Matrix

Matrix — 4x4 matrices

Functions

graphene_matrix_t * graphene_matrix_alloc ()
void graphene_matrix_free ()
graphene_matrix_t * graphene_matrix_init_identity ()
graphene_matrix_t * graphene_matrix_init_from_float ()
graphene_matrix_t * graphene_matrix_init_from_vec4 ()
graphene_matrix_t * graphene_matrix_init_from_matrix ()
graphene_matrix_t * graphene_matrix_init_from_2d ()
graphene_matrix_t * graphene_matrix_init_perspective ()
graphene_matrix_t * graphene_matrix_init_ortho ()
graphene_matrix_t * graphene_matrix_init_look_at ()
graphene_matrix_t * graphene_matrix_init_frustum ()
graphene_matrix_t * graphene_matrix_init_scale ()
graphene_matrix_t * graphene_matrix_init_translate ()
graphene_matrix_t * graphene_matrix_init_rotate ()
graphene_matrix_t * graphene_matrix_init_skew ()
bool graphene_matrix_is_identity ()
bool graphene_matrix_is_2d ()
bool graphene_matrix_is_backface_visible ()
bool graphene_matrix_is_singular ()
void graphene_matrix_to_float ()
bool graphene_matrix_to_2d ()
void graphene_matrix_get_row ()
float graphene_matrix_get_value ()
void graphene_matrix_multiply ()
float graphene_matrix_determinant ()
void graphene_matrix_transform_vec4 ()
void graphene_matrix_transform_vec3 ()
void graphene_matrix_transform_point ()
void graphene_matrix_transform_point3d ()
void graphene_matrix_transform_rect ()
void graphene_matrix_transform_bounds ()
void graphene_matrix_transform_box ()
void graphene_matrix_transform_sphere ()
void graphene_matrix_transform_ray ()
void graphene_matrix_project_point ()
void graphene_matrix_project_rect_bounds ()
void graphene_matrix_project_rect ()
bool graphene_matrix_untransform_point ()
void graphene_matrix_untransform_bounds ()
void graphene_matrix_unproject_point3d ()
void graphene_matrix_translate ()
void graphene_matrix_rotate ()
void graphene_matrix_rotate_x ()
void graphene_matrix_rotate_y ()
void graphene_matrix_rotate_z ()
void graphene_matrix_rotate_quaternion ()
void graphene_matrix_rotate_euler ()
void graphene_matrix_scale ()
void graphene_matrix_skew_xy ()
void graphene_matrix_skew_xz ()
void graphene_matrix_skew_yz ()
void graphene_matrix_transpose ()
bool graphene_matrix_inverse ()
void graphene_matrix_perspective ()
void graphene_matrix_normalize ()
float graphene_matrix_get_x_translation ()
float graphene_matrix_get_y_translation ()
float graphene_matrix_get_z_translation ()
float graphene_matrix_get_x_scale ()
float graphene_matrix_get_y_scale ()
float graphene_matrix_get_z_scale ()
bool graphene_matrix_decompose ()
void graphene_matrix_interpolate ()
bool graphene_matrix_equal ()
bool graphene_matrix_equal_fast ()
bool graphene_matrix_near ()
void graphene_matrix_print ()

Types and Values

Includes

#include <graphene.h>

Description

graphene_matrix_t is a type that provides a 4x4 square matrix, useful for representing 3D transformations.

The matrix is treated as row-major, i.e. it has four vectors (x, y, z, and w) representing rows, and elements of each vector are a column:

  ⎡ m.x ⎤    ⎛ x.x  x.y  x.z  x.w ⎞
  ⎜ m.y ⎟ -\ ⎜ y.x  y.y  y.z  y.w ⎟
  ⎜ m.z ⎟ -/ ⎜ z.x  z.y  z.z  z.w ⎟
  ⎣ m.w ⎦    ⎝ w.x  w.y  w.z  w.w ⎠

It is possible to easily convert a graphene_matrix_t to and from an array of floating point values that can be used with other libraries.

The contents of a graphene_matrix_t are private, and direct access is not possible. You can modify and read the contents of a graphene_matrix_t only through the provided API.

Functions

graphene_matrix_alloc ()

graphene_matrix_t *
graphene_matrix_alloc (void);

Allocates a new graphene_matrix_t.

