path: root/src/Matrix4f.cpp

#include "Matrix4f.h"



Matrix4f::Matrix4f()
{
  m[0][0] = 1;  m[0][1] = 0;  m[0][2] = 0;  m[0][3] = 0;
  m[1][0] = 0;  m[1][1] = 1;  m[1][2] = 0;  m[1][3] = 0;
  m[2][0] = 0;  m[2][1] = 0;  m[2][2] = 1;  m[2][3] = 0;
  m[3][0] = 0;  m[3][1] = 0;  m[3][2] = 0;  m[3][3] = 1;
}

Matrix4f Matrix4f::multiply(Matrix4f& a)
{
  Matrix4f b = identity();
  for (int i = 0; i < 4; i++)
  {
    for (int j = 0; j < 4; j++)
    {
      b.m[i][j] = ((m[i][0] * a.m[0][j]) + (m[i][1] * a.m[1][j]) + (m[i][2] * a.m[2][j]) + (m[i][3] * a.m[3][j]));
    }
  }
  return b;
}

Matrix4f Matrix4f::operator*(Matrix4f& a)
{
  Matrix4f b = identity();
  for (int i = 0; i < 4; i++)
  {
    for (int j = 0; j < 4; j++)
    {
      b.m[i][j] = ((m[i][0] * a.m[0][j]) + (m[i][1] * a.m[1][j]) + (m[i][2] * a.m[2][j]) + (m[i][3] * a.m[3][j]));
    }
  }
  return b;
}

Matrix4f Matrix4f::identity()
{
  return Matrix4f();
}

Matrix4f Matrix4f::move(float kx, float ky, float kz)
{
  Matrix4f b;
  b.m[0][0] = 1;  b.m[0][1] = 0;  b.m[0][2] = 0;  b.m[0][3] = kx;
  b.m[1][0] = 0;  b.m[1][1] = 1;  b.m[1][2] = 0;  b.m[1][3] = ky;
  b.m[2][0] = 0;  b.m[2][1] = 0;  b.m[2][2] = 1;  b.m[2][3] = kz;
  b.m[3][0] = 0;  b.m[3][1] = 0;  b.m[3][2] = 0;  b.m[3][3] = 1;
  return b;
}

Matrix4f Matrix4f::rotate(float xs, float ys, float zs)
{
  double hlp = 3.14159265 / 180.0;
  xs *= hlp;
  ys *= hlp;
  zs *= hlp;
  Matrix4f b;
  b.m[0][0] = 1;  b.m[0][1] = 0;        b.m[0][2] = 0;        b.m[0][3] = 0;
  b.m[1][0] = 0;  b.m[1][1] = cos(xs);  b.m[1][2] = -sin(xs); b.m[1][3] = 0;
  b.m[2][0] = 0;  b.m[2][1] = sin(xs);  b.m[2][2] = cos(xs);  b.m[2][3] = 0;
  b.m[3][0] = 0;  b.m[3][1] = 0;        b.m[3][2] = 0;        b.m[3][3] = 1;

  Matrix4f c;
  c.m[0][0] = cos(ys);  c.m[0][1] = 0;  c.m[0][2] = sin(ys);  c.m[0][3] = 0;
  c.m[1][0] = 0;        c.m[1][1] = 1;  c.m[1][2] = 0;        c.m[1][3] = 0;
  c.m[2][0] = -sin(ys); c.m[2][1] = 0;  c.m[2][2] = cos(ys);  c.m[2][3] = 0;
  c.m[3][0] = 0;        c.m[3][1] = 0;  c.m[3][2] = 0;        c.m[3][3] = 1;

  Matrix4f d;
  d.m[0][0] = cos(zs);  d.m[0][1] = -sin(zs); d.m[0][2] = 0;  d.m[0][3] = 0;
  d.m[1][0] = sin(zs);  d.m[1][1] = cos(zs);  d.m[1][2] = 0;  d.m[1][3] = 0;
  d.m[2][0] = 0;        d.m[2][1] = 0;        d.m[2][2] = 1;  d.m[2][3] = 0;
  d.m[3][0] = 0;        d.m[3][1] = 0;        d.m[3][2] = 0;  d.m[3][3] = 1;

  return d * c * b;
}

Matrix4f Matrix4f::scale(float px, float py, float pz)
{
  Matrix4f b;
  b.m[0][0] = px; b.m[0][1] = 0;  b.m[0][2] = 0;  b.m[0][3] = 0;
  b.m[1][0] = 0;  b.m[1][1] = py; b.m[1][2] = 0;  b.m[1][3] = 0;
  b.m[2][0] = 0;  b.m[2][1] = 0;  b.m[2][2] = pz; b.m[2][3] = 0;
  b.m[3][0] = 0;  b.m[3][1] = 0;  b.m[3][2] = 0;  b.m[3][3] = 1;
  return b;
}

Matrix4f Matrix4f::perspective(float n, float f, float fov, float aspectRatio)
{
  float l, r, t, b;
  t = n * tan((fov / 2.0f) * (3.14159265 / 180.0));
  b = -t;
  r = aspectRatio * t;
  l = -r;
  Matrix4f a;
  a.m[0][0] = ((2.0f * n) / (r - l)); a.m[0][1] = 0;                      a.m[0][2] = - ((r + l) / (r - l));  a.m[0][3] = 0;
  a.m[1][0] = 0;                      a.m[1][1] = ((2.0f * n) / (t - b)); a.m[1][2] = - ((t + b) / (t - b));  a.m[1][3] = 0;
  a.m[2][0] = 0;                      a.m[2][1] = 0;                      a.m[2][2] = - (f / (n - f));        a.m[2][3] = ((n * f) / (n - f));
  a.m[3][0] = 0;                      a.m[3][1] = 0;                      a.m[3][2] = 1;                      a.m[3][3] = 0;
  return a;
}