1 files changed, 120 insertions, 0 deletions
diff --git a/entity/collisions.gbasm b/entity/collisions.gbasm
new file mode 100644
index 0000000..186af65
--- /dev/null
+++ b/entity/collisions.gbasm
@@ -0,0 +1,120 @@
+Carve_Entity_Collision_Map: ; X in C, Y in B
+	PUSH BC
+	PUSH HL
+	PUSH AF
+
+	LD A, C
+	AND $e0
+	JR NZ, =Carve_Entity_Collision_Map.end
+
+	LD A, B
+	AND $e0
+	JR NZ, =Carve_Entity_Collision_Map.end
+
+	LD A, C
+
+	LD H, $00
+	CP $10
+	RL B
+	AND $0f
+	CP $08
+	RL B
+	AND $07
+	LD L, A
+
+	LD A, B
+	LD BC, $mem_entities_collisions
+	OR C
+	LD C, A
+	LD A, (BC)
+
+	OR (HL)
+	LD (BC), A
+
+	Carve_Entity_Collision_Map.end:
+
+	POP AF
+	POP HL
+	POP BC
+	RET
+
+Is_Collisionable: ; X in A, Y in B, Result A
+	PUSH BC
+	PUSH HL
+
+	CP $20
+	JR NC, =Is_Collisionable.Solid
+
+	LD C, A
+	LD A, B
+	CP $20
+	JR NC, =Is_Collisionable.Solid
+	LD A, C
+
+	LD H, $00
+	CP $10
+	RL B
+	AND $0f
+	CP $08
+	RL B
+	AND $07
+	LD L, A
+
+	LD C, B
+	LD B, $mem_dungeon_map_high
+	LD A, (BC)
+	PUSH AF
+	LD A, C
+	LD BC, $mem_entities_collisions
+	OR C
+	LD C, A
+	LD A, (BC)
+	XOR $ff ; 1 in the dungeon map means walkable, 1 in the entity map means unwalkable, we need to invert it.
+	LD B, A
+	POP AF
+	AND B
+
+	AND (HL)
+	CP $01
+	LD A, $00
+	RL A
+
+	POP HL
+	POP BC
+	RET
+
+	Is_Collisionable.Solid:
+	LD A, $01
+	POP HL
+	POP BC
+
+	RET
+
+Reset_Entities_Collision_Map:
+	LD A, $mem_moving_animation_step
+	CP $02
+	JR NZ, =Reset_Entities_Collision_Map.end
+
+	LD HL, $mem_entities_collisions
+	LD BC, $0080
+	CALL =bzero
+
+	LD HL, $mem_entities_list
+	Reset_Entities_Collision_Map.loop:
+		INC L
+		INC L
+		INC L
+
+		LD A, (HL)
+		CALL =Get_Position_After_Move
+		CALL =Carve_Entity_Collision_Map
+
+		LD A, L
+		AND $f8
+		ADD $08
+		LD L, A
+		CP $00
+		JR NZ, =Reset_Entities_Collision_Map.loop
+
+	Reset_Entities_Collision_Map.end:
+	RET