mirror of https://github.com/GNOME/gimp.git
887 lines
22 KiB
C
887 lines
22 KiB
C
/* LIBGIMP - The GIMP Library
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* Copyright (C) 1995-1997 Peter Mattis and Spencer Kimball
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*
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* gimpmatrix.c
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* Copyright (C) 1998 Jay Cox <jaycox@gimp.org>
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*
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* This library is free software: you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 3 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Library General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library. If not, see
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* <http://www.gnu.org/licenses/>.
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*/
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#include "config.h"
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#include <glib-object.h>
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#include "gimpmath.h"
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/**
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* SECTION: gimpmatrix
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* @title: GimpMatrix
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* @short_description: Utilities to set up and manipulate 3x3
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* transformation matrices.
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* @see_also: #GimpVector2, #GimpVector3, #GimpVector4
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*
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* When doing image manipulation you will often need 3x3
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* transformation matrices that define translation, rotation, scaling,
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* shearing and arbitrary perspective transformations using a 3x3
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* matrix. Here you'll find a set of utility functions to set up those
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* matrices and to perform basic matrix manipulations and tests.
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*
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* Each matrix class has a 2 dimensional gdouble coeff member. The
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* element for row r and column c of the matrix is coeff[r][c].
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**/
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#define EPSILON 1e-6
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static GimpMatrix2 * matrix2_copy (const GimpMatrix2 *matrix);
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/**
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* gimp_matrix2_get_type:
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*
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* Reveals the object type
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*
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* Returns: the #GType for Matrix2 objects
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*
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* Since: GIMP 2.4
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**/
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GType
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gimp_matrix2_get_type (void)
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{
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static GType matrix_type = 0;
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if (!matrix_type)
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matrix_type = g_boxed_type_register_static ("GimpMatrix2",
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(GBoxedCopyFunc) matrix2_copy,
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(GBoxedFreeFunc) g_free);
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return matrix_type;
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}
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/*
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* GIMP_TYPE_PARAM_MATRIX2
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*/
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#define GIMP_PARAM_SPEC_MATRIX2(pspec) (G_TYPE_CHECK_INSTANCE_CAST ((pspec), GIMP_TYPE_PARAM_MATRIX2, GimpParamSpecMatrix2))
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static void gimp_param_matrix2_class_init (GParamSpecClass *class);
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static void gimp_param_matrix2_init (GParamSpec *pspec);
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static void gimp_param_matrix2_set_default (GParamSpec *pspec,
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GValue *value);
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static gint gimp_param_matrix2_values_cmp (GParamSpec *pspec,
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const GValue *value1,
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const GValue *value2);
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typedef struct _GimpParamSpecMatrix2 GimpParamSpecMatrix2;
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struct _GimpParamSpecMatrix2
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{
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GParamSpecBoxed parent_instance;
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GimpMatrix2 default_value;
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};
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/**
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* gimp_param_matrix2_get_type:
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*
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* Reveals the object type
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*
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* Returns: the #GType for a GimpMatrix2 object
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*
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* Since: GIMP 2.4
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**/
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GType
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gimp_param_matrix2_get_type (void)
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{
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static GType spec_type = 0;
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if (!spec_type)
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{
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static const GTypeInfo type_info =
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{
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sizeof (GParamSpecClass),
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NULL, NULL,
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(GClassInitFunc) gimp_param_matrix2_class_init,
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NULL, NULL,
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sizeof (GimpParamSpecMatrix2),
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0,
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(GInstanceInitFunc) gimp_param_matrix2_init
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};
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spec_type = g_type_register_static (G_TYPE_PARAM_BOXED,
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"GimpParamMatrix2",
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&type_info, 0);
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}
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return spec_type;
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}
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static void
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gimp_param_matrix2_class_init (GParamSpecClass *class)
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{
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class->value_type = GIMP_TYPE_MATRIX2;
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class->value_set_default = gimp_param_matrix2_set_default;
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class->values_cmp = gimp_param_matrix2_values_cmp;
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}
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static void
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gimp_param_matrix2_init (GParamSpec *pspec)
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{
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GimpParamSpecMatrix2 *cspec = GIMP_PARAM_SPEC_MATRIX2 (pspec);
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gimp_matrix2_identity (&cspec->default_value);
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}
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static void
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gimp_param_matrix2_set_default (GParamSpec *pspec,
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GValue *value)
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{
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GimpParamSpecMatrix2 *cspec = GIMP_PARAM_SPEC_MATRIX2 (pspec);
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g_value_set_static_boxed (value, &cspec->default_value);
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}
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static gint
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gimp_param_matrix2_values_cmp (GParamSpec *pspec,
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const GValue *value1,
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const GValue *value2)
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{
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GimpMatrix2 *matrix1;
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GimpMatrix2 *matrix2;
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gint i, j;
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matrix1 = value1->data[0].v_pointer;
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matrix2 = value2->data[0].v_pointer;
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/* try to return at least *something*, it's useless anyway... */
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if (! matrix1)
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return matrix2 != NULL ? -1 : 0;
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else if (! matrix2)
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return matrix1 != NULL;
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for (i = 0; i < 2; i++)
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for (j = 0; j < 2; j++)
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if (matrix1->coeff[i][j] != matrix2->coeff[i][j])
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return 1;
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return 0;
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}
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/**
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* gimp_param_spec_matrix2:
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* @name: Canonical name of the param
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* @nick: Nickname of the param
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* @blurb: Brief desciption of param.
