cglm/docs/source/vec2.rst

.. default-domain:: C

vec2
====

Header: cglm/vec2.h

Table of contents (click to go):
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Macros:

1. GLM_VEC2_ONE_INIT
#. GLM_VEC2_ZERO_INIT
#. GLM_VEC2_ONE
#. GLM_VEC2_ZERO

Functions:

1. :c:func:`glm_vec2`
#. :c:func:`glm_vec2_copy`
#. :c:func:`glm_vec2_zero`
#. :c:func:`glm_vec2_one`
#. :c:func:`glm_vec2_dot`
#. :c:func:`glm_vec2_cross`
#. :c:func:`glm_vec2_norm2`
#. :c:func:`glm_vec2_norm`
#. :c:func:`glm_vec2_add`
#. :c:func:`glm_vec2_adds`
#. :c:func:`glm_vec2_sub`
#. :c:func:`glm_vec2_subs`
#. :c:func:`glm_vec2_mul`
#. :c:func:`glm_vec2_scale`
#. :c:func:`glm_vec2_scale_as`
#. :c:func:`glm_vec2_div`
#. :c:func:`glm_vec2_divs`
#. :c:func:`glm_vec2_addadd`
#. :c:func:`glm_vec2_subadd`
#. :c:func:`glm_vec2_muladd`
#. :c:func:`glm_vec2_muladds`
#. :c:func:`glm_vec2_maxadd`
#. :c:func:`glm_vec2_minadd`
#. :c:func:`glm_vec2_negate`
#. :c:func:`glm_vec2_negate_to`
#. :c:func:`glm_vec2_normalize`
#. :c:func:`glm_vec2_normalize_to`
#. :c:func:`glm_vec2_rotate`
#. :c:func:`glm_vec2_center`
#. :c:func:`glm_vec2_distance2`
#. :c:func:`glm_vec2_distance`
#. :c:func:`glm_vec2_maxv`
#. :c:func:`glm_vec2_minv`
#. :c:func:`glm_vec2_clamp`
#. :c:func:`glm_vec2_lerp`
#. :c:func:`glm_vec2_make`
#. :c:func:`glm_vec2_reflect`
#. :c:func:`glm_vec2_refract`

