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libart-lgpl/art_affine.h

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/* Libart_LGPL - library of basic graphic primitives
* Copyright (C) 1998 Raph Levien
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library 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.
*/
#ifndef __ART_AFFINE_H__
#define __ART_AFFINE_H__
#ifdef LIBART_COMPILATION
#include "art_config.h"
#include "art_point.h"
#else
#include <libart_lgpl/art_config.h>
#include <libart_lgpl/art_point.h>
#endif
#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */
LIBART_EXPORT void
art_affine_point (ArtPoint *dst, const ArtPoint *src,
const double affine[6]);
LIBART_EXPORT void
art_affine_invert (double dst_affine[6], const double src_affine[6]);
/* flip the matrix, FALSE, FALSE is a simple copy operation, and
TRUE, TRUE equals a rotation by 180 degrees */
LIBART_EXPORT void
art_affine_flip (double dst_affine[6], const double src_affine[6],
int horz, int vert);
LIBART_EXPORT void
art_affine_to_string (char str[128], const double src[6]);
LIBART_EXPORT void
art_affine_multiply (double dst[6],
const double src1[6], const double src2[6]);
/* set up the identity matrix */
LIBART_EXPORT void
art_affine_identity (double dst[6]);
/* set up a scaling matrix */
LIBART_EXPORT void
art_affine_scale (double dst[6], double sx, double sy);
/* set up a rotation matrix; theta is given in degrees */
LIBART_EXPORT void
art_affine_rotate (double dst[6], double theta);
/* set up a shearing matrix; theta is given in degrees */
LIBART_EXPORT void
art_affine_shear (double dst[6], double theta);
/* set up a translation matrix */
LIBART_EXPORT void
art_affine_translate (double dst[6], double tx, double ty);
/* find the affine's "expansion factor", i.e. the scale amount */
LIBART_EXPORT double
art_affine_expansion (const double src[6]);
/* Determine whether the affine transformation is rectilinear,
i.e. whether a rectangle aligned to the grid is transformed into
another rectangle aligned to the grid. */
LIBART_EXPORT int
art_affine_rectilinear (const double src[6]);
/* Determine whether two affine transformations are equal within grid allignment */
LIBART_EXPORT int
art_affine_equal (double matrix1[6], double matrix2[6]);
#ifdef __cplusplus
}
#endif /* __cplusplus */
#endif /* __ART_AFFINE_H__ */