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mutter/cogl/cogl-matrix.h
Robert Bragg 2da24ab863 Add compile time checks for size of public structs 
To help catch accidental changes to the size of public structs that can
be allocated on the stack this patch adds compile time checks that our
struct sizes haven't changed.
2011-05-16 14:12:49 +01:00

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/*
* Cogl
*
* An object oriented GL/GLES Abstraction/Utility Layer
*
* Copyright (C) 2008,2009 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, see <http://www.gnu.org/licenses/>.
*
*
*
* Authors:
* Robert Bragg <robert@linux.intel.com>
*/
#ifndef __COGL_MATRIX_H
#define __COGL_MATRIX_H
#include <glib.h>
#include "cogl-types.h"
#ifdef COGL_ENABLE_EXPERIMENTAL_API
#include "cogl-quaternion.h"
#endif
G_BEGIN_DECLS
/**
* SECTION:cogl-matrix
* @short_description: Fuctions for initializing and manipulating 4x4 matrices
*
* Matrices are used in Cogl to describe affine model-view transforms, texture
* transforms, and projective transforms. This exposes a utility API that can
* be used for direct manipulation of these matrices.
*/
/**
* CoglMatrix:
*
* A CoglMatrix holds a 4x4 transform matrix. This is a single precision,
* column-major matrix which means it is compatible with what OpenGL expects.
*
* A CoglMatrix can represent transforms such as, rotations, scaling,
* translation, sheering, and linear projections. You can combine these
* transforms by multiplying multiple matrices in the order you want them
* applied.
*
* The transformation of a vertex (x, y, z, w) by a CoglMatrix is given by:
*
* |[
* x_new = xx * x + xy * y + xz * z + xw * w
* y_new = yx * x + yy * y + yz * z + yw * w
* z_new = zx * x + zy * y + zz * z + zw * w
* w_new = wx * x + wy * y + wz * z + ww * w
* ]|
*
* Where w is normally 1
*
* <note>You must consider the members of the CoglMatrix structure read only,
* and all matrix modifications must be done via the cogl_matrix API. This
* allows Cogl to annotate the matrices internally. Violation of this will give
* undefined results. If you need to initialize a matrix with a constant other
* than the identity matrix you can use cogl_matrix_init_from_array().</note>
*/
struct _CoglMatrix
{
/* column 0 */
float xx;
float yx;
float zx;
float wx;
/* column 1 */
float xy;
float yy;
float zy;
float wy;
/* column 2 */
float xz;
float yz;
float zz;
float wz;
/* column 3 */
float xw;
float yw;
float zw;
float ww;
/*< private >*/
/* Note: we may want to extend this later with private flags
* and a cache of the inverse transform matrix. */
float COGL_PRIVATE (inv)[16];
unsigned long COGL_PRIVATE (type);
unsigned long COGL_PRIVATE (flags);
unsigned long COGL_PRIVATE (_padding3);
};
COGL_STRUCT_SIZE_ASSERT (CoglMatrix, 128 + sizeof (unsigned long) * 3);
/**
* cogl_matrix_init_identity:
* @matrix: A 4x4 transformation matrix
*
* Resets matrix to the identity matrix:
*
* |[
* .xx=1; .xy=0; .xz=0; .xw=0;
* .yx=0; .yy=1; .yz=0; .yw=0;
* .zx=0; .zy=0; .zz=1; .zw=0;
* .wx=0; .wy=0; .wz=0; .ww=1;
* ]|
*/
void
cogl_matrix_init_identity (CoglMatrix *matrix);
/**
* cogl_matrix_multiply:
* @result: The address of a 4x4 matrix to store the result in
* @a: A 4x4 transformation matrix
* @b: A 4x4 transformation matrix
*
* Multiplies the two supplied matrices together and stores
* the resulting matrix inside @result.
*
* <note>It is possible to multiply the @a matrix in-place, so
* @result can be equal to @a but can't be equal to @b.</note>
*/
void
cogl_matrix_multiply (CoglMatrix *result,
const CoglMatrix *a,
const CoglMatrix *b);
/**
* cogl_matrix_rotate:
* @matrix: A 4x4 transformation matrix
* @angle: The angle you want to rotate in degrees
* @x: X component of your rotation vector
* @y: Y component of your rotation vector
* @z: Z component of your rotation vector
*
* Multiplies @matrix with a rotation matrix that applies a rotation
* of @angle degrees around the specified 3D vector.
