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.

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;
+    }
+}