From af587dc1d7c30e8ad6af8afda09b78b584d416dc Mon Sep 17 00:00:00 2001
From: Martin Lehoux <martin@lehoux.net>
Date: Sat, 4 Apr 2020 18:23:43 -0700
Subject: feat - Antialliasing and camera

---
 camera.go | 17 +++++++++++++++++
 main.go   | 15 ++++++++++++---
 2 files changed, 29 insertions(+), 3 deletions(-)
 create mode 100644 camera.go

diff --git a/camera.go b/camera.go
new file mode 100644
index 0000000..6575390
--- /dev/null
+++ b/camera.go
@@ -0,0 +1,17 @@
+package main
+
+type Camera struct {
+	lower_left_corner            Vec3D
+	origin, horizontal, vertical Vec3D
+}
+
+func (camera Camera) GetRay(u float64, v float64) Ray {
+	return Ray{
+		camera.origin,
+		AddVec3D(AddVec3D(
+			camera.lower_left_corner,
+			ScalarProduct(u, camera.horizontal)),
+			ScalarProduct(v, camera.vertical),
+		),
+	}
+}
diff --git a/main.go b/main.go
index daf2718..f85ad8a 100644
--- a/main.go
+++ b/main.go
@@ -1,15 +1,19 @@
 package main
 
+import "math/rand"
+
 const HEIGHT = 100
 const WIDTH = 200
 const T_MIN = 0.001
 const T_MAX = 1000
+const RAY_PER_PIXEL = 100
 
 func main() {
 	LOWER_LEFT_CORNER := Vec3D{-2.0, -1.0, -1.0}
 	ORIGIN := Vec3D{0.0, 0.0, 0.0}
 	HORIZONTAL := Vec3D{4.0, 0.0, 0.0}
 	VERTICAL := Vec3D{0.0, 2.0, 0.0}
+	CAMERA := Camera{LOWER_LEFT_CORNER, ORIGIN, HORIZONTAL, VERTICAL}
 
 	SPHERE := Sphere{Vec3D{0.0, 0.0, -1.0}, 0.5}
 	EARTH := Sphere{Vec3D{0.0, -100.5, -1.0}, 100.0}
@@ -18,9 +22,14 @@ func main() {
 	frame := Frame{}
 	for x := 0; x < HEIGHT; x++ {
 		for y := 0; y < WIDTH; y++ {
-			u, v := float64(y)/float64(WIDTH), float64(x)/float64(HEIGHT)
-			ray := Ray{ORIGIN, AddVec3D(AddVec3D(LOWER_LEFT_CORNER, ScalarProduct(u, HORIZONTAL)), ScalarProduct(v, VERTICAL))}
-			color := RayColor(ray, WORLD)
+			var color_list [RAY_PER_PIXEL]Color
+			for it := 0; it < RAY_PER_PIXEL; it++ {
+				u := (float64(y) + rand.Float64()) / float64(WIDTH)
+				v := (float64(x) + rand.Float64()) / float64(HEIGHT)
+				ray := CAMERA.GetRay(u, v)
+				color_list[it] = RayColor(ray, WORLD)
+			}
+			color := ColorMeanSquare(color_list)
 			frame[HEIGHT-1-x][y] = color.ToPixel()
 		}
 	}
-- 
cgit v1.3