vec2

2D vector of floats.

alias of numarray_stack<float,2>module 02_numarraysource: numarray_stack2.hpp

43 functions take it 1 return it 17 operators

vec2, vec3 and vec4 store their floats x, y, z, w side by side (indices 0 to 3); the same element has four spellings, and the common calls are norm, normalize, dot and cross. Tap to enlarge.

Fields and methods

Members of the struct numarray_stack<T,2>. Most of what you do with a CGP type goes through the free functions listed below.

Fields

`T x`	First coordinate of the vector.
`T y`	Second coordinate of the vector.

Methods

`numarray_stack()`	Builds a vector of size 2, 3 or 4 with all coordinates value-initialized (zero for numbers).5 overloads src
`numarray_stack(T const& x, T const& y)`	Builds a 2D vector from its coordinates x and y. src
`numarray_stack(numarray_stack<T,3> const& v)`	Builds a 2D vector from the x and y coordinates of a 3D vector, dropping z (not explicit, so a vec3 converts implicitly to a vec2). src
`numarray_stack(numarray_stack<T,4> const& v)`	Builds a 2D vector from the x and y coordinates of a 4D vector, dropping z and w (not explicit, so a vec4 converts implicitly to a vec2). src
`numarray_stack(T1 const& x, T2 const& y)`	Builds a 2D vector from two coordinates of other types, converted to T. src
`int size() const`	Number of components N, fixed at compile time. src
`numarray_stack<T,2>& fill(T const& value)`	Sets the N components to the given value and returns the vector. src
`T const& operator[](int index) const` `T& operator[](int index)`	Returns the element at index, bound-checked unless CGP_NO_DEBUG is defined. src
`T const& operator()(int index) const` `T& operator()(int index)`	Returns a const reference to the element at the given index, with bound checking unless CGP_NO_DEBUG is defined. src
`T const& at(int index) const` `T& at(int index)`	Returns a const reference to the element at the given index; bound-checked for sizes 2, 3 and 4 (vec2, vec3, vec4) unless CGP_NO_DEBUG is defined, but not checked for the other sizes N. src
`T const* begin() const` `T* begin()`	Returns a const iterator to the first element (a plain pointer for sizes 2, 3 and 4). src
`T const* end() const` `T* end()`	Returns a const iterator one past the last element (a plain pointer for sizes 2, 3 and 4). src
`T const* cbegin() const`	Returns a const iterator to the first element (a plain pointer for sizes 2, 3 and 4). src
`T const* cend() const`	Returns a const iterator one past the last element (a plain pointer for sizes 2, 3 and 4). src
`T const& coeff(int index) const` `T& coeff(int index)`	Returns a const reference to the element at the given index, without bound checking. src

Shared with all vectors: 46 functions on vecN, written once for every size.

Functions taking a vec2

Construct 2

Documented on another page

tensor_productOuter product a * transpose(b), as a 2x2 matrix.on mat2
trackball_rotationRotation moving the trackball projection of p0 onto that of p1, identity if the two points are closer than 1e-4.on rotation_transform

Transform 1

orthogonal_vector

source

vec2 orthogonal_vector(vec2 const& v)

Unit vector orthogonal to v (v rotated by -90 degrees and normalized); returns (1,0) for a zero vector.

Compute 6

noise_perlin

source

float noise_perlin(
    vec2 const& p,
    int octave = 5,
    float persistency = 0.3f,
    float frequency_gain = 2.0f
)

Fractal 2D noise in [0,1] summing octave layers of simplex noise, each layer scaled in amplitude by persistency and in frequency by frequency_gain (defaults 5, 0.3, 2).

picking_mesh_vertex_as_sphere

source

picking_structure picking_mesh_vertex_as_sphere(
    vec2 const& screen_click,
    numarray<vec3> const& vertex_position,
    numarray<vec3> const& vertex_normal,
    float picking_distance,
    camera_generic_base const& camera,
    camera_projection_perspective const& projection
)

Casts the camera ray through the screen position and returns the closest vertex whose sphere of radius picking_distance it hits, with the hit point, the vertex normal and the vertex index (active is false if none).

picking_plane_orthogonal_to_camera

source

intersection_structure picking_plane_orthogonal_to_camera(
    vec2 const& screen_position,
    vec3 const& plane_position,
    camera_generic_base const& camera,
    camera_projection_perspective const& projection
)

Intersects the camera ray through the screen position (relative coordinates) with the plane through plane_position orthogonal to the front direction of the camera.

picking_spheres

source

picking_structure picking_spheres(
    vec2 const& screen_click,
    numarray<vec3> const& spheres_centers,
    float spheres_radius,
    camera_generic_base const& camera,
    camera_projection_perspective const& projection
)

Cast a ray through a screen position (normalized device coordinates) and return the closest hit among spheres of common radius, with its index, position and normal.

translation_in_plane

source

vec3 translation_in_plane(vec2 const& translation, rotation_transform const& plane_orientation)

3D vector of a 2D translation expressed in the xy plane of the given orientation.

Documented on another page

camera_ray_directionUnit world-space direction of the ray through a screen position given in normalized device coordinates [-1,1]^2, from the camera frame and the inverse projection matrix.on mat4

Convert 2

type_str

generic2 overloads

template <typename T>
std::string type_str(numarray_stack<T,2> const&)

source

Type name as a string, e.g. "numarray_stack2<int>".

std::string type_str(vec2 const&)

source

Type name as a string: "vec2".

Access 2

check_index_bounds

genericsource

template <typename T, int N, typename INDEX_TYPE>
void check_index_bounds(INDEX_TYPE index, numarray_stack<T,2> const& data)

Raises an error if the index is outside [0, 1]; no-op when CGP_NO_DEBUG is defined.

get

genericsource

template <int idx, typename T>
T const& get(numarray_stack<T,2> const& data)
T& get(numarray_stack<T,2>& data)

Component idx with the index checked at compile time (static_assert).

Other 1

Documented on another page

opengl_uniformSend a vec2 uniform to the shader; warns if the uniform is not found and expected is true.on opengl_shader_structure

Functions returning a vec2

Access 1

Documented on another page

getRow idx1 as a vector, with the index checked at compile time (static_assert).on matN

Operators

None besides the shared functions above.