summaryrefslogtreecommitdiff
path: root/pango/pango-matrix.c
diff options
context:
space:
mode:
authorBehdad Esfahbod <behdad@gnome.org>2006-07-07 05:01:06 +0000
committerBehdad Esfahbod <behdad@src.gnome.org>2006-07-07 05:01:06 +0000
commitd6c52d269cd0675fbd97d51b8ff8591d52f2b577 (patch)
treea4080cc8c61ca11e2614ccd2a8f6b0e5d4ae55e2 /pango/pango-matrix.c
parent0bad90a02bba4f8fe098187b2f8a781ac4029fe6 (diff)
downloadpango-d6c52d269cd0675fbd97d51b8ff8591d52f2b577.tar.gz
New file. Move all pango_matrix_* stuff into a separate file.
2006-07-07 Behdad Esfahbod <behdad@gnome.org> * pango/pango-matrix.c: New file. * pango/pango-utils.c: Move all pango_matrix_* stuff into a separate file.
Diffstat (limited to 'pango/pango-matrix.c')
-rw-r--r--pango/pango-matrix.c250
1 files changed, 250 insertions, 0 deletions
diff --git a/pango/pango-matrix.c b/pango/pango-matrix.c
new file mode 100644
index 00000000..58be83e1
--- /dev/null
+++ b/pango/pango-matrix.c
@@ -0,0 +1,250 @@
+/* Pango
+ * pango-matrix.c: Matrix manipulation routines
+ *
+ * Copyright (C) 2000 Red Hat Software
+ *
+ * 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.
+ */
+
+#include <config.h>
+#include <math.h>
+
+#include "pango-types.h"
+#include "pango-impl-utils.h"
+
+GType
+pango_matrix_get_type (void)
+{
+ static GType our_type = 0;
+
+ if (our_type == 0)
+ our_type = g_boxed_type_register_static (I_("PangoMatrix"),
+ (GBoxedCopyFunc) pango_matrix_copy,
+ (GBoxedFreeFunc) pango_matrix_free);
+
+ return our_type;
+}
+
+/**
+ * pango_matrix_copy:
+ * @matrix: a #PangoMatrix, can be %NULL
+ *
+ * Copies a #PangoMatrix.
+ *
+ * Return value: the newly allocated #PangoMatrix, which should
+ * be freed with pango_matrix_free(), or %NULL if
+ * @matrix was %NULL.
+ *
+ * Since: 1.6
+ **/
+PangoMatrix *
+pango_matrix_copy (const PangoMatrix *matrix)
+{
+ PangoMatrix *new_matrix;
+
+ if (matrix)
+ {
+ new_matrix = g_slice_new (PangoMatrix);
+ *new_matrix = *matrix;
+ }
+ else
+ new_matrix = NULL;
+
+ return new_matrix;
+}
+
+/**
+ * pango_matrix_free:
+ * @matrix: a #PangoMatrix, or %NULL
+ *
+ * Free a #PangoMatrix created with pango_matrix_copy().
+ * Does nothing if @matrix is %NULL.
+ *
+ * Since: 1.6
+ **/
+void
+pango_matrix_free (PangoMatrix *matrix)
+{
+ if (matrix)
+ g_slice_free (PangoMatrix, matrix);
+}
+
+/**
+ * pango_matrix_translate:
+ * @matrix: a #PangoMatrix
+ * @tx: amount to translate in the X direction
+ * @ty: amount to translate in the Y direction
+ *
+ * Changes the transformation represented by @matrix to be the
+ * transformation given by first translating by (@tx, @ty)
+ * then applying the original transformation.
+ *
+ * Since: 1.6
+ **/
+void
+pango_matrix_translate (PangoMatrix *matrix,
+ double tx,
+ double ty)
+{
+ g_return_if_fail (matrix != NULL);
+
+ matrix->x0 = matrix->xx * tx + matrix->xy * ty + matrix->x0;
+ matrix->y0 = matrix->yx * tx + matrix->yy * ty + matrix->y0;
+}
+
+/**
+ * pango_matrix_scale:
+ * @matrix: a #PangoMatrix
+ * @scale_x: amount to scale by in X direction
+ * @scale_y: amount to scale by in Y direction
+ *
+ * Changes the transformation represented by @matrix to be the
+ * transformation given by first scaling by @sx in the X direction
+ * and @sy in the Y direction then applying the original
+ * transformation.