Functions documentation
~~~~~~~~~~~~~~~~~~~~~~~

.. c:function:: void glm_vec2(float * v, vec2 dest)

    init vec2 using vec3 or vec4

    Parameters:
      | *[in]*  **v**     vector
      | *[out]* **dest**  destination

.. c:function:: void glm_vec2_copy(vec2 a, vec2 dest)

    copy all members of [a] to [dest]

    Parameters:
      | *[in]*  **a**     source
      | *[out]* **dest**  destination

.. c:function:: void glm_vec2_zero(vec2 v)

    makes all members 0.0f (zero)

    Parameters:
      | *[in, out]*  **v**     vector

.. c:function:: void  glm_vec2_one(vec2 v)

    makes all members 1.0f (one)

    Parameters:
      | *[in, out]*  **v**     vector

.. c:function:: float glm_vec2_dot(vec2 a, vec2 b)

    dot product of vec2

    Parameters:
      | *[in]*  **a**  vector1
      | *[in]*  **b**  vector2

    Returns:
      dot product

.. c:function:: void glm_vec2_cross(vec2 a, vec2 b, vec2 d)

    cross product of two vector (RH)

    | ref: http://allenchou.net/2013/07/cross-product-of-2d-vectors/

    Parameters:
      | *[in]*  **a**     vector 1
      | *[in]*  **b**     vector 2
      | *[out]* **dest**  destination

    Returns:
      Z component of cross product

.. c:function:: float glm_vec2_norm2(vec2 v)

    norm * norm (magnitude) of vector

    we can use this func instead of calling norm * norm, because it would call
    sqrtf function twice but with this func we can avoid func call, maybe this is
    not good name for this func

    Parameters:
      | *[in]*  **v**   vector

    Returns:
      square of norm / magnitude

.. c:function:: float glm_vec2_norm(vec2 vec)

    | euclidean norm (magnitude), also called L2 norm
    | this will give magnitude of vector in euclidean space

    Parameters:
      | *[in]*  **vec**   vector

.. c:function:: void glm_vec2_add(vec2 a, vec2 b, vec2 dest)

    add a vector to b vector store result in dest

    Parameters:
      | *[in]*  **a**     vector1
      | *[in]*  **b**     vector2
      | *[out]* **dest**  destination vector

.. c:function:: void glm_vec2_adds(vec2 a, float s, vec2 dest)

    add scalar to v vector store result in dest (d = v + vec(s))

    Parameters:
      | *[in]*  **v**     vector
      | *[in]*  **s**     scalar
      | *[out]* **dest**  destination vector

.. c:function:: void glm_vec2_sub(vec2 v1, vec2 v2, vec2 dest)

    subtract b vector from a vector store result in dest (d = v1 - v2)

    Parameters:
      | *[in]*  **a**     vector1
      | *[in]*  **b**     vector2
      | *[out]* **dest**  destination vector

.. c:function:: void glm_vec2_subs(vec2 v, float s, vec2 dest)

    subtract scalar from v vector store result in dest (d = v - vec(s))

    Parameters:
      | *[in]*  **v**     vector
      | *[in]*  **s**     scalar
      | *[out]* **dest**  destination vector

.. c:function:: void glm_vec2_mul(vec2 a, vec2 b, vec2 d)

    multiply two vector (component-wise multiplication)

    Parameters:
      | *[in]*  **a**     vector
      | *[in]*  **b**     scalar
      | *[out]* **d**     result = (a[0] * b[0], a[1] * b[1], a[2] * b[2])

.. c:function:: void glm_vec2_scale(vec2 v, float s, vec2 dest)

     multiply/scale vec2 vector with scalar: result = v * s


    Parameters:
      | *[in]*  **v**     vector
      | *[in]*  **s**     scalar
      | *[out]* **dest**  destination vector

.. c:function:: void glm_vec2_scale_as(vec2 v, float s, vec2 dest)

    make vec2 vector scale as specified: result = unit(v) * s

    Parameters:
      | *[in]*  **v**     vector
      | *[in]*  **s**     scalar
      | *[out]* **dest**  destination vector

.. c:function:: void glm_vec2_div(vec2 a, vec2 b, vec2 dest)

    div vector with another component-wise division: d = a / b

    Parameters:
      | *[in]*  **a**     vector 1
      | *[in]*  **b**     vector 2
      | *[out]* **dest**  result = (a[0] / b[0], a[1] / b[1], a[2] / b[2])

.. c:function:: void glm_vec2_divs(vec2 v, float s, vec2 dest)

    div vector with scalar: d = v / s

    Parameters:
      | *[in]*  **v**     vector
      | *[in]*  **s**     scalar
      | *[out]* **dest**  result = (a[0] / s, a[1] / s, a[2] / s])

.. c:function:: void glm_vec2_addadd(vec2 a, vec2 b, vec2 dest)

    | add two vectors and add result to sum
    | it applies += operator so dest must be initialized

    Parameters:
      | *[in]*  **a**     vector 1
      | *[in]*  **b**     vector 2
      | *[out]* **dest**  dest += (a + b)

.. c:function:: void glm_vec2_subadd(vec2 a, vec2 b, vec2 dest)

    | sub two vectors and add result to sum
    | it applies += operator so dest must be initialized

    Parameters:
      | *[in]*  **a**     vector 1
      | *[in]*  **b**     vector 2
      | *[out]* **dest**  dest += (a - b)

.. c:function:: void glm_vec2_muladd(vec2 a, vec2 b, vec2 dest)

    | mul two vectors and add result to sum
    | it applies += operator so dest must be initialized

    Parameters:
      | *[in]*  **a**     vector 1
      | *[in]*  **b**     vector 2
      | *[out]* **dest**  dest += (a * b)

