y(),
+            z() * other.x() - x() * other.z(),
+            x() * other.y() - y() * other.x(),
+        };
+    }
+
+    T operator[](size_t index) const {
+        return elements[index];
+    }
+
     T& operator[](size_t index) {
         return elements[index];
     }
 
     Vector<S, T> operator+(Vector<S, T> other) const {
-        Vector<S, T> result{};
-        for (int i = 0; i < S; i++) {
-            result[i] = elements[i] + other[i];
-        }
-        return result;
+        return map([&](auto i, auto x) { return x + other[i]; });
     }
 
     Vector<S, T> operator*(T scalar) const {
-        Vector<S, T> result;
-        for (size_t index; index < S; index++) {
-            result = this[index] * scalar;
-        }
-        return result;
+        return map([=](auto x) { return x * scalar; });
     }
 
     T operator*(Vector<S, T> other) const {
-        T result = 0;
-        for (size_t index = 0; index < S; index++) {
-            result += this->elements[index] * other[index];
-        }
-        return result;
+        return map([&](auto i, auto x) { return x * other[i]; }).sum();
+    }
+
+    Vector<S, T> operator-(Vector<S, T> other) const {
+        return map([&](auto i, auto x) { return x - other[i]; });
+    }
+
+    Vector<S, T> operator-() const {
+        return map([](T x) -> T { return -x; });
     }
 
-    T x() {
+    T x() const {
         static_assert(S > 0);
         return elements[0];
     }
 
-    T y() {
+    T y() const {
         static_assert(S > 1);
         return elements[1];
     }
 
-    T z() {
+    T z() const {
         static_assert(S > 2);
         return elements[2];
     }
 
-    T w() {
+    T w() const {
         static_assert(S > 3);
         return elements[3];
     }
diff --git a/src/main.cpp b/src/main.cpp
index 16eda51..32d3b4b 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -71,7 +71,7 @@ void run() {
     auto mesh = MC::Binder::load(shape);
 
     MC::Camera camera{};
-    camera.set_position({0.0f, 0.0f, -3.0f});
+    camera.set_position({0.0f, 0.0f, 3.0f});
 
     MC::ShaderProgram program(MC::Shader::create_fragment(), MC::Shader::create_vertex());
 
@@ -124,16 +124,17 @@ void process_input(MC::Window& window, MC::Camera& camera) {
 
     auto key = [&](int key) -> float { return window.key(key, GLFW_PRESS); };
 
-    float forward = key(GLFW_KEY_W) - key(GLFW_KEY_S);
-    float side = key(GLFW_KEY_D) - key(GLFW_KEY_A);
+    float x = key(GLFW_KEY_D) - key(GLFW_KEY_A);
+    float y = key(GLFW_KEY_SPACE) - key(GLFW_KEY_LEFT_SHIFT);
+    float z = key(GLFW_KEY_S) - key(GLFW_KEY_W);
 
-    float vertical = key(GLFW_KEY_UP) - key(GLFW_KEY_DOWN);
-    float horizontal = key(GLFW_KEY_LEFT) - key(GLFW_KEY_RIGHT);
+    float rx = key(GLFW_KEY_DOWN) - key(GLFW_KEY_UP);
+    float ry = key(GLFW_KEY_RIGHT) - key(GLFW_KEY_LEFT);
 
     auto speed = 0.05f;
 
-    camera.move({side * speed, forward * speed, 0.0f});
-    camera.rotate({vertical * speed, horizontal * speed, 0.0f});
+    camera.move({x * speed, y * speed, z * speed});
+    camera.rotate({rx * speed, ry * speed, 0.0f});
 }
 
 void setup_gl() {