+ *
+ * Since: 1.6
+ **/
+void
+pango_matrix_scale (PangoMatrix *matrix,
+ double scale_x,
+ double scale_y)
+{
+ g_return_if_fail (matrix != NULL);
+
+ matrix->xx *= scale_x;
+ matrix->xy *= scale_y;
+ matrix->yx *= scale_x;
+ matrix->yy *= scale_y;
+}
+
+/**
+ * pango_matrix_rotate:
+ * @matrix: a #PangoMatrix
+ * @degrees: degrees to rotate counter-clockwise
+ *
+ * Changes the transformation represented by @matrix to be the
+ * transformation given by first rotating by @degrees degrees
+ * counter-clokwise then applying the original transformation.
+ *
+ * Since: 1.6
+ **/
+void
+pango_matrix_rotate (PangoMatrix *matrix,
+ double degrees)
+{
+ PangoMatrix tmp;
+ gdouble r, s, c;
+
+ g_return_if_fail (matrix != NULL);
+
+ r = degrees * (G_PI / 180.);
+ s = sin (r);
+ c = cos (r);
+
+ tmp.xx = c;
+ tmp.xy = s;
+ tmp.yx = -s;
+ tmp.yy = c;
+ tmp.x0 = 0;
+ tmp.y0 = 0;
+
+ pango_matrix_concat (matrix, &tmp);
+}
+
+/**
+ * pango_matrix_concat:
+ * @matrix: a #PangoMatrix
+ * @new_matrix: a #PangoMatrix
+ *
+ * Changes the transformation represented by @matrix to be the
+ * transformation given by first applying transformation
+ * given by @new_matrix then applying the original transformation.
+ *
+ * Since: 1.6
+ **/
+void
+pango_matrix_concat (PangoMatrix *matrix,
+ const PangoMatrix *new_matrix)
+{
+ PangoMatrix tmp;
+
+ g_return_if_fail (matrix != NULL);
+
+ tmp = *matrix;
+
+ matrix->xx = tmp.xx * new_matrix->xx + tmp.xy * new_matrix->yx;
+ matrix->xy = tmp.xx * new_matrix->xy + tmp.xy * new_matrix->yy;
+ matrix->yx = tmp.yx * new_matrix->xx + tmp.yy * new_matrix->yx;
+ matrix->yy = tmp.yx * new_matrix->xy + tmp.yy * new_matrix->yy;
+ matrix->x0 = tmp.xx * new_matrix->x0 + tmp.xy * new_matrix->y0 + tmp.x0;
+ matrix->y0 = tmp.yx * new_matrix->y0 + tmp.yy * new_matrix->y0 + tmp.y0;
+}
+
+/**
+ * pango_matrix_get_font_scale_factor:
+ * @matrix: a #PangoMatrix, may be %NULL
+ *
+ * Returns the scale factor of a matrix on the height of the font.
+ * That is, the scale factor in the direction perpendicular to the
+ * vector that the X coordinate is mapped to.
+ *
+ * Return value: the scale factor of @matrix on the height of the font,
+ * or 1.0 if @matrix is %NULL.
+ *
+ * Since: 1.12
+ **/
+double
+pango_matrix_get_font_scale_factor (const PangoMatrix *matrix)
+{
+/*
+ * Based on cairo-matrix.c:_cairo_matrix_compute_scale_factors()
+ *
+ * Copyright 2005, Keith Packard
+ */
+ double det;
+
+ if (!matrix)
+ return 1.0;
+
+ det = matrix->xx * matrix->yy - matrix->yx * matrix->xy;
+
+ if (det == 0)
+ {
+ return 0.0;
+ }
+ else
+ {
+ double x = matrix->xx;
+ double y = matrix->yx;
+ double major, minor;
+
+ major = sqrt (x*x + y*y);
+
+ /*
+ * ignore mirroring
+ */
+ if (det < 0)
+ det = - det;
+
+ if (major)
+ minor = det / major;
+ else
+ minor = 0.0;
+
+ return minor;
+ }
+}