From 32903cd34e163346944938f32fbfd5ee62950185 Mon Sep 17 00:00:00 2001
From: scawful <justin.scofield@outlook.com>
Date: Fri, 29 Nov 2024 18:20:54 -0500
Subject: [PATCH] Add custom collision ZS source

---
 Dungeons/Collision/custom_collision.asm | 110 ++++++++++++++++++++++++
 Dungeons/dungeons.asm                   |   2 +
 2 files changed, 112 insertions(+)
 create mode 100644 Dungeons/Collision/custom_collision.asm

diff --git a/Dungeons/Collision/custom_collision.asm b/Dungeons/Collision/custom_collision.asm
new file mode 100644
index 0000000..f5a72d5
--- /dev/null
+++ b/Dungeons/Collision/custom_collision.asm
@@ -0,0 +1,110 @@
+;Custom dungeon collision code
+;mostly written by kan
+;put together by Jared_Brian_
+;meant to be used with the ZScream collision editor
+;12-18-2021
+
+; Format:
+; dw <offset> : db width, height
+; dw <tile data>, ...
+;
+; if <offset> == $F0F0, start doing single tiles
+; format:
+; dw <offset> : db <data>
+;
+; if <offset> == $FFFF, stop
+
+RoomPointer = $258090
+
+org $01B95B
+  JSL CustomRoomCollision
+  NOP #6
+
+org $258000
+CustomRoomCollision_easyout:
+{
+  RTL
+}
+
+CustomRoomCollision:
+{
+  LDA $B4 : CMP.w #$2000 : BNE .notEndOfTable
+    INC $0200
+  .notEndOfTable
+
+  REP #$30
+  LDA.b $A0 : ASL : ADC.b $A0 : TAX
+  LDA.l RoomPointer, X : BEQ .easyout
+
+  STA.b $08
+
+  LDA.l RoomPointer+1, X : STA.b $09
+
+  PHB
+
+  PEA.w $7F7F
+  PLB
+  PLB
+
+  LDY.w #$0000
+
+  .read_next
+  LDA.b [$08],Y
+  INY
+  INY
+  CMP.w #$F0F0
+  BCC .new_rectangle
+
+  .single_tiles
+  CMP.w #$FFFF
+  BEQ .done
+
+  TAX
+
+  SEP #$20
+  LDA.b [$08],Y
+  STA.w $2000,X
+  REP #$20
+  INY
+  LDA.b [$08],Y
+  INY
+  INY
+  BRA .single_tiles
+
+  .done
+  PLB
+  RTL
+
+  .new_rectangle
+  STA.b $02 ; beginning of row
+
+  LDA.b [$08],Y ; number of rows and columns
+  STA.b $06
+
+  INY
+  INY
+
+  .next_row
+  REP #$21
+  LDA.b $02
+  TAX
+  ADC.w #64
+  STA.b $02
+
+  SEP #$20
+  LDA.b $06 : STA $0C; save number of columns
+
+  .next_column
+  LDA.b [$08],Y
+  STA.w $2000,X
+  INY
+  INX
+  DEC.b $0C
+  BNE .next_column
+
+  DEC.b $07
+  BNE .next_row
+
+  REP #$21
+  JMP .read_next
+}
diff --git a/Dungeons/dungeons.asm b/Dungeons/dungeons.asm
index 676de49..d192372 100644
--- a/Dungeons/dungeons.asm
+++ b/Dungeons/dungeons.asm
@@ -51,6 +51,8 @@ incsrc "Dungeons/spike_subtype.asm"
 incsrc "Dungeons/attract_scenes.asm"
 print  "End of attract_scenes.asm         ", pc
 
+incsrc "Collision/custom_collision.asm"
+
 incsrc "Collision/CollisionTablesExpanded.asm"
 incsrc "Collision/GlobalCollisionTables.asm"