From 0631fb666d2a28a6eb9b8d1578675699b41a5de6 Mon Sep 17 00:00:00 2001
From: Mel <einebeere@gmail.com>
Date: Tue, 4 Oct 2022 01:18:19 +0200
Subject: Cube Rendering

---
 src/Math/MVP.cpp | 82 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 82 insertions(+)
 create mode 100644 src/Math/MVP.cpp

(limited to 'src/Math/MVP.cpp')

diff --git a/src/Math/MVP.cpp b/src/Math/MVP.cpp
new file mode 100644
index 0000000..37675b4
--- /dev/null
+++ b/src/Math/MVP.cpp
@@ -0,0 +1,82 @@
+#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);
+
+    return transformation * rotation;
+}
+
+Matrix<4, 4> view(Vector<3> position, Rotation angles) {
+    auto transformation = transformation_matrix(position);
+    auto rotation = rotation_matrix(angles);
+
+    return transformation * rotation;
+}
+
+Matrix<4, 4> projection(float aspect, float fov, float near, float far) {
+    auto fov_radians = (fov * M_PI) / 180.0f;
+
+    float x_scale = 1.0f / (tan(fov_radians / 2.0f) * aspect);
+    float y_scale = 1.0f / tan(fov_radians / 2.0f);
+
+    float frustum_length = far - near;
+    float z_near = -(far + near) / frustum_length;
+    float z_far = -(2 * far * near) / frustum_length;
+
+    Matrix<4, 4> projection{
+        x_scale, 0.0f,    0.0f,   0.0f,
+        0.0f,    y_scale, 0.0f,   0.0f,
+        0.0f,    0.0f,    z_near, z_far,
+        0.0f,    0.0f,    -1.0f,   0.0f,
+    };
+
+    return projection;
+}
+
+}
-- 
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