[constructor]

Returns

the newly allocated matrix.

[transfer full]

Since: 1.0


graphene_matrix_free ()

void
graphene_matrix_free (graphene_matrix_t *m);

Frees the resources allocated by graphene_matrix_alloc().

Parameters

Since: 1.0


graphene_matrix_init_identity ()

graphene_matrix_t *
graphene_matrix_init_identity (graphene_matrix_t *m);

Initializes a graphene_matrix_t with the identity matrix.

Parameters

Returns

the initialized matrix.

[transfer none]

Since: 1.0


graphene_matrix_init_from_float ()

graphene_matrix_t *
graphene_matrix_init_from_float (graphene_matrix_t *m,
                                 const float *v);

Initializes a graphene_matrix_t with the given array of floating point values.

Parameters

m

a graphene_matrix_t

 

v

an array of at least 16 floating point values.

[array fixed-size=16]

Returns

the initialized matrix.

[transfer none]

Since: 1.0


graphene_matrix_init_from_vec4 ()

graphene_matrix_t *
graphene_matrix_init_from_vec4 (graphene_matrix_t *m,
                                const graphene_vec4_t *v0,
                                const graphene_vec4_t *v1,
                                const graphene_vec4_t *v2,
                                const graphene_vec4_t *v3);

Initializes a graphene_matrix_t with the given four row vectors.

Parameters

m

a graphene_matrix_t

 

v0

the first row vector

 

v1

the second row vector

 

v2

the third row vector

 

v3

the fourth row vector

 

Returns

the initialized matrix.

[transfer none]

Since: 1.0


graphene_matrix_init_from_matrix ()

graphene_matrix_t *
graphene_matrix_init_from_matrix (graphene_matrix_t *m,
                                  const graphene_matrix_t *src);

Initializes a graphene_matrix_t using the values of the given matrix.

Parameters

Returns

the initialized matrix.

[transfer none]

Since: 1.0


graphene_matrix_init_from_2d ()

graphene_matrix_t *
graphene_matrix_init_from_2d (graphene_matrix_t *m,
                              double xx,
                              double yx,
                              double xy,
                              double yy,
                              double x_0,
                              double y_0);

Initializes a graphene_matrix_t from the values of an affine transformation matrix.

The arguments map to the following matrix layout:

  ⎛ xx  yx ⎞   ⎛  a   b  0 ⎞
  ⎜ xy  yy ⎟ = ⎜  c   d  0 ⎟
  ⎝ x0  y0 ⎠   ⎝ tx  ty  1 ⎠

This function can be used to convert between an affine matrix type from other libraries and a graphene_matrix_t.

Parameters

m

a graphene_matrix_t

 

xx

the xx member

 

yx

the yx member

 

xy

the xy member

 

yy

the yy member

 

x_0

the x0 member

 

y_0

the y0 member

 

Returns

the initialized matrix.

[transfer none]

Since: 1.0


graphene_matrix_init_perspective ()

graphene_matrix_t *
graphene_matrix_init_perspective (graphene_matrix_t *m,
                                  float fovy,
                                  float aspect,
                                  float z_near,
                                  float z_far);

Initializes a graphene_matrix_t with a perspective projection.

Parameters

m

a graphene_matrix_t

 

fovy

the field of view angle, in degrees

 

aspect

the aspect value

 

z_near

the near Z plane

 

z_far

the far Z plane

 

Returns

the initialized matrix.

[transfer none]

Since: 1.0


graphene_matrix_init_ortho ()

graphene_matrix_t *
graphene_matrix_init_ortho (graphene_matrix_t *m,
                            float left,
                            float right,
                            float top,
                            float bottom,
                            float z_near,
                            float z_far);

Initializes a graphene_matrix_t with an orthographic projection.

Parameters

m

a graphene_matrix_t

 

left

the left edge of the clipping plane

 

right

the right edge of the clipping plane

 

top

the top edge of the clipping plane

 

bottom

the bottom edge of the clipping plane

 

z_near

the distance of the near clipping plane

 

z_far

the distance of the far clipping plane

 

Returns

the initialized matrix.

