mutter/cogl/cogl-quaternion.h
Neil Roberts 4f6fe6f0e2 Fixes for --disable-glib
This fixes some problems which were stopping --disable-glib from
working properly:

• A lot of the public headers were including glib.h. This shouldn't be
  necessary because the API doesn't expose any glib types. Otherwise
  any apps would require glib in order to get the header.

• The public headers were using G_BEGIN_DECLS. There is now a
  replacement macro called COGL_BEGIN_DECLS which is defined in
  cogl-types.h.

• A similar fix has been done for G_GNUC_NULL_TERMINATED and
  G_GNUC_DEPRECATED.

• The CFLAGS were not including $(builddir)/deps/glib which was
  preventing it finding the generated glibconfig.h when building out
  of tree.

Reviewed-by: Robert Bragg <robert@linux.intel.com>

(cherry picked from commit 4138b3141c2f39cddaea3d72bfc04342ed5092d0)
2013-01-22 17:48:05 +00:00

530 lines
14 KiB
C

/*
* Cogl
*
* An object oriented GL/GLES Abstraction/Utility Layer
*
* Copyright (C) 2010 Intel Corporation.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*
* Authors:
* Robert Bragg <robert@linux.intel.com>
*/
#if !defined(__COGL_H_INSIDE__) && !defined(COGL_COMPILATION)
#error "Only <cogl/cogl.h> can be included directly."
#endif
#ifndef __COGL_QUATERNION_H__
#define __COGL_QUATERNION_H__
#include <cogl/cogl-types.h>
#include <cogl/cogl-vector.h>
COGL_BEGIN_DECLS
/**
* SECTION:cogl-quaternion
* @short_description: Functions for initializing and manipulating
* quaternions.
*
* Quaternions have become a standard form for representing 3D
* rotations and have some nice properties when compared with other
* representation such as (roll,pitch,yaw) Euler angles. They can be
* used to interpolate between different rotations and they don't
* suffer from a problem called "Gimbal lock" where two of the axis of
* rotation may become aligned and you loose a degree of freedom.
* (<ulink url="http://en.wikipedia.org/wiki/Gimbal_lock"/>).
*/
#include <cogl/cogl-vector.h>
#include <cogl/cogl-euler.h>
/**
* CoglQuaternion:
*
* A quaternion is comprised of a scalar component and a 3D vector
* component. The scalar component is normally referred to as w and the
* vector might either be referred to as v or a (for axis) or expanded
* with the individual components: (x, y, z) A full quaternion would
* then be written as <literal>[w (x, y, z)]</literal>.
*
* Quaternions can be considered to represent an axis and angle
* pair although sadly these numbers are buried somewhat under some
* maths...
*
* For the curious you can see here that a given axis (a) and angle (𝜃)
* pair are represented in a quaternion as follows:
* |[
* [w=cos(𝜃/2) ( x=sin(𝜃/2)*a.x, y=sin(𝜃/2)*a.y, z=sin(𝜃/2)*a.x )]
* ]|
*
* Unit Quaternions:
* When using Quaternions to represent spatial orientations for 3D
* graphics it's always assumed you have a unit quaternion. The
* magnitude of a quaternion is defined as:
* |[
* sqrt (w² + x² + y² + z²)
* ]|
* and a unit quaternion satisfies this equation:
* |[
* w² + x² + y² + z² = 1
* ]|
*
* Thankfully most of the time we don't actually have to worry about
* the maths that goes on behind the scenes but if you are curious to
* learn more here are some external references:
*
* <itemizedlist>
* <listitem>
* <ulink url="http://mathworld.wolfram.com/Quaternion.html"/>
* </listitem>
* <listitem>
* <ulink url="http://www.gamedev.net/reference/articles/article1095.asp"/>
* </listitem>
* <listitem>
