--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/librpg/rpg/walksprite.h	Thu Oct 15 10:32:18 2020 +0200
@@ -0,0 +1,103 @@
+/*
+ * walksprite.h -- sprite designed for walking entities
+ *
+ * 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_WALKSPRITE_H
+#define MOLKO_WALKSPRITE_H
+
+/**
+ * \file walksprite.h
+ * \brief Sprite designed for walking entities.
+ * \ingroup drawing
+ */
+
+struct sprite;
+
+/**
+ * \brief Sprite designed for walking entities.
+ *
+ * This structure works with sprite images that are defined as using the
+ * following conventions:
+ *
+ * ```
+ * 7   0   1
+ *   ↖ ↑ ↗
+ * 6 ←   → 2
+ *   ↙ ↓ ↘
+ * 5   4   3
+ * ```
+ *
+ * Where numbers define row in the sprite according to the character
+ * orientation. In other terms, your image sprite should look like this:
+ *
+ * ```
+ * row columns in your image
+ * ---|---------------------
+ *  0 | ↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑
+ *  1 | ↗↗↗↗↗↗↗↗↗↗↗↗↗↗↗↗↗↗↗↗
+ *  2 | →→→→→→→→→→→→→→→→→→→→
+ *  3 | ↘↘↘↘↘↘↘↘↘↘↘↘↘↘↘↘↘↘↘↘
+ *  4 | ↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓
+ *  5 | ↙↙↙↙↙↙↙↙↙↙↙↙↙↙↙↙↙↙↙↙
+ *  6 | ←←←←←←←←←←←←←←←←←←←←
+ *  7 | ↖↖↖↖↖↖↖↖↖↖↖↖↖↖↖↖↖↖↖↖
+ * ```
+ */
+struct walksprite {
+	struct sprite *sprite;  /*!< (+&) The sprite to use */
+	unsigned int delay;     /*!< (+) The delay between frames */
+	unsigned int index;     /*!< (-) Current column index */
+	unsigned int elapsed;   /*!< (-) Elapsed time since last frame */
+};
+
+/**
+ * Initialize the walking sprite.
+ *
+ * \pre ws != NULL
+ * \pre sprite != NULL
+ * \param ws the walking sprite
+ * \param sprite the sprite to use
+ * \param delay the delay between sprites
+ */
+void
+walksprite_init(struct walksprite *ws, struct sprite *sprite, unsigned int delay);
+
+/**
+ * Update the walking sprite
+ *
+ * \pre ws != NULL
+ * \param ws the walking sprite
+ * \param ticks the number of milliseconds between last frame
+ */
+void
+walksprite_update(struct walksprite *ws, unsigned int ticks);
+
+/**
+ * Draw the appropriate sprite cell to the screen according to the orientation
+ * given.
+ *
+ * \pre ws != NULL
+ * \pre orientation < 8
+ * \param ws the walking sprite
+ * \param orientation the orientation (or the row between 0 and 7)
+ * \param x the x coordinate
+ * \param y the y coordinate
+ */
+void
+walksprite_draw(struct walksprite *ws, unsigned int orientation, int x, int y);
+
+#endif /* !MOLKO_WALKSPRITE_H */