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* @default_value: Value to use if none is assigned.
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* @flags: a combination of #GParamFlags
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*
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* Creates a param spec to hold a #GimpMatrix2 value.
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* See g_param_spec_internal() for more information.
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*
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* Returns: a newly allocated #GParamSpec instance
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*
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* Since: GIMP 2.4
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**/
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GParamSpec *
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gimp_param_spec_matrix2 (const gchar *name,
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const gchar *nick,
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const gchar *blurb,
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const GimpMatrix2 *default_value,
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GParamFlags flags)
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{
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GimpParamSpecMatrix2 *cspec;
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g_return_val_if_fail (default_value != NULL, NULL);
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cspec = g_param_spec_internal (GIMP_TYPE_PARAM_MATRIX2,
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name, nick, blurb, flags);
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cspec->default_value = *default_value;
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return G_PARAM_SPEC (cspec);
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}
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static GimpMatrix2 *
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matrix2_copy (const GimpMatrix2 *matrix)
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{
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return (GimpMatrix2 *) g_memdup (matrix, sizeof (GimpMatrix2));
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}
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/**
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* gimp_matrix2_identity:
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* @matrix: A matrix.
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*
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* Sets the matrix to the identity matrix.
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*/
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void
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gimp_matrix2_identity (GimpMatrix2 *matrix)
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{
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static const GimpMatrix2 identity = { { { 1.0, 0.0 },
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{ 0.0, 1.0 } } };
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*matrix = identity;
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}
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/**
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* gimp_matrix2_mult:
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* @matrix1: The first input matrix.
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* @matrix2: The second input matrix which will be overwritten by the result.
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*
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* Multiplies two matrices and puts the result into the second one.
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*/
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void
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gimp_matrix2_mult (const GimpMatrix2 *matrix1,
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GimpMatrix2 *matrix2)
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{
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GimpMatrix2 tmp;
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tmp.coeff[0][0] = (matrix1->coeff[0][0] * matrix2->coeff[0][0] +
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matrix1->coeff[0][1] * matrix2->coeff[1][0]);
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tmp.coeff[0][1] = (matrix1->coeff[0][0] * matrix2->coeff[0][1] +
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matrix1->coeff[0][1] * matrix2->coeff[1][1]);
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tmp.coeff[1][0] = (matrix1->coeff[1][0] * matrix2->coeff[0][0] +
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matrix1->coeff[1][1] * matrix2->coeff[1][0]);
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tmp.coeff[1][1] = (matrix1->coeff[1][0] * matrix2->coeff[0][1] +
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matrix1->coeff[1][1] * matrix2->coeff[1][1]);
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*matrix2 = tmp;
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}
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static GimpMatrix3 * matrix3_copy (const GimpMatrix3 *matrix);
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/**
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* gimp_matrix3_get_type:
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*
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* Reveals the object type
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*
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* Returns: the #GType for Matrix3 objects
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*
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* Since: GIMP 2.8
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**/
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GType
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gimp_matrix3_get_type (void)
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{
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static GType matrix_type = 0;
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if (!matrix_type)
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matrix_type = g_boxed_type_register_static ("GimpMatrix3",
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(GBoxedCopyFunc) matrix3_copy,
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(GBoxedFreeFunc) g_free);
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return matrix_type;
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}
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/*
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* GIMP_TYPE_PARAM_MATRIX3
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*/
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#define GIMP_PARAM_SPEC_MATRIX3(pspec) (G_TYPE_CHECK_INSTANCE_CAST ((pspec), GIMP_TYPE_PARAM_MATRIX3, GimpParamSpecMatrix3))
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static void gimp_param_matrix3_class_init (GParamSpecClass *class);
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static void gimp_param_matrix3_init (GParamSpec *pspec);
