From 092a066281d01d539b55e53896d08689faa28bb5 Mon Sep 17 00:00:00 2001
From: Lukas Krickl <lukas@krickl.dev>
Date: Sun, 20 Apr 2025 08:16:44 +0200
Subject: [PATCH] cells: Added additional input to cells

cells now also get passed the screen ptr to their tile in bc
---
 src/cells.s      |  1 +
 src/defs.s       |  6 +++++-
 src/simulation.s | 10 +++++++++-
 src/update.s     |  1 -
 src/wram.s       |  4 ++++
 5 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/src/cells.s b/src/cells.s
index fe20de1..84f8ca2 100644
--- a/src/cells.s
+++ b/src/cells.s
@@ -3,6 +3,7 @@
   ; does not call c_st_routine if c_head_offset != 0
   ; inputs:
   ;   de: cell ptr
+  ;   bc: screen ptr 
 cell_update:
   inc de ; de = flags
   ld a, [de] ; a = head offset
diff --git a/src/defs.s b/src/defs.s
index c2b94d4..fe813c4 100644
--- a/src/defs.s
+++ b/src/defs.s
@@ -64,8 +64,12 @@
   ; if a c_st_rotuine returns a non-zero value in bc
   ; the rotuine pointed to will be used during the next 
   ; cell update
+  ; additionally bc will point to the current screen 
+  ; pointer for the cell
+  ; inputs:
+  ;   de: cell ptr 
+  ;   bc: screen ptr
 .de c_st_routine, 2 
-
 .de c_size, 0
 
   ; cell type enum
diff --git a/src/simulation.s b/src/simulation.s
index eb0d470..c3a98a9 100644
--- a/src/simulation.s
+++ b/src/simulation.s
@@ -11,11 +11,19 @@ sim_update:
   ; cells in a single go
   ; later we want a limit 
   ld de, state_cells
+  ld bc, SCRN0 
 @loop:
 
     ; advance to next cell
     .rep i, c_size, 1, inc de
-   
+    inc bc
+
+    push de
+    push bc
+    call cell_update
+    pop bc
+    pop de
+    
     ; check if we need to exit
     ld a, state_cells_end LO
     cp a, e
diff --git a/src/update.s b/src/update.s
index 076d2d6..2e6c2d5 100644
--- a/src/update.s
+++ b/src/update.s
@@ -9,7 +9,6 @@ update_game:
   ld de, actor_player 
   call st_update
 
-  ; call player_update
   ; call sim_update 
 
   ldnull bc
diff --git a/src/wram.s b/src/wram.s
index 4376b05..e8fbee1 100644
--- a/src/wram.s
+++ b/src/wram.s
@@ -68,6 +68,10 @@ r_population: .adv 2
   ; for cell update loop
   ; big endian
 cell_ptr: .adv 2
+  
+  ; cell screen ptr 
+  ; points to tile that this cell owns
+cell_screen_ptr: .adv 2
 
 state_cells: .adv c_size * MAP_SIZE
 state_cells_end:
-- 
2.30.2