From 6815404ba8b5625cedaa22e3abeadc814f263880 Mon Sep 17 00:00:00 2001
From: ubuntu20 <klm777x7@gmail.com>
Date: Sun, 8 Nov 2020 14:18:05 +0800
Subject: [PATCH] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=E9=87=91=E5=B1=9E=E6=9D=90?=
 =?UTF-8?q?=E8=B4=A8?=
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---
 Material.cpp | 6 ++++++
 Material.h   | 6 ++++++
 Scene.cpp    | 4 +++-
 Vector3.cpp  | 5 +++++
 Vector3.h    | 1 +
 5 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/Material.cpp b/Material.cpp
index c5f1c27..dd140fa 100644
--- a/Material.cpp
+++ b/Material.cpp
@@ -8,3 +8,9 @@ bool LamberMaterial::Scatter(const Ray & input_ray, const HitPoint & hit_point,
 	out_ray.Set(hit_point.mPosition, new_direction, input_ray.mLightAttenuation*mDiffuse);
 	return true;
 }
+bool MetalMaterial::Scatter(const Ray & input_ray, const HitPoint & hit_point, Ray & out_ray)
+{
+	Vector3 new_direction = Reflect(input_ray.mDirection, hit_point.mNormal);
+	out_ray.Set(hit_point.mPosition, new_direction, input_ray.mLightAttenuation*mDiffuse);
+	return true;
+}
\ No newline at end of file
diff --git a/Material.h b/Material.h
index a0a2472..44aa762 100644
--- a/Material.h
+++ b/Material.h
@@ -10,4 +10,10 @@ public:
 	Vector3 mDiffuse;
 	LamberMaterial(const Vector3 diffuse) { mDiffuse = diffuse; }
 	bool Scatter(const Ray& input_ray, const HitPoint& hit_point, Ray& out_ray);
+};
+class MetalMaterial : public Material {
+public:
+	Vector3 mDiffuse;
+	MetalMaterial(const Vector3 diffuse) { mDiffuse = diffuse; }
+	bool Scatter(const Ray& input_ray, const HitPoint& hit_point, Ray& out_ray);
 };
\ No newline at end of file
diff --git a/Scene.cpp b/Scene.cpp
index ea2169a..2a1fcc6 100644
--- a/Scene.cpp
+++ b/Scene.cpp
@@ -13,7 +13,7 @@ static Camera* sCamera = nullptr;
 Sphere sphere(Vector3(0.0f, 0.5f, 0.0f), 0.5f);
 static Object* sRootObject = nullptr;
 static Material* lambert = nullptr;
-static int sSampleCount = 64;
+static int sSampleCount = 128;
 static int sMaxBounceTime = 30;
 void AddObject(Object* object) {
 	if (sRootObject == nullptr) {
@@ -31,7 +31,9 @@ void Init(int width, int height)
 	sCamera = new Camera(45.0f, float(width) / float(height));
 	sCamera->LookAt(Vector3(3.0f, 1.0f, 3.0f), Vector3(0.0f, 0.0f, 0.0f), Vector3(0.0f, 1.0f, 0.0f));
 	Material* earth_material = new LamberMaterial(Vector3(0.5f, 0.3f, 0.1f));
+	Material* metal_material = new MetalMaterial(Vector3(0.9f,0.9f,0.9f));
 	AddObject(new Object(new Sphere(Vector3(0.0f, -1000.0f, 0.0), 1000.0f), earth_material));
+	AddObject(new Object(new Sphere(Vector3(-1.0f, 0.5f, 0.3), 0.5f), metal_material));
 	lambert = new LamberMaterial(Vector3(0.1f, 0.4f, 0.7f));
 	AddObject(new Object(&sphere, lambert));
 }
diff --git a/Vector3.cpp b/Vector3.cpp
index 5d791a9..7bfc18d 100644
--- a/Vector3.cpp
+++ b/Vector3.cpp
@@ -71,6 +71,11 @@ Vector3 Cross(const Vector3 & l, const Vector3 & r)
 	return Vector3(l.y*r.z - l.z*r.y, l.z*r.x - l.x*r.z, l.x*r.y - l.y*r.x);
 }
 
+Vector3 Reflect(const Vector3 & v, const Vector3 & n)
+{
+	return v - 2.0f * (Dot(v, n) * n);
+}
+
 Vector3 UnitRandomVector3InSphere()
 {
 	Vector3 random_vector(srandf(), srandf(), srandf());
diff --git a/Vector3.h b/Vector3.h
index 301334c..e537efc 100644
--- a/Vector3.h
+++ b/Vector3.h
@@ -38,6 +38,7 @@ public:
 Vector3 operator*(float f, const Vector3& v);
 float Dot(const Vector3& l, const Vector3& r);
 Vector3 Cross(const Vector3& l, const Vector3& r);
+Vector3 Reflect(const Vector3& v, const Vector3& n);
 class Material;
 struct HitPoint {
 	Vector3 mPosition;