raytracer/include/camera.h

#pragma once

#include "ray.h"

class Camera {
public:
    Camera() : position(glm::vec3(0)), direction(glm::vec3(0)) {}

    Camera(glm::vec3 position, glm::vec3 direction) : position(position), direction(direction) {}

    void look_at(glm::vec3 eye, glm::vec3 target) {
        position = eye;
        direction = glm::normalize(target - eye);
    }

    Ray get_ray(const int32_t x, const int32_t y, const int32_t width, const int32_t height) const {
        const glm::vec3 up = glm::vec3(0, 1, 0);
        const glm::vec3 right = glm::normalize(glm::cross(direction, up));

        const float h2 = height / 2.0f;
        const float w2 = width / 2.0f;

        const glm::vec3 ray_dir = position + (h2 / tan(glm::radians(fov) / 2)) * direction + (y - h2) * up +
                                  static_cast<float>(x - w2) * right;
        return Ray(position, ray_dir);
    }

    glm::vec3 position, direction;
    float fov = 45.0f;
};