--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libcore/core/maths.h	Mon Oct 05 13:25:06 2020 +0200
@@ -0,0 +1,68 @@
+/*
+ * maths.h -- basic maths
+ *
+ * Copyright (c) 2020 David Demelier <markand@malikania.fr>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, 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.
+ */
+
+#ifndef MOLKO_MATHS_H
+#define MOLKO_MATHS_H
+
+#include <stdbool.h>
+
+/**
+ * \file maths.h
+ * \brief Basic maths.
+ */
+
+/**
+ * Tells if a coordinate is within a rectangle region.
+ *
+ * \param x the region start
+ * \param y the region start
+ * \param w the region width
+ * \param h the region height
+ * \param px the point to test
+ * \param py the point to test
+ * \return True if within the region
+ */
+bool
+maths_is_boxed(int x, int y, unsigned int w, unsigned int h, int px, int py);
+
+/**
+ * Update x, y to be centered into a parent region.
+ *
+ * You can select to ignore horizontal/vertical centering by passing NULL to x
+ * or y respectively.
+ *
+ * \param x the pointer to x coordinate to modify
+ * \param y the pointer yo y coordinate to modify
+ * \param w the object width
+ * \param h the object height
+ * \param px the parent region start
+ * \param py the parent region start
+ * \param pw the parent region width
+ * \param ph the parent region height
+ */
+void
+maths_centerize(int *x,
+                int *y,
+                unsigned int w,
+                unsigned int h,
+                int px,
+                int py,
+                unsigned int pw,
+                unsigned int ph);
+
+#endif /* !MOLKO_MATHS_H */