From 3396a44710415bde9509afeb02f3ec10a22c6661 Mon Sep 17 00:00:00 2001
From: Roland Hieber <rohieb@rohieb.name>
Date: Wed, 27 Jan 2010 12:57:24 +0100
Subject: [PATCH 1/1] not finished yet, but better than before

---
 Image.cxx       | 18 ++++++++++++------
 PhongShader.cxx | 13 +++++++------
 PointLight.cxx  |  7 +++++--
 3 files changed, 24 insertions(+), 14 deletions(-)

diff --git a/Image.cxx b/Image.cxx
index b45cac9..bc8134b 100644
--- a/Image.cxx
+++ b/Image.cxx
@@ -39,28 +39,34 @@ Image::operator()(int x, int y)
 {
   assert(x >= 0 && x < m_resX);
   assert(y >= 0 && y < m_resY);
-	 
-  return m_pixel[y*m_resX+x];	 
+
+  return m_pixel[y*m_resX+x];
 }
 
 void Image::WritePPM(const std::string& fileName)
 {
   std::cerr << "(Image): Writing to file " << fileName << std::endl;
   std::ofstream file(fileName.c_str());
-  
+
   if(!file.is_open())
     {
       std::cerr << "(Image): Could not open file " << fileName << std::endl;
       return;
     }
-  
+
   file << "P3" << std::endl;
   file << m_resX << " " << m_resY << " " << 255 << std::endl;
-  for (int y=m_resY-1;y>=0;y--) 
+  for (int y=m_resY-1;y>=0;y--)
     {
       for (int x=0;x<m_resX;x++)
 	{
-	  file 
+        if ((*this)(x,y)[0] < 0) (*this)(x,y)[0] = 0;
+        if ((*this)(x,y)[1] < 0) (*this)(x,y)[1] = 0;
+        if ((*this)(x,y)[2] < 0) (*this)(x,y)[2] = 0;
+        if ((*this)(x,y)[0] > 255) (*this)(x,y)[0] = 255;
+        if ((*this)(x,y)[1] > 255) (*this)(x,y)[1] = 255;
+        if ((*this)(x,y)[2] > 255) (*this)(x,y)[2] = 255;
+	  file
 	    << (int)(255.99999999 * (*this)(x,y)[0]) << " "
 	    << (int)(255.99999999 * (*this)(x,y)[1]) << " "
 	    << (int)(255.99999999 * (*this)(x,y)[2]) << " "
diff --git a/PhongShader.cxx b/PhongShader.cxx
index 67363a6..c44966e 100644
--- a/PhongShader.cxx
+++ b/PhongShader.cxx
@@ -34,16 +34,16 @@ PhongShader::Shade(Ray& ray)
 {
   // surface normal at hit point of object
   Vec3f normal = ray.hit()->GetNormal(ray);
-  // turn to fron if angle < 90°
+  // turn to front if angle > 90°
   if(normal.dot(ray.direction()) < 0) {
     normal = normal * -1;
   }
   // direction of reflection
-  Vec3f refl_dir = ray.direction() - normal * 2 * (normal % ray.direction());
+  Vec3f refl_dir = ray.direction() - normal * 2 * normal.dot(ray.direction());
   refl_dir.normalize();
 
-  // ambient color term - radiance is 1 since we have point light
-  Vec3f amb_color = m_ambient_color * m_ka * 1.0f;
+  // ambient color term
+  Vec3f amb_color = m_ambient_color * m_ka;
 
   Vec3f intensity, light_dir;
 
@@ -55,10 +55,11 @@ PhongShader::Shade(Ray& ray)
     Ray light_ray;
     (*it)->Illuminate(light_ray, intensity);
     diff_sum += intensity * light_ray.direction().dot(normal);
-    spec_sum += intensity * light_ray.direction().dot(refl_dir);
+    Vec3f view_dir = ray.direction()*-1; // direction from hitpoint to viewer
+    spec_sum += intensity * pow(fmax(view_dir.dot(refl_dir),0), m_ke);
   }
   Vec3f diff_color = m_diffuse_color * m_kd * diff_sum;
   Vec3f spec_color = m_specular_color * m_ks * spec_sum;
 
-  return amb_color + diff_color + spec_sum;
+  return amb_color + diff_color + spec_color;
 }
diff --git a/PointLight.cxx b/PointLight.cxx
index 2efe585..925a6b5 100644
--- a/PointLight.cxx
+++ b/PointLight.cxx
@@ -21,15 +21,18 @@ PointLight::PointLight()
 bool
 PointLight::Illuminate(Ray& ray, Vec3f& intensity)
 {
-  float dist = ((ray.origin() + ray.direction() * ray.t()) - m_pos).norm();
+  Vec3f dir = (ray.origin() + ray.direction() * (ray.t()-Epsilon)) - m_pos;
+  float dist = dir.norm();
+  dir.normalize();
 
   float c1 = 1, c2 = 0.5, c3 = 0;
+  //float f_att = 1 / (dist*dist);
   float f_att = 1 / (c1 + c2*dist + c3*dist*dist);
 
   intensity = m_intensity * f_att;
 
   // store direction from light to hitpoint
-  ray.setDir(ray.origin() + ray.direction() * (ray.t()-Epsilon) - m_pos);
+  ray.setDir(dir);
   return true;
 }
 
-- 
2.20.1