struct GimpVector2

struct GimpVector2 {

  gdouble x, y;
};

A two dimensional vector.

struct GimpVector3

struct GimpVector3 {

  gdouble x, y, z;
};

A three dimensional vector.

struct GimpVector4

struct GimpVector4 {

  gdouble x, y, z, w;
};

A four dimensional vector.

gimp_vector2_new ()

GimpVector2 gimp_vector2_new                (gdouble x,
                                             gdouble y);

Creates a GimpVector2 of coordinates x and y.

gimp_vector2_set ()

void        gimp_vector2_set                (GimpVector2 *vector,
                                             gdouble x,
                                             gdouble y);

Sets the X and Y coordinates of vector to x and y.

gimp_vector2_length ()

gdouble     gimp_vector2_length             (const GimpVector2 *vector);

Computes the length of a 2D vector.

gimp_vector2_length_val ()

gdouble     gimp_vector2_length_val         (GimpVector2 vector);

This function is identical to gimp_vector2_length() but the vector is passed by value rather than by reference.

gimp_vector2_mul ()

void        gimp_vector2_mul                (GimpVector2 *vector,
                                             gdouble factor);

Multiplies each component of the vector by factor. Note that this is equivalent to multiplying the vectors length by factor.

gimp_vector2_mul_val ()

GimpVector2 gimp_vector2_mul_val            (GimpVector2 vector,
                                             gdouble factor);

This function is identical to gimp_vector2_mul() but the vector is passed by value rather than by reference.

gimp_vector2_normalize ()

void        gimp_vector2_normalize          (GimpVector2 *vector);

Normalizes the vector so the length of the vector is 1.0. The nul vector will not be changed.

gimp_vector2_normalize_val ()

GimpVector2 gimp_vector2_normalize_val      (GimpVector2 vector);

This function is identical to gimp_vector2_normalize() but the vector is passed by value rather than by reference.

gimp_vector2_neg ()

void        gimp_vector2_neg                (GimpVector2 *vector);

Negates the vector (i.e. negate all its coordinates).

gimp_vector2_neg_val ()

GimpVector2 gimp_vector2_neg_val            (GimpVector2 vector);

This function is identical to gimp_vector2_neg() but the vector is passed by value rather than by reference.

gimp_vector2_add ()

void        gimp_vector2_add                (GimpVector2 *result,
                                             const GimpVector2 *vector1,
                                             const GimpVector2 *vector2);

Computes the sum of two 2D vectors. The resulting GimpVector2 is stored in result.

gimp_vector2_add_val ()

GimpVector2 gimp_vector2_add_val            (GimpVector2 vector1,
                                             GimpVector2 vector2);

This function is identical to gimp_vector2_add() but the vectors are passed by value rather than by reference.

gimp_vector2_sub ()

void        gimp_vector2_sub                (GimpVector2 *result,
                                             const GimpVector2 *vector1,
                                             const GimpVector2 *vector2);

Computes the difference of two 2D vectors (vector1 minus vector2). The resulting GimpVector2 is stored in result.

gimp_vector2_sub_val ()

GimpVector2 gimp_vector2_sub_val            (GimpVector2 vector1,
                                             GimpVector2 vector2);

This function is identical to gimp_vector2_sub() but the vectors are passed by value rather than by reference.

gimp_vector2_inner_product ()

gdouble     gimp_vector2_inner_product      (const GimpVector2 *vector1,
                                             const GimpVector2 *vector2);

Computes the inner (dot) product of two 2D vectors. This product is zero if and only if the two vectors are orthognal.

gimp_vector2_inner_product_val ()

gdouble     gimp_vector2_inner_product_val  (GimpVector2 vector1,
                                             GimpVector2 vector2);

This function is identical to gimp_vector2_inner_product() but the vectors are passed by value rather than by reference.

gimp_vector2_cross_product ()

GimpVector2 gimp_vector2_cross_product      (const GimpVector2 *vector1,
                                             const GimpVector2 *vector2);

Compute the cross product of two vectors. The result is a GimpVector2 which is orthognal to both vector1 and vector2. If vector1 and vector2 are parallel, the result will be the nul vector.

Note that in 2D, this function is useful to test if two vectors are parallel or not, or to compute the area spawned by two vectors.

gimp_vector2_cross_product_val ()

GimpVector2 gimp_vector2_cross_product_val  (GimpVector2 vector1,
                                             GimpVector2 vector2);

This function is identical to gimp_vector2_cross_product() but the vectors are passed by value rather than by reference.

gimp_vector2_rotate ()

void        gimp_vector2_rotate             (GimpVector2 *vector,
                                             gdouble alpha);

Rotates the vector counterclockwise by alpha radians.

gimp_vector2_rotate_val ()

GimpVector2 gimp_vector2_rotate_val         (GimpVector2 vector,
                                             gdouble alpha);

This function is identical to gimp_vector2_rotate() but the vector is passed by value rather than by reference.

gimp_vector3_new ()

GimpVector3 gimp_vector3_new                (gdouble x,
                                             gdouble y,
                                             gdouble z);

Creates a GimpVector3 of coordinate x, y and z.

gimp_vector3_set ()

void        gimp_vector3_set                (GimpVector3 *vector,
                                             gdouble x,
                                             gdouble y,
                                             gdouble z);

Sets the X, Y and Z coordinates of vector to x, y and z.

gimp_vector3_length ()

gdouble     gimp_vector3_length             (const GimpVector3 *vector);

Computes the length of a 3D vector.

gimp_vector3_length_val ()

gdouble     gimp_vector3_length_val         (GimpVector3 vector);

This function is identical to gimp_vector3_length() but the vector is passed by value rather than by reference.

gimp_vector3_mul ()

void        gimp_vector3_mul                (GimpVector3 *vector,
                                             gdouble factor);