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static void gimp_param_matrix3_set_default (GParamSpec *pspec,
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GValue *value);
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static gint gimp_param_matrix3_values_cmp (GParamSpec *pspec,
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const GValue *value1,
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const GValue *value2);
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typedef struct _GimpParamSpecMatrix3 GimpParamSpecMatrix3;
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struct _GimpParamSpecMatrix3
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{
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GParamSpecBoxed parent_instance;
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GimpMatrix3 default_value;
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};
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/**
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* gimp_param_matrix3_get_type:
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*
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* Reveals the object type
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*
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* Returns: the #GType for a GimpMatrix3 object
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*
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* Since: GIMP 2.8
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**/
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GType
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gimp_param_matrix3_get_type (void)
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{
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static GType spec_type = 0;
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if (!spec_type)
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{
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static const GTypeInfo type_info =
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{
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sizeof (GParamSpecClass),
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NULL, NULL,
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(GClassInitFunc) gimp_param_matrix3_class_init,
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NULL, NULL,
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sizeof (GimpParamSpecMatrix3),
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0,
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(GInstanceInitFunc) gimp_param_matrix3_init
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};
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spec_type = g_type_register_static (G_TYPE_PARAM_BOXED,
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"GimpParamMatrix3",
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&type_info, 0);
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}
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return spec_type;
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}
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static void
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gimp_param_matrix3_class_init (GParamSpecClass *class)
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{
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class->value_type = GIMP_TYPE_MATRIX3;
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class->value_set_default = gimp_param_matrix3_set_default;
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class->values_cmp = gimp_param_matrix3_values_cmp;
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}
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static void
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gimp_param_matrix3_init (GParamSpec *pspec)
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{
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GimpParamSpecMatrix3 *cspec = GIMP_PARAM_SPEC_MATRIX3 (pspec);
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gimp_matrix3_identity (&cspec->default_value);
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}
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static void
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gimp_param_matrix3_set_default (GParamSpec *pspec,
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GValue *value)
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{
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GimpParamSpecMatrix3 *cspec = GIMP_PARAM_SPEC_MATRIX3 (pspec);
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g_value_set_static_boxed (value, &cspec->default_value);
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}
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static gint
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gimp_param_matrix3_values_cmp (GParamSpec *pspec,
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const GValue *value1,
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const GValue *value2)
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{
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GimpMatrix3 *matrix1;
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GimpMatrix3 *matrix2;
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gint i, j;
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matrix1 = value1->data[0].v_pointer;
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matrix2 = value2->data[0].v_pointer;
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/* try to return at least *something*, it's useless anyway... */
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if (! matrix1)
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return matrix2 != NULL ? -1 : 0;
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else if (! matrix2)
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return matrix1 != NULL;
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for (i = 0; i < 3; i++)
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for (j = 0; j < 3; j++)
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if (matrix1->coeff[i][j] != matrix2->coeff[i][j])
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return 1;
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return 0;
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}
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/**
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* gimp_param_spec_matrix3:
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* @name: Canonical name of the param
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* @nick: Nickname of the param
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* @blurb: Brief desciption of param.
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* @default_value: Value to use if none is assigned.
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* @flags: a combination of #GParamFlags
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*
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* Creates a param spec to hold a #GimpMatrix3 value.
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* See g_param_spec_internal() for more information.
