Files
omath/source/projection/Camera.cpp
2024-08-30 02:54:41 +03:00

96 lines
2.9 KiB
C++

//
// Created by Vlad on 27.08.2024.
//
#include "omath/projection/Camera.h"
#include <complex>
#include "omath/angles.h"
namespace omath::projection
{
Camera::Camera(const Vector3 &position, const Vector3 &viewAngles, const Vector3 &viewPort, const float fov, const float near,
const float far)
{
m_origin = position;
m_viewAngles = viewAngles;
m_viewPort = viewPort;
m_fieldOfView = fov;
m_nearPlaneDistance = near;
m_farPlaneDistance = far;
}
Matrix Camera::GetViewMatrix() const
{
return GetTranslationMatrix() * GetOrientationMatrix();
}
Matrix Camera::GetProjectionMatrix() const
{
const float fRight = std::tan(angles::DegreesToRadians(m_fieldOfView) / 2.f);
const float fLeft = -fRight;
const float vFov = angles::DegreesToRadians(m_fieldOfView) * (m_viewPort.y / m_viewPort.x);
const float fTop = std::tan(vFov / 2.f);
const float fBottom = -fTop;
const auto m_fFar = m_farPlaneDistance;
const auto m_fNear = m_nearPlaneDistance;
return Matrix({
{2.f / (fRight - fLeft), 0.f, 0.f, 0.f},
{0.f, 2.f / (fTop - fBottom), 0.f, 0.f},
{0.f, 0.f, (m_fFar + m_fNear) / (m_fFar - m_fNear), 1.f},
{0.f, 0.f, -2.f * m_fNear * m_fFar / (m_fFar - m_fNear), 0.f},
});
}
Matrix Camera::GetTranslationMatrix() const
{
return Matrix(
{
{1.f, 0.f, 0.f, 0.f},
{0.f, 1.f, 0.f, 1.f},
{0.f, 0.f, 1.f, 0.f},
{-m_origin.x, -m_origin.y, -m_origin.z, 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.x, forward.x, 0.f},
{right.y, up.y, forward.y, 0.f},
{right.z, up.z, 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, 2), projected.At(0, 1)};
}
}