Projection.h

#pragma once
 
#include <glm/vec3.hpp>
 
namespace Cogs
{
  namespace Geometry
  {
 
    inline bool projectToPlane(glm::vec3 rayOrigin, glm::vec3 rayDir, glm::vec3 planeOrigin, glm::vec3 planeDir, glm::vec3 & coordinates, float * pT = nullptr)
    {
      rayDir = glm::normalize(rayDir);
      planeDir = glm::normalize(planeDir);
 
      float planeRayDot = glm::dot(rayDir, planeDir);
 
      if (glm::abs(planeRayDot) < std::numeric_limits<float>::epsilon()) {
        return false;
      }
 
      float distance = glm::dot(-planeDir, planeOrigin);
 
      float t = -(glm::dot(rayOrigin, planeDir) + distance) / planeRayDot;
 
      if (pT) *pT = t;
 
      coordinates = rayOrigin + rayDir * t;
 
      return true;
    }
 
  }
}