From 37f54190e8b190b403d7832da9f0e101df94541a Mon Sep 17 00:00:00 2001
From: Michael Zhang <mail@mzhang.io>
Date: Wed, 15 Feb 2023 02:08:21 -0600
Subject: [PATCH] impl depth cueing

---
 assignment-1b/Makefile                  |  2 +-
 assignment-1b/examples/objects.txt      | 20 ++++++++++++---
 assignment-1b/src/scene/data.rs         | 10 ++++----
 assignment-1b/src/scene/illumination.rs | 34 ++++++++++++++++++++++---
 assignment-1b/src/scene/input_file.rs   | 26 ++++++++++++++++---
 5 files changed, 76 insertions(+), 16 deletions(-)

diff --git a/assignment-1b/Makefile b/assignment-1b/Makefile
index de80502..8f1e734 100644
--- a/assignment-1b/Makefile
+++ b/assignment-1b/Makefile
@@ -33,7 +33,7 @@ $(HANDIN): $(BINARY) $(WRITEUP) Makefile Cargo.toml Cargo.lock README.md $(EXAMP
 	$(ZIP) -r $@ src examples $^
 
 examples/%.ppm: examples/%.txt $(SOURCES)
-	cargo run -- -o $@ $<
+	cargo run --release -- -o $@ $<
 
 examples/%.png: examples/%.ppm
 	convert $< $@
diff --git a/assignment-1b/examples/objects.txt b/assignment-1b/examples/objects.txt
index 8b68339..f7ba514 100644
--- a/assignment-1b/examples/objects.txt
+++ b/assignment-1b/examples/objects.txt
@@ -5,8 +5,10 @@ hfov 60
 updir 0 1 0
 bkgcolor 0.1 0.1 0.1
 
-light -10 10 -3 0 0 0.4 0.4
-light 10 10 -3 1 0.4 0 0.4
+depthcueing 0.1 0.1 0.1 1 0.2 100 5
+
+light -10 10 -3 0 0.8 0.8 0.8
+light -10 10 -3 1 0.8 0.8 0.8
 
 mtlcolor 0 0.5 0.5 1 1 1 0.2 0.4 0 10
 sphere -1 -2 -5 2
@@ -16,10 +18,20 @@ mtlcolor 0.5 0.5 1 0.4 0.4 0.4 0.2 0.4 0 10
 sphere 1 2 -3 3
 sphere -6 3 -4 1
 
+mtlcolor 1.0 0 0.5 0.6 0.4 0.2 0.2 0.4 0 10
+sphere 20 20 -50 6
+
 mtlcolor 0.5 0 0.5 0.6 0.4 0.2 0.2 0.4 0 10
-sphere 5 5 -1 1
 sphere -6 -4 -8 7
-cylinder -2 4 -3 0 0 5 1 4
+
+mtlcolor 0.8 0 0.3 0.6 0.4 0.2 0.2 0.4 0 10
+cylinder -2 2 -3 0 0 5 1 4
+
+mtlcolor 0.8 0.8 0.3 0.6 0.4 0.2 0.2 0.4 0 10
+sphere -40 35 -80 7
+sphere -25 20 -60 5
+sphere -12.5 15 -40 3
+sphere -6 11 -20 1.5
 
 mtlcolor 0.5 1 0.5 0.2 0.4 0.8 0.2 0.4 0 10
 cylinder 5 1 -2 1 -2 1 1 2
diff --git a/assignment-1b/src/scene/data.rs b/assignment-1b/src/scene/data.rs
index d375357..6ce9b0f 100644
--- a/assignment-1b/src/scene/data.rs
+++ b/assignment-1b/src/scene/data.rs
@@ -67,11 +67,11 @@ pub struct Light {
 
