RayTracer.cpp

#include "RayTracer.h"
#include "Camera.h"
#include "Collision.h"
#include "Plane.h"
#include "Lighting.h"
#include "Material.h"


#include <chrono>
#include <iostream>
#include <memory>
#include <thread>
using namespace std;
//Frankie
void RayTracer::clear() const {//makes a blank white screen
  for(int i = 0; i< m_width * m_height; i++){
    m_frame[i]=glm::vec4(0.f,0.f,0.f,0.f);
  }
}
//Frankie/Patrick
glm::vec3 getDirection(float col, float right, float left, float pixelX, 
                       float row, float top, float bott, float pixelY, const Camera& c){
  
  float tau = left + ((right - left)/pixelX)*(col + 0.5);
  float sigma = bott + ((top - bott)/pixelY)*(row + 0.5);
  glm::vec3 dir = -c.getFocal()*glm::vec3{0, 0, 1} + tau*glm::vec3{1, 0, 0} + sigma*glm::vec3{0, 1, 0};
  //u, v, w will just be the unit vectors
  return glm::normalize(dir);

}

//Patrick/Kristina
Collision isCollision(const Ray& r, const Scene& s){

  Collision dummy = Collision();

  for(int k = 0; k<s.getObj().size(); k++){//iterates through objects in scene to look for collisions with the ray
        Collision h_ = s.getObj()[k]->collide(r);//tests to see if a ray has collided with scene object

        //figure out if it hits something and then get the color of the x value
        //get the x value and the color and then send it into the g_frame
        if(h_.m_type==Collision::Type::kHit){
          if(dummy.m_t == 0){
            dummy = h_;
          }else if(h_.m_t < dummy.m_t){//used to compare t values if our ray hits more than one obj
            dummy = h_;
          }
          
        }
  }
  return dummy;
  
}

//Frankie Z/Patrick L/Kristina
void RayTracer::render(const Scene& _scene) const {
  const Camera &camera = _scene.getCam();
  int length=1360;
  int height= 768;

  for(int i = 0; i<length; i++){//length is # of col
    for(int j = 0; j<height; j++){//height is # of rows
      
      glm::vec3 direction = getDirection(i, camera.getRight(), camera.getLeft(), length, j, camera.getTop(), camera.getBott(), height, camera);//calculates direction from camera to fragment

      Ray r(camera.getEye(),direction);//using ray struct that takes in some origin and direction
      Collision pointOfColl = isCollision(r, _scene);
      

      if(pointOfColl.m_type == Collision::Type::kHit){
        glm::vec4 color = pointOfColl.m_material->ka*glm::vec4(0.1,0.1,0.1,1);

        for(int k = 0; k<_scene.getLights().size(); k++){
          color+=pointOfColl.m_material->ka*_scene.getLights()[k].getIa();
          glm::vec3 lightDir = _scene.getLights()[k].getPoint() - pointOfColl.m_x;//ray direction from point of collision to light source
          Ray toLight(pointOfColl.m_x, lightDir);

          Collision shadow = isCollision(toLight, _scene);//sees if shadow occurs at this point based on other objects
          if(shadow.m_type == Collision::Type::kMiss){
           float dist = glm::distance(_scene.getLights()[k].getPoint(), pointOfColl.m_x);//gets distance needed for attenuation

            //float al = 1/((_scene.getLights()[k].getLAC()[0]) + (_scene.getLights()[k].getLAC()[1]*dist) + (_scene.getLights()[k].getLAC()[2] * (dist * dist)));//attenuation
            //float al = 1;//this needs to be fixed
            color+= (pointOfColl.m_material->lambertian(_scene.getLights()[k], pointOfColl.m_normal, pointOfColl.m_x));//lambertian shading
            color+= (pointOfColl.m_material->blinnPhong(_scene.getLights()[k], camera.getEye(), pointOfColl.m_normal, pointOfColl.m_x));//adding Blinnfong shading
          }
          
        }
        m_frame[length*j+i]= color;
       
      }

    }
    
  }
  glDrawPixels(m_width, m_height, GL_RGBA, GL_FLOAT, m_frame.get());
}