[transfer none]

Since: 1.0


graphene_matrix_init_look_at ()

graphene_matrix_t *
graphene_matrix_init_look_at (graphene_matrix_t *m,
                              const graphene_vec3_t *eye,
                              const graphene_vec3_t *center,
                              const graphene_vec3_t *up);

Initializes a graphene_matrix_t so that it positions the "camera" at the given eye coordinates towards an object at the center coordinates. The top of the camera is aligned to the direction of the up vector.

Parameters

m

a graphene_matrix_t

 

eye

the vector describing the position to look from

 

center

the vector describing the position to look at

 

up

the vector describing the world's upward direction; usually, this is the graphene_vec3_y_axis() vector

 

Returns

the initialized matrix.

[transfer none]

Since: 1.0


graphene_matrix_init_frustum ()

graphene_matrix_t *
graphene_matrix_init_frustum (graphene_matrix_t *m,
                              float left,
                              float right,
                              float bottom,
                              float top,
                              float z_near,
                              float z_far);

Initializes a graphene_matrix_t compatible with graphene_frustum_t.

See also: graphene_frustum_init_from_matrix()

Parameters

m

a graphene_matrix_t

 

left

distance of the left clipping plane

 

right

distance of the right clipping plane

 

bottom

distance of the bottom clipping plane

 

top

distance of the top clipping plane

 

z_near

distance of the near clipping plane

 

z_far

distance of the far clipping plane

 

Returns

the initialized matrix.

[transfer none]

Since: 1.2


graphene_matrix_init_scale ()

graphene_matrix_t *
graphene_matrix_init_scale (graphene_matrix_t *m,
                            float x,
                            float y,
                            float z);

Initializes a graphene_matrix_t with the given scaling factors.

Parameters

m

a graphene_matrix_t

 

x

the scale factor on the X axis

 

y

the scale factor on the Y axis

 

z

the scale factor on the Z axis

 

Returns

the initialized matrix.

[transfer none]

Since: 1.0


graphene_matrix_init_translate ()

graphene_matrix_t *
graphene_matrix_init_translate (graphene_matrix_t *m,
                                const graphene_point3d_t *p);

Initializes a graphene_matrix_t with a translation to the given coordinates.

Parameters

m

a graphene_matrix_t

 

p

the translation coordinates

 

Returns

the initialized matrix.

[transfer none]

Since: 1.0


graphene_matrix_init_rotate ()

graphene_matrix_t *
graphene_matrix_init_rotate (graphene_matrix_t *m,
                             float angle,
                             const graphene_vec3_t *axis);

Initializes m to represent a rotation of angle degrees on the axis represented by the axis vector.

Parameters

m

a graphene_matrix_t

 

angle

the rotation angle, in degrees

 

axis

the axis vector as a graphene_vec3_t

 

Returns

the initialized matrix.

[transfer none]

Since: 1.0


graphene_matrix_init_skew ()

graphene_matrix_t *
graphene_matrix_init_skew (graphene_matrix_t *m,
                           float x_skew,
                           float y_skew);

Initializes a graphene_matrix_t with a skew transformation with the given factors.

Parameters

m

a graphene_matrix_t

 

x_skew

skew factor, in radians, on the X axis

 

y_skew

skew factor, in radians, on the Y axis

 

Returns

the initialized matrix.

[transfer none]

Since: 1.0


graphene_matrix_is_identity ()

bool
graphene_matrix_is_identity (const graphene_matrix_t *m);

Checks whether the given graphene_matrix_t is the identity matrix.

Parameters

Returns

true if the matrix is the identity matrix

Since: 1.0


graphene_matrix_is_2d ()

bool
graphene_matrix_is_2d (const graphene_matrix_t *m);

Checks whether the given graphene_matrix_t is compatible with an a 2D affine transformation matrix.

Parameters

Returns

true if the matrix is compatible with an affine transformation matrix

Since: 1.0


graphene_matrix_is_backface_visible ()

bool
graphene_matrix_is_backface_visible (const graphene_matrix_t *m);

Checks whether a graphene_matrix_t has a visible back face.

Parameters

Returns

true if the back face of the matrix is visible

Since: 1.0


graphene_matrix_is_singular ()

bool
graphene_matrix_is_singular (const graphene_matrix_t *m);

Checks whether a matrix is singular.

