Bouncing nearly works'

Ball.cpp

@@ -24,6 +24,7 @@ void Ball::_compute_pos(double dt) {
     Center.x += dt * v_x;
     Center.z += dt * v_z;
     surface.update_center_pos(Center);
+    surface.check_horizontal_plan_collision(0.0);
 }
 
 void Ball::_compute_T_n() {
@@ -48,7 +49,7 @@ void Ball::_compute_v_x(Point normal) {
 }
 
 void Ball::_compute_v_z(Point normal) {
-    double factor = normal.x / (4*(normal.x + normal.z));
+    double factor = normal.z / (4*(normal.x + normal.z));
     v_z *= (0.5 + factor);
 }
 

spheroid.cpp

@@ -3,6 +3,7 @@
  **/
 
 #include "spheroid.hpp"
+#include <iostream>
 
 Spheroid::Spheroid(const Point& _center, double _min_p, double _p, double _q) :
     ImplicitSurface(_center), normal_vector(Point(0,0,1)), min_p(_min_p),
@@ -18,11 +19,11 @@ void Spheroid::_compute_volume() {
 
 
 void Spheroid::update_radius() {
-    q = sqrt((3/4) * V / PI / p);
+    q = sqrt((3./4.) * V / PI / p);
 }
 
 void Spheroid::update_height() {
-    q = (3/4) * V / PI / (p*p);
+    q = (3./4.) * V / PI / (p*p);
 }
 
 
@@ -30,10 +31,11 @@ void Spheroid::update_center_pos(Point& _center) {
     center = _center;
 }
 
-void Spheroid::check_horizontal_plan_collision(double& height) {
-    if ((center.y - p) <= height) {
+void Spheroid::check_horizontal_plan_collision(double height) {
+    if (((center.y - p) <= height) || (p <= init_p)) {
         p = fmin(init_p, center.y-height);
         update_radius();
+        std::cout << "p:" << p << "q:" << q << '\n';
     }
 }
 
@@ -71,6 +73,6 @@ void Spheroid::check_perlin_collision(PerlinNoise perlin) {
 
 double Spheroid::operator() (double _x, double _y, double _z) const {
             return (pow(_x, 2) / pow(q, 2)
-                  + pow(_y, 2) / pow(q, 2)
-                  + pow(_z, 2) / pow(p, 2) -1);
+                  + pow(_y, 2) / pow(p, 2)
+                  + pow(_z, 2) / pow(q, 2) -1);
 }

spheroid.hpp

@@ -17,7 +17,7 @@ class Spheroid : public ImplicitSurface {
         void update_center_pos(Point& _center);
         void update_radius();
         void update_height();
-        void check_horizontal_plan_collision(double& height);
+        void check_horizontal_plan_collision(double height);
         void check_vertical_plan_collision(double& abscissa);
         Cuboid max_bounding_box() const;
         void check_perlin_collision(PerlinNoise perlin);