--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libmlk-rpg/rpg/battle-entity-state-blinking.c	Sat Nov 28 22:37:30 2020 +0100
@@ -0,0 +1,87 @@
+/*
+ * battle-entity-state-blinking.c -- the entity is blinking
+ *
+ * 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.
+ */
+
+#include <assert.h>
+#include <stdlib.h>
+
+#include <core/alloc.h>
+#include <core/panic.h>
+#include <core/sprite.h>
+#include <core/texture.h>
+
+#include "battle-entity.h"
+#include "battle-entity-state-blinking.h"
+#include "battle-entity-state.h"
+#include "character.h"
+
+#define TRANSPARENT     (150)
+#define OPAQUE          (255)
+
+struct blink {
+	struct battle_entity_state state;
+	struct texture *tex;
+	unsigned int elapsed;
+	unsigned int count;
+};
+
+static bool
+update(struct battle_entity_state *st, struct battle_entity *et, unsigned int ticks)
+{
+	(void)et;
+
+	struct blink *blk = st->data;
+
+	blk->elapsed += ticks;
+
+	if (blk->elapsed >= 80) {
+		blk->count += 1;
+		blk->elapsed = 0;
+	}
+
+	texture_set_alpha_mod(blk->tex, blk->count % 2 == 0 ? TRANSPARENT : OPAQUE);
+
+	return blk->count >= 3;
+}
+
+static void
+finish(struct battle_entity_state *st, struct battle_entity *et)
+{
+	(void)et;
+
+	free(st->data);
+}
+
+void
+battle_entity_state_blinking(struct battle_entity *et)
+{
+	assert(et);
+
+	struct blink *blk;
+
+	if (!(blk = alloc_new0(sizeof (*blk))))
+		panic();
+
+	blk->tex = et->ch->sprites[CHARACTER_SPRITE_NORMAL]->texture;
+	texture_set_alpha_mod(blk->tex, TRANSPARENT);
+
+	blk->state.data = blk;
+	blk->state.update = update;
+	blk->state.finish = finish;
+
+	battle_entity_switch(et, &blk->state);
+}