From 752b8c4b4703a5bc43d32b815aa713fab12e653c Mon Sep 17 00:00:00 2001
From: "Juan J. Martinez" <jjm@usebox.net>
Date: Thu, 6 Jul 2023 22:06:28 +0100
Subject: Add free enemy (Old Miner)

---
 src/map.c    |   2 +
 src/old.c    | 158 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 src/old.h    |   7 +++
 src/player.c |   7 ---
 src/player.h |   9 ++++
 5 files changed, 176 insertions(+), 7 deletions(-)
 create mode 100644 src/old.c
 create mode 100644 src/old.h

(limited to 'src')

diff --git a/src/map.c b/src/map.c
index d34a5a9..bc7b283 100644
--- a/src/map.c
+++ b/src/map.c
@@ -10,6 +10,7 @@
 #include "player.h"
 #include "snake.h"
 #include "bat.h"
+#include "old.h"
 #include "pickup.h"
 
 #include "map.h"
@@ -23,6 +24,7 @@ static void (* const init[])(Entity *) =
 {
     snake_init,
     bat_init,
+    old_init,
     pickup_time_init,
     pickup_bonus_init,
     pickup_pickaxe_init,
diff --git a/src/old.c b/src/old.c
new file mode 100644
index 0000000..3451118
--- /dev/null
+++ b/src/old.c
@@ -0,0 +1,158 @@
+#include <stdint.h>
+#include <stdlib.h>
+
+#include "vga.h"
+#include "map.h"
+#include "entities.h"
+
+#include "player.h"
+
+#include "old.h"
+
+#define FRAME_STANDING 0
+#define FRAME_JUMPING 1
+#define WALK_CYCLE_FRAMES 4
+
+#define JUMP_DELAY 2
+
+static const Rect frames[2 * 4] =
+{
+    /* right */
+    { 0, 80, 144, 144 },
+    { 16, 80, 144, 144 },
+    { 0, 80, 144, 144 },
+    { 32, 80, 144, 144 },
+
+    /* left */
+    { 48, 80, 144, 144 },
+    { 64, 80, 144, 144 },
+    { 48, 80, 144, 144 },
+    { 80, 80, 144, 144 },
+};
+
+void old_init(Entity *e)
+{
+    e->frames = (const Rect *)frames;
+    e->update = old_update;
+}
+
+static uint8_t is_bottom_deadly(uint16_t x, uint16_t y)
+{
+    while (1)
+    {
+        if (map_is_deadly(x, y))
+            return 1;
+
+        if (map_is_blocked(x, y))
+            return 0;
+
+        y += 8;
+    }
+}
+
+void old_update(Entity *e)
+{
+    if (e->gravity == GRAVITY_OFF
+            && !map_is_blocked(e->x + 4, e->y + 16)
+            && !map_is_blocked(e->x + 11, e->y + 16))
+    {
+        e->gravity = GRAVITY_DOWN;
+        e->frame = FRAME_JUMPING;
+    }
+
+    if (e->gravity != GRAVITY_OFF)
+    {
+        uint8_t steps = gravity_seq[e->gravity - 1];
+
+        if (e->gravity > GRAVITY_DOWN)
+        {
+            /* going down! */
+            for (uint8_t i = 0; i < steps; i++)
+            {
+                /* hit the floor */
+                if ((map_is_blocked(e->x + 11, e->y + 16)
+                        || map_is_blocked(e->x + 4, e->y + 16))
+                        && !map_is_blocked(e->x + 4, e->y + 15)
+                        && !map_is_blocked(e->x + 11, e->y + 15))
+                {
+                    e->gravity = GRAVITY_OFF;
+                    e->frame = FRAME_STANDING;
+                    e->flags = rand() % (JUMP_DELAY * 2);
+                    break;
+                }
+                e->y++;
+            }
+        }
+        else
+        {
+            /* going up! */
+            if (e->y < steps)
+                e->y = 0;
+            else
+                e->y -= steps;
+        }
+
+        if (e->gravity != GRAVITY_OFF && e->gravity != GRAVITY_SEQ_LEN)
+            e->gravity++;
+    }
+    else
+    {
+        if (e->delay & 1)
+        {
+            if (e->dir == DIR_RIGHT)
+            {
+                if (map_is_blocked(e->x + 16, e->y + 15)
+                        || is_bottom_deadly(e->x + 16, e->y + 16))
+                {
+                    e->dir = DIR_LEFT;
+                    e->flags++;
+                }
+                else
+                    e->x++;
+
+                if (e->flags > JUMP_DELAY
+                        && map_is_blocked(e->x + 7, e->y - 1)
+                        && !map_is_blocked(e->x + 7, e->y - 9))
+                {
+                    e->gravity = GRAVITY_UP;
+                    e->frame = FRAME_JUMPING;
+                }
+            }
+            else
+            {
+                /* dir is LEFT */
+                if (map_is_blocked(e->x - 1, e->y + 15)
+                        || is_bottom_deadly(e->x - 1, e->y + 16))
+                {
+                    e->dir = DIR_RIGHT;
+                    e->flags++;
+                }
+                else
+                    e->x--;
+
+                if (e->flags > JUMP_DELAY
+                        && map_is_blocked(e->x + 7, e->y - 1)
+                        && !map_is_blocked(e->x + 7, e->y - 9))
+                {
+                    e->gravity = GRAVITY_UP;
+                    e->frame = FRAME_JUMPING;
+                }
+            }
+        }
+
+        if (e->delay++ == WALK_DELAY)
+        {
+            e->delay = 0;
+            e->frame++;
+            if (e->frame == WALK_CYCLE_FRAMES)
+                e->frame = FRAME_STANDING;
+        }
+    }
+
+    if (player_collision(e))
+    {
+        player_hit();
+        /* change direction */
+        e->dir ^= 1;
+    }
+}
diff --git a/src/old.h b/src/old.h
new file mode 100644
index 0000000..de70158
--- /dev/null
+++ b/src/old.h
@@ -0,0 +1,7 @@
+#ifndef _OLD_H
+#define _OLD_H
+
+void old_init(Entity *e);
+void old_update(Entity *e);
+
+#endif /* _OLD_H */
diff --git a/src/player.c b/src/player.c
index 49c032c..7394857 100644
--- a/src/player.c
+++ b/src/player.c
@@ -16,13 +16,6 @@
 
 #define WALK_CYCLE_FRAMES 4
 
-#define GRAVITY_OFF 0
-/* XXX: subtract 1 to get the value from gravity_seq */
-#define GRAVITY_DOWN 14
-#define GRAVITY_UP 1
-
-#define GRAVITY_SEQ_LEN 24
-
 /* used for "coyote time" */
 #define MAX_MOMENTUM 8
 
diff --git a/src/player.h b/src/player.h
index d0acc93..95bc14a 100644
--- a/src/player.h
+++ b/src/player.h
@@ -14,4 +14,13 @@ void player_hit();
 uint16_t player_x();
 uint16_t player_y();
 
+#define GRAVITY_OFF 0
+/* XXX: substract 1 to get the value from gravity_seq */
+#define GRAVITY_DOWN 14
+#define GRAVITY_UP 1
+
+#define GRAVITY_SEQ_LEN 24
+
+extern const uint8_t gravity_seq[GRAVITY_SEQ_LEN];
+
 #endif /* _PLAYER_H */
-- 
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