added pbd simulaton class and restructured classes

src/sph/sph_particle.cpp → src/simulation/particle.cpp

-#include "sph_particle.h"
+#include "particle.h"
 
 namespace sph {
 

src/sph/sph_particle.h → src/simulation/particle.h

-#ifndef MADID_SPH_PARTICLE
-#define MADID_SPH_PARTICLE
+#ifndef MADID_PARTICLE
+#define MADID_PARTICLE
 
 #include <glm/glm.hpp>
 
-namespace sph {
 class Particle {
     public:
         typedef glm::vec3 vector;
@@ -136,6 +135,5 @@ class Particle {
 //        const float &radius() const;
         
 };
-}
 
 #endif

src/simulation/pbd/pbd_system.cpp

+#include "pbd_system.h"

src/simulation/pbd/pbd_system.h

+#ifndef MADID_PBD_SYSTEM_H
+#define MADID_PBD_SYSTEM_H
+
+#include <cstddef>
+#include <vector>
+#include <glm/glm.hpp>
+
+#include "../particle.h"
+
+typedef glm::vec3 vec3;
+
+class pbd_system {
+    void solve_distance_constraint(Particle *p1, Particle *p2, float dist);
+
+    void solve_bending_constraint(Particle *p1, Particle *p2, float dist);
+
+    void solve_collision_constraint(Particle *p, vec3 &q1, vec3 &q2, vec3 &q3);
+
+public:
+    //// mid-point of the head
+    HeadObject *head;
+
+    //// number of hair strands to be placed on the head
+    size_t nrStrands;
+
+    //// how many segments a strand will be sub-divided into
+    size_t nrSegments;
+
+    //// length of a segment
+    float lSeg;
+
+    ////
+    std::vector<std::vector<Particle *>> strands;
+
+    ////
+    vec3 externalForces;
+
+    ////
+    std::vector<vec3> collisionTriangles;
+
+    void addForce(vec3 force);
+
+    PBDSimulation(HeadObject *_head, size_t _nr_sims, size_t _nr_segments, float _l_seg);
+
+    void propagateHead();
+
+    void update(float dt);
+
+    void Draw();
+
+    vec3 getExternalForces() const;
+
+    void resetExternalForces();
+
+    std::vector<Particle *> CreateStrand(size_t segments, float l, vec3 startPos, vec3 color);
+};
+
+
+#endif //MADID_PBD_SYSTEM_H

src/sph/sph_system.cpp → src/simulation/sph/sph_system.cpp

@@ -77,7 +77,7 @@ namespace sph {
 
                 glm::vec3 f_gravity = G * p_i->rho;
 
-//                p_i->f = f_pressure + f_viscosity + f_gravity;
+                p_i->f = f_pressure + f_viscosity + f_gravity;
                 p_i->f = f_gravity + f_pressure;// * 0.001f;
             }
         }