1 files changed, 69 insertions, 0 deletions
diff --git a/hw6/src/spotLightsource.cpp b/hw6/src/spotLightsource.cpp
new file mode 100644
index 0000000..9b4d0ab
--- /dev/null
+++ b/hw6/src/spotLightsource.cpp
@@ -0,0 +1,69 @@
+/******************************************************************/
+/* This file is part of the homework assignments for CSCI-427/527 */
+/* at The College of William & Mary and authored by Pieter Peers. */
+/* No part of this file, whether altered or in original form, can */
+/* be distributed or used outside the context of CSCI-427/527     */
+/* without consent of either the College of William & Mary or     */
+/* Pieter Peers.                                                  */
+/******************************************************************/
+#include <cmath>
+#include "constants.h"
+#include "spotLightsource.h"
+
+//////////////////
+// Constructors //
+//////////////////
+spotLightsource::spotLightsource(const vec3d& position, const vec3d& direction, float cutoffDegrees, float sharpness, const color& power, const vec3d& attenuation)
+{
+  _position = position;
+  _direction = normalize(direction);
+  _cutoff = cos(cutoffDegrees * PI / 180.0f);
+  _sharpness = sharpness;
+  _power = power;
+  _attenuation = attenuation;
+}
+
+
+/////////////
+// Methods //
+/////////////
+lightSample spotLightsource::intensityAt(const vec3d& point) const
+{
+  vec3d direction = point - _position;
+  float distance = direction.length();
+  float cosAngle = _direction.dot(direction) / distance;
+
+  // check if outside cone
+  if(cosAngle < _cutoff) return lightSample(direction, color(0.0f, 0.0f, 0.0f), distance);
+
+  // compute attenuation & scale
+  float attenuation = ((_attenuation[2]*distance + _attenuation[1])*distance + _attenuation[0]);
+  float scale = pow(cosAngle, _sharpness);
+
+  // Done.
+  return lightSample(direction, _power * scale / attenuation, distance);
+}
+
+
+lightSample spotLightsource::emittanceAt(const vec3d& point, float r1, float r2) const
+{
+  vec3d direction = point - _position;
+  float distance = direction.length();
+  float cosAngle = _direction.dot(direction) / distance;
+
+  // compute emittance
+  color emittance = (cosAngle < _cutoff) ? color(0.0f, 0.0f, 0.0f) : _power * pow(cosAngle, _sharpness) / (4.0f * PI);
+
+  // Done.
+  // PDF = 1.0 => there is only a single point
+  // Foreshortening => no normal
+  return lightSample(direction, emittance, distance, 1.0f, 1.0f);
+}
+
+/////////////////////
+// Private Methods //
+/////////////////////
+void spotLightsource::_print(std::ostream& s) const
+{
+  s << "Spot Lightsource: position=" << _position << ", direction=" << _direction << ", cutoff=" << (acos(_cutoff)*180.0f/PI) << ", sharpness=" << _sharpness << ", power=" << _power << ", attenuation=" << _attenuation;  
+}