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diff --git a/art_affine.h b/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_point.h"
+#else
+#include <libart_lgpl/art_point.h>
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+void
+art_affine_point (ArtPoint *dst, const ArtPoint *src,
+		  const double affine[6]);
+
+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 */
+void
+art_affine_flip (double dst_affine[6], const double src_affine[6],
+                 int horz, int vert);
+
+void
+art_affine_to_string (char str[128], const double src[6]);
+
+void
+art_affine_multiply (double dst[6],
+		     const double src1[6], const double src2[6]);
+
+/* set up the identity matrix */
+void
+art_affine_identity (double dst[6]);
+
+/* set up a scaling matrix */
+void
+art_affine_scale (double dst[6], double sx, double sy);
+
+/* set up a rotation matrix; theta is given in degrees */
+void
+art_affine_rotate (double dst[6], double theta);
+
+/* set up a shearing matrix; theta is given in degrees */
+void
+art_affine_shear (double dst[6], double theta);
+
+/* set up a translation matrix */
+void
+art_affine_translate (double dst[6], double tx, double ty);
+
+
+/* find the affine's "expansion factor", i.e. the scale amount */
+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. */
+int
+art_affine_rectilinear (const double src[6]);
+
+/* Determine whether two affine transformations are equal within grid allignment */
+int
+art_affine_equal (double matrix1[6], double matrix2[6]);
+
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+
+#endif /* __ART_AFFINE_H__ */