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Functions
void  cogl_vector3_init () 
void  cogl_vector3_init_zero () 
CoglBool  cogl_vector3_equal () 
CoglBool  cogl_vector3_equal_with_epsilon () 
float *  cogl_vector3_copy () 
void  cogl_vector3_free () 
void  cogl_vector3_invert () 
void  cogl_vector3_add () 
void  cogl_vector3_subtract () 
void  cogl_vector3_multiply_scalar () 
void  cogl_vector3_divide_scalar () 
void  cogl_vector3_normalize () 
float  cogl_vector3_magnitude () 
void  cogl_vector3_cross_product () 
float  cogl_vector3_dot_product () 
float  cogl_vector3_distance () 
Description
This exposes a utility API that can be used for basic manipulation of 3 component float vectors.
Functions
cogl_vector3_init ()
void cogl_vector3_init (float *vector
,float x
,float y
,float z
);
Initializes a 3 component, single precision float vector which can then be manipulated with the cogl_vector convenience APIs. Vectors can also be used in places where a "point" is often desired.
Parameters
vector 
The 3 component vector you want to initialize 

x 
The x component 

y 
The y component 

z 
The z component 
Since: 1.4
Stability Level: Unstable
cogl_vector3_init_zero ()
void
cogl_vector3_init_zero (float *vector
);
Initializes a 3 component, single precision float vector with zero for each component.
Since: 1.4
Stability Level: Unstable
cogl_vector3_equal ()
CoglBool cogl_vector3_equal (const void *v1
,const void *v2
);
Compares the components of two vectors and returns TRUE if they are the same.
The comparison of the components is done with the '==' operator such that 0 is considered equal to 0, but otherwise there is no fuzziness such as an epsilon to consider vectors that are essentially identical except for some minor precision error differences due to the way they have been manipulated.
Parameters
v1 
The first 3 component vector you want to compare 

v2 
The second 3 component vector you want to compare 
Since: 1.4
Stability Level: Unstable
cogl_vector3_equal_with_epsilon ()
CoglBool cogl_vector3_equal_with_epsilon (const float *vector0
,const float *vector1
,float epsilon
);
Compares the components of two vectors using the given epsilon and returns TRUE if they are the same, using an internal epsilon for comparing the floats.
Each component is compared against the epsilon value in this way:
1 
if (fabsf (vector0>x  vector1>x) < epsilon) 
Parameters
vector0 
The first 3 component vector you want to compare 

vector1 
The second 3 component vector you want to compare 

epsilon 
The allowable difference between components to still be considered equal 
Since: 1.4
Stability Level: Unstable
cogl_vector3_copy ()
float *
cogl_vector3_copy (const float *vector
);
Allocates a new 3 component float vector on the heap initializing
the components from the given vector
and returns a pointer to the
newly allocated vector. You should free the memory using
cogl_vector3_free()
Since: 1.4
Stability Level: Unstable
cogl_vector3_free ()
void
cogl_vector3_free (float *vector
);
Frees a 3 component vector that was previously allocated with
cogl_vector3_copy()
Since: 1.4
Stability Level: Unstable
cogl_vector3_invert ()
void
cogl_vector3_invert (float *vector
);
Inverts/negates all the components of the given vector
.
Since: 1.4
Stability Level: Unstable
cogl_vector3_add ()
void cogl_vector3_add (float *result
,const float *a
,const float *b
);
Adds each of the corresponding components in vectors a
and b
storing the results in result
.
Parameters
result 
Where you want the result written 

a 
The first vector operand 

b 
The second vector operand 
Since: 1.4
Stability Level: Unstable
cogl_vector3_subtract ()
void cogl_vector3_subtract (float *result
,const float *a
,const float *b
);
Subtracts each of the corresponding components in vector b
from
a
storing the results in result
.
Parameters
result 
Where you want the result written 

a 
The first vector operand 

b 
The second vector operand 
Since: 1.4
Stability Level: Unstable
cogl_vector3_multiply_scalar ()
void cogl_vector3_multiply_scalar (float *vector
,float scalar
);
Multiplies each of the vector
components by the given scalar.
Parameters
vector 
The 3 component vector you want to manipulate 

scalar 
The scalar you want to multiply the vector components by 
Since: 1.4
Stability Level: Unstable
cogl_vector3_divide_scalar ()
void cogl_vector3_divide_scalar (float *vector
,float scalar
);
Divides each of the vector
components by the given scalar.
Parameters
vector 
The 3 component vector you want to manipulate 

scalar 
The scalar you want to divide the vector components by 
Since: 1.4
Stability Level: Unstable
cogl_vector3_normalize ()
void
cogl_vector3_normalize (float *vector
);
Updates the vector so it is a "unit vector" such that the
vector
s magnitude or length is equal to 1.
Since: 1.4
Stability Level: Unstable
cogl_vector3_magnitude ()
float
cogl_vector3_magnitude (const float *vector
);
Calculates the scalar magnitude or length of vector
.
Since: 1.4
Stability Level: Unstable
cogl_vector3_cross_product ()
void cogl_vector3_cross_product (float *result
,const float *u
,const float *v
);
Calculates the cross product between the two vectors u
and v
.
The cross product is a vector perpendicular to both u
and v
. This
can be useful for calculating the normal of a polygon by creating
two vectors in its plane using the polygons vertices and taking
their cross product.
If the two vectors are parallel then the cross product is 0.
You can use a right hand rule to determine which direction the
perpendicular vector will point: If you place the two vectors tail,
to tail and imagine grabbing the perpendicular line that extends
through the common tail with your right hand such that you fingers
rotate in the direction from u
to v
then the resulting vector
points along your extended thumb.
Parameters
result 
Where you want the result written 

u 
Your first 3 component vector 

v 
Your second 3 component vector 
Since: 1.4
Stability Level: Unstable
cogl_vector3_dot_product ()
float cogl_vector3_dot_product (const float *a
,const float *b
);
Calculates the dot product of the two 3 component vectors. This can be used to determine the magnitude of one vector projected onto another. (for example a surface normal)
For example if you have a polygon with a given normal vector and some other point for which you want to calculate its distance from the polygon, you can create a vector between one of the polygon vertices and that point and use the dot product to calculate the magnitude for that vector but projected onto the normal of the polygon. This way you don't just get the distance from the point to the edge of the polygon you get the distance from the point to the nearest part of the polygon.
The dot product is calculated as:
1 
(a>x * b>x + a>y * b>y + a>z * b>z) 
For reference, the dot product can also be calculated from the angle between two vectors as:
1 
abcos𝜃 
Since: 1.4
Stability Level: Unstable
cogl_vector3_distance ()
float cogl_vector3_distance (const float *a
,const float *b
);
If you consider the two given vectors as (x,y,z) points instead then this will compute the distance between those two points.
Since: 1.4
Stability Level: Unstable