/*-----------------------------------------------------------------------------

  glVector3.cpp

  2006 Shamus Young

-------------------------------------------------------------------------------

  Functions for dealing with 3d vectors.

-----------------------------------------------------------------------------*/

#include <windows.h>
#include <float.h>
#include <math.h>
#include <gl\gl.h>

#include "macro.h"
#include "math.h"
#include "glTypes.h"

/*-----------------------------------------------------------------------------
                           
-----------------------------------------------------------------------------*/

GLvector glVectorReflect (GLvector3 ray, GLvector3 normal)
{

  float       dot;

  dot = glVectorDotProduct (ray, normal);
  return ray - (normal * (2.0f * dot));

}


/*-----------------------------------------------------------------------------
                           
-----------------------------------------------------------------------------*/

GLvector3 glVector (float x, float y, float z)
{

  GLvector3 result;

  result.x = x;
  result.y = y;
  result.z = z;
  return result;

}

/*-----------------------------------------------------------------------------
                           
-----------------------------------------------------------------------------*/

GLvector3 glVectorInterpolate (GLvector3 v1, GLvector3 v2, float scalar)
{

  GLvector3 result;

  result.x = MathInterpolate (v1.x, v2.x, scalar);
  result.y = MathInterpolate (v1.y, v2.y, scalar);
  result.z = MathInterpolate (v1.z, v2.z, scalar);
  return result;

}  

/*-----------------------------------------------------------------------------
                           
-----------------------------------------------------------------------------*/

float glVectorLength (GLvector3 v)
{

  return (float)sqrt (v.x * v.x + v.y * v.y + v.z * v.z);

}

/*-----------------------------------------------------------------------------
                           
-----------------------------------------------------------------------------*/

float glVectorDotProduct (GLvector3 v1, GLvector3 v2)
{

  return v1.x * v2.x + v1.y * v2.y + v1.z * v2.z;

}

/*-----------------------------------------------------------------------------
                           
-----------------------------------------------------------------------------*/

GLvector3 glVectorCrossProduct (GLvector3 v1, GLvector3 v2)
{

  GLvector3 result;
  
  result.x = v1.y * v2.z - v2.y * v1.z;
  result.y = v1.z * v2.x - v2.z * v1.x;
  result.z = v1.x * v2.y - v2.x * v1.y;
  return result;

}

/*-----------------------------------------------------------------------------
                           
-----------------------------------------------------------------------------*/

GLvector3 glVectorInvert (GLvector3 v)
{

  v.x *= -v.x;
  v.y *= -v.y;
  v.z *= -v.z;
  return v;

}

/*-----------------------------------------------------------------------------
                           
-----------------------------------------------------------------------------*/

GLvector3 glVectorScale (GLvector3 v, float scale)
{

  v.x *= scale;
  v.y *= scale;
  v.z *= scale;
  return v;

}

/*-----------------------------------------------------------------------------
                           
-----------------------------------------------------------------------------*/

GLvector3 glVectorNormalize (GLvector3 v)
{

  float length;

  length = glVectorLength (v);
  if (length < 0.000001f)
    return v;
  return glVectorScale (v, 1.0f / length);

}

/*-----------------------------------------------------------------------------
+                           
-----------------------------------------------------------------------------*/

GLvector GLvector::operator+ (const GLvector& c)
{
  return glVector (x + c.x, y + c.y, z + c.z);
}

GLvector GLvector::operator+ (const float& c)
{
  return glVector (x + c, y + c, z + c);
}

void GLvector::operator+= (const GLvector& c)
{
  x += c.x;
  y += c.y;
  z += c.z;
}

void GLvector::operator+= (const float& c)
{
  x += c;
  y += c;
  z += c;
}

GLvector GLvector::operator- (const GLvector& c)
{
  return glVector (x - c.x, y - c.y, z - c.z);
}

GLvector GLvector::operator- (const float& c)
{
  return glVector (x - c, y - c, z - c);
}

void GLvector::operator-= (const GLvector& c)
{
  x -= c.x;
  y -= c.y;
  z -= c.z;
}

void GLvector::operator-= (const float& c)
{
  x -= c;
  y -= c;
  z -= c;
}

GLvector GLvector::operator* (const GLvector& c)
{
  return glVector (x * c.x, y * c.y, z * c.z);
}

GLvector GLvector::operator* (const float& c)
{
  return glVector (x * c, y * c, z * c);
}

void GLvector::operator*= (const GLvector& c)
{
  x *= c.x;
  y *= c.y;
  z *= c.z;
}

void GLvector::operator*= (const float& c)
{
  x *= c;
  y *= c;
  z *= c;
}

GLvector GLvector::operator/ (const GLvector& c)
{
  return glVector (x / c.x, y / c.y, z / c.z);
}

GLvector GLvector::operator/ (const float& c)
{
  return glVector (x / c, y / c, z / c);
}

void GLvector::operator/= (const GLvector& c)
{
  x /= c.x;
  y /= c.y;
  z /= c.z;
}

void GLvector::operator/= (const float& c)
{
  x /= c;
  y /= c;
  z /= c;
}

bool GLvector::operator== (const GLvector& c)
{
  if (x == c.x && y == c.y && z == c.z)
    return true;
  return false;
}