Parameters

Returns

true if the matrix is singular

Since: 1.0


graphene_matrix_to_float ()

void
graphene_matrix_to_float (const graphene_matrix_t *m,
                          float *v);

Converts a graphene_matrix_t to an array of floating point values.

Parameters

m

a graphene_matrix_t

 

v

return location for an array of floating point values. The array must be capable of holding at least 16 values.

[array fixed-size=16][out caller-allocates]

Since: 1.0


graphene_matrix_to_2d ()

bool
graphene_matrix_to_2d (const graphene_matrix_t *m,
                       double *xx,
                       double *yx,
                       double *xy,
                       double *yy,
                       double *x_0,
                       double *y_0);

Converts a graphene_matrix_t to an affine transformation matrix, if the given matrix is compatible.

The returned values have the following layout:

  ⎛ xx  yx ⎞   ⎛  a   b  0 ⎞
  ⎜ xy  yy ⎟ = ⎜  c   d  0 ⎟
  ⎝ x0  y0 ⎠   ⎝ tx  ty  1 ⎠

This function can be used to convert between a graphene_matrix_t and an affine matrix type from other libraries.

Parameters

m

a graphene_matrix_t

 

xx

return location for the xx member.

[out]

yx

return location for the yx member.

[out]

xy

return location for the xy member.

[out]

yy

return location for the yy member.

[out]

x_0

return location for the x0 member.

[out]

y_0

return location for the y0 member.

[out]

Returns

true if the matrix is compatible with an affine transformation matrix

Since: 1.0


graphene_matrix_get_row ()

void
graphene_matrix_get_row (const graphene_matrix_t *m,
                         unsigned int index_,
                         graphene_vec4_t *res);

Retrieves the given row vector at index_ inside a matrix.

Parameters

m

a graphene_matrix_t

 

index_

the index of the row vector, between 0 and 3

 

res

return location for the graphene_vec4_t that is used to store the row vector.

[out caller-allocates]

Since: 1.0


graphene_matrix_get_value ()

float
graphene_matrix_get_value (const graphene_matrix_t *m,
                           unsigned int row,
                           unsigned int col);

Retrieves the value at the given row and col index.

Parameters

m

a graphene_matrix_t

 

row

the row index

 

col

the column index

 

Returns

the value at the given indices

Since: 1.0


graphene_matrix_multiply ()

void
graphene_matrix_multiply (const graphene_matrix_t *a,
                          const graphene_matrix_t *b,
                          graphene_matrix_t *res);

Multiplies two graphene_matrix_t.

Matrix multiplication is not commutative in general; the order of the factors matters. The product of this multiplication is (a × b )

Parameters

a

a graphene_matrix_t

 

b

a graphene_matrix_t

 

res

return location for the matrix result.

[out caller-allocates]

Since: 1.0


graphene_matrix_determinant ()

float
graphene_matrix_determinant (const graphene_matrix_t *m);

Computes the determinant of the given matrix.

Parameters

Returns

the value of the determinant

Since: 1.0


graphene_matrix_transform_vec4 ()

void
graphene_matrix_transform_vec4 (const graphene_matrix_t *m,
                                const graphene_vec4_t *v,
                                graphene_vec4_t *res);

Transforms the given graphene_vec4_t using the matrix m .

See also: graphene_simd4x4f_vec4_mul()

Parameters

m

a graphene_matrix_t

 

v

a graphene_vec4_t

 

res

return location for a graphene_vec4_t.

[out caller-allocates]

Since: 1.0


graphene_matrix_transform_vec3 ()

void
graphene_matrix_transform_vec3 (const graphene_matrix_t *m,
                                const graphene_vec3_t *v,
                                graphene_vec3_t *res);

Transforms the given graphene_vec3_t using the matrix m .

This function will multiply the X, Y, and Z row vectors of the matrix m with the corresponding components of the vector v . The W row vector will be ignored.

See also: graphene_simd4x4f_vec3_mul()

Parameters

m

a graphene_matrix_t

 

v

a graphene_vec3_t

 

res

return location for a graphene_vec3_t.

[out caller-allocates]

Since: 1.0


graphene_matrix_transform_point ()

void
graphene_matrix_transform_point (const graphene_matrix_t *m,
                                 const graphene_point_t *p,
                                 graphene_point_t *res);

Transforms the given graphene_point_t using the matrix m .

