teapot.h

// Copyright 2020,  Savvy Sine, Aline Normoyle
 
#ifndef AGL_MESH_TEAPOT_H_
#define AGL_MESH_TEAPOT_H_
 
#include "agl/mesh/triangle_mesh.h"
#include <vector>
#include <glm/glm.hpp>
 
namespace agl {
 
class Teapot : public TriangleMesh {
 public:
  Teapot(int grid, const glm::mat4& lidTransform);
 
 protected:
  void init() override;
 
 private:
  int _grid;
  glm::mat4 _lidTransform;
 
  // From: OpenGL 4.0 Shading language cookbook (David Wolf 2011)
  void generatePatches(std::vector<GLfloat> & p,
                       std::vector<GLfloat> & n,
                       std::vector<GLfloat> & tc,
                       std::vector<GLuint> & el, int grid);
 
  void buildPatchReflect(int patchNum,
                         std::vector<GLfloat> & B, std::vector<GLfloat> & dB,
                         std::vector<GLfloat> & v, std::vector<GLfloat> & n,
                         std::vector<GLfloat> & tc, std::vector<GLuint> & el,
                         int &index, int &elIndex, int &tcIndex, int grid,
                         bool reflectX, bool reflectY);
 
  void buildPatch(glm::vec3 patch[][4],
                  std::vector<GLfloat> & B, std::vector<GLfloat> & dB,
                  std::vector<GLfloat> & v, std::vector<GLfloat> & n,
                  std::vector<GLfloat> & tc, std::vector<GLuint> & el,
                  int &index, int &elIndex, int &tcIndex, int grid, 
                  glm::mat3 reflect, bool invertNormal);
 
  void getPatch(int patchNum, glm::vec3 patch[][4], bool reverseV);
 
  void computeBasisFunctions(std::vector<GLfloat> & B, 
      std::vector<GLfloat>& dB, int grid);
 
  glm::vec3 evaluate(int gridU, int gridV, std::vector<GLfloat> & B, 
      glm::vec3 patch[][4]);
 
  glm::vec3 evaluateNormal(int gridU, int gridV, std::vector<GLfloat>& B, 
      std::vector<GLfloat> & dB, glm::vec3 patch[][4]);
 
  void fitUnitBox(std::vector<GLfloat>& p, std::vector<GLfloat>& n);
 
  void moveLid(int grid, std::vector<GLfloat>& p, 
      const glm::mat4& lidTransform);
 
};
 
}  // namespace agl
#endif  // AGL_MESH_TEAPOT_H_