added camera

source/projection/Camera.cpp

@@ -0,0 +1,74 @@
+//
+// Created by Vlad on 27.08.2024.
+//
+#include "omath/projection/Camera.h"
+#include "omath/angles.h"
+
+
+namespace omath::projection
+{
+    Matrix Camera::GetViewMatrix() const
+    {
+        return GetOrientationMatrix() * GetTranslationMatrix();
+    }
+
+    Matrix Camera::GetProjectionMatrix() const
+    {
+        const auto aspectRatio = m_viewPort.x / m_viewPort.y;
+        const auto verticalFov = std::tan(angles::DegreesToRadians(m_fieldOfView) / 2.f);
+
+
+        return Matrix(
+            {
+                {1.f / (aspectRatio * verticalFov), 0.f, 0.f, 0.f},
+                {0.f, 1.f / verticalFov, 0.f, 0.f},
+                {0.f, 0.f, m_farPlaneDistance / (m_farPlaneDistance-m_nearPlaneDistance), -m_farPlaneDistance*m_nearPlaneDistance / (m_farPlaneDistance-m_nearPlaneDistance)},
+                {0.f, 0.f, 1.f, 0.f}
+            });
+    }
+
+    Matrix Camera::GetTranslationMatrix() const
+    {
+        return Matrix(
+        {
+            {1.f, 0.f, 0.f, m_origin.x},
+            {0.f, 1.f, 0.f, m_origin.y},
+            {0.f, 0.f, 1.f, m_origin.z},
+            {0.f, 0.f, 0.f, 1.f},
+        });
+    }
+
+    Matrix Camera::GetOrientationMatrix() const
+    {
+        const auto forward = Vector3::ForwardVector(m_viewAngles.x, m_viewAngles.y);
+        const auto right = Vector3::RightVector(m_viewAngles.x, m_viewAngles.y, m_viewAngles.z);
+        const auto up = Vector3::UpVector(m_viewAngles.x, m_viewAngles.y, m_viewAngles.z);
+
+
+        return Matrix(
+        {
+            {right.x,    up.y,        right.z,          0.f},
+            {up.x,       up.y,        up.y,             0.f},
+            {forward.x,  forward.y,   forward.z,        0.f},
+            {0.f,        0.f,         0.f,              1.f},
+        });
+    }
+
+    std::expected<Vector3, std::string_view> Camera::WorldToScreen(const Vector3 &worldPosition) const
+    {
+        const auto posVecAsMatrix = Matrix({{worldPosition.x, worldPosition.y, worldPosition.z, 1.f}});
+
+        const auto viewProjectionMatrix = GetViewMatrix() * GetProjectionMatrix();
+
+        auto projected = posVecAsMatrix * viewProjectionMatrix;
+
+        if (projected.At(0, 3) <= 0.f)
+            return std::unexpected("Projection point is out of camera field of view");
+
+        projected /= projected.At(0, 3);
+
+        projected *= Matrix::ToScreenMatrix(m_viewPort.x, m_viewPort.y);
+
+        return Vector3{projected.At(0, 0), projected.At(0, 1), projected.At(0, 2)};
+    }
+}