*/
void
cogl_matrix_rotate (CoglMatrix *matrix,
float angle,
float x,
float y,
float z);
/**
* cogl_matrix_translate:
* @matrix: A 4x4 transformation matrix
* @x: The X translation you want to apply
* @y: The Y translation you want to apply
* @z: The Z translation you want to apply
*
* Multiplies @matrix with a transform matrix that translates along
* the X, Y and Z axis.
*/
void
cogl_matrix_translate (CoglMatrix *matrix,
float x,
float y,
float z);
/**
* cogl_matrix_scale:
* @matrix: A 4x4 transformation matrix
* @sx: The X scale factor
* @sy: The Y scale factor
* @sz: The Z scale factor
*
* Multiplies @matrix with a transform matrix that scales along the X,
* Y and Z axis.
*/
void
cogl_matrix_scale (CoglMatrix *matrix,
float sx,
float sy,
float sz);
/**
* cogl_matrix_frustum:
* @matrix: A 4x4 transformation matrix
* @left: coord of left vertical clipping plane
* @right: coord of right vertical clipping plane
* @bottom: coord of bottom horizontal clipping plane
* @top: coord of top horizontal clipping plane
* @z_near: positive distance to near depth clipping plane
* @z_far: positive distance to far depth clipping plane
*
* Multiplies @matrix by the given frustum perspective matrix.
*/
void
cogl_matrix_frustum (CoglMatrix *matrix,
float left,
float right,
float bottom,
float top,
float z_near,
float z_far);
/**
* cogl_matrix_perspective:
* @matrix: A 4x4 transformation matrix
* @fov_y: A field of view angle for the Y axis
* @aspect: The ratio of width to height determining the field of view angle
* for the x axis.
* @z_near: The distance to the near clip plane. Never pass 0 and always pass
* a positive number.
* @z_far: The distance to the far clip plane. (Should always be positive)
*
* Multiplies @matrix by the described perspective matrix
*
* <note>You should be careful not to have to great a @z_far / @z_near ratio
* since that will reduce the effectiveness of depth testing since there wont
* be enough precision to identify the depth of objects near to each
* other.</note>
*/
void
cogl_matrix_perspective (CoglMatrix *matrix,
float fov_y,
float aspect,
float z_near,
float z_far);
/**
* cogl_matrix_ortho:
* @matrix: A 4x4 transformation matrix
* @left: The coordinate for the left clipping plane
* @right: The coordinate for the right clipping plane
* @bottom: The coordinate for the bottom clipping plane
* @top: The coordinate for the top clipping plane
* @z_near: The coordinate for the near clipping plane (may be negative if
* the plane is behind the viewer)
* @z_far: The coordinate for the far clipping plane (may be negative if
* the plane is behind the viewer)
*
* Multiplies @matrix by a parallel projection matrix.
*/
void
cogl_matrix_ortho (CoglMatrix *matrix,
float left,
float right,
float bottom,
float top,
float z_near,
float z_far);
#ifdef COGL_ENABLE_EXPERIMENTAL_API
#define cogl_matrix_view_2d_in_frustum cogl_matrix_view_2d_in_frustum_EXP
#define cogl_matrix_view_2d_in_perspective \
cogl_matrix_view_2d_in_perspective_EXP
/**
* cogl_matrix_view_2d_in_frustum:
* @matrix: A 4x4 transformation matrix
* @left: coord of left vertical clipping plane
* @right: coord of right vertical clipping plane
* @bottom: coord of bottom horizontal clipping plane
* @top: coord of top horizontal clipping plane
* @z_near: The distance to the near clip plane. Never pass 0 and always pass
* a positive number.
* @z_2d: The distance to the 2D plane. (Should always be positive and
* be between @z_near and the z_far value that was passed to
* cogl_matrix_frustum())
* @width_2d: The width of the 2D coordinate system
* @height_2d: The height of the 2D coordinate system
*
* Multiplies @matrix by a view transform that maps the 2D coordinates
* (0,0) top left and (@width_2d,@height_2d) bottom right the full viewport
* size. Geometry at a depth of 0 will now lie on this 2D plane.
*
* Note: this doesn't multiply the matrix by any projection matrix,
* but it assumes you have a perspective projection as defined by
* passing the corresponding arguments to cogl_matrix_frustum().
* Toolkits such as Clutter that mix 2D and 3D drawing can use this to
* create a 2D coordinate system within a 3D perspective projected
* view frustum.
*/
void
cogl_matrix_view_2d_in_frustum (CoglMatrix *matrix,
float left,
float right,
float bottom,
float top,
float z_near,
float z_2d,
float width_2d,
float height_2d);
/**
* cogl_matrix_view_2d_in_perspective:
* @fov_y: A field of view angle for the Y axis
* @aspect: The ratio of width to height determining the field of view angle
* for the x axis.
