/***********************
* Johnny Jetpack
* by Paul Adam and Jamie Bradley
* 
* physics.c
*
* this file contains velocity modification functions as well as
* geometric tranformation functions.
*************************/



#include <glut.h>
#include <GL/gl.h>
#include <GL/glu.h>
#include <math.h>

#include "johnny.h"


void UpdateVelocity(void)
{

	int temp;

	/*temp  = nextVelocity[Yv];*/

	/*Velocity[Yv] = Velocity[Yv] + (Thrust - Gravity);
	if (Velocity[Yv] > MAX_VELOCITY_Y_UP)
		Velocity[Yv] = MAX_VELOCITY_Y_UP;
	if (Velocity[Yv] < MAX_VELOCITY_Y_DOWN)
		Velocity[Yv] = MAX_VELOCITY_Y_DOWN;
	*/
	nextVelocity[Yv] = Velocity[Yv] + (Thrust - Gravity);
	if (nextVelocity[Yv] > MAX_VELOCITY_Y_UP)
		nextVelocity[Yv] = MAX_VELOCITY_Y_UP;
	if (nextVelocity[Yv] < -50)
		nextVelocity[Yv] = MAX_VELOCITY_Y_DOWN;
	Velocity[Yv] = nextVelocity[Yv];

}


void RotateVector(int angle, int vector[3], int cx, int cy)
{
	int xp, yp;
	
	float radangle;
	radangle = angle * RADIANS;
	
	

	xp = vector[Xv];
	yp = vector[Zv];

	xp -= cx;
	yp -= cy;
	
	xp = (vector[Xv] * cos(radangle)) - (vector[Zv] * sin(radangle));
	yp = (vector[Xv] * sin(radangle)) + (vector[Zv] * cos(radangle));



	xp += cx;
	yp += cy;
	
	vector[Xv] = xp;
	vector[Zv] = yp;

}