1 files changed, 73 insertions, 0 deletions
diff --git a/hitlist.h b/hitlist.h
new file mode 100644
index 0000000..18a8226
--- /dev/null
+++ b/hitlist.h
@@ -0,0 +1,73 @@
+//
+// Created by Keuin on 2022/4/12.
+//
+
+#ifndef RT_HITLIST_H
+#define RT_HITLIST_H
+
+#include "viewport.h"
+#include "timer.h"
+#include "bitmap.h"
+#include "ray.h"
+#include "vec.h"
+#include "object.h"
+#include <cstdlib>
+#include <memory>
+#include <limits>
+#include <vector>
+#include <iostream>
+#include <cstdint>
+
+
+// A world
+class hitlist {
+    std::vector<std::shared_ptr<object>> objects;
+
+public:
+    hitlist() = default;
+
+    hitlist(hitlist &other) = delete; // do not copy the world
+
+    // Add an object to the world.
+    void add_object(std::shared_ptr<object> &&obj) {
+        objects.push_back(std::move(obj));
+    }
+
+    // Given a ray, compute the color.
+    pixel8b color(const ray3d &r) const {
+        // Detect hits
+        bool hit = false;
+        double hit_t = std::numeric_limits<double>::infinity();
+        std::shared_ptr<object> hit_obj;
+        // Check the nearest object we hit
+        for (const auto &obj: objects) {
+            double t_;
+            if (obj->hit(r, t_, 0.0) && t_ < hit_t) {
+                hit = true;
+                hit_t = t_;
+                hit_obj = obj;
+            }
+        }
+        if (hit) {
+            // normal vector on hit point
+            const auto nv = hit_obj->normal_vector(r.at(hit_t));
+//                return obj->color();
+            // visualize normal vector at hit point
+            return pixel8b::from_normalized(nv);
+        }
+
+
+        // Does not hit anything. Get background color (infinity)
+        const auto u = (r.direction().y + 1.0) * 0.5;
+        return mix(
+                pixel8b::from_normalized(1.0, 1.0, 1.0),
+                pixel8b::from_normalized(0.5, 0.7, 1.0),
+                1.0 - u,
+                u
+        );
+    }
+
+
+};
+
+#endif //RT_HITLIST_H