Unlike graphene_matrix_transform_vec3(), this function will take into account the fourth row vector of the graphene_matrix_t when computing the dot product of each row vector of the matrix.

See also: graphene_simd4x4f_point3_mul()

Parameters

m

a graphene_matrix_t

 

p

a graphene_point_t

 

res

return location for the transformed graphene_point_t.

[out caller-allocates]

Since: 1.0


graphene_matrix_transform_point3d ()

void
graphene_matrix_transform_point3d (const graphene_matrix_t *m,
                                   const graphene_point3d_t *p,
                                   graphene_point3d_t *res);

Transforms the given graphene_point3d_t using the matrix m .

Unlike graphene_matrix_transform_vec3(), this function will take into account the fourth row vector of the graphene_matrix_t when computing the dot product of each row vector of the matrix.

Parameters

m

a graphene_matrix_t

 

p

a graphene_point3d_t

 

res

return location for the result.

[out caller-allocates]

Since: 1.2


graphene_matrix_transform_rect ()

void
graphene_matrix_transform_rect (const graphene_matrix_t *m,
                                const graphene_rect_t *r,
                                graphene_quad_t *res);

Transforms each corner of a graphene_rect_t using the given matrix m .

The result is a coplanar quadrilateral.

Parameters

m

a graphene_matrix_t

 

r

a graphene_rect_t

 

res

return location for the transformed quad.

[out caller-allocates]

Since: 1.0


graphene_matrix_transform_bounds ()

void
graphene_matrix_transform_bounds (const graphene_matrix_t *m,
                                  const graphene_rect_t *r,
                                  graphene_rect_t *res);

Transforms each corner of a graphene_rect_t using the given matrix m .

The result is the axis aligned bounding rectangle containing the coplanar quadrilateral.

Parameters

m

a graphene_matrix_t

 

r

a graphene_rect_t

 

res

return location for the bounds of the transformed rectangle.

[out caller-allocates]

Since: 1.0


graphene_matrix_transform_box ()

void
graphene_matrix_transform_box (const graphene_matrix_t *m,
                               const graphene_box_t *b,
                               graphene_box_t *res);

Transforms the vertices of a graphene_box_t using the given matrix m .

The result is the axis aligned bounding box containing the transformed vertices.

Parameters

m

a graphene_matrix_t

 

b

a graphene_box_t

 

res

return location for the bounds of the transformed box.

[out caller-allocates]

Since: 1.2


graphene_matrix_transform_sphere ()

void
graphene_matrix_transform_sphere (const graphene_matrix_t *m,
                                  const graphene_sphere_t *s,
                                  graphene_sphere_t *res);

Transforms a graphene_sphere_t using the given matrix m . The result is the bounding sphere containing the transformed sphere.

Parameters

m

a graphene_matrix_t

 

s

a graphene_sphere_t

 

res

return location for the bounds of the transformed sphere.

[out caller-allocates]

Since: 1.2


graphene_matrix_transform_ray ()

void
graphene_matrix_transform_ray (const graphene_matrix_t *m,
                               const graphene_ray_t *r,
                               graphene_ray_t *res);

Transform a graphene_ray_t using the given matrix m .

Parameters

m

a graphene_matrix_t

 

r

a graphene_ray_t

 

res

return location for the transformed ray.

[out caller-allocates]

Since: 1.4


graphene_matrix_project_point ()

void
graphene_matrix_project_point (const graphene_matrix_t *m,
                               const graphene_point_t *p,
                               graphene_point_t *res);

Projects a graphene_point_t using the matrix m .

Parameters

m

a graphene_matrix_t

 

p

a graphene_point_t

 

res

return location for the projected point.

[out caller-allocates]

Since: 1.0


graphene_matrix_project_rect_bounds ()

void
graphene_matrix_project_rect_bounds (const graphene_matrix_t *m,
                                     const graphene_rect_t *r,
                                     graphene_rect_t *res);

Projects a graphene_rect_t using the given matrix.

The resulting rectangle is the axis aligned bounding rectangle capable of containing fully the projected rectangle.

Parameters

m

a graphene_matrix_t

 

r

a graphene_rect_t

 

res

return location for the projected rectangle.