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*
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* Returns: a newly allocated #GParamSpec instance
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*
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* Since: GIMP 2.8
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**/
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GParamSpec *
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gimp_param_spec_matrix3 (const gchar *name,
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const gchar *nick,
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const gchar *blurb,
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const GimpMatrix3 *default_value,
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GParamFlags flags)
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{
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GimpParamSpecMatrix3 *cspec;
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cspec = g_param_spec_internal (GIMP_TYPE_PARAM_MATRIX3,
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name, nick, blurb, flags);
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if (default_value)
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cspec->default_value = *default_value;
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return G_PARAM_SPEC (cspec);
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}
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static GimpMatrix3 *
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matrix3_copy (const GimpMatrix3 *matrix)
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{
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return (GimpMatrix3 *) g_memdup (matrix, sizeof (GimpMatrix3));
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}
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/**
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* gimp_matrix3_identity:
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* @matrix: A matrix.
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*
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* Sets the matrix to the identity matrix.
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*/
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void
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gimp_matrix3_identity (GimpMatrix3 *matrix)
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{
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static const GimpMatrix3 identity = { { { 1.0, 0.0, 0.0 },
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{ 0.0, 1.0, 0.0 },
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{ 0.0, 0.0, 1.0 } } };
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*matrix = identity;
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}
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/**
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* gimp_matrix3_transform_point:
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* @matrix: The transformation matrix.
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* @x: The source X coordinate.
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* @y: The source Y coordinate.
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* @newx: The transformed X coordinate.
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* @newy: The transformed Y coordinate.
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*
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* Transforms a point in 2D as specified by the transformation matrix.
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*/
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void
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gimp_matrix3_transform_point (const GimpMatrix3 *matrix,
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gdouble x,
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gdouble y,
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gdouble *newx,
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gdouble *newy)
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{
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gdouble w;
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w = matrix->coeff[2][0] * x + matrix->coeff[2][1] * y + matrix->coeff[2][2];
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if (w == 0.0)
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w = 1.0;
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else
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w = 1.0/w;
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*newx = (matrix->coeff[0][0] * x +
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matrix->coeff[0][1] * y +
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matrix->coeff[0][2]) * w;
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*newy = (matrix->coeff[1][0] * x +
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matrix->coeff[1][1] * y +
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matrix->coeff[1][2]) * w;
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}
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/**
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* gimp_matrix3_mult:
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* @matrix1: The first input matrix.
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* @matrix2: The second input matrix which will be overwritten by the result.
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*
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* Multiplies two matrices and puts the result into the second one.
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*/
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void
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gimp_matrix3_mult (const GimpMatrix3 *matrix1,
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GimpMatrix3 *matrix2)
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{
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gint i, j;
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GimpMatrix3 tmp;
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gdouble t1, t2, t3;
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for (i = 0; i < 3; i++)
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{
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t1 = matrix1->coeff[i][0];
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t2 = matrix1->coeff[i][1];
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t3 = matrix1->coeff[i][2];
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for (j = 0; j < 3; j++)
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{
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tmp.coeff[i][j] = t1 * matrix2->coeff[0][j];
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tmp.coeff[i][j] += t2 * matrix2->coeff[1][j];
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tmp.coeff[i][j] += t3 * matrix2->coeff[2][j];
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}
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}
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*matrix2 = tmp;
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}
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/**
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* gimp_matrix3_translate:
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* @matrix: The matrix that is to be translated.
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* @x: Translation in X direction.
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* @y: Translation in Y direction.
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*
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* Translates the matrix by x and y.
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*/
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void
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gimp_matrix3_translate (GimpMatrix3 *matrix,
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gdouble x,
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gdouble y)
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{
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gdouble g, h, i;
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g = matrix->coeff[2][0];
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h = matrix->coeff[2][1];
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i = matrix->coeff[2][2];
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matrix->coeff[0][0] += x * g;
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matrix->coeff[0][1] += x * h;
|
|
matrix->coeff[0][2] += x * i;
|
|
matrix->coeff[1][0] += y * g;
|
|
matrix->coeff[1][1] += y * h;
|
|
matrix->coeff[1][2] += y * i;
|
|
}
|
|
|
|
/**
|
|
* gimp_matrix3_scale:
|
|
* @matrix: The matrix that is to be scaled.
|
|
* @x: X scale factor.
|
|
* @y: Y scale factor.
