Adding upstream version 0.30.0.upstream/0.30.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 69 insertions, 0 deletions

diff --git a/src/bezier.h b/src/bezier.h
new file mode 100644
index 0000000..7406565
--- /dev/null
+++ b/src/bezier.h
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+/*
+ * Copyright © 2016 Red Hat, Inc.
+ *
+ * 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 Red Hat
+ * not be used in advertising or publicity pertaining to distribution
+ * of the software without specific, written prior permission.  Red
+ * Hat makes no representations about the suitability of this software
+ * for any purpose.  It is provided "as is" without express or implied
+ * warranty.
+ *
+ * THE AUTHORS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN
+ * NO EVENT SHALL THE AUTHORS 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.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#ifndef BEZIER_H
+#define BEZIER_H
+
+#include <stdlib.h>
+#include <stdbool.h>
+
+struct bezier_control_point {
+	double x, y;
+};
+
+extern const struct bezier_control_point bezier_defaults[4];
+
+/**
+ * Given four control points in the range [(0.0/0.0), (1.0/1.0)]
+ * construct a Bézier curve.
+ *
+ *    ^
+ *1.0 |    c2 ______ c3
+ *    |     _/
+ *    |    /
+ *    |c1 /
+ *    |  /
+ *    | /
+ *    |/_________________>
+ *    c0           1.0
+ *
+ * This function requires that c[i].x <= c[i+1].x
+ *
+ * The curve is mapped into a canvas size [0, bezier_sz)². For each x
+ * coordiante in [0, bezier_sz), the matching y coordinate is thus
+ * bezier[x].
+ *
+ * In other words, if you have a range [0,2048) input possible values,
+ * the output is a list of 2048 points in a [0, 2048) range.
+ *
+ * @return true on success, false otherwise
+ */
+bool
+cubic_bezier(const struct bezier_control_point controls[4],
+	     int *bezier,
+	     size_t bezier_sz);
+#endif