complete lesson 2

README.md

@@ -14,4 +14,5 @@ As of lesson 1, there is no `webpack.config.js`, just run webpack since
 ## Progress
 
 - [x] Lesson 1
-- [ ] Lesson 2
+- [x] Lesson 2
+- [ ] Lesson 3

src/geometry/sphere.js

@@ -12,7 +12,7 @@ class Sphere {
 
   intersection(ray) {
 
-    let cPrime = ray.direction.origin._minus(this.center);
+    let cPrime = ray.origin._minus(this.center);
 
     // quadratic variables
     let a = ray.direction.length() * ray.direction.length();
@@ -39,4 +39,4 @@ class Sphere {
   }
 }
 
-export default Geometry;
+export default Sphere;

src/index.js

@@ -1,4 +1,4 @@
 
-import main from './lessons/lesson01';
+import main from './lessons/lesson02';
 
 main();

src/lessons/lesson02.js

@@ -0,0 +1,15 @@
+
+import Scene from '../scenes/scene';
+import View from '../view';
+
+function main() {
+
+  const view = View.createDefaultView();
+
+  let scene = new Scene();
+  scene.generateRandomSpheres();
+  let image = view.viewScene(scene);
+
+  image.renderInto(document.querySelector('body'));
+}
+export default main;

src/view/index.js

@@ -80,10 +80,41 @@ class View {
 
         let pointray = this._bilinearInterpolation(x, y);
         let color = scene.backgroundColor;
-        // loop through scene objects getting T-values
-        // add color for the lowest to value or add default color
+        let objects = scene.getObjects();
+        let bestT = null;
+        let bestO = null;
+
+        for (let i = 0; i < objects.length; ++i) {
+
+          let o = objects[i];
+          let t = o.intersection(pointray.ray);
+
+          if (t !== null) {
+
+            // console.log(t);
+
+            if (bestT === null) {
+              bestT = t;
+              bestO = o;
+            }
+            else {
+              if (t < bestT) {
+                bestT = t;
+                bestO = o;
+              }
+            }
+          }
+        }
+
+        if (bestO !== null) {
+          // console.log(bestO.color);
+          color = bestO.color.normalized();
+        }
+        image.putPixel(x, y, color);
       }
     }
+
+    return image;
   }
 };