|
|
*
|
|
* Scales the matrix by x and y
|
|
*/
|
|
void
|
|
gimp_matrix3_scale (GimpMatrix3 *matrix,
|
|
gdouble x,
|
|
gdouble y)
|
|
{
|
|
matrix->coeff[0][0] *= x;
|
|
matrix->coeff[0][1] *= x;
|
|
matrix->coeff[0][2] *= x;
|
|
|
|
matrix->coeff[1][0] *= y;
|
|
matrix->coeff[1][1] *= y;
|
|
matrix->coeff[1][2] *= y;
|
|
}
|
|
|
|
/**
|
|
* gimp_matrix3_rotate:
|
|
* @matrix: The matrix that is to be rotated.
|
|
* @theta: The angle of rotation (in radians).
|
|
*
|
|
* Rotates the matrix by theta degrees.
|
|
*/
|
|
void
|
|
gimp_matrix3_rotate (GimpMatrix3 *matrix,
|
|
gdouble theta)
|
|
{
|
|
gdouble t1, t2;
|
|
gdouble cost, sint;
|
|
|
|
cost = cos (theta);
|
|
sint = sin (theta);
|
|
|
|
t1 = matrix->coeff[0][0];
|
|
t2 = matrix->coeff[1][0];
|
|
matrix->coeff[0][0] = cost * t1 - sint * t2;
|
|
matrix->coeff[1][0] = sint * t1 + cost * t2;
|
|
|
|
t1 = matrix->coeff[0][1];
|
|
t2 = matrix->coeff[1][1];
|
|
matrix->coeff[0][1] = cost * t1 - sint * t2;
|
|
matrix->coeff[1][1] = sint * t1 + cost * t2;
|
|
|
|
t1 = matrix->coeff[0][2];
|
|
t2 = matrix->coeff[1][2];
|
|
matrix->coeff[0][2] = cost * t1 - sint * t2;
|
|
matrix->coeff[1][2] = sint * t1 + cost * t2;
|
|
}
|
|
|
|
/**
|
|
* gimp_matrix3_xshear:
|
|
* @matrix: The matrix that is to be sheared.
|
|
* @amount: X shear amount.
|
|
*
|
|
* Shears the matrix in the X direction.
|
|
*/
|
|
void
|
|
gimp_matrix3_xshear (GimpMatrix3 *matrix,
|
|
gdouble amount)
|
|
{
|
|
matrix->coeff[0][0] += amount * matrix->coeff[1][0];
|
|
matrix->coeff[0][1] += amount * matrix->coeff[1][1];
|
|
matrix->coeff[0][2] += amount * matrix->coeff[1][2];
|
|
}
|
|
|
|
/**
|
|
* gimp_matrix3_yshear:
|
|
* @matrix: The matrix that is to be sheared.
|
|
* @amount: Y shear amount.
|
|
*
|
|
* Shears the matrix in the Y direction.
|
|
*/
|
|
void
|
|
gimp_matrix3_yshear (GimpMatrix3 *matrix,
|
|
gdouble amount)
|
|
{
|
|
matrix->coeff[1][0] += amount * matrix->coeff[0][0];
|
|
matrix->coeff[1][1] += amount * matrix->coeff[0][1];
|
|
matrix->coeff[1][2] += amount * matrix->coeff[0][2];
|
|
}
|
|
|
|
/**
|
|
* gimp_matrix3_affine:
|
|
* @matrix: The input matrix.
|
|
* @a: the 'a' coefficient
|
|
* @b: the 'b' coefficient
|
|
* @c: the 'c' coefficient
|
|
* @d: the 'd' coefficient
|
|
* @e: the 'e' coefficient
|
|
* @f: the 'f' coefficient
|
|
*
|
|
* Applies the affine transformation given by six values to @matrix.
|
|
* The six values form define an affine transformation matrix as
|
|
* illustrated below:
|
|
*
|
|
* ( a c e )
|
|
* ( b d f )
|
|
* ( 0 0 1 )
|
|
**/
|
|
void
|
|
gimp_matrix3_affine (GimpMatrix3 *matrix,
|
|
gdouble a,
|
|
gdouble b,
|
|
gdouble c,
|
|
gdouble d,
|
|
gdouble e,
|
|
gdouble f)
|
|
{
|
|
GimpMatrix3 affine;
|
|
|
|
affine.coeff[0][0] = a;
|
|
affine.coeff[1][0] = b;
|
|
affine.coeff[2][0] = 0.0;
|
|
|
|
affine.coeff[0][1] = c;
|
|
affine.coeff[1][1] = d;
|
|
affine.coeff[2][1] = 0.0;
|
|
|
|
affine.coeff[0][2] = e;
|
|
affine.coeff[1][2] = f;
|
|
affine.coeff[2][2] = 1.0;
|
|
|
|
gimp_matrix3_mult (&affine, matrix);
|
|
}
|
|
|
|
/**
|
|
* gimp_matrix3_determinant:
|
|
* @matrix: The input matrix.
