C++ Small float value sets to zero when passed into functions - c++

Question

I've found an error in my code through std::cout-ing some of my small float values. I'm quite new to C++ but I don't think this is a feature on-purpose.
These values are between 1 and -1 and resemble a set of normalized coordinates I need for my OpenGL transformations.
I'm using SDL to get my windows coordinates and I offset each of them through:
...
case SDL_MOUSEMOTION:
{
xMouse=(event.motion.x-halfX)/(halfX);
yMouse=(event.motion.y-halfY)/(halfY);
std::cout<<"Mouse at: "<<xMouse<<','<<yMouse<<'\n';
}
...
halfX and halfY are half of my window's height and width, this is because I want my (0,0) to be at the centre.
Here are some prints for this cout:
Mouse at: 0.794444,-0.857639
Mouse at: 0.805556,-0.888889
Mouse at: 0.830556,-0.934028
Mouse at: 0.838889,-0.951389
Mouse at: 0.844444,-0.961806
Mouse at: 0.844444,-0.96875
Mouse at: 0.85,-0.972222
Mouse at: 0.852778,-0.979167
Mouse at: 0.855556,-0.982639
Mouse at: 0.861111,-0.986111
Mouse at: 0.863889,-0.989583
Mouse at: 0.866667,-0.993056
Mouse at: 0.869444,-0.996528
Mouse at: 0.872222,-1
Mouse at: 0.877778,-1
Looks fine. But when I pass the values into a function like this:
void draw(Ship &_player, GLfloat _rot,int _xMouse, int _yMouse)
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
std::cout<<"From draw(Ship,GLfloat,int,int):"<<'\n'<<"Mouse at: "<<_xMouse<<','<<_yMouse<<'\n';
_player.followMouse(_xMouse,_yMouse);
}
And I get my parameter values as:
From SDL_MOUSEMOTION:
Mouse at: 0.688889,-0.982639
From draw(Ship,GLfloat,int,int):
Mouse at: 0,0
From SDL_MOUSEMOTION:
Mouse at: 0.694444,-0.993056
From draw(Ship,GLfloat,int,int):
Mouse at: 0,0
From SDL_MOUSEMOTION:
Mouse at: 0.713889,-1
From draw(Ship,GLfloat,int,int):
Mouse at: 0,-1
I haven't edited the values before the the function call, it looks a bit like my compiler trying to round down the values. But I'm not sure, and how to fix it.
here's my main if we need it
#ifdef WIN32
#include <Windows.h>
#endif
#if defined (__linux__) || defined (WIN32)
#include <GL/gl.h>
#endif
#ifdef __APPLE__
#include <OpenGL/gl.h>
#endif
#include <iostream>
#include <cstdlib>
#include "GameObjects.h"
#include "Ship.h"
#include "Camera.h"
#include "SDLOpenGL.h"
#undef main
// function to init the basic OpenGL scene for this demo
void initOpenGL();
// function to render our scene.
void draw(Ship &_player,GLfloat _rot,int _xMouse, int _yMouse);
int main(int argc, char *argv[])
{
int winXLeng=720;
int winYLeng=576;
float halfX=winXLeng/2;
float halfY=winYLeng/2;
// create our SDLWindow
SDLOpenGL win("GLFunctions Demo",100,100,winXLeng,winYLeng);
// this makes sure the window is active for OpenGL calls, if we have
// more than one window we need to call this for the window we want to
// set OpenGL for
win.makeCurrent();
// setup our default OpenGL window state
initOpenGL();
Ship player;
float xMouse=0.00f;
float yMouse=0.00f;
float newRot=0.00f;
bool quit=false;
while(!quit)
{
SDL_Event event;
// grab the event from the window (note this explicitly calls make current)
win.pollEvent(event);
switch (event.type)
{
// this is the window x being clicked.
case SDL_QUIT : quit = true; break;
// now we look for a keydown event
case SDL_KEYDOWN:
{
switch( event.key.keysym.sym )
{
// if it's the escape key quit
case SDLK_ESCAPE : quit = true; break;
// make OpenGL draw wireframe
case SDLK_e : glPolygonMode(GL_FRONT_AND_BACK,GL_LINE); break;
// make OpenGL draw solid
case SDLK_r : glPolygonMode(GL_FRONT_AND_BACK,GL_FILL); break;
default : break;
} // end of key process
} // end of keydown
//Now we look for Mouse movements
case SDL_MOUSEMOTION:
{
xMouse=(event.motion.x-halfX)/(halfX);
yMouse=(event.motion.y-halfY)/(halfY);
std::cout<<"From SDL_MOUSEMOTION:"<<'\n'<<"Mouse at: "<<xMouse<<','<<yMouse<<'\n';
}
default : break;
} // end of event switch
// draw scene
draw(player,newRot,xMouse,yMouse);
// update the buffer so we can see what we have drawn.
win.swapWindow();
}
return EXIT_SUCCESS;
}
void initOpenGL()
{
// this sets the background colour
glClearColor(0,0,0,1.0);
// this is how big our window is for drawing
glViewport(0,0,720,576);
Camera::perspective(60,float(720/576),0.01,500);
Camera::lookAt(Vec4(0,30,0.1),Vec4(0,0,0),Vec4(0,1,0));
glDisable(GL_LIGHTING);
//glEnable(GL_LIGHTING);
//glEnable(GL_LIGHT0);
glColor3f(1,1,0);
glEnable(GL_COLOR_MATERIAL);
glEnable(GL_DEPTH_TEST);
glEnable(GL_NORMALIZE);
}
void draw(Ship &_player, GLfloat _rot,int _xMouse, int _yMouse)
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
std::cout<<"From draw(Ship,GLfloat,int,int):"<<'\n'<<"Mouse at: "<<_xMouse<<','<<_yMouse<<'\n';
_player.followMouse(_xMouse,_yMouse);
}
Anyone have a clue?
Thanks in advance~
Edit: nvm...but I will remember to check my parameter type next time...