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orange
8aa2dca456
Adds support for different screen origin configurations. This change allows for more accurate conversion from screen coordinates to world coordinates by correctly handling different screen origin positions (top-left and bottom-left). Includes new unit tests to verify the functionality with both configurations.
310 lines
11 KiB
C++
310 lines
11 KiB
C++
//
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// Created by Vlad on 27.08.2024.
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//
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#pragma once
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#include "omath/linear_algebra/mat.hpp"
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#include "omath/linear_algebra/vector3.hpp"
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#include "omath/projection/error_codes.hpp"
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#include <expected>
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#include <omath/trigonometry/angle.hpp>
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#include <type_traits>
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#ifdef OMATH_BUILD_TESTS
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// ReSharper disable CppInconsistentNaming
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class UnitTestProjection_Projection_Test;
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class UnitTestProjection_ScreenToNdcTopLeft_Test;
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class UnitTestProjection_ScreenToNdcBottomLeft_Test;
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// ReSharper restore CppInconsistentNaming
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#endif
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namespace omath::projection
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{
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class ViewPort final
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{
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public:
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float m_width;
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float m_height;
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[[nodiscard]] constexpr float aspect_ratio() const
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{
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return m_width / m_height;
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}
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};
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using FieldOfView = Angle<float, 0.f, 180.f, AngleFlags::Clamped>;
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template<class T, class MatType, class ViewAnglesType>
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concept CameraEngineConcept =
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requires(const Vector3<float>& cam_origin, const Vector3<float>& look_at, const ViewAnglesType& angles,
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const FieldOfView& fov, const ViewPort& viewport, float znear, float zfar) {
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// Presence + return types
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{ T::calc_look_at_angle(cam_origin, look_at) } -> std::same_as<ViewAnglesType>;
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{ T::calc_view_matrix(angles, cam_origin) } -> std::same_as<MatType>;
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{ T::calc_projection_matrix(fov, viewport, znear, zfar) } -> std::same_as<MatType>;
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// Enforce noexcept as in the trait declaration
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requires noexcept(T::calc_look_at_angle(cam_origin, look_at));
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requires noexcept(T::calc_view_matrix(angles, cam_origin));
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requires noexcept(T::calc_projection_matrix(fov, viewport, znear, zfar));
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};
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template<class Mat4X4Type, class ViewAnglesType, class TraitClass>
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requires CameraEngineConcept<TraitClass, Mat4X4Type, ViewAnglesType>
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class Camera final
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{
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#ifdef OMATH_BUILD_TESTS
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friend UnitTestProjection_Projection_Test;
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friend UnitTestProjection_ScreenToNdcTopLeft_Test;
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friend UnitTestProjection_ScreenToNdcBottomLeft_Test;
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#endif
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public:
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enum class ScreenStart
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{
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TOP_LEFT_CORNER,
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BOTTOM_LEFT_CORNER,
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};
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~Camera() = default;
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Camera(const Vector3<float>& position, const ViewAnglesType& view_angles, const ViewPort& view_port,
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const FieldOfView& fov, const float near, const float far) noexcept
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: m_view_port(view_port), m_field_of_view(fov), m_far_plane_distance(far), m_near_plane_distance(near),
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m_view_angles(view_angles), m_origin(position)
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{
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}
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void look_at(const Vector3<float>& target)
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{
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m_view_angles = TraitClass::calc_look_at_angle(m_origin, target);
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m_view_projection_matrix = std::nullopt;
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}
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protected:
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[[nodiscard]] Mat4X4Type calc_view_projection_matrix() const noexcept
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{
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return TraitClass::calc_projection_matrix(m_field_of_view, m_view_port, m_near_plane_distance,
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m_far_plane_distance)
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* TraitClass::calc_view_matrix(m_view_angles, m_origin);
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}
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public:
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[[nodiscard]] const Mat4X4Type& get_view_projection_matrix() const noexcept
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{
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if (!m_view_projection_matrix.has_value())
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m_view_projection_matrix = calc_view_projection_matrix();
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return m_view_projection_matrix.value();
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}
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void set_field_of_view(const FieldOfView& fov) noexcept
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{
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m_field_of_view = fov;
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m_view_projection_matrix = std::nullopt;
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}
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void set_near_plane(const float near) noexcept
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{
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m_near_plane_distance = near;
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m_view_projection_matrix = std::nullopt;
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}
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void set_far_plane(const float far) noexcept
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{
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m_far_plane_distance = far;
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m_view_projection_matrix = std::nullopt;
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}
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void set_view_angles(const ViewAnglesType& view_angles) noexcept
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{
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m_view_angles = view_angles;
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m_view_projection_matrix = std::nullopt;
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}
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void set_origin(const Vector3<float>& origin) noexcept
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{
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m_origin = origin;
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m_view_projection_matrix = std::nullopt;
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}
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void set_view_port(const ViewPort& view_port) noexcept
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{
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m_view_port = view_port;
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m_view_projection_matrix = std::nullopt;
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}
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[[nodiscard]] const FieldOfView& get_field_of_view() const noexcept
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{
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return m_field_of_view;
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}
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[[nodiscard]] const float& get_near_plane() const noexcept
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{
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return m_near_plane_distance;
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}
