--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/libmlk-rpg/rpg/battle-state-opening.c	Fri Oct 01 20:30:00 2021 +0200
@@ -0,0 +1,98 @@
+/*
+ * battle-state-opening.c -- battle state (opening)
+ *
+ * Copyright (c) 2020-2021 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/painter.h>
+#include <core/panic.h>
+#include <core/window.h>
+
+#include "battle.h"
+#include "battle-state.h"
+
+#define DELAY (1000U)
+
+struct opening {
+	struct battle_state self;
+	unsigned int elapsed;
+};
+
+static int
+update(struct battle_state *st, struct battle *bt, unsigned int ticks)
+{
+	assert(bt);
+
+	struct opening *opening = st->data;
+
+	opening->elapsed += ticks;
+
+	/*
+	 * Those function will effectively change state accordingly to the
+	 * order of playing.
+	 */
+	if (opening->elapsed >= DELAY)
+		battle_state_check(bt);
+
+	return 0;
+}
+
+static void
+draw(const struct battle_state *st, const struct battle *bt)
+{
+	(void)bt;
+
+	assert(bt);
+
+	const struct opening *opening = st->data;
+	const unsigned int w = window.w;
+	const unsigned int h = window.h / 2;
+	const unsigned int ch = opening->elapsed * h / DELAY;
+
+	/* Draw some bezels opening. */
+	painter_set_color(0x000000ff);
+	painter_draw_rectangle(0, 0, w, h - ch);
+	painter_draw_rectangle(0, h + ch, w, h - ch);
+}
+
+static void
+finish(struct battle_state *st, struct battle *bt)
+{
+	(void)bt;
+
+	free(st->data);
+}
+
+void
+battle_state_opening(struct battle *bt)
+{
+	assert(bt);
+
+	struct opening *opening;
+
+	if (!(opening = alloc_new0(sizeof (*opening))))
+		panic();
+
+	opening->self.data = opening;
+	opening->self.update = update;
+	opening->self.draw = draw;
+	opening->self.finish = finish;
+
+	battle_switch(bt, &opening->self);
+}