* @z_near: The distance to the near clip plane. Never pass 0 and always pass
* a positive number.
* @z_2d: The distance to the 2D plane. (Should always be positive and
* be between @z_near and the z_far value that was passed to
* cogl_matrix_frustum())
* @width_2d: The width of the 2D coordinate system
* @height_2d: The height of the 2D coordinate system
*
* Multiplies @matrix by a view transform that maps the 2D coordinates
* (0,0) top left and (@width_2d,@height_2d) bottom right the full viewport
* size. Geometry at a depth of 0 will now lie on this 2D plane.
*
* Note: this doesn't multiply the matrix by any projection matrix,
* but it assumes you have a perspective projection as defined by
* passing the corresponding arguments to cogl_matrix_perspective().
*
* Toolkits such as Clutter that mix 2D and 3D drawing can use this to
* create a 2D coordinate system within a 3D perspective projected
* view frustum.
*/
void
cogl_matrix_view_2d_in_perspective (CoglMatrix *matrix,
float fov_y,
float aspect,
float z_near,
float z_2d,
float width_2d,
float height_2d);
#endif
/**
* cogl_matrix_init_from_array:
* @matrix: A 4x4 transformation matrix
* @array: A linear array of 16 floats (column-major order)
*
* Initializes @matrix with the contents of @array
*/
void
cogl_matrix_init_from_array (CoglMatrix *matrix,
const float *array);
/**
* cogl_matrix_get_array:
* @matrix: A 4x4 transformation matrix
*
* Casts @matrix to a float array which can be directly passed to OpenGL.
*
* Return value: a pointer to the float array
*/
G_CONST_RETURN float *
cogl_matrix_get_array (const CoglMatrix *matrix);
#ifdef COGL_ENABLE_EXPERIMENTAL_API
/**
* cogl_matrix_init_from_quaternion:
* @matrix: A 4x4 transformation matrix
* @quaternion: A #CoglQuaternion
*
* Initializes @matrix from a #CoglQuaternion rotation.
*
* Return value: a pointer to the float array
*/
void
cogl_matrix_init_from_quaternion (CoglMatrix *matrix,
CoglQuaternion *quaternion);
#endif
/**
* cogl_matrix_equal:
* @v1: A 4x4 transformation matrix
* @v2: A 4x4 transformation matrix
*
* Compares two matrices to see if they represent the same
* transformation. Although internally the matrices may have different
* annotations associated with them and may potentially have a cached
* inverse matrix these are not considered in the comparison.
*
* Since: 1.4
*/
gboolean
cogl_matrix_equal (gconstpointer v1, gconstpointer v2);
/**
* cogl_matrix_copy:
* @matrix: A 4x4 transformation matrix you want to copy
*
* Allocates a new #CoglMatrix on the heap and initializes it with
* the same values as @matrix.
*
* Returns: A newly allocated #CoglMatrix which should be freed using
* cogl_matrix_free()
*
* Since: 1.6
*/
CoglMatrix *
cogl_matrix_copy (const CoglMatrix *matrix);
/**
* cogl_matrix_free:
* @matrix: A 4x4 transformation matrix you want to free
*
* Frees a #CoglMatrix that was previously allocated via a call to
* cogl_matrix_copy().
*
* Since: 1.6
*/
void
cogl_matrix_free (CoglMatrix *matrix);
/**
* cogl_matrix_get_inverse:
* @matrix: A 4x4 transformation matrix
* @inverse: (out): The destination for a 4x4 inverse transformation matrix
*
* Gets the inverse transform of a given matrix and uses it to initialize
* a new #CoglMatrix.
*
* <note>Although the first parameter is annotated as const to indicate
* that the transform it represents isn't modified this function may
* technically save a copy of the inverse transform within the given
* #CoglMatrix so that subsequent requests for the inverse transform may
* avoid costly inversion calculations.</note>
*
* Return value: %TRUE if the inverse was successfully calculated or %FALSE
* for degenerate transformations that can't be inverted (in this case the
* @inverse matrix will simply be initialized with the identity matrix)
*
* Since: 1.2
*/
gboolean
cogl_matrix_get_inverse (const CoglMatrix *matrix,
CoglMatrix *inverse);
/* FIXME: to be consistent with cogl_matrix_{transform,project}_points
* this could be renamed to cogl_matrix_project_point for Cogl 2.0...
