# Copying

[Русская версия / Russian version](copy-rus.md)

The copy functions allow you to copy the component values of one quaternion
to another quaternion.

Function for **BGC_FP32_Quaternion**:

```c
inline void bgc_fp32_quaternion_copy(BGC_FP32_Quaternion* const destination, const BGC_FP32_Quaternion* const source);
```

Function for **BGC_FP64_Quaternion**:

```c
inline void bgc_fp64_quaternion_copy(BGC_FP64_Quaternion* const destination, const BGC_FP64_Quaternion* const source);
```

Each of these functions is equivalent to the following lines of code:

```c
destination->s = source->s;
destination->x = source->x;
destination->y = source->y;
destination->z = source->z;
```

The **source** and **destination** parameters must not be invalid pointers.
The NULL (0) value is also considered invalid.

The **source** parameter must be a pointer to a quaternion which components
are to be copied. The coordinates of the **source** quaternion will
not change after the function call.

The **destination** parameter must be a pointer to a quaternion which components
are to be changed. The coordinates of the **destination** quaternion will become
the same as those of the **source** quaternion after the function call.

Example of use:

```c
#include <stdio.h>
#include <basic-geometry.h>

int main()
{
    BGC_FP32_Quaternion q1, q2;

    q1.s = 1.1f;
    q1.x = -2.0f;
    q1.y = 7.4f;
    q1.z = 1.8f;

    bgc_fp32_quaternion_copy(&q2, &q1);

    printf("s = %f, x = %f, y = %f, z = %f\n", q2.s, q2.x, q2.y, q2.z);

    return 0;
}
```

[Documentation](../intro-eng.md) / [Quaternions](../quaternion-eng.md)