12.1.Camera Viewing Geometry

src/camera.rs

@@ -2,24 +2,30 @@ use std::fs::File;
 use std::io::{BufWriter};
 
 use crate::hittable::HittableList;
-use crate::math_utils::{clamp, near_zero};
+use crate::math_utils::{clamp, degrees_to_radians};
 use crate::ppm_writer::PPMWriter;
 use crate::types_defined::{Camera, Color, HitRecord, Point, Ray, Vec3};
 use rand::rngs::ThreadRng;
-use rand::{Rng, thread_rng};
+use rand::{Rng, rng};
 use crate::material::{Material, MaterialKind};
 
 impl<'a> Camera<'a> {
     pub fn new(
+        fov: f32,
         image_width: i32,
         aspect_ratio: f32,
-        viewport_height: f32,
         camera_center: Point,
-        focal_length: Vec3,
+        focal_length: f32,
         sample_times: i8,
         reflect_depth: i8,
         ppm_file_writer: &'a mut PPMWriter<BufWriter<File>>
     ) -> Self {
+
+
+       let theta = degrees_to_radians(fov);
+       let h = f32::tan(theta / 2.);
+       let viewport_height = 2. * h * focal_length;
+
         let image_height = ((image_width as f32 / aspect_ratio) as i32).max(1);
         let viewport_width = viewport_height * (image_width as f32 / image_height as f32);
 
@@ -34,7 +40,7 @@ impl<'a> Camera<'a> {
         // height per pix
         let viewport_v_delta = viewport_v / (image_height as f32);
         let viewport_top_left_pixel =
-            camera_center - focal_length - viewport_u / 2.0 - viewport_v / 2.0;
+            camera_center - Vec3::new(0., 0., focal_length) - viewport_u / 2.0 - viewport_v / 2.0;
         // padding 0.5* delta u/v
         let viewport_top_left_pixel_center =
             viewport_top_left_pixel - viewport_u_delta / 2.0 - viewport_v_delta / 2.0;
@@ -69,7 +75,7 @@ impl<'a> Camera<'a> {
             for i in 0..self.image_width {
                 // color
                 let mut color = Color::new(0.0, 0.0, 0.0);
-                let rng = &mut thread_rng();
+                let rng = &mut rng();
                 for _ in 0..self.sample_times {
                     let bias = self.random_square(rng);
                     let pix_sample = self.viewport_top_left_pixel_center

src/main.rs

@@ -22,11 +22,12 @@ fn main() {
 
 fn camera_render() {
 
+    let fov: f32 = 90.;
     let scale = 1;
     let width: i32 = 800/scale;
     let height: i32 = 600/scale;
-    let sample_times = 127;
-    let reflect_depth = 127;
+    let sample_times = 20;
+    let reflect_depth = 20;
 
 
     let pw_r = PPMWriter::new(
@@ -40,11 +41,11 @@ fn camera_render() {
     
 
     let mut camera: Camera = Camera::new(
+        fov,
         width,
         width as f32 / height as f32,
-        2.0,
         Point::new(0.0, -0.0, 0.0),
-        Vec3::new(0.0, 0.0, 1.0),
+        1.0,
         sample_times,
         reflect_depth,
         pw

src/math_utils.rs

@@ -1,5 +1,11 @@
+use std::f32::consts::PI;
+
 use crate::types_defined::{Ray, Vec3};
 
+pub fn degrees_to_radians(deg: f32) -> f32 {
+    deg * PI / 180.
+}
+
 pub fn clamp(value: f32, low: f32, high: f32) -> f32 {
     if value < low {
         return low;