*/
/**
* cogl_matrix_transform_point:
* @matrix: A 4x4 transformation matrix
* @x: (inout): The X component of your points position
* @y: (inout): The Y component of your points position
* @z: (inout): The Z component of your points position
* @w: (inout): The W component of your points position
*
* Transforms a point whos position is given and returned as four float
* components.
*/
void
cogl_matrix_transform_point (const CoglMatrix *matrix,
float *x,
float *y,
float *z,
float *w);
#ifdef COGL_ENABLE_EXPERIMENTAL_API
#define cogl_matrix_transform_points cogl_matrix_transform_points_EXP
#define cogl_matrix_project_points cogl_matrix_project_points_EXP
/**
* cogl_matrix_transform_points:
* @matrix: A transformation matrix
* @n_components: The number of position components for each input point.
* (either 2 or 3)
* @stride_in: The stride in bytes between input points.
* @points_in: A pointer to the first component of the first input point.
* @stride_out: The stride in bytes between output points.
* @points_out: A pointer to the first component of the first output point.
* @n_points: The number of points to transform.
*
* Transforms an array of input points and writes the result to
* another array of output points. The input points can either have 2
* or 3 components each. The output points always have 3 components.
* The output array can simply point to the input array to do the
* transform in-place.
*
* If you need to transform 4 component points see
* cogl_matrix_project_points().
*
* Here's an example with differing input/output strides:
* |[
* typedef struct {
* float x,y;
* guint8 r,g,b,a;
* float s,t,p;
* } MyInVertex;
* typedef struct {
* guint8 r,g,b,a;
* float x,y,z;
* } MyOutVertex;
* MyInVertex vertices[N_VERTICES];
* MyOutVertex results[N_VERTICES];
* CoglMatrix matrix;
*
* my_load_vertices (vertices);
* my_get_matrix (&matrix);
*
* cogl_matrix_transform_points (&matrix,
* 2,
* sizeof (MyInVertex),
* &vertices[0].x,
* sizeof (MyOutVertex),
* &results[0].x,
* N_VERTICES);
* ]|
*
* Stability: Unstable
*/
void
cogl_matrix_transform_points (const CoglMatrix *matrix,
int n_components,
size_t stride_in,
const void *points_in,
size_t stride_out,
void *points_out,
int n_points);
/**
* cogl_matrix_project_points:
* @matrix: A projection matrix
* @n_components: The number of position components for each input point.
* (either 2, 3 or 4)
* @stride_in: The stride in bytes between input points.
* @points_in: A pointer to the first component of the first input point.
* @stride_out: The stride in bytes between output points.
* @points_out: A pointer to the first component of the first output point.
* @n_points: The number of points to transform.
*
* Projects an array of input points and writes the result to another
* array of output points. The input points can either have 2, 3 or 4
* components each. The output points always have 4 components (known
* as homogenous coordinates). The output array can simply point to
* the input array to do the transform in-place.
*
* Here's an example with differing input/output strides:
* |[
* typedef struct {
* float x,y;
* guint8 r,g,b,a;
* float s,t,p;
* } MyInVertex;
* typedef struct {
* guint8 r,g,b,a;
* float x,y,z;
* } MyOutVertex;
* MyInVertex vertices[N_VERTICES];
* MyOutVertex results[N_VERTICES];
* CoglMatrix matrix;
*
* my_load_vertices (vertices);
* my_get_matrix (&matrix);
*
* cogl_matrix_project_points (&matrix,
* 2,
* sizeof (MyInVertex),
* &vertices[0].x,
* sizeof (MyOutVertex),
* &results[0].x,
* N_VERTICES);
* ]|
*
* Stability: Unstable
*/
void
cogl_matrix_project_points (const CoglMatrix *matrix,
int n_components,
size_t stride_in,
const void *points_in,
size_t stride_out,
void *points_out,
int n_points);
#endif /* COGL_ENABLE_EXPERIMENTAL_API */
#ifdef _COGL_SUPPORTS_GTYPE_INTEGRATION
#define COGL_GTYPE_TYPE_MATRIX (cogl_gtype_matrix_get_type ())
/**
* cogl_gtype_matrix_get_type:
*
* Returns the GType for the registered "CoglMatrix" boxed type. This
* can be used for example to define GObject properties that accept a
* #CoglMatrix value.
*/
GType
cogl_gtype_matrix_get_type (void);
#endif /* _COGL_SUPPORTS_GTYPE_INTEGRATION */
G_END_DECLS
#endif /* __COGL_MATRIX_H */
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