From 1963d7d8dd70ee9bc4cf9b81363aeab440a6f786 Mon Sep 17 00:00:00 2001
From: Miquel Sabaté Solà <mssola@mssola.com>
Date: Fri, 3 Apr 2026 22:32:52 +0200
Subject: Add a table with tile IDs for shuttle parts
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This will allow us to select the proper shuttle depending on
'Globals::zp_shuttle_kind'. Hence, now only the actual shuttle parts on
the CHR file are missing, which is why I left a couple of TODOs on the
table itself.

Signed-off-by: Miquel Sabaté Solà <mssola@mssola.com>
---
 src/driver.s | 28 ++++++++++++++++------------
 src/items.s  | 46 +++++++++++++++++++++++++++++++++++++++-------
 2 files changed, 55 insertions(+), 19 deletions(-)

(limited to 'src')

diff --git a/src/driver.s b/src/driver.s
index 9d31604..67cba5c 100644
--- a/src/driver.s
+++ b/src/driver.s
@@ -714,34 +714,38 @@
         sta OAM::m_sprites + 44
 
         ;; Tile IDs
-        lda #$04
+        ldx Globals::zp_shuttle_kind
+        lda Items::shuttle_sprites, x
         sta OAM::m_sprites + 1
-        lda #$05
+        clc
+        adc #1
         sta OAM::m_sprites + 5
 
-        lda #$14
+        adc #$0F
         sta OAM::m_sprites + 9
-        lda #$15
+        adc #1
         sta OAM::m_sprites + 13
 
-        lda #$06
+        lda Items::shuttle_sprites, x
+        adc #2
         sta OAM::m_sprites + 17
-        lda #$07
+        adc #1
         sta OAM::m_sprites + 21
 
-        lda #$16
+        adc #$0F
         sta OAM::m_sprites + 25
-        lda #$17
+        adc #1
         sta OAM::m_sprites + 29
 
-        lda #$08
+        lda Items::shuttle_sprites, x
+        adc #4
         sta OAM::m_sprites + 33
-        lda #$09
+        adc #1
         sta OAM::m_sprites + 37
 
-        lda #$18
+        adc #$0F
         sta OAM::m_sprites + 41
-        lda #$19
+        adc #1
         sta OAM::m_sprites + 45
 
         ;; Zero out attributes
diff --git a/src/items.s b/src/items.s
index 9ad1aba..a2f867a 100644
--- a/src/items.s
+++ b/src/items.s
@@ -294,13 +294,20 @@
 
         ;; Should we allocate a part from the shuttle?
         bne @try_next_shuttle
-        lda #$04
-        bne @no_attributes
+        stx Globals::zp_tmp0
+        ldx Globals::zp_shuttle_kind
+        lda Items::shuttle_sprites, x
+        ldx Globals::zp_tmp0
+        jmp @no_attributes
     @try_next_shuttle:
         cmp #$01
         bne @do_fuel_or_regular
-        lda #$06
-        beq @do_fuel_or_regular
+        stx Globals::zp_tmp0
+        ldx Globals::zp_shuttle_kind
+        lda Items::shuttle_sprites, x
+        clc
+        adc #2
+        ldx Globals::zp_tmp0
 
     @no_attributes:
         sta Globals::zp_arg0
@@ -1157,7 +1164,14 @@
     ;;
     ;; NOTE: this has to be called with the PPU disabled.
     .proc draw_middle_part_shuttle
-        ldx #$08
+        ;; Compute the tile ID for the middle part of the shuttle depending on
+        ;; the kind.
+        ldx Globals::zp_shuttle_kind
+        lda Items::shuttle_backgrounds, x
+        clc
+        adc #4
+        tax
+
         ldy #$2A
 
         bit PPU::m_status
@@ -1184,7 +1198,11 @@
     ;;
     ;; NOTE: this has to be called with the PPU disabled.
     .proc draw_high_part_shuttle
-        ldx #$04
+        ;; Compute the tile ID for the middle part of the shuttle depending on
+        ;; the kind.
+        ldy Globals::zp_shuttle_kind
+        ldx Items::shuttle_backgrounds, y
+
         ldy #$2A
 
         bit PPU::m_status
@@ -1211,13 +1229,20 @@
     ;;
     ;; NOTE: this has to be called with the PPU disabled.
     .proc draw_low_part_shuttle
+        ;; Compute the tile ID for the low part of the shuttle depending on the
+        ;; kind.
+        ldx Globals::zp_shuttle_kind
+        lda Items::shuttle_backgrounds, x
+        clc
+        adc #8
+        tax
+
         ;; The low part of the rocket.
         bit PPU::m_status
         lda #$2A
         sta PPU::m_address
         lda #$F5
         sta PPU::m_address
-        ldx #$0C
         stx PPU::m_data
         inx
         stx PPU::m_data
@@ -1233,4 +1258,11 @@
 
         rts
     .endproc
+
+shuttle_sprites:
+    ;; TODO: rest of IDs
+    .byte $04, $00, $00, $00
+shuttle_backgrounds:
+    ;; TODO: rest of IDs
+    .byte $04, $00, $00, $00
 .endscope
-- 
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