* <ulink url="http://www.cprogramming.com/tutorial/3d/quaternions.html"/>
* </listitem>
* <listitem>
* <ulink url="http://www.isner.com/tutorials/quatSpells/quaternion_spells_12.htm"/>
* </listitem>
* <listitem>
* 3D Maths Primer for Graphics and Game Development ISBN-10: 1556229119
* </listitem>
* <listitem>
* <ulink url="http://www.cs.caltech.edu/courses/cs171/quatut.pdf"/>
* </listitem>
* <listitem>
* <ulink url="http://www.j3d.org/matrix_faq/matrfaq_latest.html#Q56"/>
* </listitem>
* </itemizedlist>
*
* @w: based on the angle of rotation it is cos(𝜃/2)
* @x: based on the angle of rotation and x component of the axis of
* rotation it is sin(𝜃/2)*axis.x
* @y: based on the angle of rotation and y component of the axis of
* rotation it is sin(𝜃/2)*axis.y
* @z: based on the angle of rotation and z component of the axis of
* rotation it is sin(𝜃/2)*axis.z
*/
struct _CoglQuaternion
{
float w;
float x;
float y;
float z;
/*< private >*/
float padding0;
float padding1;
float padding2;
float padding3;
};
COGL_STRUCT_SIZE_ASSERT (CoglQuaternion, 32);
/**
* cogl_quaternion_init:
* @quaternion: An uninitialized #CoglQuaternion
* @angle: The angle you want to rotate around the given axis
* @x: The x component of your axis vector about which you want to
* rotate.
* @y: The y component of your axis vector about which you want to
* rotate.
* @z: The z component of your axis vector about which you want to
* rotate.
*
* Initializes a quaternion that rotates @angle degrees around the
* axis vector (@x, @y, @z). The axis vector does not need to be
* normalized.
*
* Returns: A normalized, unit quaternion representing an orientation
* rotated @angle degrees around the axis vector (@x, @y, @z)
*
* Since: 2.0
*/
void
cogl_quaternion_init (CoglQuaternion *quaternion,
float angle,
float x,
float y,
float z);
/**
* cogl_quaternion_init_from_angle_vector:
* @quaternion: An uninitialized #CoglQuaternion
* @axis3f: your 3 component axis vector about which you want to rotate.
*
* Initializes a quaternion that rotates @angle degrees around the
* given @axis vector. The axis vector does not need to be
* normalized.
*
* Returns: A normalized, unit quaternion representing an orientation
* rotated @angle degrees around the given @axis vector.
*
* Since: 2.0
*/
void
cogl_quaternion_init_from_angle_vector (CoglQuaternion *quaternion,
float angle,
const float *axis3f);
/**
* cogl_quaternion_init_identity:
* @quaternion: An uninitialized #CoglQuaternion
*
* Initializes the quaternion with the canonical quaternion identity
* [1 (0, 0, 0)] which represents no rotation. Multiplying a
* quaternion with this identity leaves the quaternion unchanged.
*
* You might also want to consider using
* cogl_get_static_identity_quaternion().
*
* Since: 2.0
*/
void
cogl_quaternion_init_identity (CoglQuaternion *quaternion);
/**
* cogl_quaternion_init_from_array:
* @quaternion: A #CoglQuaternion
* @array: An array of 4 floats w,(x,y,z)
*
* Initializes a [w (x, y,z)] quaternion directly from an array of 4
* floats: [w,x,y,z].
*
* Since: 2.0
*/
void
cogl_quaternion_init_from_array (CoglQuaternion *quaternion,
const float *array);
/**
* cogl_quaternion_init_from_x_rotation:
* @quaternion: An uninitialized #CoglQuaternion
* @angle: The angle to rotate around the x axis
*
* XXX: check which direction this rotates
*
* Since: 2.0
*/
void
cogl_quaternion_init_from_x_rotation (CoglQuaternion *quaternion,
float angle);
/**