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[[nodiscard]] const float& get_far_plane() const noexcept
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{
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return m_far_plane_distance;
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}
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[[nodiscard]] const ViewAnglesType& get_view_angles() const noexcept
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{
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return m_view_angles;
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}
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[[nodiscard]] const Vector3<float>& get_origin() const noexcept
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{
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return m_origin;
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}
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template<ScreenStart screen_start = ScreenStart::TOP_LEFT_CORNER>
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[[nodiscard]] std::expected<Vector3<float>, Error>
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world_to_screen(const Vector3<float>& world_position) const noexcept
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{
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const auto normalized_cords = world_to_view_port(world_position);
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if (!normalized_cords.has_value())
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return std::unexpected{normalized_cords.error()};
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if constexpr (screen_start == ScreenStart::TOP_LEFT_CORNER)
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return ndc_to_screen_position_from_top_left_corner(*normalized_cords);
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else if constexpr (screen_start == ScreenStart::BOTTOM_LEFT_CORNER)
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return ndc_to_screen_position_from_bottom_left_corner(*normalized_cords);
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else
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std::unreachable();
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}
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[[nodiscard]] std::expected<Vector3<float>, Error>
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world_to_view_port(const Vector3<float>& world_position) const noexcept
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{
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auto projected = get_view_projection_matrix()
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* mat_column_from_vector<float, Mat4X4Type::get_store_ordering()>(world_position);
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if (projected.at(3, 0) == 0.0f)
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return std::unexpected(Error::WORLD_POSITION_IS_OUT_OF_SCREEN_BOUNDS);
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projected /= projected.at(3, 0);
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if (is_ndc_out_of_bounds(projected))
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return std::unexpected(Error::WORLD_POSITION_IS_OUT_OF_SCREEN_BOUNDS);
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return Vector3<float>{projected.at(0, 0), projected.at(1, 0), projected.at(2, 0)};
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}
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[[nodiscard]]
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std::expected<Vector3<float>, Error> view_port_to_screen(const Vector3<float>& ndc) const noexcept
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{
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const auto inv_view_proj = get_view_projection_matrix().inverted();
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if (!inv_view_proj)
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return std::unexpected(Error::INV_VIEW_PROJ_MAT_DET_EQ_ZERO);
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auto inverted_projection =
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inv_view_proj.value() * mat_column_from_vector<float, Mat4X4Type::get_store_ordering()>(ndc);
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if (!inverted_projection.at(3, 0))
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return std::unexpected(Error::WORLD_POSITION_IS_OUT_OF_SCREEN_BOUNDS);
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inverted_projection /= inverted_projection.at(3, 0);
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return Vector3<float>{inverted_projection.at(0, 0), inverted_projection.at(1, 0),
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inverted_projection.at(2, 0)};
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}
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template<ScreenStart screen_start = ScreenStart::TOP_LEFT_CORNER>
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[[nodiscard]]
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std::expected<Vector3<float>, Error> screen_to_world(const Vector3<float>& screen_pos) const noexcept
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{
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return view_port_to_screen(screen_to_ndc<screen_start>(screen_pos));
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}
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template<ScreenStart screen_start = ScreenStart::TOP_LEFT_CORNER>
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[[nodiscard]]
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std::expected<Vector3<float>, Error> screen_to_world(const Vector2<float>& screen_pos) const noexcept
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{
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const auto& [x, y] = screen_pos;
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return screen_to_world<screen_start>({x, y, 1.f});
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}
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protected:
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ViewPort m_view_port{};
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Angle<float, 0.f, 180.f, AngleFlags::Clamped> m_field_of_view;
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mutable std::optional<Mat4X4Type> m_view_projection_matrix;
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float m_far_plane_distance;
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float m_near_plane_distance;
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ViewAnglesType m_view_angles;
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Vector3<float> m_origin;
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private:
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template<class Type>
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[[nodiscard]] constexpr static bool is_ndc_out_of_bounds(const Type& ndc) noexcept
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{
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return std::ranges::any_of(ndc.raw_array(), [](const auto& val) { return val < -1 || val > 1; });
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}
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// NDC REPRESENTATION:
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/*
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^
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| y
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1 |
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-1 ---------0--------- 1 --> x
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-1 |
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v
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*/
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[[nodiscard]] Vector3<float>
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ndc_to_screen_position_from_top_left_corner(const Vector3<float>& ndc) const noexcept
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{
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/*
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+------------------------>
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| (0, 0)
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⌄
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*/
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return {(ndc.x + 1.f) / 2.f * m_view_port.m_width, (ndc.y / -2.f + 0.5f) * m_view_port.m_height, ndc.z};
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}
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[[nodiscard]] Vector3<float>
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ndc_to_screen_position_from_bottom_left_corner(const Vector3<float>& ndc) const noexcept
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{
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/*
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^
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+------------------------>
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*/
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return {(ndc.x + 1.f) / 2.f * m_view_port.m_width, (ndc.y / 2.f + 0.5f) * m_view_port.m_height, ndc.z};
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}
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template<ScreenStart screen_start = ScreenStart::TOP_LEFT_CORNER>
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[[nodiscard]] Vector3<float> screen_to_ndc(const Vector3<float>& screen_pos) const noexcept
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{
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if constexpr (screen_start == ScreenStart::TOP_LEFT_CORNER)
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return {screen_pos.x / m_view_port.m_width * 2.f - 1.f, 1.f - screen_pos.y / m_view_port.m_height * 2.f,
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screen_pos.z};
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else if (screen_start == ScreenStart::BOTTOM_LEFT_CORNER)
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return {screen_pos.x / m_view_port.m_width * 2.f - 1.f,
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(screen_pos.y / m_view_port.m_height - 0.5f) * 2.f, screen_pos.z};
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else
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std::unreachable();
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}
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};
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} // namespace omath::projection
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