From 2a9dba45c2219757dccb249737d504b922f4451e Mon Sep 17 00:00:00 2001
From: "Juan J. Martinez" <jjm@usebox.net>
Date: Wed, 10 May 2023 12:18:27 +0100
Subject: Add frame support, updated sprite

---
 game/assets/player.png | Bin 7775 -> 12406 bytes
 game/entities.asm      |  54 ++++++++++++++++++++++++++++++++++++++++++-------
 game/main.asm          |   2 ++
 game/player.asm        |  26 +++++++++++++++++++++++-
 4 files changed, 74 insertions(+), 8 deletions(-)

diff --git a/game/assets/player.png b/game/assets/player.png
index 13b7242..2e10235 100644
Binary files a/game/assets/player.png and b/game/assets/player.png differ
diff --git a/game/entities.asm b/game/entities.asm
index fd79825..6116624 100644
--- a/game/entities.asm
+++ b/game/entities.asm
@@ -63,7 +63,7 @@ entities_erase_next:
     port b, y
 
     ; next entity
-    add x, 5
+    add x, 6
     bo
     inc a
 
@@ -90,7 +90,7 @@ entities_update_next:
     push a
     push x
 
-    add x, 5
+    add x, 6
     bo
     inc a
 
@@ -117,7 +117,7 @@ entities_update_next:
     pop a
 
     ; next entity
-    add x, 7
+    add x, 8
     bo
     inc a
 
@@ -137,6 +137,8 @@ entities_draw_next:
     bz
     jmp entities_draw_done
 
+    ; two local variables to keep x, y coord
+
     inc x
     bo
     inc a
@@ -154,9 +156,9 @@ entities_draw_next:
     inc x
     bo
     inc a
-    ; a : x points to sprite data
+    ; a : x points to the frame
 
-    ; get gb data
+    ; save bg data
 
     ; settings mode
     ld y, 128
@@ -201,15 +203,53 @@ entities_draw_next:
     ; setup
     inc b
 
-    ; addr: sprite data
+    ; prepare some local variables
+
+    ; frame
     ld y, [a : x]
-    port b, y
+    inc x
+    bo
+    inc a
+    push y
+
+    ; sprite addr
+    ld y, [a : x]
+    push y
     inc x
     bo
     inc a
     ld y, [a : x]
+    push y
+
+    ; frame number
+    ld b, [sp + 2]
+entity_draw_frame:
+    dec b
+    bo
+    jmp entity_draw_frame_done
+
+    ; calculate frame
+    ld y, [sp + 0]
+    inc y
+    ld [sp + 0], y
+    jmp entity_draw_frame
+
+entity_draw_frame_done:
+
+    ; settings port
+    ld b, 0xb1
+
+    ; addr: sprite data
+    ld y, [sp + 1]
+    port b, y
+    ld y, [sp + 0]
     port b, y
 
+    ; free local variables
+    pop y
+    pop y
+    pop y
+
     ; x
     ld y, [sp + 1]
     port b, y
diff --git a/game/main.asm b/game/main.asm
index 3062ead..68d1267 100644
--- a/game/main.asm
+++ b/game/main.asm
@@ -63,6 +63,8 @@ entities:
     .db ET_PLAYER
     ; x, y
     .db 0, 0
+    ; frame
+    .db 0
     .dw player_sprite
     .dw player_update
 
diff --git a/game/player.asm b/game/player.asm
index 4a6537f..0e44411 100644
--- a/game/player.asm
+++ b/game/player.asm
@@ -44,5 +44,29 @@ player_update:
 
     ld [a : x], y
 
-    ret
+    ; update frame
+    inc x
+    bo
+    inc a
+
+    ; base frame
+    ld y, 0
+
+    ; both left and right
+    and b, 48
+    cmp b, 48
+    bz
+    jmp player_store_frame
+
+    ; left
+    bit b, 4
+    bz
+    ld y, 2
+    ; right
+    bit b, 5
+    bz
+    ld y, 1
 
+player_store_frame:
+    ld [a : x], y
+    ret
-- 
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