|
|
*
|
|
* Calculates the determinant of the given matrix.
|
|
*
|
|
* Returns: The determinant.
|
|
*/
|
|
gdouble
|
|
gimp_matrix3_determinant (const GimpMatrix3 *matrix)
|
|
{
|
|
gdouble determinant;
|
|
|
|
determinant = (matrix->coeff[0][0] *
|
|
(matrix->coeff[1][1] * matrix->coeff[2][2] -
|
|
matrix->coeff[1][2] * matrix->coeff[2][1]));
|
|
determinant -= (matrix->coeff[1][0] *
|
|
(matrix->coeff[0][1] * matrix->coeff[2][2] -
|
|
matrix->coeff[0][2] * matrix->coeff[2][1]));
|
|
determinant += (matrix->coeff[2][0] *
|
|
(matrix->coeff[0][1] * matrix->coeff[1][2] -
|
|
matrix->coeff[0][2] * matrix->coeff[1][1]));
|
|
|
|
return determinant;
|
|
}
|
|
|
|
/**
|
|
* gimp_matrix3_invert:
|
|
* @matrix: The matrix that is to be inverted.
|
|
*
|
|
* Inverts the given matrix.
|
|
*/
|
|
void
|
|
gimp_matrix3_invert (GimpMatrix3 *matrix)
|
|
{
|
|
GimpMatrix3 inv;
|
|
gdouble det;
|
|
|
|
det = gimp_matrix3_determinant (matrix);
|
|
|
|
if (det == 0.0)
|
|
return;
|
|
|
|
det = 1.0 / det;
|
|
|
|
inv.coeff[0][0] = (matrix->coeff[1][1] * matrix->coeff[2][2] -
|
|
matrix->coeff[1][2] * matrix->coeff[2][1]) * det;
|
|
|
|
inv.coeff[1][0] = - (matrix->coeff[1][0] * matrix->coeff[2][2] -
|
|
matrix->coeff[1][2] * matrix->coeff[2][0]) * det;
|
|
|
|
inv.coeff[2][0] = (matrix->coeff[1][0] * matrix->coeff[2][1] -
|
|
matrix->coeff[1][1] * matrix->coeff[2][0]) * det;
|
|
|
|
inv.coeff[0][1] = - (matrix->coeff[0][1] * matrix->coeff[2][2] -
|
|
matrix->coeff[0][2] * matrix->coeff[2][1]) * det;
|
|
|
|
inv.coeff[1][1] = (matrix->coeff[0][0] * matrix->coeff[2][2] -
|
|
matrix->coeff[0][2] * matrix->coeff[2][0]) * det;
|
|
|
|
inv.coeff[2][1] = - (matrix->coeff[0][0] * matrix->coeff[2][1] -
|
|
matrix->coeff[0][1] * matrix->coeff[2][0]) * det;
|
|
|
|
inv.coeff[0][2] = (matrix->coeff[0][1] * matrix->coeff[1][2] -
|
|
matrix->coeff[0][2] * matrix->coeff[1][1]) * det;
|
|
|
|
inv.coeff[1][2] = - (matrix->coeff[0][0] * matrix->coeff[1][2] -
|
|
matrix->coeff[0][2] * matrix->coeff[1][0]) * det;
|
|
|
|
inv.coeff[2][2] = (matrix->coeff[0][0] * matrix->coeff[1][1] -
|
|
matrix->coeff[0][1] * matrix->coeff[1][0]) * det;
|
|
|
|
*matrix = inv;
|
|
}
|
|
|
|
|
|
/* functions to test for matrix properties */
|
|
|
|
/**
|
|
* gimp_matrix3_is_identity:
|
|
* @matrix: The matrix that is to be tested.