Multiplies each component of the vector by factor. Note that this is equivalent to multiplying the vectors length by factor.

gimp_vector3_mul_val ()

GimpVector3 gimp_vector3_mul_val            (GimpVector3 vector,
                                             gdouble factor);

This function is identical to gimp_vector3_mul() but the vector is passed by value rather than by reference.

gimp_vector3_normalize ()

void        gimp_vector3_normalize          (GimpVector3 *vector);

Normalizes the vector so the length of the vector is 1.0. The nul vector will not be changed.

gimp_vector3_normalize_val ()

GimpVector3 gimp_vector3_normalize_val      (GimpVector3 vector);

This function is identical to gimp_vector3_normalize() but the vector is passed by value rather than by reference.

gimp_vector3_neg ()

void        gimp_vector3_neg                (GimpVector3 *vector);

Negates the vector (i.e. negate all its coordinates).

gimp_vector3_neg_val ()

GimpVector3 gimp_vector3_neg_val            (GimpVector3 vector);

This function is identical to gimp_vector3_neg() but the vector is passed by value rather than by reference.

gimp_vector3_add ()

void        gimp_vector3_add                (GimpVector3 *result,
                                             const GimpVector3 *vector1,
                                             const GimpVector3 *vector2);

Computes the sum of two 3D vectors. The resulting GimpVector3 is stored in result.

gimp_vector3_add_val ()

GimpVector3 gimp_vector3_add_val            (GimpVector3 vector1,
                                             GimpVector3 vector2);

This function is identical to gimp_vector3_add() but the vectors are passed by value rather than by reference.

gimp_vector3_sub ()

void        gimp_vector3_sub                (GimpVector3 *result,
                                             const GimpVector3 *vector1,
                                             const GimpVector3 *vector2);

Computes the difference of two 3D vectors (vector1 minus vector2). The resulting GimpVector3 is stored in result.

gimp_vector3_sub_val ()

GimpVector3 gimp_vector3_sub_val            (GimpVector3 vector1,
                                             GimpVector3 vector2);

This function is identical to gimp_vector3_sub() but the vectors are passed by value rather than by reference.

gimp_vector3_inner_product ()

gdouble     gimp_vector3_inner_product      (const GimpVector3 *vector1,
                                             const GimpVector3 *vector2);

Computes the inner (dot) product of two 3D vectors. This product is zero if and only if the two vectors are orthognal.

gimp_vector3_inner_product_val ()

gdouble     gimp_vector3_inner_product_val  (GimpVector3 vector1,
                                             GimpVector3 vector2);

This function is identical to gimp_vector3_inner_product() but the vectors are passed by value rather than by reference.

gimp_vector3_cross_product ()

GimpVector3 gimp_vector3_cross_product      (const GimpVector3 *vector1,
                                             const GimpVector3 *vector2);

Compute the cross product of two vectors. The result is a GimpVector3 which is orthognal to both vector1 and vector2. If vector1 and vector2 and parallel, the result will be the nul vector.

This function can be used to compute the normal of the plane defined by vector1 and vector2.

gimp_vector3_cross_product_val ()

GimpVector3 gimp_vector3_cross_product_val  (GimpVector3 vector1,
                                             GimpVector3 vector2);

This function is identical to gimp_vector3_cross_product() but the vectors are passed by value rather than by reference.

gimp_vector3_rotate ()

void        gimp_vector3_rotate             (GimpVector3 *vector,
                                             gdouble alpha,
                                             gdouble beta,
                                             gdouble gamma);

Rotates the vector around the three axis (Z, Y, and X) by alpha, beta and gamma, respectively.

Note that the order of the rotation is very important. If you expect a vector to be rotated around X, and then around Y, you will have to call this function twice. Also, it is often wise to call this function with only one of alpha, beta and gamma non-zero.

gimp_vector3_rotate_val ()

GimpVector3 gimp_vector3_rotate_val         (GimpVector3 vector,
                                             gdouble alpha,
                                             gdouble beta,
                                             gdouble gamma);

This function is identical to gimp_vector3_rotate() but the vectors are passed by value rather than by reference.

gimp_vector_2d_to_3d ()

void        gimp_vector_2d_to_3d            (gint sx,
                                             gint sy,
                                             gint w,
                                             gint h,
                                             gint x,
                                             gint y,
                                             const GimpVector3 *vp,
                                             GimpVector3 *p);

\"Compute screen (sx, sy) - (sx + w, sy + h) to 3D unit square mapping. The plane to map to is given in the z field of p. The observer is located at position vp (vp->z != 0.0).\"

In other words, this computes the projection of the point (x, y) to the plane z = p->z (parallel to XY), from the vp point of view through the screen (sx, sy)->(sx + w, sy + h)

gimp_vector_2d_to_3d_val ()

GimpVector3 gimp_vector_2d_to_3d_val        (gint sx,
                                             gint sy,
                                             gint w,
                                             gint h,
                                             gint x,
                                             gint y,
                                             GimpVector3 vp,
                                             GimpVector3 p);

This function is identical to gimp_vector_2d_to_3d() but the position of the observer and the resulting point p are passed by value rather than by reference.

gimp_vector_3d_to_2d ()

void        gimp_vector_3d_to_2d            (gint sx,
                                             gint sy,
                                             gint w,
                                             gint h,
                                             gdouble *x,
                                             gdouble *y,
                                             const GimpVector3 *vp,
                                             const GimpVector3 *p);

Convert the given 3D point to 2D (project it onto the viewing plane, (sx, sy, 0) - (sx + w, sy + h, 0). The input is assumed to be in the unit square (0, 0, z) - (1, 1, z). The viewpoint of the observer is passed in vp.

This is basically the opposite of gimp_vector_2d_to_3d().