1 /* ADG - Automatic Drawing Generation
2 * Copyright (C) 2007,2008,2009 Nicola Fontana <ntd at entidi.it>
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with this library; if not, write to the
16 * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
17 * Boston, MA 02110-1301, USA.
23 * @short_description: A wrapper for the cairo_matrix_t struct
25 * The AdgMatrix is essentially a wrapper for #cairo_matrix_t structures.
28 #include "adg-matrix.h"
34 static AdgMatrix null_matrix
= { 0., 0., 0., 0., 0., 0. };
35 static AdgMatrix identity_matrix
= { 1., 0., 0., 1., 0., 0. };
39 adg_matrix_get_type(void)
41 static int matrix_type
= 0;
43 if (G_UNLIKELY(matrix_type
== 0))
44 matrix_type
= g_boxed_type_register_static("AdgMatrix",
45 (GBoxedCopyFunc
) adg_matrix_dup
,
53 * @matrix: an #AdgMatrix structure
57 * Return value: the duplicate of @matrix: must be freed with g_free()
58 * when no longer needed.
61 adg_matrix_dup(const AdgMatrix
*matrix
)
63 g_return_val_if_fail(matrix
!= NULL
, NULL
);
65 return g_memdup(matrix
, sizeof(AdgMatrix
));
69 * adg_matrix_get_fallback:
71 * Gets a fallback matrix. The fallback matrix is a statically allocated
74 * Return value: the fallback matrix
77 adg_matrix_get_fallback(void)
79 return &identity_matrix
;
83 * adg_matrix_init_null:
84 * @matrix: the #AdgMatrix to nullify
86 * Nullifies a matrix, setting all its components to 0.
89 adg_matrix_init_null(AdgMatrix
*matrix
)
91 memcpy(matrix
, &null_matrix
, sizeof(AdgMatrix
));
96 * @matrix: the #AdgMatrix to check
98 * Checks if a matrix is a nullified matrix.
100 * Return value: %TRUE if the matrix is a null matrix, %FALSE otherwise
103 adg_matrix_is_null(const AdgMatrix
*matrix
)
105 return memcmp(matrix
, &null_matrix
, sizeof(AdgMatrix
)) == 0;
110 * @matrix: the destination #AdgMatrix
111 * @src: the source #AdgMatrix
113 * Copies @matrix to @dst.
115 * Return value: @matrix
118 adg_matrix_copy(AdgMatrix
*matrix
, const AdgMatrix
*src
)
120 g_return_val_if_fail(matrix
!= NULL
, matrix
);
121 g_return_val_if_fail(src
!= NULL
, matrix
);
123 memcpy(matrix
, src
, sizeof(AdgMatrix
));
130 * @matrix1: an #AdgMatrix
131 * @matrix2: an #AdgMatrix
133 * Compares @matrix1 and @matrix2 and returns %TRUE if the matrices are equal.
135 * Return value: %TRUE if @matrix1 is equal to @matrix2, %FALSE otherwise
138 adg_matrix_equal(const AdgMatrix
*matrix1
, const AdgMatrix
*matrix2
)
140 g_return_val_if_fail(matrix1
!= NULL
, FALSE
);
141 g_return_val_if_fail(matrix2
!= NULL
, FALSE
);
143 return memcmp(matrix1
, matrix2
, sizeof(AdgMatrix
)) == 0;
147 * adg_matrix_init_reflection:
148 * @matrix: the destination #AdgMatrix
149 * @radians: angle of the mirroring axis, in radians
151 * Initialized @matrix to a transformation that reflects arond an axis
152 * rotated by @radians and passing throught the origin (0, 0).
155 adg_matrix_init_reflection(AdgMatrix
*matrix
, double radians
)
157 double s2
= sin(2*radians
);
158 double c2
= cos(2*radians
);
160 cairo_matrix_init(matrix
, c2
, s2
, s2
, -c2
, 0, 0);