#include "directxmath/directxmath.h"

extern "C" void rotate(float angle, float aspect, float * buffer);

void rotate(float angle, float aspect, float * buffer)
{
  //XMMATRIX mat = XMMatrixRotationZ(angle);
  //XMMATRIX mat2 = XMMatrixRotationX(angle);
  //XMMATRIX mat2 = XMMatrixTranslation(0, 0, 1);
  //XMStoreFloat4x4((XMFLOAT4X4*)buffer, mat * mat2);

  float d = 1.9;
  XMVECTOR eye = XMVectorSet(d, d / 2, d, 0);
  XMVECTOR at = XMVectorSet(0, 0, 0, 0);
  XMVECTOR up = XMVectorSet(0, 1, 0, 0);
  XMMATRIX view = XMMatrixLookAtRH(eye, at, up);

  float fov_angle_y = XMConvertToRadians(45);
  float near_z = 0.01;
  float far_z = 1000.0;
  XMMATRIX projection = XMMatrixPerspectiveFovRH(fov_angle_y, aspect, near_z, far_z);

  XMMATRIX rot = XMMatrixRotationY(angle);
  XMStoreFloat4x4((XMFLOAT4X4*)buffer, rot * view * projection);
  XMStoreFloat4x4((XMFLOAT4X4*)(buffer + 4 * 4), rot);
}