Chapter 6: Antialiasing

code/rt_weekend.cpp

@@ -1,48 +1,53 @@
+#include <float.h>
 #include "rt_weekend.h"
-#include "ray.h"
+#include "sphere.h"
+#include "target_list.h"
+#include "camera.h"
 
-bool hit_sphere(const vec3 &center, float radius, const ray &r)
+vec3 color(const ray &r, target *world)
 {
-    vec3 oc = r.origin() - center;
-    float a = dot(r.direction(), r.direction());
-    float b = 2.0 * dot(oc, r.direction());
-    float c = dot(oc, oc) - radius * radius;
-    float discriminant = b * b - 4 * a * c;
-
-    return (discriminant > 0);
-}
-
-vec3 color (const ray &r)
-{
-    if (hit_sphere(vec3(0, 0, -1), 0.5, r))
-        return vec3(1, 0, 0);
-    vec3 unit_direction = unit_vector(r.direction());
-    float t = 0.5 * (unit_direction.y() + 1.0);
-    return (1.0 - t) * vec3(1.0, 1.0, 1.0) + t * vec3(0.5, 0.7, 1.0);
+    hit_record rec;
+    if (world->hit(r, 0.0, MAXFLOAT, rec))
+    {
+        return 0.5 * vec3(rec.normal.x() + 1, rec.normal.y() + 1, rec.normal.z() + 1);
+    }
+    else
+    {
+        vec3 unit_direction = unit_vector(r.direction());
+        float t = 0.5 * (unit_direction.y() + 1.0);
+        return (1.0 - t) * vec3(1.0, 1.0, 1.0) + t * vec3(0.5, 0.7, 1.0);
+    }
 }
 
 extern "C"
 void
 PluginUpdateAndRender(plugin_offscreen_buffer *Buffer)
 {
+    int ns = 1;
     int Pitch = Buffer->Pitch;
     uint8_t *Row = (uint8_t *)Buffer->Memory;
 
-    vec3 lower_left_corner(-2.0, -1.0, -1.0);
-    vec3 horizontal(4.0, 0.0, 0.0);
-    vec3 vertical(0.0, 2.0, 0.0);
-    vec3 origin(0.0, 0.0, 0.0);
-
+    target *list[2];
+    list[0] = new sphere(vec3(0, 0, -1), 0.5);
+    list[1] = new sphere(vec3(0, -100.5, -1), 100);
+    target *world = new target_list(list, 2);
+    camera cam;
 
     for(int j = Buffer->Height - 1; j >= 0; j--)
     {
         uint32_t *Pixel = (uint32_t *)Row;
         for(int i = 0; i < Buffer->Width; i++)
         {
-            float u = float(i) / float(Buffer->Width);
-            float v = float(j) / float(Buffer->Height);
-            ray r(origin, lower_left_corner + u * horizontal + v * vertical);
-            vec3 col = color(r);
+            vec3 col(0, 0, 0);
+            for (int s = 0; s < ns; s++)
+            {
+                float u = float(i + drand48()) / float(Buffer->Width);
+                float v = float(j + drand48()) / float(Buffer->Height);
+                ray r = cam.get_ray(u, v);
+                vec3 p = r.point_at_parameter(2.0);
+                col += color(r, world);
+            }
+            col /= float(ns);
             int ir = int(255.99 * col[0]);
             int ig = int(255.99 * col[1]);
             int ib = int(255.99 * col[2]);