[out caller-allocates]

Since: 1.0


graphene_matrix_project_rect ()

void
graphene_matrix_project_rect (const graphene_matrix_t *m,
                              const graphene_rect_t *r,
                              graphene_quad_t *res);

Projects a graphene_rect_t using the given matrix.

Parameters

m

a graphene_matrix_t

 

r

a graphene_rect_t

 

res

return location for the projected rectangle.

[out caller-allocates]

Since: 1.2


graphene_matrix_untransform_point ()

bool
graphene_matrix_untransform_point (const graphene_matrix_t *m,
                                   const graphene_point_t *p,
                                   const graphene_rect_t *bounds,
                                   graphene_point_t *res);

Undoes the transformation of a graphene_point_t using the given matrix, within the given axis aligned rectangular bounds .

Parameters

m

a graphene_matrix_t

 

p

a graphene_point_t

 

bounds

the bounds of the transformation

 

res

return location for the untransformed point.

[out caller-allocates]

Returns

true if the point was successfully untransformed

Since: 1.0


graphene_matrix_untransform_bounds ()

void
graphene_matrix_untransform_bounds (const graphene_matrix_t *m,
                                    const graphene_rect_t *r,
                                    const graphene_rect_t *bounds,
                                    graphene_rect_t *res);

Undoes the transformation on the corners of a graphene_rect_t using the given matrix, within the given axis aligned rectangular bounds .

Parameters

m

a graphene_matrix_t

 

r

a graphene_rect_t

 

bounds

the bounds of the transformation

 

res

return location for the untransformed rectangle.

[out caller-allocates]

Since: 1.0


graphene_matrix_unproject_point3d ()

void
graphene_matrix_unproject_point3d (const graphene_matrix_t *projection,
                                   const graphene_matrix_t *modelview,
                                   const graphene_point3d_t *point,
                                   graphene_point3d_t *res);

Unprojects the given point using the projection matrix and a modelview matrix.

Parameters

projection

a graphene_matrix_t for the projection matrix

 

modelview

a graphene_matrix_t for the modelview matrix; this is the inverse of the modelview used when projecting the point

 

point

a graphene_point3d_t with the coordinates of the point

 

res

return location for the unprojected point.

[out caller-allocates]

Since: 1.2


graphene_matrix_translate ()

void
graphene_matrix_translate (graphene_matrix_t *m,
                           const graphene_point3d_t *pos);

Adds a translation transformation to m using the coordinates of the given graphene_point3d_t.

This is the equivalent of calling graphene_matrix_init_translate() and then multiplying m with the translation matrix.

Parameters

Since: 1.0


graphene_matrix_rotate ()

void
graphene_matrix_rotate (graphene_matrix_t *m,
                        float angle,
                        const graphene_vec3_t *axis);

Adds a rotation transformation to m , using the given angle and axis vector.

This is the equivalent of calling graphene_matrix_init_rotate() and then multiplying the matrix m with the rotation matrix.

Parameters

m

a graphene_matrix_t

 

angle

the rotation angle, in degrees

 

axis

the rotation axis, as a graphene_vec3_t

 

Since: 1.0


graphene_matrix_rotate_x ()

void
graphene_matrix_rotate_x (graphene_matrix_t *m,
                          float angle);

Adds a rotation transformation around the X axis to m , using the given angle .

See also: graphene_matrix_rotate()

Parameters

m

a graphene_matrix_t

 

angle

the rotation angle, in degrees

 

Since: 1.0


graphene_matrix_rotate_y ()

void
graphene_matrix_rotate_y (graphene_matrix_t *m,
                          float angle);

Adds a rotation transformation around the Y axis to m , using the given angle .

See also: graphene_matrix_rotate()

Parameters

m

a graphene_matrix_t

 

angle

the rotation angle, in degrees

 

Since: 1.0


graphene_matrix_rotate_z ()

void
graphene_matrix_rotate_z (graphene_matrix_t *m,
                          float angle);

Adds a rotation transformation around the Z axis to m , using the given angle .

See also: graphene_matrix_rotate()

Parameters

m

a graphene_matrix_t

 

angle

the rotation angle, in degrees

 

Since: 1.0


graphene_matrix_rotate_quaternion ()

void
graphene_matrix_rotate_quaternion (graphene_matrix_t *m,
                                   const graphene_quaternion_t *q);

Adds a rotation transformation to m , using the given graphene_quaternion_t.

