From c2cd75a61ca1e935b5083a1e8e42649d1aae36af Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9mi=20Oudin?= <oudin@crans.org>
Date: Mon, 12 Feb 2018 13:54:39 +0100
Subject: [PATCH] Add movement on y-axis

---
 Ball.cpp      | 11 +++++++++--
 Ball.hpp      |  4 ++--
 main_ball.cpp |  2 +-
 3 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/Ball.cpp b/Ball.cpp
index 82338a4..390fa56 100644
--- a/Ball.cpp
+++ b/Ball.cpp
@@ -2,7 +2,7 @@
 #include <iostream>
 #include <cmath>
 
-Ball::Ball(Point& _center, double _min_height, double _v_x, double _p, double _q) :
+Ball::Ball(Point& _center, double _min_height, double _v_x, double _v_y, double _p, double _q) :
     Center(_center),
     surface(_center, _p, _q),
     init_h(_center.z),
@@ -13,13 +13,15 @@ Ball::Ball(Point& _center, double _min_height, double _v_x, double _p, double _q
     B(0),
     U(sqrt(2 * G_CTE * _center.z)),
     T(sqrt(2.0 * _center.z / G_CTE)),
-    v_x(_v_x)
+    v_x(_v_x),
+    v_y(_v_y)
 {
 }
 
 void Ball::_compute_pos(double dt) {
     Center.z = fmax(0.0, A + B * crt_time - (G_CTE / 2) * crt_time * crt_time + min_height);
     Center.x += dt * v_x;
+    Center.y += dt * v_y;
     surface.update_center_pos(Center);
 }
 
@@ -43,6 +45,10 @@ void Ball::_compute_v_x() {
     v_x *= 0.5;
 }
 
+void Ball::_compute_v_y() {
+    v_y *= 0.5;
+}
+
 void Ball::update_pos(double dt) {
     crt_time += dt;
     if (crt_time >= T) {
@@ -52,6 +58,7 @@ void Ball::update_pos(double dt) {
         _compute_B_n();
         _compute_T_n();
         _compute_v_x();
+        _compute_v_y();
         std::cout << "New bounce :";
         std::cout << "U:" << U << ":";
         std::cout << "A:" << A << ":";
diff --git a/Ball.hpp b/Ball.hpp
index 0ab1a86..4ddad91 100644
--- a/Ball.hpp
+++ b/Ball.hpp
@@ -24,7 +24,7 @@ class Ball {
         size_t bounce_number;
         double crt_time;
         double A, B, U, T; // Coefficients for the physical model.
-        double v_x;
+        double v_x, v_y;
         void _compute_pos(double dt);
         void _compute_v_x();
         void _compute_A_n();
@@ -32,7 +32,7 @@ class Ball {
         void _compute_U_n();
         void _compute_T_n();
     public:
-        Ball(Point& _center, double _min_height, double _v_x, double p, double q);
+        Ball(Point& _center, double _min_height, double _v_x, double _v_y, double p, double q);
         void update_pos(double dt);
         Point getCenter() const {return Center;}
         double accessT() const { return T;}
diff --git a/main_ball.cpp b/main_ball.cpp
index 00fb7c4..aa3ab02 100644
--- a/main_ball.cpp
+++ b/main_ball.cpp
@@ -11,7 +11,7 @@ using namespace std;
 int main(int argc, char** argv) {
     int i;
     Point center(0,0,10);
-    Ball ball(center, 0, 0.25, 1, 1);
+    Ball ball(center, 0, 0.25, 0,  1, 1);
     for(i=0; i< 10000; i++) {
         ball.update_pos(0.001);
         cout << ball << "\n";