From cb8db6a0b6466a934f637441d64a6bfc6b3227a6 Mon Sep 17 00:00:00 2001
From: Nathan Vegdahl <cessen@cessen.com>
Date: Sat, 2 Jan 2016 11:17:52 -0800
Subject: [PATCH] Added command-line control of sample count, and more
 interesting default scene.

---
 src/main.rs | 48 ++++++++++++++++++++++++++++--------------------
 1 file changed, 28 insertions(+), 20 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index c1ca8aa..006ecf0 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -31,18 +31,22 @@ const USAGE: &'static str = r#"
 Psychopath <VERSION>
 
 Usage:
-  psychopath <imgpath>
+  psychopath [options] <imgpath>
   psychopath (-h | --help)
   psychopath --version
 
 Options:
-  -h --help     Show this screen.
-  --version     Show version.
+  -i <input_file>       Input .psy file
+  -s <n>, --spp <n>     Number of samples per pixel [default: 16].
+  -h, --help            Show this screen.
+  --version             Show version.
 "#;
 
 #[derive(Debug, RustcDecodable)]
 struct Args {
     arg_imgpath: String,
+    flag_input_file: Option<String>,
+    flag_spp: Option<u32>,
     flag_version: bool,
 }
 
@@ -73,25 +77,30 @@ fn main() {
         return;
     }
 
+    let samples_per_pixel = args.flag_spp.unwrap_or_else(|| 16);
+    println!("Sample count: {}", samples_per_pixel);
+
     println!("Ray size: {} bytes", mem::size_of::<Ray>());
 
     // Generate a scene of triangles
     let mut triangles = {
         let mut triangles = Vec::new();
-        let xres = 16;
-        let yres = 16;
+        let xres = 32;
+        let yres = 32;
         let xinc = 512.0 / (xres as f32);
         let yinc = 512.0 / (yres as f32);
         for x in 0..xres {
             for y in 0..yres {
-                let cx = x as f32 * xinc;
-                let cy = y as f32 * yinc;
-                triangles.push((Point::new(cx, cy, 1.0),
-                                Point::new(cx + xinc, cy, 1.1),
-                                Point::new(cx, cy + yinc, 1.2)));
-                triangles.push((Point::new(cx + xinc, cy + yinc, 1.0),
-                                Point::new(cx, cy + yinc, 1.1),
-                                Point::new(cx + xinc, cy, 1.2)));
+                let i = y * xres + x;
+                let cx = halton::sample(0, i) * 512.0;
+                let cy = halton::sample(1, i) * 512.0;
+                let cz = halton::sample(2, i) * 512.0;
+                triangles.push((Point::new(cx, cy, cz + 1.0),
+                                Point::new(cx + xinc, cy, cz + 1.1),
+                                Point::new(cx, cy + yinc, cz + 1.2)));
+                triangles.push((Point::new(cx + xinc, cy + yinc, cz + 1.0),
+                                Point::new(cx, cy + yinc, cz + 1.1),
+                                Point::new(cx + xinc, cy, cz + 1.2)));
             }
         }
         triangles
@@ -114,17 +123,16 @@ fn main() {
     for y in 0..img.height() {
         for x in 0..img.width() {
             let offset = hash_u32(((x as u32) << 16) ^ (y as u32), 0);
-            const SAMPLES: usize = 16;
 
             // Generate rays
             rays.clear();
             isects.clear();
-            for si in 0..SAMPLES {
-                let mut ray = Ray::new(Point::new(x as f32 +
+            for si in 0..samples_per_pixel {
+                let mut ray = Ray::new(Point::new(0.5 + x as f32 +
                                                   fast_logit(halton::sample(0,
                                                                             offset + si as u32),
                                                              1.5),
-                                                  y as f32 +
+                                                  0.5 + y as f32 +
                                                   fast_logit(halton::sample(3,
                                                                             offset + si as u32),
                                                              1.5),
@@ -162,9 +170,9 @@ fn main() {
                     b += 0.1;
                 }
             }
-            r *= 255.0 / SAMPLES as f32;
-            g *= 255.0 / SAMPLES as f32;
-            b *= 255.0 / SAMPLES as f32;
+            r *= 255.0 / samples_per_pixel as f32;
+            g *= 255.0 / samples_per_pixel as f32;
+            b *= 255.0 / samples_per_pixel as f32;
 
             // Set pixel color
             img.set(x, y, (r as u8, g as u8, b as u8));