* cogl_quaternion_init_from_y_rotation:
* @quaternion: An uninitialized #CoglQuaternion
* @angle: The angle to rotate around the y axis
*
*
* Since: 2.0
*/
void
cogl_quaternion_init_from_y_rotation (CoglQuaternion *quaternion,
float angle);
/**
* cogl_quaternion_init_from_z_rotation:
* @quaternion: An uninitialized #CoglQuaternion
* @angle: The angle to rotate around the z axis
*
*
* Since: 2.0
*/
void
cogl_quaternion_init_from_z_rotation (CoglQuaternion *quaternion,
float angle);
/**
* cogl_quaternion_init_from_euler:
* @quaternion: A #CoglQuaternion
* @euler: A #CoglEuler with which to initialize the quaternion
*
* Since: 2.0
*/
void
cogl_quaternion_init_from_euler (CoglQuaternion *quaternion,
const CoglEuler *euler);
/**
* cogl_quaternion_init_from_quaternion:
* @quaternion: A #CoglQuaternion
* @src: A #CoglQuaternion with which to initialize @quaternion
*
* Since: 2.0
*/
void
cogl_quaternion_init_from_quaternion (CoglQuaternion *quaternion,
CoglQuaternion *src);
/**
* cogl_quaternion_init_from_matrix:
* @quaternion: A Cogl Quaternion
* @matrix: A rotation matrix with which to initialize the quaternion
*
* Initializes a quaternion from a rotation matrix.
*
* Since: 1.10
* Stability: unstable
*/
void
cogl_quaternion_init_from_matrix (CoglQuaternion *quaternion,
const CoglMatrix *matrix);
/**
* cogl_quaternion_equal:
* @v1: A #CoglQuaternion
* @v2: A #CoglQuaternion
*
* Compares that all the components of quaternions @a and @b are
* equal.
*
* An epsilon value is not used to compare the float components, but
* the == operator is at least used so that 0 and -0 are considered
* equal.
*
* Returns: %TRUE if the quaternions are equal else %FALSE.
*
* Since: 2.0
*/
CoglBool
cogl_quaternion_equal (const void *v1, const void *v2);
/**
* cogl_quaternion_copy:
* @src: A #CoglQuaternion
*
* Allocates a new #CoglQuaternion on the stack and initializes it with
* the same values as @src.
*
* Returns: A newly allocated #CoglQuaternion which should be freed
* using cogl_quaternion_free()
*
* Since: 2.0
*/
CoglQuaternion *
cogl_quaternion_copy (const CoglQuaternion *src);
/**
* cogl_quaternion_free:
* @quaternion: A #CoglQuaternion
*
* Frees a #CoglQuaternion that was previously allocated via
* cogl_quaternion_copy().
*
* Since: 2.0
*/
void
cogl_quaternion_free (CoglQuaternion *quaternion);
/**
* cogl_quaternion_get_rotation_angle:
* @quaternion: A #CoglQuaternion
*
*
* Since: 2.0
*/
float
cogl_quaternion_get_rotation_angle (const CoglQuaternion *quaternion);
/**
* cogl_quaternion_get_rotation_axis:
* @quaternion: A #CoglQuaternion
*
*
* Since: 2.0
*/
void
cogl_quaternion_get_rotation_axis (const CoglQuaternion *quaternion,
float *vector3);
/**
* cogl_quaternion_normalize:
* @quaternion: A #CoglQuaternion
*
*
* Since: 2.0
*/
void
cogl_quaternion_normalize (CoglQuaternion *quaternion);
/**
* cogl_quaternion_dot_product:
* @a: A #CoglQuaternion
* @b: A #CoglQuaternion
*
* Since: 2.0
*/
float
cogl_quaternion_dot_product (const CoglQuaternion *a,
const CoglQuaternion *b);
/**
* cogl_quaternion_invert:
* @quaternion: A #CoglQuaternion
*
*
* Since: 2.0
*/
void
cogl_quaternion_invert (CoglQuaternion *quaternion);
/**
* cogl_quaternion_multiply:
* @result: The destination #CoglQuaternion
* @left: The second #CoglQuaternion rotation to apply
* @right: The first #CoglQuaternion rotation to apply
*
* This combines the rotations of two quaternions into @result. The
* operation is not commutative so the order is important because AxB
