From ee83b7986c30d775f37b58ca59db53bfe35b1ab3 Mon Sep 17 00:00:00 2001
From: KikooDX <kikoodx@paranoici.org>
Date: Thu, 23 Dec 2021 15:54:44 +0100
Subject: [PATCH] playback demo

---
 inc/input.h |  9 ++++---
 src/input.c | 67 ++++++++++++++++++++++++++++++++++++++++++++---------
 src/main.c  |  9 ++++++-
 3 files changed, 70 insertions(+), 15 deletions(-)

diff --git a/inc/input.h b/inc/input.h
index 4495338..d2536e1 100644
--- a/inc/input.h
+++ b/inc/input.h
@@ -14,22 +14,25 @@ enum Key {
 	K_SCROLL_UP,
 	K_SCROLL_DOWN,
 	K_DEBUG,
+	K_SAVE_REPLAY,
+	K_PLAYBACK,
 	K_COUNT
 };
 enum KeyState { KS_UP, KS_DOWN, KS_PRESS };
 
-typedef unsigned char PackedFrame;
+typedef short PackedFrame;
 
 struct Input {
 	enum Key keys[K_COUNT];
 	enum KeyState states[K_COUNT];
-	int replay_cursor;
+	int replay_cursor, replay_end, playback;
 	PackedFrame replay[REPLAY_SIZE];
 };
 
 void input_init(void);
 void input_update(void);
-void input_write_replay(void);
+void input_dump_replay(void);
+void input_load_replay(void);
 
 int input_down(enum Key);
 int input_pressed(enum Key);
diff --git a/src/input.c b/src/input.c
index 17ede90..e345aec 100644
--- a/src/input.c
+++ b/src/input.c
@@ -6,10 +6,13 @@
 
 static struct Input input;
 static const int default_map[K_COUNT] = {
-    KEY_LEFT, KEY_RIGHT, KEY_UP, KEY_DOWN, KEY_SHIFT, KEY_ALPHA,
-    KEY_EXIT, KEY_TAN,   KEY_F3, KEY_F2,   KEY_F1,    KEY_F6};
+    KEY_LEFT, KEY_RIGHT, KEY_UP, KEY_DOWN, KEY_SHIFT, KEY_ALPHA, KEY_EXIT,
+    KEY_TAN,  KEY_F3,    KEY_F2, KEY_F1,   KEY_F4,    KEY_F5,    KEY_F6};
+static const char *replay_path = "jtmm2.fls";
 
+static void next_state(int i, int kdown);
 static PackedFrame pack_frame(void);
+static void unpack_frame(PackedFrame);
 
 void
 input_init(void)
@@ -22,6 +25,7 @@ input_init(void)
 	}
 	i = REPLAY_SIZE;
 	input.replay_cursor = 0;
+	input.playback = 0;
 }
 
 void
@@ -29,21 +33,32 @@ input_update(void)
 {
 	int i = K_COUNT;
 	clearevents();
-	while (i-- > 0) {
+	while (i-- > K_EXIT) {
 		const int kdown = keydown(input.keys[i]);
-		input.states[i] = (input.states[i] == KS_UP)
-		                      ? (kdown ? KS_PRESS : KS_UP)
-		                      : (kdown ? KS_DOWN : KS_UP);
+		next_state(i, kdown);
+	}
+	if (input.playback) {
+		unpack_frame(input.replay[input.replay_cursor++]);
+		if (input.replay_cursor >= input.replay_end ||
+		    input.replay_cursor >= REPLAY_SIZE) {
+			input.replay_cursor--;
+			input.playback = 0;
+		}
+	} else {
+		i++;
+		while (i-- > 0) {
+			const int kdown = keydown(input.keys[i]);
+			next_state(i, kdown);
+		}
+		input.replay[input.replay_cursor++] = pack_frame();
+		if (input.replay_cursor >= REPLAY_SIZE) input.replay_cursor--;
 	}
-	input.replay[input.replay_cursor++] = pack_frame();
-	if (input.replay_cursor >= REPLAY_SIZE)
-		input.replay_cursor = REPLAY_SIZE - 1;
 }
 
 void
-input_write_replay(void)
+input_dump_replay(void)
 {
-	const int fd = open("jtmm2.rep", O_WRONLY | O_CREAT | O_TRUNC);
+	const int fd = open(replay_path, O_WRONLY | O_CREAT | O_TRUNC);
 	if (fd != -1) {
 		write(fd, input.replay,
 		      input.replay_cursor * sizeof(PackedFrame));
@@ -51,6 +66,20 @@ input_write_replay(void)
 	}
 }
 
+void
+input_load_replay(void)
+{
+	const int fd = open(replay_path, O_RDONLY);
+	if (fd != -1) {
+		input.playback = 1;
+		input.replay_cursor = 0;
+		input.replay_end =
+		    read(fd, input.replay, REPLAY_SIZE) / sizeof(PackedFrame);
+		if (!input.replay_end) input.replay_cursor = REPLAY_SIZE;
+		close(fd);
+	}
+}
+
 int
 input_down(enum Key k)
 {
@@ -69,6 +98,14 @@ input_up(enum Key k)
 	return input.states[k] == KS_UP;
 }
 
+static void
+next_state(int i, int kdown)
+{
+	input.states[i] = (input.states[i] == KS_UP)
+	                      ? (kdown ? KS_PRESS : KS_UP)
+	                      : (kdown ? KS_DOWN : KS_UP);
+}
+
 static PackedFrame
 pack_frame(void)
 {
@@ -78,3 +115,11 @@ pack_frame(void)
 		r |= input_down(i) << i;
 	return r;
 }
+
+static void
+unpack_frame(PackedFrame f)
+{
+	int i = K_EXIT;
+	while (i-- > 0)
+		next_state(i, (f & (1 << i)) != 0);
+}
diff --git a/src/main.c b/src/main.c
index 4937703..2ec235a 100644
--- a/src/main.c
+++ b/src/main.c
@@ -73,7 +73,6 @@ deinit(void)
 {
 	level_deinit();
 	missile_manager_free();
-	gint_world_switch(GINT_CALL(input_write_replay));
 
 	timer_stop(timer);
 }
@@ -86,6 +85,14 @@ update(void)
 	player_update(&player);
 	/* enter editor */
 	if (input_pressed(K_EDITOR)) editor();
+	/* save replay */
+	if (input_pressed(K_SAVE_REPLAY)) {
+		gint_world_switch(GINT_CALL(input_dump_replay));
+		has_ticked = 0;
+	}
+	/* playback */
+	if (input_pressed(K_PLAYBACK))
+		gint_world_switch(GINT_CALL(input_load_replay));
 }
 
 static void