 #[derive(Debug, Default)]
 pub struct DepthCueing {
-  color: Color,
-  a_max: f64,
-  a_min: f64,
-  dist_max: f64,
-  dist_min: f64,
+  pub color: Color,
+  pub a_max: f64,
+  pub a_min: f64,
+  pub dist_max: f64,
+  pub dist_min: f64,
 }
 
 impl Scene {
diff --git a/assignment-1b/src/scene/illumination.rs b/assignment-1b/src/scene/illumination.rs
index 250a5eb..f129ec5 100644
--- a/assignment-1b/src/scene/illumination.rs
+++ b/assignment-1b/src/scene/illumination.rs
@@ -3,7 +3,10 @@ use ordered_float::NotNan;
 
 use crate::image::Color;
 
-use super::{data::LightKind, Scene};
+use super::{
+  data::{DepthCueing, LightKind},
+  Scene,
+};
 
 /// Information about an intersection
 #[derive(Derivative)]
@@ -86,9 +89,34 @@ impl Scene {
       })
       .sum();
 
-    let result = ambient_component + diffuse_and_specular;
+    let color = ambient_component + diffuse_and_specular;
+
+    // Apply depth cueing to the result
+    let a_dc = {
+      // Distance from the viewer
+      let d_obj = (intersection_context.point - self.eye_pos).norm();
+      let DepthCueing {
+        dist_max,
+        dist_min,
+        a_max,
+        a_min,
+        ..
+      } = self.depth_cueing;
+
+      if d_obj < dist_min {
+        a_max
+      } else if d_obj < dist_max {
+        a_min + (a_max - a_min) * (dist_max - d_obj) / (dist_max - dist_min)
+      } else {
+        a_min
+      }
+    };
+
+    let color = a_dc * color + (1.0 - a_dc) * self.depth_cueing.color;
 
     // Need to clamp the result so none of the components goes over 1
-    result.map(|v| v.min(1.0))
+    let clamped_result = color.map(|v| v.min(1.0));
+
+    clamped_result
   }
 }
diff --git a/assignment-1b/src/scene/input_file.rs b/assignment-1b/src/scene/input_file.rs
index a1c7226..e2114f8 100644
--- a/assignment-1b/src/scene/input_file.rs
+++ b/assignment-1b/src/scene/input_file.rs
@@ -10,6 +10,8 @@ use crate::scene::{
   Scene,
 };
 
+use super::data::DepthCueing;
+
 impl Scene {
   /// Parse the input file into a scene
   pub fn from_input_file(path: impl AsRef<Path>) -> Result<Self> {
@@ -50,9 +52,8 @@ impl Scene {
           .collect::<Result<Vec<_>>>()?;
 
         let read_vec3 = |start: usize| {
-          if parts.len() < start + 3 {
-            bail!("Vec3 requires 3 components.");
-          }
+          ensure!(parts.len() >= start + 3, "Vec3 requires 3 components.");
+
           Ok(Vector3::new(
             parts[start],
             parts[start + 1],
@@ -68,7 +69,10 @@ impl Scene {
           "hfov" => scene.hfov = parts[0],
           "bkgcolor" => scene.bkg_color = read_vec3(0)?,
 
+          // light x y z w r g b
           "light" => {
+            ensure!(parts.len() == 7, "Light requires 7 params");
+
             let kind = match parts[3] as usize {
               0 => LightKind::Directional {
                 direction: read_vec3(0)?,
@@ -85,8 +89,24 @@ impl Scene {
             scene.lights.push(light);
           }
 
+          // depthcueing dcr dcg dcb amax amin distmax distmin
+          "depthcueing" => {
+            ensure!(parts.len() == 7, "Depth cueing requires 7 params");
+
+            let color = read_vec3(0)?;
+            scene.depth_cueing = DepthCueing {
+              color,
+              a_max: parts[3],
+              a_min: parts[4],
+              dist_max: parts[5],
+              dist_min: parts[6],
+            };
+          }
+
           // mtlcolor Odr Odg Odb Osr Osg Osb ka kd ks n
           "mtlcolor" => {
+            ensure!(parts.len() == 10, "Material color requires 10 params");
+
             let diffuse_color = read_vec3(0)?;
             let specular_color = read_vec3(3)?;