From 1207c2c55c772155d02a148d76616881f3f6c125 Mon Sep 17 00:00:00 2001
From: Rosyid Haryadi <rosyid_haryadi@protonmail.com>
Date: Sun, 2 Mar 2025 00:25:53 +0700
Subject: upd: anti aliasing

---
 src/camera.rs | 46 +++++++++++++++++++++++++++++++++-------------
 1 file changed, 33 insertions(+), 13 deletions(-)

(limited to 'src/camera.rs')

diff --git a/src/camera.rs b/src/camera.rs
index 587a312..8e9cf68 100644
--- a/src/camera.rs
+++ b/src/camera.rs
@@ -1,16 +1,18 @@
-use crate::calculus::calculus::{Point3, Ray, Vec3};
-use crate::global::{get_image_height, Color, DisplayBuffer, Pixel, ASPECT_RATIO, CAMERA_CENTER, FOCAL_LENGTH, IMG_WIDTH, VIEWPORT_HEIGHT};
+use crate::calculus::calculus::{sample_square, Point3, Ray, Vec3};
+use crate::global::{get_image_height, Color, DisplayBuffer, Pixel, ASPECT_RATIO, CAMERA_CENTER, FOCAL_LENGTH, IMG_WIDTH, SAMPLES_PER_PIXEL, VIEWPORT_HEIGHT};
 use crate::interval::Interval;
-use crate::object::{HitRecord, Hittable, HittableList, Sphere};
+use crate::object::{HitRecord, Hittable, HittableList};
 
 pub struct Camera {
     pub aspect_ratio: f32,
     pub image_width: usize,
+    pub samples_per_pixel: usize,
     image_height: usize,
     center: Point3,
     pixel_upper_left: Point3,
     delta_pixel_u: Vec3,
     delta_pixel_v: Vec3,
+    pixel_samples_scale: f32,
 }
 
 impl Camera {
@@ -23,6 +25,9 @@ impl Camera {
         let center = CAMERA_CENTER;
         let focal_length = FOCAL_LENGTH;
 
+        let samples_per_pixel = SAMPLES_PER_PIXEL;
+        let pixel_samples_scale = 1.0 / samples_per_pixel as f32;
+
         let viewport_height = VIEWPORT_HEIGHT;
         let viewport_width = viewport_height * (image_width as f32 / image_height as f32);
 
@@ -48,6 +53,23 @@ impl Camera {
             pixel_upper_left,
             delta_pixel_u,
             delta_pixel_v,
+            samples_per_pixel,
+            pixel_samples_scale,
+        }
+    }
+
+    fn get_ray(&self, i: usize, j: usize) -> Ray {
+        let offset = sample_square();
+        let pixel_sample = self.pixel_upper_left
+            .add(&self.delta_pixel_u.scalar_mul(i as f32 + offset.x))
+            .add(&self.delta_pixel_v.scalar_mul(j as f32 + offset.y));
+
+        let ray_origin = self.center;
+        let ray_direction = pixel_sample.sub(&ray_origin);
+
+        Ray {
+            origin: ray_origin,
+            direction: ray_direction,
         }
     }
 
@@ -75,16 +97,14 @@ impl Camera {
     pub fn render(&self, display_buffer: &mut DisplayBuffer, world: &HittableList) {
         (0..self.image_height).for_each(|j| {
             (0..self.image_width).for_each(|i| {
-                let pixel_center = self.pixel_upper_left
-                    .add(&self.delta_pixel_u.scalar_mul(i as f32))
-                    .add(&self.delta_pixel_v.scalar_mul(j as f32));
-                let ray_direction = pixel_center.sub(&self.center);
-                let ray = Ray {
-                    origin: &self.center,
-                    direction: &ray_direction,
-                };
-                let color = self.ray_color(&ray, &world);
-                display_buffer[j][i] = Pixel::from_color(&color);
+                let mut pixel_color = Color::new(0.0, 0.0, 0.0);
+                (0..self.samples_per_pixel).for_each(|_| {
+                    let r = self.get_ray(i, j);
+                    let ray_color = self.ray_color(&r, world);
+                    pixel_color = pixel_color.add(&ray_color);
+                });
+                pixel_color = pixel_color.mul_scalar(self.pixel_samples_scale);
+                display_buffer[j][i] = Pixel::from_color(&pixel_color);
             })
         })
     }
-- 
cgit v1.2.3-70-g09d2