|
|
*
|
|
* Checks if the given matrix is the identity matrix.
|
|
*
|
|
* Returns: %TRUE if the matrix is the identity matrix, %FALSE otherwise
|
|
*/
|
|
gboolean
|
|
gimp_matrix3_is_identity (const GimpMatrix3 *matrix)
|
|
{
|
|
gint i, j;
|
|
|
|
for (i = 0; i < 3; i++)
|
|
{
|
|
for (j = 0; j < 3; j++)
|
|
{
|
|
if (i == j)
|
|
{
|
|
if (fabs (matrix->coeff[i][j] - 1.0) > EPSILON)
|
|
return FALSE;
|
|
}
|
|
else
|
|
{
|
|
if (fabs (matrix->coeff[i][j]) > EPSILON)
|
|
return FALSE;
|
|
}
|
|
}
|
|
}
|
|
|
|
return TRUE;
|
|
}
|
|
|
|
/**
|
|
* gimp_matrix3_is_diagonal:
|
|
* @matrix: The matrix that is to be tested.
|
|
*
|
|
* Checks if the given matrix is diagonal.
|
|
*
|
|
* Returns: %TRUE if the matrix is diagonal, %FALSE otherwise
|
|
*/
|
|
gboolean
|
|
gimp_matrix3_is_diagonal (const GimpMatrix3 *matrix)
|
|
{
|
|
gint i, j;
|
|
|
|
for (i = 0; i < 3; i++)
|
|
{
|
|
for (j = 0; j < 3; j++)
|
|
{
|
|
if (i != j && fabs (matrix->coeff[i][j]) > EPSILON)
|
|
return FALSE;
|
|
}
|
|
}
|
|
|
|
return TRUE;
|
|
}
|
|
|
|
/**
|
|
* gimp_matrix3_is_affine:
|
|
* @matrix: The matrix that is to be tested.
|
|
*
|
|
* Checks if the given matrix defines an affine transformation.
|
|
*
|
|
* Returns: %TRUE if the matrix defines an affine transformation,
|
|
* %FALSE otherwise
|
|
*
|
|
* Since: GIMP 2.4
|
|
*/
|
|
gboolean
|
|
gimp_matrix3_is_affine (const GimpMatrix3 *matrix)
|
|
{
|
|
return (fabs (matrix->coeff[2][0]) < EPSILON &&
|
|
fabs (matrix->coeff[2][1]) < EPSILON &&
|
|
fabs (matrix->coeff[2][2] - 1.0) < EPSILON);
|
|
}
|
|
|
|
/**
|
|
* gimp_matrix3_is_simple:
|
|
* @matrix: The matrix that is to be tested.
|
|
*
|
|
* Checks if we'll need to interpolate when applying this matrix as
|
|
* a transformation.
|
|
*
|
|
* Returns: %TRUE if all entries of the upper left 2x2 matrix are
|
|
* either 0 or 1, %FALSE otherwise
|
|
*/
|
|
gboolean
|
|
gimp_matrix3_is_simple (const GimpMatrix3 *matrix)
|
|
{
|
|
gdouble absm;
|
|
gint i, j;
|
|
|
|
for (i = 0; i < 2; i++)
|
|
{
|
|
for (j = 0; j < 2; j++)
|
|
{
|
|
absm = fabs (matrix->coeff[i][j]);
|
|
if (absm > EPSILON && fabs (absm - 1.0) > EPSILON)
|
|
return FALSE;
|
|
}
|
|
}
|
|
|
|
return TRUE;
|
|
}
|
|
|
|
/**
|
|
* gimp_matrix4_to_deg:
|
|
* @matrix:
|
|
* @a:
|
|
* @b:
|
|
* @c:
|
|
*
|
|
*
|
|
**/
|
|
void
|
|
gimp_matrix4_to_deg (const GimpMatrix4 *matrix,
|
|
gdouble *a,
|
|
gdouble *b,
|
|
gdouble *c)
|
|
{
|
|
*a = 180 * (asin (matrix->coeff[1][0]) / G_PI_2);
|
|
*b = 180 * (asin (matrix->coeff[2][0]) / G_PI_2);
|
|
*c = 180 * (asin (matrix->coeff[2][1]) / G_PI_2);
|
|
}
|