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authorBehdad Esfahbod <behdad@behdad.org>2015-04-30 17:23:38 -0400
committerBehdad Esfahbod <behdad@behdad.org>2015-04-30 17:23:38 -0400
commitd4e0fb667815ad80bff60491a2125321ee88d1b7 (patch)
tree66135cf849c359170a40039d8e6f3162c64c2a84 /pango/pango-matrix.c
parentc089b1f7b0e3006b88c1a76784dcb4d8a2da7547 (diff)
downloadpango-d4e0fb667815ad80bff60491a2125321ee88d1b7.tar.gz
Bug 602257 - Make pango_matrix_get_font_scale_factors() public
Diffstat (limited to 'pango/pango-matrix.c')
-rw-r--r--pango/pango-matrix.c69
1 files changed, 45 insertions, 24 deletions
diff --git a/pango/pango-matrix.c b/pango/pango-matrix.c
index b4c27d71..4ec54d63 100644
--- a/pango/pango-matrix.c
+++ b/pango/pango-matrix.c
@@ -192,7 +192,8 @@ pango_matrix_concat (PangoMatrix *matrix,
*
* 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.
+ * vector that the X coordinate is mapped to. If the scale in the X
+ * coordinate is needed as well, use pango_matrix_get_font_scale_factors().
*
* Return value: the scale factor of @matrix on the height of the font,
* or 1.0 if @matrix is %NULL.
@@ -202,43 +203,63 @@ pango_matrix_concat (PangoMatrix *matrix,
double
pango_matrix_get_font_scale_factor (const PangoMatrix *matrix)
{
+ double yscale;
+ pango_matrix_get_font_scale_factors (matrix, NULL, &yscale);
+ return yscale;
+}
+
+/**
+ * pango_matrix_get_font_scale_factors:
+ * @matrix: (nullable): a #PangoMatrix, or %NULL
+ * @xscale: (out) (allow-none): output scale factor in the x direction, or %NULL
+ * @rect: (inout) (allow-none): output scale factor perpendicular to the x direction, or %NULL
+ *
+ * Calculates the scale factor of a matrix on the width and height of the font.
+ * That is, @xscale is the scale factor in the direction of the X coordinate,
+ * and @yscale is the scale factor in the direction perpendicular to the
+ * vector that the X coordinate is mapped to.
+ *
+ * Note that output numbers will always be non-negative.
+ *
+ * Since: 1.38
+ **/
+void
+pango_matrix_get_font_scale_factors (const PangoMatrix *matrix,
+ double *xscale, double *yscale)
+{
/*
* Based on cairo-matrix.c:_cairo_matrix_compute_scale_factors()
*
* Copyright 2005, Keith Packard
*/
- double det;
+ double major = 1., minor = 1.;
- if (!matrix)
- return 1.0;
-
- det = matrix->xx * matrix->yy - matrix->yx * matrix->xy;
-
- if (det == 0)
- {
- return 0.0;
- }
- else
+ if (matrix)
{
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;
+ {
+ double det = matrix->xx * matrix->yy - matrix->yx * matrix->xy;
+
+ /*
+ * ignore mirroring
+ */
+ if (det < 0)
+ det = - det;
- return minor;
+ minor = det / major;
+ }
+ else
+ minor = 0.;
}
+
+ if (xscale)
+ *xscale = major;
+ if (yscale)
+ *yscale = minor;
}
/**