.. c:function:: void glm_vec2_muladds(vec2 a, float s, vec2 dest)

    | mul vector with scalar and add result to sum
    | it applies += operator so dest must be initialized

    Parameters:
      | *[in]*  **a**     vector
      | *[in]*  **s**     scalar
      | *[out]* **dest**  dest += (a * b)

.. c:function:: void glm_vec2_maxadd(vec2 a, vec2 b, vec2 dest)

    | add max of two vector to result/dest
    | it applies += operator so dest must be initialized

    Parameters:
      | *[in]*  **a**     vector 1
      | *[in]*  **b**     vector 2
      | *[out]* **dest**  dest += (a * b)

.. c:function:: void glm_vec2_minadd(vec2 a, vec2 b, vec2 dest)

    | add min of two vector to result/dest
    | it applies += operator so dest must be initialized

    Parameters:
      | *[in]*  **a**     vector 1
      | *[in]*  **b**     vector 2
      | *[out]* **dest**  dest += (a * b)

.. c:function:: void glm_vec2_negate(vec2 v)

    negate vector components

    Parameters:
      | *[in, out]*  **v**    vector

.. c:function:: void glm_vec2_negate_to(vec2 v, vec2 dest)

    negate vector components and store result in dest

    Parameters:
      | *[in]*  **v**       vector
      | *[out]* **dest**    negated vector

.. c:function:: void glm_vec2_normalize(vec2 v)

    normalize vec2 and store result in same vec

    Parameters:
      | *[in, out]*  **v**    vector

.. c:function:: void glm_vec2_normalize_to(vec2 vec, vec2 dest)

     normalize vec2 to dest

    Parameters:
      | *[in]*   **vec**   source
      | *[out]*  **dest**  destination

.. c:function:: void glm_vec2_rotate(vec2 v, float angle, vec2 dest)

     rotate vec2 around axis by angle using Rodrigues' rotation formula

    Parameters:
      | *[in]*  **v**      vector
      | *[in]*  **axis**   axis vector
      | *[out]* **dest**   destination

.. c:function:: void  glm_vec2_center(vec2 v1, vec2 v2, vec2 dest)

    find center point of two vector

    Parameters:
      | *[in]*  **v1**    vector1
      | *[in]*  **v2**    vector2
      | *[out]* **dest**  center point

.. c:function:: float glm_vec2_distance2(vec2 v1, vec2 v2)

    squared distance between two vectors

    Parameters:
      | *[in]*  **mat**   vector1
      | *[in]*  **row1**  vector2

    Returns:
      | squared distance (distance * distance)

.. c:function:: float glm_vec2_distance(vec2 v1, vec2 v2)

    distance between two vectors

    Parameters:
      | *[in]*  **mat**   vector1
      | *[in]*  **row1**  vector2

    Returns:
      | distance

.. c:function:: void glm_vec2_maxv(vec2 v1, vec2 v2, vec2 dest)

    max values of vectors

    Parameters:
      | *[in]*  **v1**    vector1
      | *[in]*  **v2**    vector2
      | *[out]* **dest**  destination

.. c:function:: void glm_vec2_minv(vec2 v1, vec2 v2, vec2 dest)

    min values of vectors

    Parameters:
      | *[in]*  **v1**    vector1
      | *[in]*  **v2**    vector2
      | *[out]* **dest**  destination

.. c:function:: void glm_vec2_clamp(vec2 v, float minVal, float maxVal)

    constrain a value to lie between two further values

    Parameters:
      | *[in, out]*  **v**       vector
      | *[in]*       **minVal**  minimum value
      | *[in]*       **maxVal**  maximum value

.. c:function:: void glm_vec2_lerp(vec2 from, vec2 to, float t, vec2 dest)

    linear interpolation between two vector

    | formula:  from + s * (to - from)

    Parameters:
      | *[in]*  **from**   from value
      | *[in]*  **to**     to value
      | *[in]*  **t**      interpolant (amount) clamped between 0 and 1
      | *[out]* **dest**   destination

.. c:function:: void glm_vec2_make(const float * __restrict src, vec2 dest)

    Create two dimensional vector from pointer

    .. note:: **@src** must contain at least 2 elements.

    Parameters:
      | *[in]*  **src**  pointer to an array of floats
      | *[out]* **dest** destination vector

.. c:function:: void glm_vec2_reflect(vec2 I, vec2 N, vec2 dest) 

    Reflection vector using an incident ray and a surface normal

    Parameters:
      | *[in]*  **I**     incident vector
      | *[in]*  **N**     *❗️ normalized ❗️* normal vector
      | *[out]* **dest**  destination: reflection result

.. c:function:: bool glm_vec2_refract(vec2 I, vec2 N, float eta, vec2 dest)

    Computes refraction vector for an incident vector and a surface normal.
   
    Calculates the refraction vector based on Snell's law. If total internal reflection
    occurs (angle too great given eta), dest is set to zero and returns false.
    Otherwise, computes refraction vector, stores it in dest, and returns true.

    Parameters:
      | *[in]*  **I**     *❗️ normalized ❗️* incident vector
      | *[in]*  **N**     *❗️ normalized ❗️* normal vector
      | *[in]*  **eta**   ratio of indices of refraction (incident/transmitted)
      | *[out]* **dest**  refraction vector if refraction occurs; zero vector otherwise

    Returns:
      returns true if refraction occurs; false if total internal reflection occurs.