This is the equivalent of calling graphene_quaternion_to_matrix() and then multiplying m with the rotation matrix.

Parameters

m

a graphene_matrix_t

 

q

a rotation described by a graphene_quaternion_t

 

Since: 1.2


graphene_matrix_rotate_euler ()

void
graphene_matrix_rotate_euler (graphene_matrix_t *m,
                              const graphene_euler_t *e);

Adds a rotation transformation to m , using the given graphene_euler_t.

Parameters

m

a graphene_matrix_t

 

e

a rotation described by a graphene_euler_t

 

Since: 1.2


graphene_matrix_scale ()

void
graphene_matrix_scale (graphene_matrix_t *m,
                       float factor_x,
                       float factor_y,
                       float factor_z);

Adds a scaling transformation to m , using the three given factors.

This is the equivalent of calling graphene_matrix_init_scale() and then multiplying the matrix m with the scale matrix.

Parameters

m

a graphene_matrix_t

 

factor_x

scaling factor on the X axis

 

factor_y

scaling factor on the Y axis

 

factor_z

scaling factor on the Z axis

 

Since: 1.0


graphene_matrix_skew_xy ()

void
graphene_matrix_skew_xy (graphene_matrix_t *m,
                         float factor);

Adds a skew of factor on the X and Y axis to the given matrix.

Parameters

m

a graphene_matrix_t

 

factor

skew factor

 

Since: 1.0


graphene_matrix_skew_xz ()

void
graphene_matrix_skew_xz (graphene_matrix_t *m,
                         float factor);

Adds a skew of factor on the X and Z axis to the given matrix.

Parameters

m

a graphene_matrix_t

 

factor

skew factor

 

Since: 1.0


graphene_matrix_skew_yz ()

void
graphene_matrix_skew_yz (graphene_matrix_t *m,
                         float factor);

Adds a skew of factor on the Y and Z axis to the given matrix.

Parameters

m

a graphene_matrix_t

 

factor

skew factor

 

Since: 1.0


graphene_matrix_transpose ()

void
graphene_matrix_transpose (const graphene_matrix_t *m,
                           graphene_matrix_t *res);

Transposes the given matrix.

Parameters

m

a graphene_matrix_t

 

res

return location for the transposed matrix.

[out caller-allocates]

Since: 1.0


graphene_matrix_inverse ()

bool
graphene_matrix_inverse (const graphene_matrix_t *m,
                         graphene_matrix_t *res);

Inverts the given matrix.

Parameters

m

a graphene_matrix_t

 

res

return location for the inverse matrix.

[out caller-allocates]

Returns

true if the matrix is invertible

Since: 1.0


graphene_matrix_perspective ()

void
graphene_matrix_perspective (const graphene_matrix_t *m,
                             float depth,
                             graphene_matrix_t *res);

Applies a perspective of depth to the matrix.

Parameters

m

a graphene_matrix_t

 

depth

the depth of the perspective

 

res

return location for the perspective matrix.

[out caller-allocates]

Since: 1.0


graphene_matrix_normalize ()

void
graphene_matrix_normalize (const graphene_matrix_t *m,
                           graphene_matrix_t *res);

Normalizes the given graphene_matrix_t.

Parameters

m

a graphene_matrix_t

 

res

return location for the normalized matrix.

[out caller-allocates]

Since: 1.0


graphene_matrix_get_x_translation ()

float
graphene_matrix_get_x_translation (const graphene_matrix_t *m);

Retrieves the translation component on the X axis from m .

Parameters

Returns

the translation component

Since: 1.10


graphene_matrix_get_y_translation ()

float
graphene_matrix_get_y_translation (const graphene_matrix_t *m);

Retrieves the translation component on the Y axis from m .

Parameters

Returns

the translation component

Since: 1.10


graphene_matrix_get_z_translation ()

float
graphene_matrix_get_z_translation (const graphene_matrix_t *m);

Retrieves the translation component on the Z axis from m .

Parameters

Returns

the translation component

Since: 1.10


graphene_matrix_get_x_scale ()

float
graphene_matrix_get_x_scale (const graphene_matrix_t *m);

Retrieves the scaling factor on the X axis in m .

