Files
stupidsimcpp/util/grid/camera.hpp
2026-01-27 16:11:09 -05:00

107 lines
3.0 KiB
C++

#ifndef camera_hpp
#define camera_hpp
#include "../../eigen/Eigen/Dense"
#include <cmath>
#include "../basicdefines.hpp"
using Eigen::Vector3f;
using Eigen::Matrix3f;
struct Camera {
Vector3f origin;
Vector3f direction;
Vector3f up;
float fov;
Camera(const Vector3f& pos, const Vector3f& viewdir, const Vector3f& up, float fov = 80)
: origin(pos), direction(viewdir), up(up.normalized()), fov(fov) {}
void rotateYaw(float angle) {
float cosA = cos(angle);
float sinA = sin(angle);
Vector3f right = direction.cross(up).normalized();
// Rotate around up vector (yaw)
Matrix3f rotation;
rotation = Eigen::AngleAxisf(angle, up);
direction = rotation * direction;
}
void rotatePitch(float angle) {
// Clamp pitch to avoid gimbal lock
Vector3f right = direction.cross(up).normalized();
// Rotate around right vector (pitch)
Matrix3f rotation;
rotation = Eigen::AngleAxisf(angle, right);
direction = rotation * direction;
direction.normalize();
// Recalculate up vector to maintain orthogonality
up = right.cross(direction).normalized();
}
Vector3f forward() const {
return direction.normalized();
}
Vector3f right() const {
return forward().cross(up).normalized();
}
float fovRad() const {
return fov * (M_PI / 180.0f);
}
// Additional useful methods
void moveForward(float distance) {
origin += forward() * distance;
}
void moveRight(float distance) {
origin += right() * distance;
}
void moveUp(float distance) {
origin += up * distance;
}
// Get view matrix (lookAt matrix)
Eigen::Matrix4f getViewMatrix() const {
Vector3f f = forward();
Vector3f r = right();
Vector3f u = up;
Eigen::Matrix4f view = Eigen::Matrix4f::Identity();
view(0, 0) = r.x(); view(0, 1) = r.y(); view(0, 2) = r.z();
view(1, 0) = u.x(); view(1, 1) = u.y(); view(1, 2) = u.z();
view(2, 0) = -f.x(); view(2, 1) = -f.y(); view(2, 2) = -f.z();
view(0, 3) = -r.dot(origin);
view(1, 3) = -u.dot(origin);
view(2, 3) = f.dot(origin);
return view;
}
// Get projection matrix (perspective)
Eigen::Matrix4f getProjectionMatrix(float aspectRatio, float nearPlane = 0.1f, float farPlane = 100.0f) const {
float fovrad = fovRad();
float tanHalfFov = tan(fovrad / 2.0f);
Eigen::Matrix4f projection = Eigen::Matrix4f::Zero();
projection(0, 0) = 1.0f / (aspectRatio * tanHalfFov);
projection(1, 1) = 1.0f / tanHalfFov;
projection(2, 2) = -(farPlane + nearPlane) / (farPlane - nearPlane);
projection(3, 2) = -1.0f;
projection(2, 3) = -(2.0f * farPlane * nearPlane) / (farPlane - nearPlane);
return projection;
}
};
#endif