Made all changes necessary to abandon the Xc library, (sucking the functionality up into cairo_surface_t instead). Eliminated most of the remaining X datatypes (XFixed, XPointFixed, XLineFixed, XTrapezoid). Fixed some numerical problems relating to pen initialization and intersection calculation.

1 files changed, 58 insertions, 0 deletions

diff --git a/src/cairo-slope.c b/src/cairo-slope.c
new file mode 100644
index 000000000..619ced1db
--- /dev/null
+++ b/src/cairo-slope.c
@@ -0,0 +1,58 @@
+/*
+ * Copyright © 2002 USC, Information Sciences Institute
+ *
+ * Permission to use, copy, modify, distribute, and sell this software
+ * and its documentation for any purpose is hereby granted without
+ * fee, provided that the above copyright notice appear in all copies
+ * and that both that copyright notice and this permission notice
+ * appear in supporting documentation, and that the name of the
+ * University of Southern California not be used in advertising or
+ * publicity pertaining to distribution of the software without
+ * specific, written prior permission. The University of Southern
+ * California makes no representations about the suitability of this
+ * software for any purpose.  It is provided "as is" without express
+ * or implied warranty.
+ *
+ * THE UNIVERSITY OF SOUTHERN CALIFORNIA DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL THE UNIVERSITY OF
+ * SOUTHERN CALIFORNIA BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
+ * OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
+ * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ * Author: Carl D. Worth <cworth@isi.edu>
+ */
+
+#include "cairoint.h"
+
+void
+_cairo_slope_init (cairo_slope_t *slope, cairo_point_t *a, cairo_point_t *b)
+{
+    slope->dx = b->x - a->x;
+    slope->dy = b->y - a->y;
+}
+
+/* Is a clockwise of b?
+ *
+ * NOTE: The strict equality here is not significant in and of itself,
+ * but there are functions up above that are sensitive to it,
+ * (cf. _cairo_pen_find_active_cw_vertex_index).
+ */
+int
+_cairo_slope_clockwise (cairo_slope_t *a, cairo_slope_t *b)
+{
+    return ((cairo_fixed_48_16_t) b->dy * (cairo_fixed_48_16_t) a->dx 
+	    > (cairo_fixed_48_16_t) a->dy * (cairo_fixed_48_16_t) b->dx);
+}
+
+int
+_cairo_slope_counter_clockwise (cairo_slope_t *a, cairo_slope_t *b)
+{
+    return ! _cairo_slope_clockwise (a, b);
+}
+
+
+
+