Parameters

Returns

the value of the scaling factor

Since: 1.0


graphene_matrix_get_y_scale ()

float
graphene_matrix_get_y_scale (const graphene_matrix_t *m);

Retrieves the scaling factor on the Y axis in m .

Parameters

Returns

the value of the scaling factor

Since: 1.0


graphene_matrix_get_z_scale ()

float
graphene_matrix_get_z_scale (const graphene_matrix_t *m);

Retrieves the scaling factor on the Z axis in m .

Parameters

Returns

the value of the scaling factor

Since: 1.0


graphene_matrix_decompose ()

bool
graphene_matrix_decompose (const graphene_matrix_t *m,
                           graphene_vec3_t *translate,
                           graphene_vec3_t *scale,
                           graphene_quaternion_t *rotate,
                           graphene_vec3_t *shear,
                           graphene_vec4_t *perspective);

Decomposes a transformation matrix into its component transformations.

The algorithm for decomposing a matrix is taken from the CSS3 Transforms specification; specifically, the decomposition code is based on the equivalent code published in "Graphics Gems II", edited by Jim Arvo, and available online.

Parameters

m

a graphene_matrix_t

 

translate

the translation vector.

[out caller-allocates]

scale

the scale vector.

[out caller-allocates]

rotate

the rotation quaternion.

[out caller-allocates]

shear

the shear vector.

[out caller-allocates]

perspective

the perspective vector.

[out caller-allocates]

Returns

true if the matrix could be decomposed


graphene_matrix_interpolate ()

void
graphene_matrix_interpolate (const graphene_matrix_t *a,
                             const graphene_matrix_t *b,
                             double factor,
                             graphene_matrix_t *res);

Linearly interpolates the two given graphene_matrix_t by interpolating the decomposed transformations separately.

If either matrix cannot be reduced to their transformations then the interpolation cannot be performed, and this function will return an identity matrix.

Parameters

a

a graphene_matrix_t

 

b

a graphene_matrix_t

 

factor

the linear interpolation factor

 

res

return location for the interpolated matrix.

[out caller-allocates]

Since: 1.0


graphene_matrix_equal ()

bool
graphene_matrix_equal (const graphene_matrix_t *a,
                       const graphene_matrix_t *b);

Checks whether the two given graphene_matrix_t matrices are equal.

Parameters

Returns

true if the two matrices are equal, and false otherwise

Since: 1.10


graphene_matrix_equal_fast ()

bool
graphene_matrix_equal_fast (const graphene_matrix_t *a,
                            const graphene_matrix_t *b);

Checks whether the two given graphene_matrix_t matrices are byte-by-byte equal.

While this function is faster than graphene_matrix_equal(), it can also return false negatives, so it should be used in conjuction with either graphene_matrix_equal() or graphene_matrix_near(). For instance:

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if (graphene_matrix_equal_fast (a, b))
  {
    // matrices are definitely the same
  }
else
  {
    if (graphene_matrix_equal (a, b))
      // matrices contain the same values within an epsilon of FLT_EPSILON
    else if (graphene_matrix_near (a, b, 0.0001))
      // matrices contain the same values within an epsilon of 0.0001
    else
      // matrices are not equal
  }

Parameters

Returns

true if the matrices are equal. and false otherwise

Since: 1.10


graphene_matrix_near ()

bool
graphene_matrix_near (const graphene_matrix_t *a,
                      const graphene_matrix_t *b,
                      float epsilon);

Compares the two given graphene_matrix_t matrices and checks whether their values are within the given epsilon of each other.

Parameters

a

a graphene_matrix_t

 

b

a graphene_matrix_t

 

epsilon

the threshold between the two matrices

 

Returns

true if the two matrices are near each other, and false otherwise

Since: 1.10


graphene_matrix_print ()

void
graphene_matrix_print (const graphene_matrix_t *m);

Prints the contents of a matrix to the standard error stream.

This function is only useful for debugging; there are no guarantees made on the format of the output.

Parameters

m

The matrix to print

 

Since: 1.0

Types and Values

graphene_matrix_t

typedef struct {
} graphene_matrix_t;

A structure capable of holding a 4x4 matrix.

The contents of the graphene_matrix_t structure are private and should never be accessed directly.