camera.h

#ifndef camera_h
#define camera_h

#include <curand_kernel.h>
#include "ray.h"
#include "vec3.h"


class camera {
public:
    float width;//create constant width&length
    float height;
    vec3 orgin;
    vec3 left_corner;
    vec3 horizontal;
    vec3 vertical;
    vec3 u, v, w;
    float lens_radius;
    __device__ camera(vec3 from, vec3 lookat, vec3 vup, float deg, float aspect,
        float aperture, float focus) {
        lens_radius = aperture / 2.0f;
        float rad = deg * 3.14159265359f / 180.0f;
        height = tan(rad / 2.0f);
        width = height * aspect;

        orgin = from;
        w = (from - lookat).normalize();
        u = (vup.cross(w)).normalize();
        v = w.cross(u);

        left_corner = orgin - u * width * focus - v * height * focus - w * focus;
        horizontal = u * 2.0f * width * focus;
        vertical = v * 2.0f * height * focus;
    }

    __device__ ray get_ray(float a, float b, curandState* local_rand_state) {
        vec3 rd = random_unit_sphere(local_rand_state) * lens_radius;
        vec3 offset = u * rd.x + v * rd.y;
        return ray(orgin + offset, left_corner + horizontal * a + vertical * b - orgin - offset);
    }
};

#endif