File content as of revision 2:5aa75c3d8cc3:

/* This file is part of the Razor AHRS Firmware */
#include <math.h>

// Computes the dot product of two vectors
float Vector_Dot_Product(float vector1[3], float vector2[3])
{
  float op=0;
  
  for(int c=0; c<3; c++)
  {
    op+=vector1[c]*vector2[c];
  }
  
  return op; 
}

// Computes the cross product of two vectors
void Vector_Cross_Product(float vectorOut[3], float v1[3], float v2[3])
{
  vectorOut[0]= (v1[1]*v2[2]) - (v1[2]*v2[1]);
  vectorOut[1]= (v1[2]*v2[0]) - (v1[0]*v2[2]);
  vectorOut[2]= (v1[0]*v2[1]) - (v1[1]*v2[0]);
}

// Multiply the vector by a scalar. 
void Vector_Scale(float vectorOut[3], float vectorIn[3], float scale2)
{
  for(int c=0; c<3; c++)
  {
    vectorOut[c]=vectorIn[c]*scale2; 
  }
}

// Adds two vectors
void Vector_Add(float vectorOut[3], float vectorIn1[3], float vectorIn2[3])
{
  for(int c=0; c<3; c++)
  {
    vectorOut[c]=vectorIn1[c]+vectorIn2[c];
  }
}

//Multiply two 3x3 matrixs. This function developed by Jordi can be easily adapted to multiple n*n matrix's. (Pero me da flojera!). 
void Matrix_Multiply(float a[3][3], float b[3][3],float mat[3][3])
{
  float op[3]; 
  for(int x=0; x<3; x++)
  {
    for(int y=0; y<3; y++)
    {
      for(int w=0; w<3; w++)
      {
       op[w]=a[x][w]*b[w][y];
      } 
      mat[x][y]=0;
      mat[x][y]=op[0]+op[1]+op[2];
      
      float test=mat[x][y];
    }
  }
}

// Init rotation matrix using euler angles
void init_rotation_matrix(float m[3][3], float yaw, float pitch, float roll)
{
  float c1 = cos(roll);
  float s1 = sin(roll);
  float c2 = cos(pitch);
  float s2 = sin(pitch);
  float c3 = cos(yaw);
  float s3 = sin(yaw);

  // Euler angles, right-handed, intrinsic, XYZ convention
  // (which means: rotate around body axes Z, Y', X'') 
  m[0][0] = c2 * c3;
  m[0][1] = c3 * s1 * s2 - c1 * s3;
  m[0][2] = s1 * s3 + c1 * c3 * s2;

  m[1][0] = c2 * s3;
  m[1][1] = c1 * c3 + s1 * s2 * s3;
  m[1][2] = c1 * s2 * s3 - c3 * s1;

  m[2][0] = -s2;
  m[2][1] = c2 * s1;
  m[2][2] = c1 * c2;
}

float constrain(float in, float min, float max)
{
    in = in > max ? max : in;
    in = in < min ? min : in;
    return in;
}