* != BxA. Cogl follows the standard convention for quaternions here
* so the rotations are applied @right to @left. This is similar to the
* combining of matrices.
*
* <note>It is possible to multiply the @a quaternion in-place, so
* @result can be equal to @a but can't be equal to @b.</note>
*
* Since: 2.0
*/
void
cogl_quaternion_multiply (CoglQuaternion *result,
const CoglQuaternion *left,
const CoglQuaternion *right);
/**
* cogl_quaternion_pow:
* @quaternion: A #CoglQuaternion
*
*
* Since: 2.0
*/
void
cogl_quaternion_pow (CoglQuaternion *quaternion, float exponent);
/**
* cogl_quaternion_slerp:
*
* Performs a spherical linear interpolation between two quaternions.
*
* Noteable properties:
* <itemizedlist>
* <listitem>
* commutative: No
* </listitem>
* <listitem>
* constant velocity: Yes
* </listitem>
* <listitem>
* torque minimal (travels along the surface of the 4-sphere): Yes
* </listitem>
* <listitem>
* more expensive than cogl_quaternion_nlerp()
* </listitem>
* </itemizedlist>
*/
void
cogl_quaternion_slerp (CoglQuaternion *result,
const CoglQuaternion *a,
const CoglQuaternion *b,
float t);
/**
* cogl_quaternion_nlerp:
* @result: The destination #CoglQuaternion
* @a: The first #CoglQuaternion
* @b: The second #CoglQuaternion
* @t: The factor in the range [0,1] used to interpolate between
* quaterion @a and @b.
*
* Performs a normalized linear interpolation between two quaternions.
* That is it does a linear interpolation of the quaternion components
* and then normalizes the result. This will follow the shortest arc
* between the two orientations (just like the slerp() function) but
* will not progress at a constant speed. Unlike slerp() nlerp is
* commutative which is useful if you are blending animations
* together. (I.e. nlerp (tmp, a, b) followed by nlerp (result, tmp,
* d) is the same as nlerp (tmp, a, d) followed by nlerp (result, tmp,
* b)). Finally nlerp is cheaper than slerp so it can be a good choice
* if you don't need the constant speed property of the slerp() function.
*
* Notable properties:
* <itemizedlist>
* <listitem>
* commutative: Yes
* </listitem>
* <listitem>
* constant velocity: No
* </listitem>
* <listitem>
* torque minimal (travels along the surface of the 4-sphere): Yes
* </listitem>
* <listitem>
* faster than cogl_quaternion_slerp()
* </listitem>
* </itemizedlist>
*/
void
cogl_quaternion_nlerp (CoglQuaternion *result,
const CoglQuaternion *a,
const CoglQuaternion *b,
float t);
/**
* cogl_quaternion_squad:
*
*
* Since: 2.0
*/
void
cogl_quaternion_squad (CoglQuaternion *result,
const CoglQuaternion *prev,
const CoglQuaternion *a,
const CoglQuaternion *b,
const CoglQuaternion *next,
float t);
/**
* cogl_get_static_identity_quaternion:
*
* Returns a pointer to a singleton quaternion constant describing the
* canonical identity [1 (0, 0, 0)] which represents no rotation.
*
* If you multiply a quaternion with the identity quaternion you will
* get back the same value as the original quaternion.
*
* Returns: A pointer to an identity quaternion
*
* Since: 2.0
*/
const CoglQuaternion *
cogl_get_static_identity_quaternion (void);
/**
* cogl_get_static_zero_quaternion:
*
* Returns: a pointer to a singleton quaternion constant describing a
* rotation of 180 degrees around a degenerate axis:
* [0 (0, 0, 0)]
*
* Since: 2.0
*/
const CoglQuaternion *
cogl_get_static_zero_quaternion (void);
COGL_END_DECLS
#endif /* __COGL_QUATERNION_H__ */